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1
Daigle, Claude, Michel Crête, Louis Lesage, Jean-Pierre Ouellet, and Jean Huot. "Summer Diet of Two White-tailed Deer, Odocoileus virginianus, Populations Living at Low and High Density in Southern Québec." Canadian Field-Naturalist 118, no. 3 (July 1, 2004): 360. http://dx.doi.org/10.22621/cfn.v118i3.13.
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We investigated summer diets of two White-tailed Deer (Odocoileus virginianus) populations through rumen content analyses. Samples from 93 deer were collected in a low density, LD (1 deer/km2) and a high density, HD (14 deer/km2) area of southern Québec during the growing seasons of 1997 and 1998. Availability of preferred forage in forests was greater in LD than in HD, whereas agriculture covered a larger proportion of the area in HD than LD. Rumen composition differed between the two populations. Deer from HD consumed less forbs and leaves of shrubs and trees than did LD deer, whereas they consumed more fruits, grasses and farm crops. The rarity in HD rumens of food items common in LD, as well as in many parts of the White-tailed Deer range (i.e., Lilliacae), indicated that deer could not compensate for the rarity of preferred forest forage by increasing foraging time and had to feed on cultivated crops. Rumen contents of LD deer had a higher level of cell solubles and lignin, which reflected their greater reliance on quality forage growing in forests. Feeding habits and forage quality can explain why deer body size decreased in HD between the 1970s and 1990s whereas LD deer remained large.Nous avons examiné le régime alimentaire estival de deux populations de cerf de Virginie (Odocoileus virginianus) par l’analyse du contenu des rumens. Des échantillons ont été prélevés sur 93 cerfs provenant d’un secteur à faible densité de cerfs, LD, (1 cerf/km2) et d’un secteur à haute densité, HD, (14 cerfs/km2) du sud du Québec durant la saison de croissance des végétaux de 1997 et 1998. La disponibilité des aliments forestiers préférés des cerfs était plus grande dans LD que dans HD alors que la proportion du territoire agricole était supérieure dans HD. La composition des rumens des cerfs de chacune des régions différait. Les cerfs de HD ont consommé de moins grandes proportions de plantes herbacées et de feuilles d’arbustes et d’arbres que ceux du secteur LD, mais de plus grandes proportions de fruits, de graminées et de plantes agricoles. La rareté dans les rumens du secteur HD d’aliments communs dans ceux du secteur LD et dans plusieurs autres régions de l’aire de répartition du cerf (e.g., Lilliacae), indique que les cerfs du secteur HD ne pouvaient compenser pour la rareté de leurs aliments préférés par un accroissement de la durée de la quête alimentaire, et qu’ils devaient consommer des plantes agricoles. Les cerfs de LD ont mangé des aliments contenant plus de solubles cellulaires et de lignine que ceux de HD, ce qui reflète une consommation de plantes forestières de bonne qualité. Le régime alimentaire et la qualité de la nourriture peuvent expliquer pourquoi la taille des cerfs de HD a diminué entre les années 1970 et 1990 alors que celle des cerfs de LD est demeurée grande.
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Bergeron, Normand, and André G. Roy. "Le rôle de la végétation sur la morphologie d’un petit cours d’eau." Géographie physique et Quaternaire 39, no. 3 (December 4, 2007): 323–26. http://dx.doi.org/10.7202/032613ar.
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RÉSUMÉ Dans cette étude, on démontre que la forme du chenal le long d'un petit affluent de la rivière au Saumon (Québec) varie en fonction des propriétés des racines des végétaux qui bordent les berges. Le cours d'eau est étroit et profond lorsque les deux berges sont occupées par des graminées, alors qu'il est plus large et moins profond lorsqu'au moins une des deux berges est couverte d'aulnes. Ces variations morphologiques sont en partie expliquées par la forme des berges, qui est elle-même contrôlée par la densité, la taille et le déploiement des racines des plantes qui y poussent.
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Hiernaux, P. H. Y., M. I. Cissé, L. Diarra, and P. N. De Leeuw. "Fluctuations saisonnières de la feuillaison des arbres et des buissons sahéliens. Conséquences pour la quantification des ressources fourragères." Revue d’élevage et de médecine vétérinaire des pays tropicaux 47, no. 1 (January 1, 1994): 117–25. http://dx.doi.org/10.19182/remvt.9123.
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Les auteurs analysent la saisonnalité de la feuillaison de 28 espèces ligneuses sahéliennes afin de caractériser les disponibilités saisonnières en feuillage fourrager ainsi que leurs variations interannuelles. Pour chacune des espèces, des branchettes de même calibre ont été échantillonnées chaque mois entre 1979 et 1992, dans une ou plusieurs populations dont les sites sont répartis tout le long du gradient bioclimatique sahélien du Mali. Cinq groupes d'espèces ont été caractérisés par le régime saisonnier de leur feuillaison. Trois rassemblent des espèces caducifoliées distinguées entre elles par la durée de cette période; deux regroupent des espèces sempervirentes distinguées par la date de renouvellement du feuillage. Les variations de densité foliaire inter-sites et interannuelles sont quantifiées, leur écologie est étudiée par analyses de variance. On démontre ainsi que la densité maximale de feuillaison au cours de l'année dépend avant tout des infiltrations hydriques accumulées dans le sol au cours de l'année précédente. En conclusion, il est proposé de tenir compte de cette saisonnalité et de ces fluctuations interannuelles dans l'évaluation des ressources fourragères apportées par les plantes ligneuses et, plus généralement, dans toute quantification du rôle des ligneux dans l'écosystème sahélien.
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Coyne, Daniel, and Richard Plowright. "Heterodera sacchari: field population dynamics and damage to upland rice in Côte d'Ivoire." Nematology 2, no. 5 (2000): 541–50. http://dx.doi.org/10.1163/156854100509466.
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Abstract In field studies in Côte d'Ivoire, West Africa, Heterodera sacchari severely reduced upland rice (Oryza sativa cv. IDSA6) grain yield. In 1995, pre-sowing treatments with carbofuran did not affect crop height, number of tillers at 84 days after sowing (DAS) nor grain yield of O. sativa cv. IDSA6 or O. glaberrima cv. CG14. The protection of eggs within cysts and a delayed hatching pattern are thought to have contributed to this. In 1996 and 1997, cultural methods were used to modify initial population densities and grain yield was correlated negatively with mid-season (56 and 84 DAS) H. sacchari population densities. The relationship between yield (Y) and population densities at 56 DAS was described by the equation Y = Ymean.Ymin + Ymean(1 - Ymin).z(P-T). The crop tolerance limit at 56 DAS was calculated as 1.67 and 2.39 eggs/cm3 soil, and z as 0.15 and 0.65 in 1996 and 1997, respectively. Population densities of H. sacchari at sowing, 28 DAS, 42 DAS and harvest were not correlated with grain yield in regression analysis of individual plots, but grain yield was significantly greater in groups of plots which had lowest initial egg density. Initial egg population densities were correlated negatively with leaf area index at 84 and 96 DAS in 1996 and 1997, respectively, with implications for growth of and competition from weeds. In 1997, mean initial egg density was 63% more and mean yield 57% less than in 1996. Drought in 1997 exacerbated yield losses. In 1996 and 1997, crop height, number of tillers and relative leaf chlorophyll content were significantly less in plots with higher mean egg density at sowing. Heterodera sacchari: dynamique des populations au champ et dommages causés au riz de plateau en Côte d'lvoire - Des études au champ menées en Côte d'lvoire (Afrique de l'Ouest) ont montré qu' Heterodera sacchari diminue de façon importante la récolte en grain du riz de plateau (Oryza sativa cv. IDSA6). En 1955, un traitement avant semis au carbofuran n'a pas influé sur la hauteur des pieds, ni sur le nombre de chaumes, non plus que sur la récolte en grain d' O. sativa cv. IDSA6 ou d' O. glaberrima cv. CG14, cela 84 jours après le semis (JAS). La protection apportée aux œufs par les kystes ainsi qu'un type d'éclosion différée sont supposés avoir contribué à ce phénomène. En 1996 et 1997, les méthodes culturales adoptées ont permis de modifier la densité des populations initiales; de ce fait la récolte en grain s'est trouvée corrélée négativement, à la mi-saison (56 et 84 JAS), avec la densité des population d' H. sacchari . La relation entre la récolte (Y) et la densité de la population à 56 JAS est définie par l'équation: Y = Ymoy.Ymin + Ymoy(1 - Ymin).z(P-T). Le calcul de la limite de tolérance à 56 JAS donne des chiffres de 1,67 et 2,39 œufs/cm3 et une valeur de z de 0.15 et 0.65 pour 1996 et 1997, respectivement. Une analyse de régression - portant sur les parcelles individuelles - entre densité des populations à 28 et 42 JAS et à la récolte n'a pas montré de corrélation avec le niveau de la récolte en grain; cependant, cette récolte était significativement plus élevée dans le groupe des parcelles où la densité initiale des œufs était la plus faible. Ces densités initiales d'œufs sont corrélées négativement avec l'indice de surface foliaire à 84 et 96 JAS, en 1996 et 1997 respectivement, cela ayant certaines implications dans la croissance du riz et sa compétition avec les plantes adventices. En 1997, la densité moyenne initiale des œufs était de 63% supérieure à celle de 1996, tandis que la récolte moyenne était inférieure de 57% à celle de 1996. En 1997, la sécheresse a exacerbé les pertes de récolte. En 1996 et 1997, la hauteur des pieds, le nombre de chaumes et le contenu relatif des feuilles en chlorophylle étaient significativement plus faibles dans les parcelles où la densité moyenne des œufs au moment du semis était la plus élevée.
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Hounkpèvi, Achille, Armand Sèdami Igor Yévidé, Jean Cossi Ganglo, Jean-Louis Devineau, Anasthase Hessou Azontonde, Victor Adjakidjè, Euloge Kossi Agbossou, and Bruno De Foucault. "Structure et écologie de la forêt à Diospyros mespiliformis Hochst. ex A.DC. et à Dialium guineense Willd. de la réserve de Massi (La Lama), Bénin." BOIS & FORETS DES TROPIQUES 308, no. 308 (June 1, 2011): 33. http://dx.doi.org/10.19182/bft2011.308.a20472.
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La forêt naturelle de Massi au sein du massif de la Lama constitue un écosystème particulier unique au Bénin, sur vertisols argileux périodiquement inondés par les eaux de pluie. Par souci de contribution à sa protection, un inventaire phytosociologique a été réalisé suivant l'approche synusiale intégrée afin de mieux étudier la végétation spontanée de cette forêt. Il a permis d'identifier plusieurs phytocénoses dont la plus étendue s'avère être le peuplement forestier à Diospyros mespiliformis et Dialium guineense. Une étude dendrométrique et écologique de ce peuplement a été réalisée, dont les principaux résultats ont montré des densités d'arbres convenables de 230 tiges à l'hectare et une surface terrière de 14 m2/ha. En outre, la forte densité de régénération de jeunes plantes issues de semis confère à cette forêt un potentiel de résilience indiscu - table. En ce qui concerne les hauteurs, Afzelia africana et Mimusops andongensis présentent les valeurs les plus élevées. La distribution en classe de diamètres des arbres s'ajuste à la distribution théorique de Weibull qui présente une allure typique en " J renversé " avec une bonne représentation de tiges de petite taille. Ce travail est le point de départ d'un programme devant aboutir à une gestion éclairée de l'ensemble du massif de 1 500 hectares de la Lama, dont les principes d'action sont présentés en guise de conclusion. (Résumé d'auteur)
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Kémeuzé, Victor Aimé, Marie Caroline Momo Solefack, Bernard-Aloys Nkongmeneck, Guy Decocq, René Bernardin Jiofack Tafokou, and Madeleine Johnson. "Variation altitudinale de la distribution des plantes à activité insecticide dans la forêt communautaire de Kilum-Ijim : cas de Clausena anisata (Willd.) Hook. f. ex-Benth." BOIS & FORETS DES TROPIQUES 299, no. 299 (March 1, 2009): 71. http://dx.doi.org/10.19182/bft2009.299.a20425.
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Dans le souci de contribuer à la valorisation des plantes à activité insecticide, une étude a été réalisée sur la distribution altitudinale de Clausena anisata dans la forêt de Kilum-Ijim, dans la province du Nord-Ouest (Cameroun), sur le versant appartenant aux villages de Manchock et Keyon. Grâce à la méthode phytosociologique synusiale intégrée, on constate qu'en dehors de la synusie arborescente Clausena anisata est présent dans toutes les autres synusies. La synusie arbustive contient le plus grand nombre d'individus, avec une fréquence de 40 %, suivie de la synusie herbacée et de la synusie sous-arbustive et herbacée haute dont les fréquences respectives sont de 38 % et 22 %. Son aire de distribution va de 2 100 m à 2 500 m, avec un point de forte densité (175 individus par hectare) entre 2 300 m et 2 350 m. Cette espèce présente une bonne régénération dans le milieu. L'absence de jeunes individus autour des pieds adultes a suscité un certain nombre de questions pouvant orienter des recherches future. (Résumé d'auteur)
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Bognounou, Fidèle, Renée Morton, Sarah Ayangma, Laurence Jonkers, Christer Björkman, Helena Bylund, Colin Orians, Andres Vega, and Per Christer Oden. "Structure des peuplements de Monocotyledones et Dicotyledones lors de differents stades de succession dans le parc national de Corcovado au Costa Rica." BOIS & FORETS DES TROPIQUES 307, no. 307 (March 1, 2011): 33. http://dx.doi.org/10.19182/bft2011.307.a20480.
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Les deux grands groupes d'angiospermes, monocotylédones et dicotylédones, diffèrent à plusieurs égards au niveau de leur cycle de vie. Malgré les différences évidentes entre ces deux groupes, peu d'études se sont penchées de façon approfondie sur la manière dont cela pourrait influencer leur succession écologique. L'étude compare les densités relatives de ces deux groupes fondamentaux à l'évolution contrastée, lors de deux stades de succession forestière à la station de Sirena dans le Parc national de Corcovado au Costa Rica, en Amérique centrale. Selon l'hypothèse de départ, le rapport monocotylédones/ dicotylédones devrait diminuer aux stades plus avancés de la succession. L'échantillonnage a porté sur un ensemble de 40 placettes triangulaires à angle droit ((5 × 5 m)/2), où les plantes ont été classées en quatre catégories selon la dimension des houppiers, ainsi qu'en monocotylédones et dicotylédones. Une analyse de la distribution des densités et des classes de dimension des houppiers a été effectuée par ANOVA selon la procédure de modélisation linéaire généralisée. La densité moyenne totale de la forêt secondaire apparaît significativement plus importante que celle de la forêt primaire (P < 0,001). Cependant, la structure de la distribution des classes de dimension des houppiers est proche entre monocotylédones et dicotylédones, mais aussi entre forêt primaire et secondaire. Il n'apparaît aucune différence significative entre les deux types de forêt dans le rapport monocotylédones / dicotylédones (P = 0,99). Les résultats concernant la distribution des classes de dimension des houppiers indiquent une tendance similaire dans la distribution des successions de monocotylédones et dicotylédones, même si les dicotylédones sont toujours plus nombreux. Ces résultats amènent à conclure qu'il est nécessaire d'avoir une importante différence entre les stades de succession avant de percevoir la différence anticipée dans cette étude. (Résumé d'auteur)
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Ruf, François. "Cocoa combined with palm wine in Côte d’Ivoire: An unexpected resilience." BOIS & FORETS DES TROPIQUES 321, no. 321 (July 17, 2014): 33. http://dx.doi.org/10.19182/bft2014.321.a31216.
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La vigueur du palmier à huile sauvage est telle que cette espèce fait presque figure de « mauvaise herbe » dans les planta- tions de cacao négligées ou abandon- nées. Pourtant, le palmier à huile en Afrique de l’Ouest est très apprécié pour la production de vin de palme, et pourrait permettre aux agriculteurs de compléter et diversifier leurs revenus. Dans le cen- tre-ouest de la Côte d’Ivoire, la reprise du palmier à huile sauvage dans les an- ciennes plantations de cacao a joué un rôle important dans les années 1990, lorsque les paysans se sont trouvés confrontés à l’effondrement des cours du cacao et à des conflits d’héritage, qui ont entraîné l’abandon de nombreuses plan- tations de cacao où la densité des pal- miers à huile a rapidement augmenté. L’abattage des palmiers permettait de produire du vin de palme pour la vente et l’autoconsommation, générant ainsi des revenus, réduisant les risques et créant de l’emploi et de nouveaux dispositifs in- tergénérationnels et institutionnels. Dans les régions tropicales humides, les plantes d’importance économique locale comme les palmiers à huile peuvent ac- croître la résilience des agriculteurs aux chocs extérieurs. Au lieu de concentrer les efforts sur la seule intensification, il conviendrait d’évaluer les cultures de re- lais et leur impact sur la résilience de l’ar- boriculture sur l’ensemble du cycle de vie des exploitations.
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Savadogo, Abdoulaye, Boniface Babo Bakouan, Mathieu Wendnéyidé Sawadogo, Karim Nébié, Rémy Dabiré, Djakaria Son, Irénée Somda, et al. "Distribution et dégâts associés au thrips de l’oignon, Thrips tabaci L. (Thysanoptera : Thripidae) en fonction de la zone agro-climatique au Burkina Faso." International Journal of Biological and Chemical Sciences 14, no. 6 (October 6, 2020): 2037–48. http://dx.doi.org/10.4314/ijbcs.v14i6.9.
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L’oignon est le premier légume produit au Burkina Faso. Thrips tabaci constitue son principal insecte ravageur. Ce travail avait pour objectif d’évaluer la distribution, l’incidence et la sévérité des attaques de T. tabaci sur l’oignon. L’étude a été réalisée dans trois bassins de production représentatifs de deux zones agroécologiques du Burkina Faso : la zone sahélienne caractérisée par une pluviosité moyenne annuelle inférieure à 600 mm et une température moyenne annuelle de 35 °C ; contre une pluviosité moyenne annuelle comprise entre 600 et 900 mm et une température moyenne annuelle de 33 °C pour la zone nord soudanienne Nous avons réalisé des prospections dans 45 parcelles paysannes dans les zones de production ciblées. Des plantes d’oignon ont été prélevées dans trois quadrats posés sur une des diagonales de chaque parcelle, et les thrips trouvés sur chaque plante de chaque quadrat comptés. Tous les plants à l’intérieur du quadrat ont été donc observés. La densité moyenne la plus élevée (216 ±385 thrips au m2) a été observée dans la région du Nord tandis que l’incidence moyenne la plus élevée (95,91±8,92%) a été observée dans la Boucle du Mouhoun. La plus faible sévérité (19,29±13,27%) a été enregistrée dans le Plateau central. Cette étude est un premier pas vers le développement de stratégies alternatives de lutte contre les parasites dans le cadre de systèmes de production végétale durables à l’aide de bonnes pratiques agricoles et de l’utilisation des pesticides biologiques.Mots clés : Oignon, Thrips tabaci, incidence, sévérité, répartition, Burkina Faso.
English Title: Distribution and damage associated with the onion thrips, Thrips tabaci L. (Thysanoptera: Thripidae) according to the agro-climatic zone in Burkina FasoOnion is the first vegetable produced in Burkina Faso. Thrips tabaci is its main insect pest. We assessed the distribution, incidence and severity of T. tabaci attacks on onion in three-production areas representative of two agroecological zones of Burkina Faso: the the Sahelian zone characterized by an average annual rainfall of less than 600 mm and an average annual temperature of 35 °C; compared to an average annual rainfall of between 600 and 900 mm and an average annual temperature of 33 °C for the northern Sudanian zone. We carried out surveys in 45 farmer plots in the targeted production zones. Thus, onion plants were taken from three quadrats placed on one of the diagonals of each plot, and the thrips found on each plant were counted. All plants within the quadrat were therefore observed. The highest average density (216±385 thrips per m²) was observed in the North while the highest average incidence (95.91±8.92%) was observed in the Boucle du Mouhoun. The lowest severity (19.29±13.27%) was recorded in the Plateau central region. This study is a first step towards the development of alternative pest control strategies within sustainable crop production systems using good agricultural practices and the use of biopesticides.Keywords: Onion, Thrips tabaci, incidence, severity, distribution, Burkina Faso.
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GARANE, Ali, Koussao SOME, Jeanne NiKIEMA, Mamoudou TRAORE, and Mahamadou SAWADOGO. "Etude du comportement de neuf cultivars de tomates (Solanum Lycopersicum L.) dans différentes zones agro-écologiques du Burkina Faso pendant l’hivernage." Journal of Animal & Plant Sciences 40, no. 3 (June 28, 2019): 6656–73. http://dx.doi.org/10.35759/janmplsci.v40-3.1.
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Etude du comportement de neuf cultivars de tomates (Solanum Lycopersicum L.) dans différentes zones agro-écologiques du Burkina Faso pendant l’hivernage. Ali GARANE1*, Koussao SOME1, Jeanne NiKIEMA1, Mamoudou TRAORE2 et Mahamadou SAWADOGO3 1* Institut de l’Environnement et de Recherches Agricoles (INERA/CREAF-Kamboinse), Département Production Végétale/Programme Cultures Maraîchères, Fruitières, Plantes à Tubercules, 01 BP 470 Ouagadougou 01, Burkina Faso. 2Institut de l’Environnement et de Recherches Agricoles (INERA/CREAF-Kamboinsè), Département Gestion des Ressources Naturelles/Système de Production, 03 BP 470 Ouagadougou 03, Burkina Faso. 3Université Ouaga I Pr Joseph KI-ZERBO/Unité de Formation et de Recherche en Science de la Vie et de la Terre (UO/UFR-SVT), Laboratoire de Génétique et Biotechnologie Végétale, 03 BP 7021 Ouagadougou 03, Burkina Faso. * Correspondance, courriel: ali_garane@yahoo.fr Mots clés: Tomate, performance, hivernage, maladies, Burkina Faso. Key words: Tomato, wintering, performance, diseases, Burkina Faso. Publication date 30/06/2019 http://www.m.elewa.org/JAPS 1. RESUME Objectif: Au cours de la saison hivernale 2014-2015, une étude portant sur neuf cultivars améliorés de tomate a été réalisée dans 5 zones agro-écologiques (Kamboinsè, Loumbila, Komgoussi, Yako et Salgo) du Burkina Faso. Les observations et mesures ont porté sur la sensibilité au flétrissement bactérien, le rendement et ces composants essentiels afin de déterminer les cultivars les mieux adaptés aux conditions de culture d’hivernage dans les zones de l’étude. Méthodologie et résultats: Le dispositif expérimental est un bloc complet de Fisher randomisé de 4 répétitions avec des traitements constitués des variétés V1, V2, V3, V4, V5 , V6, V7, V8 et V9. Les plants ont été repiqués en ligne simple en parcelles élémentaires de 37,5 m2. Les écartements sont de 0,75 m sur 0,40 m, soit une densité de 33333 pieds/ha. Les variables suivantes de productivité ont été supérieures à Yako pour la densité chez les cultivars Thorgal, Gempride, Jaguard, Mongal, Nadira respectives de 67,75; 71,75; 80,12; 99,5 et 108,75 plants/37,5 m². A Salgo pour le poids moyen du fruit chez Jaguard (56,06 g) Mongal (55,63g), FBT5 (51,1 g) et Thorgal (48,8 g) et à Kongoussi pour Gempride (55,63 g). Les cultivars Rs et Nadira ont observé des rendements meilleurs à Yako respectifs de 28,72 et 28,73 t/ha. A Salgo, les hybrides Gempride, Mongal, FBT5, Jaguard et Thorgal ont été plus performant avec respectivement 21,65; 20,3; 20,0; 17,46 et 15,14 t/ha. Conclusion et application des résultats: Selon la moyenne des rendements, les meilleurs sites ont été par ordres décroissant Yako (19,044 t/ha), Salgo (17,44), Kongoussi (7,06 t/ha), Loumbila (6,87 t/ha) et Kamboinsè (2,97 t/ha). Dans le même ordre, les meilleures variétés ont été Nadira, Rs, Gempride, Jaguar, Thorgal, Mongal, FBT5 avec respectivement 13,87, 10,79; 10,23; 9,66; 8,23 et 7,08 t/ha. Si nous couplons à cela la tolérance aux flétrissements, Jaguar, Nadira et Gempride demeurent les meilleures variétés suivies de Mongal et FBT5. Les résultats obtenus sur les 5 sites ont montré une variabilité importante. Ce qui est peut-être du à la maitrise des techniques de production qui n’ont pas été homogènes d’un site à un autre et à la particularité de chaque variété. Pour améliorer la performance de ces variétés, il paraît indiqué de poursuivre les recherches dans une approche agronomique visant la maîtrise de l’eau d’irrigation, une gestion intégrée des ravageurs et maladies pendant le cycle cultural.
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DJEKOTA, Christophe, Mame Samba MBAYE, Doudou DIOP, and Kandioura NOBA. "Poils épidermiques, types stomatiques et taxonomie chez les morphotypes de karité Vitellaria paradoxa C.F. Gaertn subsp. paradoxa)." Journal of Animal & Plant Sciences 45, no. 1 (July 31, 2020): 7758–70. http://dx.doi.org/10.35759/janmplsci.v45-1.1.
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Les poils épidermiques et les types stomatiques chez les morphotypes de karité (Vitellaria paradoxa C.F. Gaertn subsp. paradoxa) ont été étudiés au Tchad en 2010, de Juillet à Septembre. L’objectif est la recherche des caractères micro morphologiques discriminants susceptibles d’améliorer l’identification des morphotypes de cette espèce. En fait, des morphotypes de karité ont été décrits et nommés par les ruraux dans la province du Mandoul au Tchad. Les amandes de karité sont transformées en beurre, ce qui lui confère une importance sur le plan socio-économique. Des fragments de bourgeon apical prélevés sur des jeunes plantes issues de la germination des graines des cinq (5) morphotypes ont permis d’observer les types de poils épidermiques. Aussi, des échantillons de feuilles prélevés distinctement de chaque morphotype ont été préparés selon la méthode de Barfod (1988). Cette méthode a été privilégiée car l’épiderme de la feuille de karité n’est pas facilement détachable. Elle consiste à bouillir les échantillons de feuilles dans de l’eau distillée pendant 10 minutes puis ils sont trempés dans l’acide nitrique à 40% pendant 16 à 20 heures. Cette opération a permis de ramollir le mésophyle et facilite la desquamation de la cuticule. La surface du fragment de la feuille ramollie placée sur une lame de microscope dans une goutte d'eau est grattée délicatement et progressivement à l’aide du bord de ciseaux jusqu'à ce qu'un fragment d'épiderme transparent apparaisse. Les épidermes foliaires ainsi obtenus sont placés dans du Lugol pendant 10 minutes puis montés après rinçage entre lame et lamelle dans la gélatine glycérinée et observés au microscope optique de type MOTIC. Au total 30 dénombrements ont été effectués sur les deux faces soit en moyenne 6 observations par morphotype. Ces dénombrements ont permis de calculer la densité stomatique et l’indice stomatique de chaque morphotype. La densité stomatique est la moyenne des 6 dénombrements par unité de surface (mm²). Les résultats ont montré 4 groupes de morphotypes : 1- des poils épidermiques simples longs observés chez le morphotype A, appelé localement « Bogrombaye » ; 2- des poils simples courts observés Djekota et al., 2020 Journal of Animal & Plant Sciences (J.Anim.Plant Sci. ISSN 2071-7024) Vol.45 (1): 7758-7770 https://doi.org/10.35759/JAnmPlSci.v45-1.1 7759 chez les morphotypes C, E et F « Komane, Mbabète, Ngoïtokoro » ; 3- des poils glanduleux longs observés chez le morphotype D « Meingré » et ; 4- des poils glanduleux courts observés chez le morphotype B « Kiankos ». De plus, des stomates de type anomocytique périgène à subsidiaire dicyclique sont observés chez tous les morphotypes étudiés. La densité stomatique évaluée est 362±5 st/mm² et l’indice stomatique varie de 45,1±0,7% chez les morphotypes de karité étudiés. Ces connaissances pourraient améliorer la systématique des morphotypes et fournir une base pour la sélection du matériel végétal approprié pour les programmes locaux de reboisement et/ou pour la production agronomique, car le beurre de cette espèce est de plus en plus sollicité. Epidermal hair, stomatal types and taxonomy in shea morphotypes (Vitellaria paradoxa C.F. Gaertn subsp. Paradoxa) ABSTRACT Epidermal hair and stomatal types in shea morphotypes (Vitellaria paradoxa C.F. Gaertn subsp. paradoxa) were studied in Chad in 2010, from July to September. The objective is the search for discriminating micro morphological characters likely to improve the identification of the morphotypes of this species. In fact, shea morphotypes have been described and named by rural people in the province of Mandoul in Chad. Shea kernels are transformed into butter, which gives it socio-economic importance. Fragments of the apical bud taken from young plants from the germination of the seeds of the five (5) morphotypes made it possible to observe the types of epidermal hair. Also, leaf samples taken separately from each morphotype were prepared according to the method of Barfod (1988). This method was preferred because the epidermis of the shea leaf is not easily detachable. It involves boiling the leaf samples in distilled water for 10 minutes and then soaking them in 40% nitric acid for 16-20 hours. This operation allowed to soften the mesophyle and facilitates the scaling of the cuticle. The surface of the fragment of the softened leaf placed on a microscope slide in a drop of water is gently and gradually scraped off using the edge of the scissors until a transparent epidermis fragment appears. The leaf epidermis thus obtained are placed in Lugol for 10 minutes and then mounted after rinsing between slide and coverslip in glycerol gelatin and observed under an optical microscope of the MOTIC type. A total of 30 counts were made on both sides, an average of 6 observations per morphotype. These counts made it possible to calculate the stomatal density and the stomatic index of each morphotype. The stomatal density is the average of the 6 counts per unit area (mm²). The results showed 4 groups of morphotypes: 1- long single epidermal hairs observed in morphotype A, locally called "Bogrombaye"; 2- short simple hairs observed in morphotypes C, E and F "Komane, Mbabète, Ngoïtokoro"; 3- long glandular hairs observed in the morphotype D "Meingré" and; 4- short glandular hairs observed in morphotype B "Kiankos". In addition, stomata of the perigenic anomocytic type with dicyclic subsidiary are observed in all the morphotypes studied. The stomatal density evaluated is 362 ± 5 st / mm² and the stomatic index varies from 45.1 ± 0.7% in the shea morphotypes studied. This knowledge could improve the system of morphotypes and provide a basis for the selection of appropriate plant material for local reforestation programs and / or for agronomic production, as butter from this species is in increasing demand.
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Lundeto, S. W., S. D. Anis, W. B. Kaunang, and C. I. J. Sumolang. "Pengaruh tingkat kepadatan tanaman terhadap pertumbuhan Sorgum Brown Mid Rib (BMR) yang diberi pupuk bokashi kotoran ayam pada kondisi ternaung." ZOOTEC 41, no. 1 (February 17, 2021): 158. http://dx.doi.org/10.35792/zot.41.1.2021.32533.
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THE IMPACT OF PLANT’S DENSITY ON THE GROWTH OF SORGHUM BROWN MID RIB WITH CHICKEN MANURE FERTILIZER IN AN ELEVATED STATE. The purpose of this research was determines growth of sorghum BMR with different population density use chicken manure fertilizer in an elevated state. This experiment was conducted using Completely Randomized Design (CRD). The treatment consisted of four planting density, (P1=(1 plant/Polybag) P2=(2 plants/polybag) P3=(3 plants/polybag) P4=(4 plants/polibag), each treatment had seven replications. Data were analyzed using analysis of variance and HSD test. The variables measured were growth that are plant’s height, leaf length, and number of leaves. The results showed that different planting population were significant different (P<0.01) on plant’s height, leaf length, and number of leaves. HSD test showed that planting population P1=(1 plant/Polybag) were significant (P<0.01) have higher plant’s height, leaf length, and number of leaves than P3=(3 plants/polybag) and P4=(4 plants/polybag). It can be concluded that planting density P1=(1 plant/Polybag) have the highest growth of sorghum BMR that were highest plant’s height, leaf length, and number of leaves.
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Amonmidé, Isidore, Germain D. Fayalo, and Gustave D. Dagbenonbakin. "Effet de la période et densité de semis sur la croissance et le rendement du cotonnier au Bénin." Journal of Applied Biosciences 152 (August 31, 2020): 15676–97. http://dx.doi.org/10.35759/jabs.152.7.
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Objectif : L’objectif de l’étude était d’identifier les meilleures périodes et densités de semis dans les différentes zones agro-écologiques cotonnières du Bénin dans un contexte de changement climatique. Méthodologie et résultats : Les expérimentations ont été conduites pendant deux ans (2017 et 2018) en station au Bénin dans un dispositif expérimental en split-plot à deux facteurs, la période (facteur principal) et la densité de semis (facteur secondaire) respectivement à quatre et cinq variantes avec quatre répétitions. Les données collectées ont été soumises à une analyse de variance sous le logiciel R.3.6.1 au seuil de 5% de probabilité d’erreur. Les résultats ont montré au cours des deux années d’expérimentation que les semis tardifs ont enregistré les plus faibles rendements en coton graine dans la zone centre-nord tandis que toutes les dates de semis ont donné des rendements équivalents dans la zone nord. La densité de semis à 62500 plants/ha a donné le meilleur rendement. Conclusion et applications des résultats : Le semis du cotonnier peut s’étendre sur quatre décades (20 mai au 30 juin) dans la zone nord contrairement au centre-nord où la période optimale de semis s’étend seulement sur les deux dernières décades de juin (10-30 juin). La densité à 62500 plants/ha (0,20m x 0,80m à 1 plant/poquet) pourrait être recommandée pour l’amélioration des rendements en culture cotonnière au Bénin. L’adoption de cette densité de semis offre aux producteurs l’opportunité de mécaniser les opérations de semis et de fertilisation, compte tenu de la faible distance inter-poquets par rapport aux densités en vulgarisation. Mots clés : Période de semis, densité de semis, rendement coton graine, zones cotonnières, Bénin. Effect of sowing time and plant density on growth, development and yield in Benin ABSTRACT Objective: This study aimed at identifying the best sowing date and plant densities in the different cotton agro-ecological zones of Benin in a context of climate change. Methodology and results: On-station trials were conducted during two years (2017 and 2018) in Benin in a split-plot experimental design with two factors, the sowing date (main factor) and the plant density (secondary factor) with four and five levels, respectively with four replications. Collected data were submitted to an analysis of variance under R.3.6.1 software at 5% probability threshold error. Results showed other the two Amonmidé et al., J. Appl. Biosci. 2020 Effet de la période et densité de semis sur la croissance et le rendement du cotonnier au Bénin 15677 years of trial that late sowings recorded the lowest cotton seed yields in the northern central zone while all sowing date gave similar yields in the northern zone. Planting density of 62500 plants/ha gave the best yields. Conclusion and applications of the results: Cotton sowing could be extended over four decades (20 May to 30 June) in the northern zone contrarily to the northern central zone where the optimal sowing time covers only the last two decades of June (10-30 June). Plant density of 62500 plants/ha (0.20 m x 0.80 m at 1 plant/pot) could be recommended to improve cotton seed yields in Benin. The adoption of this new plant density offers producers the opportunity to mechanize sowing and fertilizer application, given low inter-plant space compared to the recommendation in Benin. Key words: Sowing date, plant density, cotton seed yield, cotton agro-ecological zones, Benin.
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KAMARA, ALPHA Y., ABDULLAHI I. TOFA, STEPHEN KYEI-BOAHEN, REUBEN SOLOMON, HAKEEM A. AJEIGBE, and NKEKI KAMAI. "EFFECTS OF PLANT DENSITY ON THE PERFORMANCE OF COWPEA IN NIGERIAN SAVANNAS." Experimental Agriculture 54, no. 1 (October 21, 2016): 120–32. http://dx.doi.org/10.1017/s0014479716000715.
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SUMMARYGrain yields of cowpea [Vigna unguiculata (L.) Walp.] in the Nigerian savannas are low even with the cultivation of improved varieties. The recommended spacing for cowpea is 75 × 20 cm with two seeds planted per stand. This corresponds to plant population of 133333 plants ha−1, which may not be sufficient for optimal cowpea yield. Field experiments were conducted to determine plant density effects on cowpea performance in the Northern Guinea and the Sudan savannas of Nigeria and also to determine if genotypes varied in their response to plant density. Four cowpea varieties with contrasting maturity duration were planted in single, double and triple rows on ridges spaced 75 cm apart to achieve corresponding densities of 133333, 266666 and 400000 plants ha−1, respectively. Plant densities of 266666 and 400000 plants ha−1 gave higher crop performance in terms of light interception, biomass production, yield and yield components for all cowpea varieties. Yield increases were related largely to increased pod and seed production but the effect of seed size on yield was relatively minor. Our results provide evidence that the current density of 133333 plants ha−1 used by farmers is not optimum for cowpea production. Smallholder farmers can increase cowpea grain and fodder yields if they use a density of 266666 plants ha−1 in cowpea cultivation. Further yield increases when cowpea is planted at 400000 plants ha−1 may not be sufficient to offset the cost of seed.
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Esechie, H. A., S. Elias, V. Rodriguez, and H. S. Al-Asmi. "Response of sunflower (Helianthus annuus) to planting pattern and population density in a desert climate." Journal of Agricultural Science 126, no. 4 (June 1996): 455–61. http://dx.doi.org/10.1017/s0021859600075547.
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SUMMARYThe effects of three planting patterns (ridge, furrow and flat) and three population densities (31800, 47600 and 71400 plants/ha) on the growth and yield of three sunflower hybrids, Flamme, Upsolveraflor and Isostar, were investigated at the Sultan Qaboos University Experiment Station, 1990–93. Seed and oil yields were higher in the ridge-planted sunflower than those planted in furrow or flat patterns, the order being ridge > flat > furrow. However, the magnitude of yield differences between ridge-planted and flat-planted sunflower was not sufficiently high to compensate for the additional labour and materials required for making ridges. Based on this, planting in the flat was recommended. Although increased population density resulted in taller plants, lodging was generally low and did not constitute a serious problem. Biomass/plant, head weight, receptacle weight, head diameter, number of seeds/head and 1000-seed weight decreased with increase in plant population density. Flamme had its highest seed and oil yield at 71400 plants/ha, while Isostar attained its highest yield at 47600 plants/ha. Isostar outyielded the other two hybrids and appeared to have a potential for commercial production in a desert climate.
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Ghosheh, Hani Z., David L. Holshouser, and James M. Chandler. "Influence of Density on Johnsongrass (Sorghum halepense) Interference in Field Corn (Zea mays)." Weed Science 44, no. 4 (December 1996): 879–83. http://dx.doi.org/10.1017/s0043174500094868.
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Experiments were conducted from 1990 to 1994 to investigate the density-dependent effects of rhizome and seedling johnsongrass on the magnitude of full-season interference in field corn. Corn grain yield was decreased as rhizome johnsongrass density increased. A maximum density of 3 rhizome johnsongrass plants 9.8 m−1of row was considered critical to avoid yield losses above 5% of full-season weed-free corn. Interference of johnsongrass plants originating from seed and growing at densities up to 128 plants 9.8 m−1of row did not affect grain yield. Seedling johnsongrass plants growing at a constant density of 9.8 plants m−1of row did not affect yield from corn planted at five densities.
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Araya, Mario, Alfonso Vargas, and Alexander Cheves. "Nematode distribution in roots of banana (Musa AAA cv. Valery) in relation to plant height, distance from the pseudostem and soil depth." Nematology 1, no. 7 (1999): 711–16. http://dx.doi.org/10.1163/156854199508739.
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AbstractThe horizontal and vertical distribution of plant parasitic root nematodes on banana (Musa AAA cv. Valery) was determined in a sandy clay loam in Costa Rica. Root samples were taken from soil blocks at distances of 0 to 30, 30 to 60, and 60 to 90 cm from the pseudostem, from 0 to 120 cm depth at intervals of 15 cm, and from plants of 120, 150, 180 or 210 cm high (non-flowering), plus a set from plants at flower stalk. The horizontal distance from the pseudostem affected the percentage of Radopholus similis, Pratylenchus spp., and total nematodes (R. similis + Helicotylenchus spp. + Meloidogyne spp. + Pratylenchus spp.). There was a significant effect of soil depth on the density of each genus. An interaction between soil depth and plant height and with horizontal distance was found for R. similis and total nematodes. For the three horizontal distances from the pseudostem, the percentage of each genus decreased with soil depth. Higher percentages of R. similis and total nematodes were found at 0 to 30 cm horizontal distance from the pseudostem than at greater distances in the upper 30 cm of the soil profile. Therefore, samples for monitoring nematode populations in bananas should be taken within a horizontal distance of 0 to 30 cm from the plant base and down to 30 cm deep from the soil surface. Additional studies are needed to relate the nematode population density at this sampling point to yield. Repartition des nematodes dans les racines du bananier (Musa AAA cv. Valery) en relation avec la hauteur de la plante, la distance au pseudo tronc et la profondeur du sol - La repartition horizontale et verticale des nematodes parasites du bananier (Musa AAA cv. Valery) a ete determinee dans un sol sablo-argileux, au Costa Rica. Les echantillons de racines ont ete preleves dans les blocs de sol extraits a differentes distances (de 0-30, de 30-60 et 60-90 cm) et profondeurs (de 0 a 120 cm avec des intervalles de 15 cm) du pseudo tronc des plantes: ces plantes, non encore fleuries, etaient de differentes hauteurs (120, 150, 180 et 210 cm). Quelques plantes entre le premier et le huitieme jour apres floraison ont egalement ete testees. La distance horizontale affecte le pourcentage de Radopholus similis et de Pratylenchus spp., et le nombre total de nematodes (R. similis + Helicotylenchus spp. + Meloidogyne spp. + Pratylenchus spp.). La profondeur du sol affecte la densite de population pour chaque genre. Pour R. similis et le nombre total de nematodes; il existe des interactions entre la profondeur du sol et la hauteur de la plante et entre la profondeur du sol et la distance horizontale. Le pourcentage de chacun des genres decroit avec la profondeur du sol aux trois distances au pseudo tronc. Les pourcentages les plus eleves de R. similis et du nombre total de nematodes ont ete trouves de 0 a 30 cm de profondeur. De ces resultats, il est conclu que pour etudier correctement les populations des nematodes du bananier, les echantillons de racines devraient ete preleves dans les premiers 30 cm de distance au pseudo tronc et jusqu'aux premiers 30 cm de profondeur du sol. Des etudes complementaires sont necessaires pour mieux etablir les rapports entre la densite des populations de nematodes dans ces points d'echantillonnage et le rendement.
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Castro, B. A., T. J. Riley, and B. R. Leonard. "Evaluation of Selected Hopper Box and Seed Treatments for Control of Red Imported Fire Ant in Grain Sorghum, 1994." Arthropod Management Tests 20, no. 1 (January 1, 1995): 231. http://dx.doi.org/10.1093/amt/20.1.231a.
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Abstract The efficacy of selected insecticide treatments applied as in-furrow granules at planting (IFGAP), T-banded granules (TBAND) and seed treatments (SEEDT) was evaluated for control of the RIFA at the Macon Ridge Branch of the Northeast Research Station in Franklin Parish, LA. The test was planted no till with a John Deere 7300 planter into a bermuda grass sod containing a high density of RIFA mounds. Plots consisting of 4 rows (40 inch centers) by 30 ft were planted on 3 May in a RCB with 4 replications. RIFA no. were estimated on 1 Jun by placing an unruled index card (3X5 inches) baited with peanut butter in each plot and recording the no. of ants attracted after 3 h. No. of chinch bugs were obtained on 15 Jun by counting the no. per 20 plants in the 2 center rows. Plant stand densities were recorded on 31 May by sampling the entire 2 center rows in each plot. Plant heights were estimated on 31 May by measuring 20 plants in each plot. Intra-row plant skips were recorded on 13 Jun by counting the no. of skips > 12 inches per plot.
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Skaria, Mani, and Zhang Tao. "309 Rapid Growth of Microbudded Citrus Planted Ultra-high Density." HortScience 35, no. 3 (June 2000): 445C—445. http://dx.doi.org/10.21273/hortsci.35.3.445c.
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High-density or ultra-high-density orchards have had positive economic return up to 12 years after planting. However, an initial higher investment on more number of trees needed is a limiting factor for high-density planting. Our preliminary studies have shown that a microbudding technique that we had developed would produce less-expensive, budded citrus trees. In June 1997, several hundred microbudded citrus trees were planted in a field, under drip irrigation. The planting continued monthly until Dec. 1997. The cultivars planted were: `Marrs' orange, `Rio Red' grapefruit, `Meyer' and `Ponderosa' lemon, and satsuma mandarin. All plants were microbudded on sour orange rootstock grown in 5′′ long “conetainers.” Our objectives were to study the growth performance of small, microbudded trees planted in the field. The plants grew normally and even out-performed the conventionally budded trees in a field nursery next to the test plot. In Dec. 1999, tree height reached 60 inches. Five percent of the trees produced fruit and they were normal in shape, color, and quality.
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Gagnon, V., F. Chazarenc, Y. Comeau, and J. Brisson. "Influence of macrophyte species on microbial density and activity in constructed wetlands." Water Science and Technology 56, no. 3 (August 1, 2007): 249–54. http://dx.doi.org/10.2166/wst.2007.510.
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It is often assumed that planted wastewater treatment systems outperform unplanted ones, mainly because plants stimulate belowground microbial population. Yet, fundamental interactions between plants and associated microorganisms remain only partly understood. The aim of our project was to evaluate microbial density and activity associated to the rhizosphere of three plant species. Experimental set-up, in six replicates, consisted of four 1.8-L microcosms respectively planted in monoculture of Typha angustifolia, Phragmites australis, Phalaris arundinacea and unplanted control. Plants were grown for two months with 25 L m−2 d−1 of secondary effluent (in g m−2 d−1: 1.3 TSS, 7.5 COD, 1.0 TKN). Sampling of substrate, roots and interstitial water was made according to depth (0–10, 10–20 cm). Biofilm was extracted with 500 mL of a buffer solution. Microbial density was directly estimated by flow cytometry and indirectly by protein measurements. Biological activity was determined using respirometry assays, dehydrogenase and enzymatic activity measurements. Our results show that microbial density and activity are higher in the presence of plants, with significantly higher values associated with Phalaris arundinacea. Greater density of aerobic or facultative bacteria was present in planted microcosm, particularly on root surface, suggesting root oxygen release. Microbes were present on substrate and roots as an attached biofilm and abundance was correlated to root surface throughout depth. Plant species root morphology and development seem to be a key factor influencing microbial–plant interaction.
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Burris, Gene, Don Cook, B. R. Leonard, J. B. Graves, and J. Pankey. "Evaluations of In-Furrow Insecticides and Fungicides, 1995." Arthropod Management Tests 21, no. 1 (January 1, 1996): 241. http://dx.doi.org/10.1093/amt/21.1.241.
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Abstract The test was conducted at the Northeast Research Station in St. Joseph, LA. Plots were replicated 4 times in a RCB design and were four rows (40-inch spacing) X 65 ft. ‘Stoneville LA 887’ cotton seed was planted 2 and 3 May on a commerce silt soil which was fertilized sidedress with 90 lb N/acre. Cotton seed were planted with a John Deere model 7100 series planter which was equipped with 10 inch seed cones mounted to replace the seed hoppers. The seed rate was 4 seed/row ft. Granular in-furrow treatments were applied with 8 inch belt cone applicators mounted to replace the standard granular applicators. Control of thrips and aphids was evaluated on 5 randomly selected plants/plot. Evaluations were made on 18, 19, 24, 26, and 29 May and 8 Jun. Plant height counts were taken on 10 randomly selected plants/plot on 8 Jun. Stand density and leaf area was determined by counting the number of plants in a randomly selected meter on 29 May. Leaf area was recorded using a Li Cor leaf area machine. The data was recorded as cm2 and converted to a leaf area index (LAI). Major pests and/or secondary pest control was initiated in Jun and continued on an “as needed” basis through Aug.
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Pekar, G. S. "Аutomated method for determining the etch pits density on crystallographic planes of large semiconductor crystals." Semiconductor Physics Quantum Electronics and Optoelectronics 19, no. 1 (April 8, 2016): 23–27. http://dx.doi.org/10.15407/spqeo19.01.023.
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Bani, Aida, Guillaume Echevarria, Xin Zhang, Emile Benizri, Baptiste Laubie, Jean Louis Morel, and Marie-Odile Simonnot. "The effect of plant density in nickel-phytomining field experiments with Alyssum murale in Albania." Australian Journal of Botany 63, no. 2 (2015): 72. http://dx.doi.org/10.1071/bt14285.
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Ultramafic vertisols cover large areas in Albania and offer opportunities for phytomining. We undertook a field experiment with native Alyssum murale on two representative Vertisols at a distance of 20 km from each other (Pojskë and Domosdovë, Albania), to test the effect of planting density (transplanted seedlings) on a phytomining cropping system. Both areas were cleared in late summer 2012 and then ploughed and the soils were characterised. At Domosdovë, an area of 0.5 ha was planted with local native seedlings at a density of six plants per square metre in September 2012. Spontaneous plants that had germinated in Spring 2012 were left to grow without any competition from other plants on a second 0.1-ha plot at Domosdovë. All plots were weeded manually in the autumn of 2012 and spring of 2013. Individual plants occupied ~1 m2 at maturity. At Pojskë, an area of 0.3 ha was also planted in September 2012 with local native seedlings of A. murale at a density of four plants per square metre. Plants grown at initial densities of four and six plants per square metre did not fully cover the ground; gaps were filled in naturally by a second spontaneous generation of A. murale seedlings (recruits) that had germinated in Autumn 2012. Other weeds were eliminated with herbicides. At Domosdovë, at densities of one and six plants and at Pojskë of four plants per square metre, the biomass yield was 10, 5 and 10 t ha–1, respectively. Concentration of phytoextracted nickel was 77, 41 and 112 kg ha–1. We suggest that a density of four plants per square metre is suitable for phytoextraction with native populations of A. murale. A. murale can be a weed itself and lower the nickel phytoextraction yield. Plants responded differently in their native environment than in previous field trials in North America.
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Armitage, A. M., and M. A. Dirr. "Influence of Spacing on Yield of Buddleia and Salix Grown as Cut Flowers and Stems." Journal of Environmental Horticulture 13, no. 4 (December 1, 1995): 176–77. http://dx.doi.org/10.24266/0738-2898-13.4.176.
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Abstract Plants of Buddleia davidii ‘Black Knight’ were planted on 165, 80 or 45 cm (5.5, 3 or 1.5 ft) centers in September 1991 and plants of Salix alba ‘Britzensis’, Salix × erythroflexuosa ‘Scarlet Curls’ and Salix chaenomeloides were planted on 90, 60 or 30 cm (3, 2 and 1 ft) centers in April 1991. Stems of all taxa were harvested for three years. The number of harvested stems per plant decreased but the number of stems/m2 increased with increasing plant density in all taxa. No significant differences in stem length or stem diameter occurred except with Salix alba ‘Britzensis’ in which the longest stems occurred at the highest density, regardless of year of harvest.
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Stanton, D., A. W. Grombacher, R. Pinnisch, H. Mason, and D. Spaner. "Hybrid and population density affect yield and quality of silage maize in central Alberta." Canadian Journal of Plant Science 87, no. 4 (October 1, 2007): 867–71. http://dx.doi.org/10.4141/cjps06024.
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Four maize (Zea mays L.) hybrids planted at varying plant densities were evaluated for their yield, maturity, and quality across environments in north central Alberta. Given the balance of yield and quality, very early maturing hybrids [2000 corn heat units (CHU)] planted at ~100 000 plants ha-1 are recommended for north central Alberta. Key words: Corn; Zea mays L.; northern latitudes; corn heat units
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Reeder, R. K., R. L. Darnell, and T. A. Obreza. "Blueberry Production in a High-density, Evergreen System." HortScience 30, no. 4 (July 1995): 800E—800. http://dx.doi.org/10.21273/hortsci.30.4.800e.
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Blueberry plants fertilized at 3-week intervals with nitrogen (N) throughout the year and protected from freezing temperatures avoid dormancy and produce an off-season “winter” crop. Southwestern Florida offers a climate where this production system can be implemented without undue fear of freezes. `Sharpblue', `Gulfcoast', and `Warmabe' southern highbush blueberry cultivars have been planted at high density (10,000 plants/ha) to determine the feasibility of successfully establishing an evergreen production system for blueberry. Three rates of N fertilization (84, 168, and 252 kg·ha–1) and the use of peat or municipal solid waste (MSW) compost as soil amendments are being evaluated in this study. Initial data on plant growth indicate that, during the first 9 months of the planting, 168 kg N/ha will produce plants similar in height, but with significantly less volume, to those receiving 252 kg N/ha. MSW compost appears to be a beneficial soil amendment for blueberry establishment despite an increase in soil pH associated with the compost amendment.
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Neushul, M., and B. W. W. Harger. "Studies of Biomass Yield From a Near-Shore Macroalgal Test Farm." Journal of Solar Energy Engineering 107, no. 1 (February 1, 1985): 93–96. http://dx.doi.org/10.1115/1.3267661.
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This paper reports the results of studies in 1981 and 1982 of marine biomass yield from a near-shore, 0.48 hectare test farm at Ellwood, California. The experimental planting was made to ascertain whether or not the plants would maintain a high yield after repeated cutting, and to see what effect planting density has on yield. The test farm was planted with 722 plants and operated in all seasons of the year. Quarterly harvests were made from plants planted at densities of one plant per m2, one plant per 4 m2 and one plant per 16 m2. Eleven metric tons of biomass were planted initially on a sandy sea floor. This produced a total of 50 wet metric tons of harvested biomass in 12 months.
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Ahmad, Iftikhar, Waqas Hassain Naeem, and Bilal Abdullah. "Optimal planting density for cut Lilium and tuberose production." Ornamental Horticulture 25, no. 2 (June 14, 2019): 144–48. http://dx.doi.org/10.14295/oh.v25i2.1736.
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Lilium and tuberose are promising geophytic flowers, which have high market demand in global floral markets. A study was conducted to optimize planting densities for cut lilium and tuberose production. Bulbs of Asiatic lily ‘Brunello’ and tuberose ‘Single’ were planted on 7.5 cm, 15.0 cm and 22.5 cm between bulbs while ridge were spaced at 60 cm apart. Lilium bulbs planted at 22.5 cm took 185 d, while tuberose took 101 d to produce flowers as compared to 7.5 cm spacing (173 d and 93 d, respectively). Bulbs of lilium and tuberose planted at 22.5 cm resulted in tallest plants with highest leaf area for both tested species, 69.1 cm and 11.4 cm2 for lilium and 110.6 cm and 30.2 cm2 for tuberose, respectively. Both species had highest number of florets with longer stem/ spike length and stem/spike diameter when planted 22.5 cm apart, while close planting further decrease number of buds/florets and stem/spike length. Similar results were recorded for fresh weight of a stem, while vase life and dry weight of a stem were relatively less affected by plant spacing. However, lilium and tuberose bulbs when planted at 22.5 cm plant spacing produced higher number of best quality stems for market as compared to other planting densities.
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Sissoko, Fagaye, Sidiki Diarra, and Mamadou Traore. "Le semis direct sous couverture végétale : une opportunité de mise en place rapide du cotonnier en culture pluviale au Mali." International Journal of Biological and Chemical Sciences 14, no. 3 (June 18, 2020): 722–38. http://dx.doi.org/10.4314/ijbcs.v14i3.7.
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En zone soudano-sahélienne, la productivité des cultures est limitée par la disponibilité de l’eau et la fertilité des sols. Le cotonnier en est particulièrement affecté lors de sa culture L’objet de cette étude est d’évaluer l’effet du semis direct sous couverture végétale sur le rendement du cotonnier. Deux variétés de cotonnier (NTA MS334 et BRS 293) ont été utilisées pour comparer 6 systèmes de culture. Le dispositif statistique utilisé a été un Split plot. Les données collectées ont concerné les échantillons de sol, les délais de levée des cotonniers, les densités, les hauteurs, les nombres de capsules et les rendements en graine. La levée a été plus rapide dans les systèmes de culture en semis sous couverture végétale. La densité à la récolte des cinq systèmes en SCV a été de 65 076 plants ha-1 contre 60 564 en SC. Les systèmes de culture n’ont pas eu d’effets statistiquement significatifs sur les rendements en coton graine, mais une différence significative a été observée entre les deux variétés. Le SCV est possible en zone soudano-sahélienne, la levée est plus rapide et permet d’améliorer la densité et le rendement (2 452 kg ha-1 contre 2 373 kg ha-1 en SC) des cultures.Mots clés : Systèmes de culture, cotonnier, densité, capsules, rendement.
English Title: Direct sowing under cover crop: an opportunity for rapid establishment of rainfed cotton in MaliIn Sudano-Sahelian zone, crop productivity is limited by water availability and soil fertility. The purpose of this study is to evaluate the effect of direct sowing under cover crop on cotton yield. Two cotton varieties (NTA MS334 and BRS 293) were used to compare 6 cropping systems. The statistical design used was a split plot. The data collected concerned soil samples, cotton plant emergence times, densities, heights, number of bolls and cotton yields. Emergence was faster in seedling cropping systems under cover crop. Harvest density in the five SCV systems was 65 076 plants ha-1 versus 60 564 plants ha-1 in SC. The cropping systems had no statistically significant effect on seed cotton yields, but a significant difference was observed between the two varieties. SCV is possible in Sudano-Sahelian zone, emergence is faster and improves crop density and yield (2 452 kg ha-1 compared to 2 373 kg ha-1 in SC).Keywords: Cropping systems, cotton, density, bolls, yield
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Prehaten, Daryono, Suryo Hardiwinoto, Mohammad Na’iem, Haryono Supriyo, Widiyatno Widiyatno, and Dian Rodiana. "Productivity of Arrowroots and Taro Grown Under Superior Teak Clones with Several Levels of Stand Density." Biosaintifika: Journal of Biology & Biology Education 13, no. 1 (April 10, 2021): 51–57. http://dx.doi.org/10.15294/biosaintifika.v13i1.26428.
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Perum Perhutani has an important role in providing food and wood for people. Diversity and diversification of food will reduce the need for one type of food, namely rice as a staple food. Some tuber and rhizome are source of alternative foodstuffs, such as taro and arrowroot. This study aimed to determine the suitability and productivity of arrowroot and taro planted under old superior teak clones with several levels of stand density. Arrowroot and taro were planted under 14-year-old teak stands with 4 levels of density. Both plants were planted in the form of an array, measuring of 3m x 15m, with a spacing of 75cm x 75cm between plants. They were arranged in Randomized Completely with Block Design (RCBD) placed in 4 blocks of observation as replications. The results showed that under superior teak clone had the potential to be planted with arrowroot and taro. Teak stand density influenced significantly some characteristics of arrowroot (leaves number, leaves area, stem height, stem diameter, root length) and taro (stem diameter, tuber diameter). Arrowroot productivity per hectare increased with low density of teak stands, accounted for 55, 59, 80, and 88 kg respectively. Meanwhile, taro productivity from very high to low teak density were 365, 301, 523, and 426 kg/ha. The novelty of this study is that there is no record of intercropping studies on old superior teak clones, so this is among the first studies. The benefit of from this research result, it could be employed by Perhutani to support the Indonesian government in the national food security program
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Maciel, Norberto, and Richard A. Criley. "156 Effects of the Inductive Period, Shoot Density, and Leaf Removal on the Flowering of Heliconia rostrata Ruiz & Pavon." HortScience 35, no. 3 (June 2000): 416E—417. http://dx.doi.org/10.21273/hortsci.35.3.416e.
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Heliconia rostrata is a herbaceous-musoid sympodial rhizomatous plant that grows as clump. After three leaves are produced, each shoot of the clump may bear an inflorescence if it is induced by short days (SD). However, the relationship between shoot density and flowering has not been quantified. To evaluate the effects of the inductive period, number of shoots, and leaf removal on flowering, rhizomes were planted in 120 pots (8 L). One-third of the pots were planted with two rhizomes, while the remainder was planted with one. One-half of the pots with one rhizome were allowed to develop all their shoots for three generations, while in the remaining pots only one shoot per generation was allowed to grow. In addition, one-half of the plants in all the treatments were subjected to selective leaf removal. The plants were grown under long days (LD) >13 h in a glasshouse until four leaves were produced. Inductive SD was supplied to all the plants from 5:00 pm to 8:00 am. After 8 weeks of SD, one-half of the plants were given LD, while the other half continued under SD (conSD) until flowering. The highest percentage of flowering shoots (39% to 35%) was observed in plants under conSD; plants under SD-LD were 10% to 9%. The second generation of shoots showed the highest flowering (74% conSD and 21% SD-LD), followed by the first (62% conSD and 18% SD-LD), and third (31% conSD and 0% SD-LD) generations. Non-flowering shoots of the first generation were aborted or dead. Shoots of the third were still vegetative, since they had few leaves to be induced. Fewer flowers occurred in clumps allowed to develop all their shoots. Intact plants from rhizomes with one shoot per generation flowered more than the partially defoliated ones under conSD.
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Mladenović, Emina, Sandra Cvejić, Siniša Jocić, Nemanja Ćuk, Jelena Čukanović, Milan Jocković, and Ana Marjanović Jeromela. "Effect of plant density on stem and flower quality of single-stem ornamental sunflower genotypes." Horticultural Science 47, No. 1 (March 31, 2020): 45–52. http://dx.doi.org/10.17221/10/2019-hortsci.
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The aim of this research was to determine the optimum planting density for the production of high-quality cut flowers with desirable characteristics. 25 single-stem ornamental sunflower genotypes were planted at different densities and evaluated for flowering time, flower diameter, and stem circumference and length over a two-year production cycle. Three spacing patterns were used: 25 × 25 cm, 30 × 30 cm, and 70 × 30 cm, which led to the planting densities of 160 000, 90 000, and 60 000 plants/ha, respectively. The plant density had the most important effect on the stem circumference, flower diameter, and stem length (total variation 52, 60, and 58%, AMMI analysis) and a small effect on the flowering time (total variation 1%, AMMI analysis). Based on environment-focused scaling, all high-density environments could be suitable for the production of single-stem sunflower genotypes. The results demonstrated the adaptation of several sunflower genotypes G9, G11, G12, G21, and G22 as the most suitable based on the optimum flower diameter, stem circumference, and stem length. These results may lead to progress in growing ornamental sunflowers as a cut flower.
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Anderson, Robert G., and Robert L. Geneve. "EFFECT OF PLANTING DATE, PINCHING, AND PLANT DENSITY ON QUALITY AND YIELD OF FIELD-GROWN GODETIA." HortScience 27, no. 6 (June 1992): 649d—649. http://dx.doi.org/10.21273/hortsci.27.6.649d.
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Different planting dates, plant densities and pinching practices were used to determine the production practices that produced the best quality cut stems from field grown godetia under Kentucky conditions. Godetia `Grace Salmon' transplants were planted at a plant density of 40 plants m-2 on Mar 23, Apr 8 and Apr 23, 1991 in ground beds with black plastic mulch. All plants flowered in early to mid June, but plants from the Mar 23 planting date had the highest yields of commercial quality stems (387 stems m-2) and over 80% of the stems were longer than 55 cm. In a separate experiment, transplants of `Grace Red' and `Grace Rose Pink' were planted on April 5 at plant densities of 4.5 m-2 (unpinched), 10 m-2 (soft pinch on May 1) and 23 m-2 (hard pinch on May 1). Pinching treatments were used to increase the number of secondary and tertiary branches on each plant. Although the pinching treatments produced more branches, a low percentage of the branches were commercial quality cut stems.
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Feng, Gao, Zhao Zi-Hua, Jifon John, and Liu Tong-Xian. "Impact of potato psyllid density and timing of infestation on Zebra chip disease expression in potato plants." Plant Protection Science 52, No. 4 (September 26, 2016): 262–69. http://dx.doi.org/10.17221/186/2015-pps.
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The impact of vector density and timing of infestation on potato were investigated. Healthy potato plants at different growth stages (4, 5, and 7 weeks after germination) were exposed separately to four different B. cockerelli densities (0, 5, 20, and 40 psyllids per cage) in field cages and Zebra chip (ZC) symptoms, leaf photosynthetic rates, tuber yield, and total nonstructural carbohydrate accumulation in leaves and tubers of healthy and B. cockerelli-infested plants were monitored. Potato psyllid nymph and egg populations reached a seasonal peak at 6 weeks after the exposure to insect. Younger plants at 4-week growth stage after germination were more susceptible to B. cockerelli infestation and ZC expression than older plants. As few as five B. cockerelli adults were enough to transmit the ZC pathogen and cause ZC expression both in foliage and tuber. At the density of 20 psyllids per cage, more than 50% of plants showed ZC symptoms in tubers. Furthermore, B. cockerelli infestation reduced leaf photosynthesis rates (P<sub>n</sub>), resulting in less starch and more reducing sugars in tubers, and hence reduced tuber weight and yield, especially when psyllid infestation occurred at the early growth stages. The results indicate that early B. cockerelli infestation of younger plants was associated with more severe ZC expression in both foliage and tubers, leading to earlier dead plants. The data suggest that strategies for controlling B. cockerelli during early potato crop development could thus lessen the severity of ZC development.
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Gaion, Lucas Aparecido, Letícia Akemi Ito, Francine Souza Galatti, and Leila Trevisan Braz. "DENSITY PLANTING THE CULTURE OF OKRA." Nucleus 10, no. 2 (October 30, 2013): 199–206. http://dx.doi.org/10.3738/1982.2278.917.
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Abd-Elaal, Alaa-Eldin M., Amany Aboelkassem, Ali A. M. Gad, and Saber A. S. Ahmed. "Removal of heavy metals from wastewater by natural growing plants on River Nile banks in Egypt." Water Practice and Technology 15, no. 4 (August 3, 2020): 947–59. http://dx.doi.org/10.2166/wpt.2020.073.
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Abstract Green remediation is a known technology that uses different types of plants to extract contaminants from the environment. This study aims to remove heavy metals from treated wastewater by using natural growing plants on River Nile banks in Egypt. Secondary treated effluent was collected from West Gerga wastewater treatment plant, located in Sohag city, Egypt. Experiments using two types of aquatic plants were carried out. They were planted individually and in combination with different densities on the secondary treated wastewater surface for 10 days' retention time to remove cadmium (Cd), nickel (Ni) and lead (Pb). It was concluded that both plants have high capabilities to remove heavy metals directly from treated wastewater. The removal efficiency of Cd and Pb was higher when they were planted together than when individually planted. A positive relationship was observed between detention time and heavy metals removal. The removal efficiency of heavy metals increased with the increase of plant density for both plant types. Also, the availability of aquatic plants and their free cost makes their use an economically attractive alternative. In addition, the removal of these plants from River Nile improves the performance of water distribution networks in Egypt.
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Li, J., R. Z. Xie, K. R. Wang, P. Hou, B. Ming, G. Q. Zhang, G. Z. Liu, M. Wu, Z. S. Yang, and S. K. Li. "Response of canopy structure, light interception and grain yield to plant density in maize." Journal of Agricultural Science 156, no. 6 (August 2018): 785–94. http://dx.doi.org/10.1017/s0021859618000692.
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AbstractGood canopy structure is essential for optimal maize (Zea mays L.) production. However, creating appropriate maize canopy structure can be difficult, because the characteristics of individual plants are altered by changes in plant age, density and interactions with neighbouring plants. The objective of the current study was to find a reliable method for building good maize canopy structure by analysing changes in canopy structure, light distribution and grain yield (GY). A modern maize cultivar (ZhengDan958) was planted at 12 densities ranging from 1.5 to 18 plants/m2 at two field locations in Xinjiang, China. At the silking stage (R1), plant and ear height increased with plant density as well as leaf area index (LAI), whereas leaf area per plant decreased logarithmically. The fraction of light intercepted by the plant (F) increased with increasing plant density, but the light extinction coefficient (K) decreased linearly from 0.61 to 0.39. Taking the optimum value of F (95%) as an example, and using measured values of K for each plant density at R1 and the equation from Beer's law, the corresponding (theoretical) LAI for each plant density was calculated and optimum plant density (9.72 plants/m2) obtained by calculating the difference between theoretical LAIs and actual observations. Further analysis showed that plant density ranging from 10.64 to 11.55 plants/m2 yielded a stable GY range. Therefore, taking into account the persistence time for maximum LAI, the plant density required to obtain an ideal GY maize canopy structure should be increased by 10–18% from 9.72 plants/m2.
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Kulig, Bogdan, Edward Gacek, Roman Wojciechowski, Andrzej Oleksy, Marek Kołodziejczyk, Wojciech Szewczyk, and Agnieszka Klimek-Kopyra. "Biomass yield and energy efficiency of willow depending on cultivar, harvesting frequency and planting density." Plant, Soil and Environment 65, No. 8 (September 3, 2019): 377–86. http://dx.doi.org/10.17221/594/2018-pse.
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The study aimed at comparing the yield of dry biomass and energy efficiency of 22 willow cultivars depending on the harvesting frequency and variable plant density. The field experiment was established in 2010. The willow cultivars were planted in two densities; 13 300 and 32 500 plants per ha. Among the compared cultivars in the second year (2013) of full production, high yield of dry matter was obtained from cvs. Tordis (33.1 t/ha/year), Inger (30.4 t/ha/year) and Klara (29.0 t/ha/year). After six years of cultivation, the highest aboveground dry matter was given by cvs. Tora (27.4 t/ha/year) and Tordis (27.0 t/ha/year). The gross calorific value of willow biomass ranged from 15.2–20.1 GJ/t dry weight. Greater energy efficiency (329.3 GJ/ha/year) occurred in willow cultivars collected in a two-year cycle than in the one-year cycle (286.4 GJ/ha/year). In the two-year cycle collected in the third year after planting, energy efficiency was greater (379.5 GJ/ha/year) than in the two-year cycle harvested in the sixth year after planting (279.15 GJ/ha/year). The initial slower growth of biomass does not determine plant yielding.
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Dias, Guilherme Faus da Silva, Pedro Luís da Costa Aguiar Alves, and Tomás Carneiro de Souza Dias. "Brachiaria decumbens supresses the initial growth of Coffea arabica." Scientia Agricola 61, no. 6 (December 2004): 579–83. http://dx.doi.org/10.1590/s0103-90162004000600003.
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Brachiaria decumbens is becoming one the most common weeds growing in young coffee orchards because, besides its fast growth and difficulty of control, new coffee orchards are usually established in pasture areas. In order to verify the effect of B. decumbens plant density on the early growth of coffee (Coffea arabica L. cv. Catuaí Amarelo), a competition experiment was conducted under semi-controlled humidity conditions. Soil collected in a Typic Haplustox was placed in 70 L asbestos cement boxes and one coffee seedling was planted in each box. The B. decumbens seedlings were transplanted to the boxes at the 2-4 leaf stage. Treatments consisted of 0, 4, 8, 12, 16, 20, 24, 36, 48, and 60 weeds m-2. The experimental period started 120 days after transplanting and the experimental design was organized as completely randomized blocks, with four replicates. All coffee plant parameters evaluated were negatively affected by the interference. The most sensitive characteristics were leaf area (41.8% reduction with 8 plants m-2, reaching 68.7% at a density of 60 plants m-2). Therefore, at a density of 8 plants m-2 the reduction in leaf dry biomass was 41.4% compared with the check. At the density of 60 plants m-2 it was 72.8%. B. decumbens, at a density of 8 or more plants m-2, suppressed coffee plants during a growth period of 120 days.
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Ajayi, Emmanuel, Christopher Okonji, Olamide Ayanlola, Temidayo Olofintoye, and Deborah Oyelowo. "Improving the growth and yield of okra by intercropping with varying populations of legumes." Journal of Agricultural Sciences, Belgrade 65, no. 3 (2020): 213–24. http://dx.doi.org/10.2298/jas2003213a.
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An experiment was conducted at the Vegetable Research Farm of the National Horticultural Research Institute, Ibadan, Oyo State, Nigeria, in the rain-forest agro-ecological zone in 2016 and 2017 to determine suitable cropping systems to increase the yield of okra. The seed of okra (Abelmoschus esculentus (L.) Moench), cv. LD-88, was planted at a spacing of 60 ? 40 cm as an intercrop and monocrop to produce an average density of 4.2 plants?m-2; the intercrops cowpea (Vigna unguiculata (L.) Walp.), var. Ife brown, and peanut (Arachis hypogaea L.), var. Kampala, were planted to provide average densities of 5.6 plants?m-2, 4.2 plants?m-2, 3.3 plants?m-2 and 2.7 plants?m-2. Data were collected on plant height, number of leaves, leaf area, stem diameter and fruit yield of okra. Year affected plant height, number of leaves, leaf area, stem diameter and fruit yield of okra intercropped with legumes at different densities. Legume densities affected plant height, number of leaves, stem diameter, leaf area and fruit yield. The interaction of year ? legume densities affected plant height, number of leaves, stem diameter, leaf area and fruit yield of okra. Intercropping okra with peanut at the density of 2.7 plants?m-2 enhanced its growth and yield and appeared to be the best configuration for these crops.
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Yang, Seung-Ku, Kyong-Ju Choi, Soon-Ju Chung, and Wol-Soo Kim*. "High-density Planting System with Nursery Plants by Cutting of Tomato." HortScience 39, no. 4 (July 2004): 802D—802. http://dx.doi.org/10.21273/hortsci.39.4.802d.
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In order to cultivate tomato of the first fruit cluster harvest a lot of nursery plants were required as much as 75,000 to 100,000 plants per hectare in green house in Korea. Therefore, it needs too many expenses to buy tomato seeds. This study was carried out to confirm the possibility of alternative use of the tomato cuttings instead of tomato seedlings of two varieties. The cutting materials of each node were taken from the suitable transplanting tomato seedling nursery plants in commercial green house. Four to five nodes of seedling nursery plants were cut into plug tray with 50 to 128 cells, 23 to 80 mL/cell in cell capacity. At 5 days after cutting rooting was initiated and the rooted plants could be transplanted as cutting nursery plants. The cutting nursery plants of Rockusanmaru and Momotarou-yoku varieties were planted to the perlite media in hydroponics bench in green house with 111,110 plants/ha (90 cm × 10 cm) in planting density at 8 May 2002. The matured fruits were harvested from 9 July through 26 July 2002. The number of harvested fruits was 2.9 to 3.3 for the two varieties. The fruit weight was 138 to 153 g for `Rockusanmaru', and 127 to 146 g for `Momotarou-yoku'. The cutting nursery plants of `Rockusanmaru' showed higher fruit yields as much as 51.5 tons/ha than that of seedlings as 40.3 tons/ha. There was a similar result in `Momotarou-yoku'. The duration from cutting to harvest of first fruit cluster was required 89 to 105 days, as well as 63 to 79 days from field planting to harvest. In conclusion the cultivation with tomato cutting nursery plants was considered as better effects in shorter periods in nursery raising and higher yields in comparison to conventional cultivation with seedlings.
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Petersen, Terry D., and Bruce D. Maxwell. "Water stress of Pinusponderosa in relation to foliage density of neighboring plants." Canadian Journal of Forest Research 17, no. 12 (December 1, 1987): 1620–22. http://dx.doi.org/10.1139/x87-247.
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The relationship of predawn needle water potential of ponderosa pine (Pinusponderosa Dougl. ex Laws.) and the foliage density of neighboring plants was examined after experimental gradients of foliage were established on two sites in northwestern Montana. In late summer, soil water content linearly decreased in relation to the amount of foliage of herbs and shrubs. Predawn needle water potential of pine seedlings planted along the gradient ranged from −0.5 MPa when competitor foliage was near zero to less than −3.0 MPa when such foliage was more extensive. Even when neighboring plants had a small amount of transpiring foliage at this time of year, the pine seedlings had an increased level of water stress.
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Yu, Xiaofang, Qi Zhang, Julin Gao, Zhigang Wang, Qinggeer Borjigin, Shuping Hu, Baolin Zhang, and Daling Ma. "Planting Density Tolerance of High-Yielding Maize and the Mechanisms Underlying Yield Improvement with Subsoiling and Increased Planting Density." Agronomy 9, no. 7 (July 11, 2019): 370. http://dx.doi.org/10.3390/agronomy9070370.
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This study examined the planting density tolerance, grain yield improvement potential, and mechanisms of high-yielding spring maize varieties under increasing planting density and subsoiling. We planted two high-yielding spring maize varieties with a high or low tolerance to high planting densities (LM33 and XD20, respectively) at five different densities (D1: 60,000 plants ha−1, D2: 75,000 plants ha−1, D3: 90,000 plants ha−1, D4: 105,000 plants ha−1, and D5: 120,000 plants ha−1) using two tillage methods (35-cm subsoiling and 15-cm traditional rotary tillage). The response characteristics used to compare the performance of the two maize varieties under different planting densities and tillage methods included root characteristics, canopy physiology, yield, and yield components. The results show that: (1) Under rotary tillage, with the increase of planting density from 75,000 plants ha−1 to 90,000 plants ha−1, yields of high-yielding spring maize varieties improved. However, when the planting densities were beyond 90,000 plants ha−1, the yields stopped increase, or even decrease. Subsoiling increased the planting density by 15,000 plants ha−1, enhanced the highest yield by 1080 kg ha−1–1940 kg ha−1, and raised the yield gain by 11.17–30.72%. (2) Under rotary tillage, the functional indexes of the roots and canopy of high-yielding spring maize decreased as planting density increased, and the largest reductions of root dry weight, leaf area index (LAI) of post-anthesis, light transmission percentage (LTP) of ear leaves, bottom leaves LTP, and dry matter accumulation all occurred between D2 and D4. The largest decline of high tolerance variety emerged between D3 and D5, and the extent was smaller than the low tolerance variety. (3) Compared with rotary tillage, subsoiling reduced the extent declines in root dry weight, root length, and root surface area; delayed the attenuation of LAI and the relative chlorophyll content (SPAD) determined in leaves; and improved the LTP of ear layers and bottom layer during the late growth stage. The post-anthesis populations dry matter accumulation of XD20 and LM33 increased by 7.07% and 13.18%, respectively. In addition, subsoiling significantly increased the number of kernels/spike and 1000-grain weight as the planting density increased. Meanwhile, the planting densities at which dry root weight, population LAI, ear leaf LTP, bottom leaf LTP, and dry matter accumulation arose the largest reductions was raised to 15,000 plants ha−1. The effects of subsoiling in the high density-tolerant variety were more pronounced than the low density-tolerant variety.
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Barbosa, Jaqueline de Araújo, Ivonei Perego, Claudia Tochetto, and Neumarcio Vilanova da Costa. "Efeito da Inoculação de Azospirillum Brasilense em Plantas de Trigo Submetidas a Convivência com Azevém." Ensaios e Ciência: Ciências Biológicas, Agrárias e da Saúde 23, no. 2 (December 9, 2019): 115. http://dx.doi.org/10.17921/1415-6938.2019v23n2p115-120.
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A matocompetição limita o crescimento e o desenvolvimento da cultura do trigo. Porém, a inoculação com bactérias diazotróficas pode reduzir os efeitos da matocompetição. Este trabalho teve como objetivo avaliar a inoculação de Azospirillum brasilense em sementes de trigo, e seus efeitos nos estádios iniciais de desenvolvimento, sendo submetidas em convivência com plantas de azevém. Utilizou-se delineamento experimental em blocos casualizados, e esquema fatorial 2x3, com quatro repetições. O primeiro fator correspondeu a inoculação de sementes trigo com A. brasilense, e o segundo fator a três densidades populacionais de azevém (0, 25, 50). Avaliações foram realizadas nas plantas de trigo aos 18 e 34 dias após a emergência (DAE). Aos 18 DAE, na densidade de 50 plantas de azevém, as plantas de trigo inoculadas foram 30% maiores em altura. Houve redução no número de folhas, em que as plantas de trigo inoculadas apresentaram número de folhas 33% maior do que as não inoculadas, além de índice de SPAD 23% maior. Aos 34 DAE, na densidade de 50 plantas de azevém, houve aumento de 21% na altura das plantas de trigo, índice SPAD 13% maior, e área foliar 15% maior em relação às plantas não inoculadas. Apesar do aumento de 68% no acúmulo de massa seca, as plantas inoculadas não diferiram em biomassa em relação à testemunha, quando em matocompetição. Conclui-se que a inoculação com A. brasilense favorece a cultura do trigo em matocompetição até os 18 DAE, mas ao final de 34 DAE, não se observam efeitos satisfatórios. Palavras-chave: Diazotróficas. Lolium multiflorum. Matocompetição. Plantas Daninhas. AbstractThe weed competition limits the growth and development of the wheat crop. However, the inoculation with diazotrophic bacteria can reduce the effects of weed competition. The objective of this work was to evaluate the inoculation with Azospirillum brasilense in seeds, and its effects in the early stages of development, and subjected to coexistence with plants of azevém. A completely randomized block design, and factorial 2x3, with four replications were used. The first factor corresponded to wheat seed inoculation with A. brasilense, and the second factor to three population densities of azevém (0, 25, 50). Evaluations were performed in wheat plants at 18 and 34 days after emergence (DAE). At 18 DAE, the density of 50 plants of azevém, the wheat plants inoculated were 30% greater in height. There was a reduction in the number of leaves, in which the wheat plants inoculated presented a number of sheets 33% higher than those not inoculated, in addition to SPAD index 23% higher. At 34 DAE, the density of 50 plants of azevém, there was an increase of 21% in the height of wheat plants, SPAD index 13% higher leaf area, and 15% higher than the non-inoculated plants. Despite the increase of 68% in the accumulation of dry mass, the inoculated plants did not differ in biomass in relation to the control , when in weed competition. It is concluded that inoculation with A. brasilense favors wheat cultivation in weed competition up to 18 DAE, but at the end of 34 DAE, no satisfactory effects are observed. Keywords: Diazotrophic. Lolium multiflorum. Matocompetition. Weeds.
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Hammer, Chad F., and John S. Gunn. "Planting native trees to restore riparian forests increases biotic resistance to nonnative plant invasions." Invasive Plant Science and Management 14, no. 2 (March 31, 2021): 126–33. http://dx.doi.org/10.1017/inp.2021.11.
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AbstractNonnative invasive plant species are a major cause of ecosystem degradation and impairment of ecosystem service benefits in the United States. Forested riparian areas provide many ecosystem service benefits and are vital to maintaining water quality of streams and rivers. These systems are also vulnerable to natural disturbances and invasion by nonnative plants. We assessed whether planting native trees on disturbed riparian sites may increase biotic resistance to invasive plant establishment in central Vermont in the northeastern United States. The density (stems per square meter) of invasive stems was higher in non-planted sites (x̄ = 4.1 stems m−2) compared with planted sites (x̄ = 1.3 stems m−2). More than 90% of the invasive plants were Japanese knotweed [Fallopia japonica (Houtt.) Ronse Decr.; syn. Polygonum cuspidatum Siebold & Zucc.]. There were no significant differences in total stem density of native vegetation between planted and non-planted sites. Other measured response variables such as native tree regeneration, species diversity, soil properties, and soil function showed no significant differences or trends in the paired riparian study sites. The results of this case study indicate that tree planting in disturbed riparian forest areas may assist conservation efforts by minimizing the risk of invasive plant colonization.
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BOIAGO, RAFAEL, RENATO GARCIA, ADILSON RICKEN SCHUELTER, RAFAEL BARRETO, GLACY JAQUELINE DA SILVA, and IVAN SCHUSTER. "COMBINAÇÃO DE ESPAÇAMENTO ENTRELINHAS E DENSIDADE POPULACIONAL NO AUMENTO DA PRODUTIVIDADE EM MILHO." Revista Brasileira de Milho e Sorgo 16, no. 3 (December 29, 2017): 440. http://dx.doi.org/10.18512/1980-6477/rbms.v16n3p440-448.
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RESUMO - Este trabalho teve como objetivo avaliar os efeitos do arranjo espacial e da densidade de semeadura na produtividade de cinco híbridos de milho, em dois locais no cultivo de verão. Foram utilizados espaçamentos de 80 cm e de 45 cm entrelinhas, e densidades de semeadura de 42.000, 52.000, 62.000 e 85.000 plantas ha-1. As avaliações foram conduzidas em Cascavel-PR e em Rio Verde-GO. Foram observados efeitos significativos para os fatores principais (híbrido, espaçamento entrelinhas e densidade), mas não foram observadas interações entre os fatores, com exceção da interação densidade x híbrido em Rio Verde. Houve maior efeito do espaçamento entrelinhas do que da densidade populacional na produtividade de todos os híbridos. No espaçamento de 45 cm entrelinhas, os híbridos produziram, em média, 36% a mais do que no espaçamento de 80 cm, nos dois locais avaliados. Houve aumento de produtividade com aumento da densidade de semeadura até 75 mil plantas ha-1 em Cascavel, e até 85 mil plantas ha-1 em Rio Verde. Palavras-chave: Zea mays, arranjo espacial de plantas, sistemas de cultivo. COMBINING ROW SPACING AND POPULATION DENSITY IN INCREASING MAIZE YIELD ABSTRACT - This study aimed to evaluate the effects of spatial arrangement and plant density from five corn hybrids at two locations in the summer season. Row spacing used were 80 cm and 45 cm between rows and plant densities were 42,000, 52,000, 62,000 and 85,000 plants ha-1. The evaluations were conducted in Cascavel, State of Paraná, and Rio Verde, State of Goiás, Brazil. Significant effects were observed for the main effects (hybrid, row spacing and density), but there were no interactions between the main effects, with the exception of the interaction between density x hybrid in Rio Verde. There was a greater effect of row spacing than the population density on yield of all hybrids. With the row spacing at 45 cm the hybrids yielded, on average, 36% more than at a spacing of 80 cm, in the two locations. There was a trend for increased productivity with increased seeding rate up to 75,000 plants ha-1 in Cascavel, and up to 85,000 plants ha-1 in Rio Verde. Keywords: Zea mays, spatial arrangements, cultivation systems.
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Dobosz, Renata, and Roman Krawczyk. "Meloidogyne hapla development on growing legume plants – Short Communication." Plant Protection Science 55, No. 4 (September 13, 2019): 273–76. http://dx.doi.org/10.17221/156/2018-pps.
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The legume genus lupine, pea, faba bean and common vetch were cultivated under natural conditions in pots filled with soil naturally infected with Meloidogyne hapla Chitwood, 1949. The nematode population density increased relevantly in the soil planted with the faba bean (cultivars (cvs.) Bobas, Amulet, Albus) and the pea cv. Lasso, in which numerous root galls and egg masses appeared. The narrow-leaved lupine (cvs. Karo, Zeus), yellow lupine (cvs. Parys, Lord) and white lupine (cv. Boros) cultivation decreased the nematode population density and these were not statistically significant when compared with the nematode density in a fallow soil.
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Sandoval-Herazo, Luis Carlos, Alejandro Alvarado-Lassman, María Cristina López-Méndez, Albino Martínez-Sibaja, Alberto A. Aguilar-Lasserre, Sergio Zamora-Castro, and José Luis Marín-Muñiz. "Effects of Ornamental Plant Density and Mineral/Plastic Media on the Removal of Domestic Wastewater Pollutants by Home Wetlands Technology." Molecules 25, no. 22 (November 12, 2020): 5273. http://dx.doi.org/10.3390/molecules25225273.
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Wastewater treatment (WWT) is a priority around the world; conventional treatments are not widely used in rural areas owing to the high operating and maintenance costs. In Mexico, for instance, only 40% of wastewater is treated. One sustainable option for WWT is through the use of constructed wetlands (CWs) technology, which may remove pollutants using cells filled with porous material and vegetation that works as a natural filter. Knowing the optimal material and density of plants used per square meter in CWs would allow improving their WWT effect. In this study, the effect of material media (plastic/mineral) and plant density on the removal of organic/inorganic pollutants was evaluated. Low (three plants), medium (six plants) and high (nine plants) densities were compared in a surface area of 0.3 m2 of ornamental plants (Alpinia purpurata, Canna hybrids and Hedychium coronarium) used in polycultures at the mesocosm level of household wetlands, planted on the two different substrates. Regarding the removal of contaminants, no significant differences were found between substrates (p ≥ 0.05), indicating the use of plastic residues (reusable) is an economical option compared to typical mineral materials. However, differences (p = 0.001) in removal of pollutants were found between different plant densities. For both substrates, the high density planted CWs were able to remove COD in a range of 86–90%, PO4-P 22–33%, NH4-N in 84–90%, NO3-N 25–28% and NO2-N 38–42%. At medium density, removals of 79–81%, 26–32, 80–82%, 24–26%, and 39–41%, were observed, whereas in CWs with low density, the detected removals were 65–68%, 20–26%, 79–80%, 24–26% and 31–40%, respectively. These results revealed that higher COD and ammonia were removed at high plant density than at medium or low densities. Other pollutants were removed similarly in all plant densities (22–42%), indicating the necessity of hybrid CWs to increase the elimination of PO4-P, NO3-N and NO2-N. Moreover, high density favored 10 to 20% more the removal of pollutants than other plant densities. In addition, in cells with high density of plants and smaller planting distance, the development of new plant shoots was limited. Thus, it is suggested that the appropriate distance for this type of polyculture plants should be from 40 to 50 cm in expansion to real-scale systems in order to take advantage of the harvesting of species in these and allow species of greater foliage, favoring its growth and new shoots with the appropriate distance to compensate, in the short time, the removal of nutrients.
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Bottenberg, Harry, and Michael E. Irwin. "Flight and Landing Activity of Rhopalosiphum maidis (Homoptera: Aphididae) in Bean Monocultures and Bean-Corn Mixtures." Journal of Entomological Science 27, no. 2 (April 1, 1992): 143–53. http://dx.doi.org/10.18474/0749-8004-27.2.143.
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Rhopalosiphum maidis (Fitch) dominated the aerial aphid plankton in bean (Phaseolus vulgaris L.) monocultures and mixed cultures of bean with corn (Zea mays L.) in Illinois. It was also the most common species landing on bean plants in this study during the summer of 1987. More flight activity was recorded in the monocultures than in the mixtures. More R. maidis flew at the top of the bean canopy than at the level of the corn canopy. Densely planted corn rows suppressed flight activity more than did sparsely planted rows. Plots that were planted early had lower aphid catches over the same time than did plots planted 13 and 24 days later. Aphid flight activity was negatively correlated with ground cover, corn barrier height, and corn barrier density. Aphid landing activity was not affected by planting date or corn row density but was negatively and significantly correlated with ground cover. Stepwise regression analysis revealed that ground cover was more important than barrier height and barrier density in suppressing flight and landing activity of R. maidis.
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McGowan, AA, and GL Mathews. "Effect of inter-row spacing on the production of tagasaste and associated pastures." Australian Journal of Experimental Agriculture 34, no. 4 (1994): 487. http://dx.doi.org/10.1071/ea9940487.
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Tagasaste (Chamaecytisus proliferus (L. fil.) Link ssp. palmensis) was planted at 4 densities (2500, 5000, 10000, 20000 plants/ha with row spacings of 0.5, 1, 2 or 4 m). Plants were 1 m apart within rows for all densities, The tagasaste was harvested at about 6-monthly intervals in February and August over a 5-year period at a height of 0.5 m. Pasture growing between the rows was harvested at the same time to about 50 mm height. Growth per tree was reduced by increasing density, especially as the trees matured, but even after 4 years, yield per ha was more than 200% greater at the lowest density. Although there was an adverse effect of tagasaste density on pasture harvested (up to 32%), the total dry matter harvested in the final year was still 40% greater at the highest density of tagasaste.