Academic literature on the topic 'Fruit set'

Bibliography: leaves 190-211. Research was carried out to evaluate pollination efficiency, gene flow by pollen and fruit set in Packham Triumph cultivar pear trees located in a mixed planting of pear cultivars in a commercial orchard in the Coromandel Valley region of South Australia.

Thesis (MScAgric)--Stellenbosch University, 2013.<br>ENGLISH ABSTRACT: Maintaining constant high yields in „Abate Fetel‟ and „Forelle‟ orchards in South Africa is challenging. Improving productivity in these orchards could be achieved by increasing fruit set and fruit size. Fruit size is an important marketing and quality parameter and has a significant effect on the economic value of fruit. Various protocols to improve fruit set are used by South African producers but these are not well researched. We therefore evaluated different combinations of plant growth regulators including gibberellic acid (GA3), gibberellins 4+7 (GA4+7), GA4+7 combined with 6-benzyladenine (6-BA), aminoethoxyvinylglycine (AVG) and prohexadione-calcium (P-Ca) in combination with trunk girdling during flowering on „Forelle‟ and „Abate Fetel‟ to determine the best fruit set strategy. All applied growth regulators improved fruit set relative to an untreated control over two consecutive seasons, but GA3 and P-Ca reduced return bloom and AVG resulted in smaller fruit size relative to the other treatments. The application of synthetic cytokinins are believed to enhance fruit size by stimulating and extending the cell division period in fruit when applied at the correct stage of fruit growth. In addition, combination of P-Ca with GA4+7 was used successfully on Japanese pear (Pyrus pyrifolia Nakai) and „Bing‟ sweet cherry to improve fruit size. This combination of GA4+7 and P-Ca was evaluated and combined with 6-BA treatments on European pear (Pyrus communis L.) cultivars, Forelle and Abate Fetel, to see if a similar effect on fruit size could be achieved under South African growing conditions. On both „Forelle‟ and „Abate Fetel‟ the combination of GA4+7 and P-Ca increased fruit size, but was more pronounced in „Abate Fetel‟. Growth regulators N-phenyl-N‟ -1,2,3-thiadiazol-5-ylurea (TDZ), N (2-chloro-4-pyridyl)-N‟ -phenylurea (CPPU), 6-BA and 2,4-dichlorophenoxyacetic acid (2,4-D) successfully increased fruit size in pear cultivars Coscia and Spadona in Israel. These growth regulators were applied to „Forelle‟ and „Abate Fetel‟ to determine if a similar effect could be achieved. None of the synthetic cytokinins applied had a significant effect on increasing fruit size in these two cultivars over two consecutive seasons although 6-BA increased return bloom and 2,4-D application resulted in increased fruit set. The stage when the cell division period in „Forelle‟ and „Abate Fetel‟ ends was also determined as 34 and 45 days after full bloom respectively, which can be used in the future to better plan the timing of fruit size enhancement treatments. Based on results from various fruit set and fruit size improvement trials, it can be recommended to use GA4+7 or AVG to increase fruit set on „Forelle‟ and „Abate Fetel‟, depending on the fruit set history of the orchard. Results from fruit size improvement trials were variable, and emphasises the fact that a balance between yield and fruit size must be determined for an orchard to achieve good fruit size and maximum return.<br>AFRIKAANSE OPSOMMING: Die handhawing van konstante, hoë opbrengste in „Abate Fetel‟ en „Forelle‟ boorde in Suid-Afrika is 'n uitdaging. Produktiwiteit in hierdie boorde kan verhoog word deur vrugset en vruggrootte te verbeter. Vruggrootte is 'n belangrike bemarkings- en kwaliteitsparameter en het 'n betekenisvolle effek op die ekonomiese waarde van vrugte. 'n Verskeidenheid protokolle om vrugset te verbeter word deur Suid-Afrikaanse produsente gevolg, maar hierdie protokolle is nog nie goed nagevors nie. Verskillende kombinasies van plantgroeireguleerders insluitend gibberelliensuur (GA3), gibberellien 4+7 (GA4+7), GA4+7 in kombinasie met 6-bensieladenien (6-BA), aminoetoksievinielglisien (AVG) en prohexadioon-kalsium (P-Ca) in kombinasie met stamringelering is aan „Forelle‟ en „Abate Fetel‟ bome gedurende blomtyd toegedien om die beste vrugsetstrategie te bepaal. Alle plantgroeireguleerdes wat toegedien is het vrugset verbeter relatief tot 'n onbehandelde kontrole oor twee opeenvolgende seisoene, maar GA3 en P-Ca het die aantal blomme in die daaropvolgende seisoen verlaag en AVG het kleiner vruggrootte gelewer relatief tot alle ander behandelings. Dit is wel bekend dat die toediening van sintetiese sitokiniene vruggrootte verbeter deur die stimulering en bevordering van seldeling in vrugte wanneer dit in die regte groeifase toegedien word. Die kombinasie van P-Ca en GA4+7 was suksesvol om vruggrootte te verbeter toe dit aan Japanese pere (Pyrus pyrifolia Nakai) en „Bing‟ kersies toegedien is. Hierdie kombinasie van GA4+7 en P-Ca is geëvalueer en gekombineer met 6-BA-behandelings op die Europese peer (Pyrus communis L.) kultivars, Forelle en Abate Fetel, om te bepaal of dieselfde effek op vruggrootte bereik kan word onder Suid-Afrikaanse groei kondisies. Op beide „Forelle‟ en „Abate Fetel‟ het die kombinasies van GA4+7 en P-Ca vruggrootte verbeter, maar dit was meer opmerklik in die geval van „Abate Fetel‟. Die groeireguleerders N-feniel-N‟ -1,2,3-thiadiazol-5-ylurea (TDZ), N (2-chloro-4-piridiel)-N‟ -fenielurea (CPPU), 6-BA en 2,4- dichloorfenoksieasynsuur (2,4-D) het vruggrootte verbeter in „Coscia‟ en „Spadona‟ pere in Israel. Hierdie plantgroeireguleerders is toegedien aan „Forelle‟ en „Abate Fetel‟ om vas te stel of dieselfde effek verkry kon word. Nie enige van die sintetiese sitokiniene wat toegedien is het 'n betekenisvolle effek op die verbetering van vruggrootte in hierdie twee kultivars oor twee opeenvolgende seisoene getoon nie, alhoewel 6-BA die verbetering van blom in die daaropvolgende seisoen tot gevolg gehad en 2,4-D vrugset verbeter het. Die stadium waar seldeling in „Forelle‟ en „Abate Fetel‟ eindig is vasgestel as 34 en 45 dae na volblom, onderskeidelik, wat in die toekoms gebruik kan word om die beplanning en tydsberekening van vruggrootte behandelings te verbeter. Na verskeie vrugset en vruggroote verbeterings proewe, kan aanbeveel word dat GA4+7 of AVG gebruik kan word om vrugset in „Forelle‟ en „Abate Fetel‟ te verbeter, afhangende van die vrugset geskiedenis van die boord. Resultate van vruggrootte verbeterings proewe het gevarieër en beklemtoon net weer die feit dat 'n balans tussen opbrengs en vruggrootte bepaal moet word om optimale vruggrootte te handhaaf en so hoë winste te verseker.<br>SAAPPA

Groundnuts (Arachis hypogaea L.) grown in the semi-arid tropics are commonly exposed to air and soil temperatures> 35°C. This research in controlled environments has shown that continuous exposure of plants to hot air (day/night, 38°/22°C) and/or hot soil (38°/30°C) temperatures during the reproductive .phase (from flower bud appearance until reproductive maturity) significantly reduces total dry matter production, the partitioning of dry matter to pods and seed yields. The effects of hot air and hot soil temperature were additive and without interaction. Hot air temperature had no effect on flower production but significantlyreduced the proportion of flowers setting pegs (fruit-set) and hence the number of fruits. In contrast, hot soils significantly reduced flower production, the proportion of pegs forming pods and 100 seed weight. There was no evidence that plants dependent on symbiotic N2 fixation were more susceptible to heat stress than those dependent on inorganic N. Sensitivity to short (6 d) episodes of hot air temperature (38°/22°C) was acute during the period between 6 d before until 15 d after first flowering (OAF). The magnitude of that sensitivity depended on the number of floral buds exposed to heat stress before anthesis. In the Spanish cv. ICGV 86015, daytime air temperatures ~34°C imposed for only 6 d beginning at 9 DAF, significantly reduced flower number, pollen production and viability, fruit-set and seed yield. Fruit-set was most sensitive to heat stress during the first 6 h of the daylight period (AM). Warmer nights (28° cl 22°C) had no effect on flower numbers, but significantly reduced both pollen production and viability, and hence fruit-set. There were negative quantitative relations between flower number and day temperatures between 28° and 48°C. In contrast, reductions in fruit-set were quantitatively related to AM temperature >37.3°C. Pollen production and viability were also linearly reduced when day temperature was >34°C. These data will help plant breeders to screen germplasm and identify heat-tolerant cultivars, and should also improve simulation models of groundnut crops in the semi-arid tropics.

Made available in DSpace on 2016-12-08T16:44:41Z (GMT). No. of bitstreams: 1 PGPV12MA094.pdf: 1832158 bytes, checksum: 12087c58319ad6a4e92485eaff5983f5 (MD5) Previous issue date: 2012-02-16<br>The pear is the third most temperature fruit consumed in Brazil, representing the largest percentage of total frsh fruit imports by country (50.7% of the amount). Brazilian production is not significant, with low fruit set as one of the main problems of low productivity of pear trees in southern Brazil. In this context, this study aimed to evaluate the main growth regulators (Promalin®, Viviful®, Retain®, and TDZ) for the cultivation of the pear growing in different locations in southern brazil and its effect on fruit ser and yield of pear Packam s Triumph and William s . The experiments were conducted in the regions of São Joaquim, SC, Rio Rufino, SC and São Francisco de Paula, RS, during the growing seasons 2009/2010 and 2010/2011, with cultivars Packam s Triumph and William s. We evaluate the fruit set, number of fruits per plant, yield per plant, estimated yield, fruit diameter, deformation, flesh firmness, number of viable and unviable seeds, soluble solids, pH and titratable acidity. The results indicate that cv. Packam s Triumph is more responsive to the action of growth regulators than cv. William s. Since, Promalin® (1 ml L-1) applied at the full bloom + Retain® (2 g L-1) applied 15 days after the full bloom increases the productivity of pear Packham s Trimph, and pear William s, the increase only happened in the counties of São Joaquim and São Francisco de Paula. The use growth regulators did not increase the productivity of the pear tree William s in the experimental area of São Joaquim. The application of Viviful® increased the productivity of pear William s in the experimental area of San Francisco de Paula. The use growth regulators Retain®, Viviful®, TDZ and Promaline® + Retain® increase the fruit set of pear Packham s Triumph, emphasizing the application of Promaline® (1 ml L-1) applied at full bloom + Retain® (2 f L-1) applied 15 days after full bloom, which increased fruit set and productivity<br>A pera é a terceira fruta de clima temperado mais consumida no Brasil, representando a maior porcentagem no total dos frutos in natura importados pelo país (50,7% da quantidade). A produção brasileira é pouco expressiva, apresentando baixo pegamento de frutos como um dos principais problemas da baixa produtividade das pereiras no sul do Brasil. Neste contexto, o presente trabalho teve como objetivo, avaliar os principais fitorreguladores (Promalin®, Viviful®, Retain® e Thidiazuron) para a cultura da pereira em diferentes locais de cultivo no sul do Brasil e o seu efeito na fruit set e produtividade das pereiras Packham&#8223;s Triumph e William&#8223;s . Os experimentos foram conduzidos nas regiões de São Joaquim, SC, Rio Rufino, SC e São Francisco de Paula, RS durante as safras 2009/2010 e 2010/2011, com as cultivares Packham&#8223;s Triumph e William&#8223;s. Foram avaliados a fruit set, nº de frutos por planta, produtividade por planta, produtividade estimada, diâmetro de frutos, deformação, firmeza de polpa, nº de sementes viáveis e inviáveis, sólidos solúveis, pH e acidez titulável. Os resultados obtidos indicam que a cv. Packham&#8223;s Triumph responde mais à ação dos fitorreguladores do que a cv. William&#8223;s. Sendo que, Promalin® (1 ml L-1) aplicado no estádio de plena floração + Retain® (2 g L-1) aplicado 15 dias após a plena floração aumentam a produtividade da pereira Packham&#8223;s Triumph, e na pereira William&#8223;s, o aumento só aconteceu nos municípios de São Joaquim e São Francisco de Paula. O uso de fitorreguladores não aumentou a produtividade da pereira William&#8223;s na área experimental de São Joaquim. A aplicação de Viviful® aumentou a produtividade das pereiras William&#8223;s na área experimental de São Francisco de Paula. O uso dos fitorreguladores Retain®, Viviful®, TDZ e Promalin® + Retain® aumentam a fruit set da pereira Packham&#8223;s Triumph, destacando-se a aplicação de Promalin® (1 ml L-1) aplicado no estádio de plena floração + Retain® (2 g L-1) aplicados 15 dias após a plena floração, o qual aumentou a fruit set e a produtividade

Field experiments were established during the 1988 and 1989 growing seasons, to determine the effect of mini-tunnel management systems on floral development and fruit set of tomato (Lycopersicon esculentum Mill.). Two types of floral abnormalities reported to be caused by temperatures above 30$ sp circ$C were observed, namely: style exsertion and splitting of the antheridial cone. Clear vented and white non-vented mini-tunnels reduced the incidence of both these abnormalities compared to the controls in 1988. As a consequence these two types of mini-tunnels also had the greatest percentage fruit set and total marketable yield of the first three clusters. In 1989, none of the mini-tunnels tested significantly increased percentage fruit set or marketable yield. The cultivar Springset produced ripe fruits an average of 4 days before Hope#1 and 7 days before Celebrity in both 1988 and 1989.

Under favourable conditions, the avocado sets more fruits than the tree is able to bring to maturity, so that the plant adjusts, during the early stages of development, its ability to nourish them by modifying their number, that is, causing the fruit drop of those who can not maintain their growth rate. Accordingly, carbohydrate availability could be a key factor in the physiological abscission of these fruits. Since this species presents dichogamy, the abscission of fruits has also been attributed to the absence of pollination, but at the same time it has been related to failures in seed development, embryo abortion, seed coat collapse, and with the effect of an environmental stress, especially by cold or heat. In order to demonstrate if in avocado the competition between flowers is responsible for fruit set and initial development of the fruit, it has been determined the influence of the flowering intensity in the time course of carbohydrate and hormonal content, in the rate of fruits abscission and its evolution, and finally, on percentage of fruits set. For this purpose experiments have been designed in order to: 1) reduce flowering, and with it the competition between flowers, 2) reduce vegetative growth, and 3) promote fruit set. The experiments were carried out in commercial orchards of avocado (Persea americana Mill.) cv. Hass (group A flowering), located in Torrent and Llaurí (Valencia), Spain, and in Caronia Marina (Messina), Italy. Adult trees (5-8 years), planted at a distance of 5 x 6 m. In all of them there were cv. Fuerte (flowering group B) to ensure pollination. The results showed that gibberellic acid applied during the floral bud inductive period delayed sprouting, reduced the number of flowers per panicle, increased apical shoot length, and delayed fruitlet abscission. Gibberellic acid applied at anthesis enhanced fruit set and delayed fruitlet abscission. It correlated with an immediate and temporary increase of GA1, IAA and tZ content. But the GA1 immeditely derived in its catabolite GA8. Since IAA synthesis precedes fruit set and tZ increasing content, the possibility that fertilization triggers the tZ synthesis mediated by auxin cannot be discarded. Gibberellic acid applied at the beginning of fruit set also, temporarily, increased the endogenous concentration of GA1 and GA8, As well as the number of fruits that initiated the development and delayed their abscission. Paclobutrazol applied at anthesis reduced the growth of the terminal shoot y anticipated flowers abscission, but did not affect initial fruit set. In no case it was possible to increase the total number of fruits per panicle, so that the competition between developing organs is not the cause of the lack of fruit set in this species.<br>En condiciones favorables, el aguacate cuaja más frutos de los que el árbol es capaz de llevar a la madurez, de modo que la planta ajusta, durante las primeras fases del desarrollo, su capacidad de nutrirlos modificando su número, esto es, provocando la caída de los que no pueden mantener su tasa de crecimiento. De acuerdo con ello, la disponibilidad de carbohidratos podría ser un factor clave en la abscisión fisiológica de estos frutos. Dado que esta especie presenta dicogamia, la abscisión de frutos también se ha atribuido a la ausencia de polinización, pero al mismo tiempo se ha relacionado con fallos en el desarrollo de la semilla, el aborto del embrión, el colapso de la cubierta seminal, y con el efecto de un estrés ambiental, especialmente por frío o calor. Con el fin de demostrar si en el aguacate la competencia entre flores es responsable del cuajado y desarrollo inicial del fruto, se ha determinado la influencia que la intensidad de floración tiene en la evolución del contenido en carbohidratos y hormonas, en la tasa de abscisión de frutos y su evolución, y, finalmente, sobre porcentaje de frutos cuajados. Para ello se han diseñado experimentos para 1) reducir la floración, y con ello la competencia entre flores, 2) reducir el desarrollo vegetativo, y 3) promover el cuajado de frutos. Los experimentos se llevaron a cabo en huertos comerciales de aguacate cv. Hass (grupo A de floración), localizados en Torrent y Llaurí (Valencia), España, y en Caronia Marina, Messina, Italia. Se utilizaron árboles adultos (5-8 años de edad), plantados a una distancia de 5 x 6 m. En todos ellos había árboles del cv. Fuerte (grupo B de floración) para asegurar la polinización. Los resultados demuestran que la aplicación de ácido giberélico durante la inducción floral retrasó la brotación, redujo el número de flores por panícula, aumentó la longitud del brote desarrollado a partir de la yema terminal de la panícula, y retrasó la abscisión fisiológica de frutos. Su aplicación en antesis promovió el cuajado de frutos y retrasó su abscisión. Ello se corresponde con un aumento inmediato y temporal de la síntesis endógena de GA1, IAA y tZ. Pero la GA1 derivó inmediatamente en su catabolito GA8. Puesto que la síntesis de IAA precedió al cuajado y al contenido creciente de tZ, la posibilidad de que la fecundación desencadene la síntesis de tZ mediada por la auxina no puede ser descartada. La aplicación de ácido giberélico al inicio del cuajado también aumentó, temporalmente, la concentración endógena de GA1 y GA8, así como el número de frutos que iniciaron el desarrollo, y retrasó su abscisión. La aplicación de paclobutrazol en antesis redujo el crecimiento del brote terminal y anticipó la abscisión de las flores, pero no afectó el cuajado inicial. En ningún caso se consiguió aumentar el número total de frutos por panícula, de modo que la competencia entre órganos en desarrollo no es la causa de la falta de cuajado en esta especie.<br>En condicions favorables, l'alvocat qualla més fruits dels que l'arbre és capaç de portar a la maduresa, de manera que la planta s'ajusta, durant les primeres fases del desenvolupament, la capacitat de nodrir-modificant el nombre, és a dir, provocant la caiguda dels que no poden mantenir la seva taxa de creixement. D'acord amb això, la disponibilitat de carbohidrats podria ser un factor clau en la abscisió fisiològica d'aquests fruits. Atès que aquesta espècie presenta dicogàmia, la abscisió de fruits també s'ha atribuït a l'absència de pol·linització, però al mateix temps s'ha relacionat amb errors en el desenvolupament de la llavor, l'avortament de l'embrió, el col·lapse de la coberta seminal, i amb l'efecte d'un estrès ambiental, especialment per fred o calor. Per tal de demostrar si en l'alvocat la competència entre flors és responsable del quallat i desenvolupament inicial del fruit, s'ha determinat la influència que la intensitat de floració té en l'evolució del contingut en carbohidrats i hormones, en la taxa d'abscisió de fruits i la seva evolució, i, finalment, sobre percentatge de fruits quallats. Per això s'han dissenyat experiments per a 1) reduir la floració, i amb això la competència entre flors, 2) reduir el desenvolupament vegetatiu, i 3) promoure el quallat de fruits. Els experiments es van dur a terme en horts comercials d'alvocat cv. Hass (grup A de floració), localitzats a Torrent i Llaurí (València), Espanya, i en Caronia Marina, Messina, Itàlia. Es van utilitzar arbres adults (5-8 anys d'edat), plantats a una distància de 5 x 6 m. En tots ells hi havia arbres del cv. Fort (grup B de floració) per assegurar la pol·linització. Els resultats demostren que l'aplicació d'àcid giberèlic durant la inducció floral retardar la brotada, va reduir el nombre de flors per panícula, va augmentar la longitud del brot desenvolupat a partir del rovell terminal de la panícula, i va retardar la abscissió fisiològica de fruits. La seva aplicació en antesi va promoure el quallat de fruits i va retardar la seva abscisió. Això es correspon amb un augment immediat i temporal de la síntesi endògena de GA1, IAA i tZ. Però la GA1 va derivar immediatament en el seu catabolit GA8. Ja que la síntesi de IAA va precedir al quallat i al contingut creixent de tZ, la possibilitat que la fecundació desencadeni la síntesi de tZ intervinguda per l'auxina no pot ser descartada. L'aplicació d'àcid giberèlic a l'inici del quallat també va augmentar, temporalment, la concentració endògena de GA1 i GA8, així com el nombre de fruits que van iniciar el desenvolupament, i va retardar la seva abscisió. L'aplicació de paclobutrazol en antesi va reduir el creixement del brot terminal i va anticipar la abscisió de les flors, però no va afectar el quallat inicial. En cap cas es va aconseguir augmentar el nombre total de fruits per panícula, de manera que la competència entre òrgans en desenvolupament no és la causa de la manca de quallat en aquesta espècie.<br>D'asaro, A. (2017). NUTRITIONAL AND HORMONAL FACTORS AFFECTING FRUIT SET IN AVOCADO (Persea americana Mill.) [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/79875<br>TESIS

Boron was applied as a foliar spray to pecan trees in a pecan orchard located in Cochise County. Single or repeated application prior to pollination did not affect nutlet set. Leaf analysis indicated that the boron levels in all trees were in the sufficient range for optimum growth and production.

The importance of European honey bees in improving fruit set, yield and fruit weight of kiwifruit on the central east coast of Australia was investigated. Field investigations were carried out using different bee saturations and different types of male pollen parents. These investigations confirmed the importance of honey bees in kiwifruit fruit set, yield and fruit weight. However, the results suggested that increasing bee activity alone may not increase pollination of kiwifruit by honey bees. Many factors need to be understood before introducing bees into the orchard. Bees were more effective during the early part of the flowering period, and bee activity varied according to the sex of the vine, planting design and the time of day. The type of male pollen parents also influenced fruit size and quality. Flowers pollinated by different pollen parents were assessed for pollen tube growth and histochemical changes. The resulting fruit were also examined for weight and seed numbers. Honey bees play the major role in the size and yield of kiwifruit, but the design of male vines, their age and type of male pollen may also contribute. The kiwifruit pistil also possesses important features that can be considered as adaptations to insect pollination.<br>Doctor of Philosophy (PhD)