Academic literature on the topic 'Peas Diseases and pests'

To increase the efficiency and safety of phytosanitary measures, it is necessary to combine all available methods and means aimed at long-term suppression of the number of pests below economic threshold of harmfulness. In this regard, the article provides data on the influence of external environmental factors (weather conditions, preparations for pre-sowing seed treatment) on disease susceptibility and yield of peas. The hydrothermal conditions corresponded to climatic conditions of the Trans-Urals during the period of the experiments and were favorable for cultivation of agricultural crops. It was established that the most common and harmful diseases of peas are fusarium (in the forms of root rot and wilting) and ascochitis. Pre-sowing seed treatment with fungicides was effective not only against root rot and wilting of peas, the development of the disease decreased by 1.2-1.6 times, but also against a group of leaf-stem diseases, susceptibility to ascochitosis decreased by 1.4-1.7 times. The influence strength of pre-sowing seed treatment on susceptibility of peas to Fusarium was 9.5-74.6 %, and weather conditions - 4.0-76.9 %. The development of leaf-stem infections was largely influenced by weather conditions of the growing season, the share of this factor was 13.7-88.7 %. Treatment of pea seeds with all the studied preparations provided a significant increase of yield by 9.7 ... 23.4 %. The influence of "Weather conditions of the year" factor in yield formation of peas was 72.8 ... 76.1 %, while the share of "Preparations" factor influence did not exceed 15.9 ... 18.3 %.

The article emphasizes the importance of peas as a source of vegetative protein, and indicates on insufficient areas under peas both in Russia and in the Altai. One of the reasons of reducing its acreage is the high costs on peas planting and protecting from pests, diseases and weeds. Climate changing contributes to rapid development of such harmful diseases as ascohitoz, bacteriosis, fusarium, rust, significant number of weevil, pea aphid and moth mullet. Considering the main directions in pea breeding, it should be emphasized that the Altai Area, with its vast territory and diverse natural and climatic conditions, requires highly productive, well-adapted varieties of different use which are capable to effectively use agro-climatic resources of different zones. All this requires the active study of the source material, the selection of new, economically valuable forms and their introduction into the breeding process. It has been noted that the production requires more advanced varieties, the development of which is impossible without the presence of diverse source material. The purpose of the study was to identify the best productive plants in the pea collection of 2012-2017. The material has been represented by 113 variety samples of domestic and foreign selection. The varieties with best productivity were ‘Mnogoplodny 163’, ‘Rheinperle’, ‘Flagman 12’, ‘806’9, ‘Varyag’, ‘Altaisky Usaty’, ‘Pioner’, ‘LittleMarwel’, ‘Mnogoplodny 27’, ‘Zeleny Tsukat’, ‘Ryadovoy’, ‘576/80’. The best forage productivity was produced by ‘Novosibirets’, ‘Varyag’, ‘Pino’, ‘Zeleny Tsukat’, ‘Mnogoplodny 105’. The most fast-ripening varieties were ‘Rheinperle’ and ‘Pyrama’. The samples ‘Novosibirets’, ‘Varyag’, ‘Pino’ and ‘8067’ were characterized with high plant height. The samples ‘Pyrama’, ‘Flagman 12’, ‘Novosibirets’, ‘Sihirobana-Kinusaja’, the line ‘312’ produced large-sized kernels. The great lodge resistance has been shown by ‘Altaisky Usaty’, ‘Svetozar’, ‘Kamerton’, ‘Flagman 12’.

The main directions of research on chemical means of protecting fodder crops from diseases, pests and weeds in the field fodder production of the All-Russian Fodder Research Institute are given. Studies on toxicological assessment of feed and soil are given. Plant Protection Department included three laboratories: the Herbicide Laboratory, the Plant Protection Laboratory and the Feed Toxicological Evaluation Laboratory. The Laboratory of Herbicides was established in 1967 to conduct research on the chemical method of controlling weeds on fodder crops, hayfields and pastures. Research on the study of pests of fodder crops was started in 1939 in the newly created laboratory for the protection of fodder crops from pests and diseases. The Feed Toxicology Assessment Laboratory was established in 1980 to assess pesticide residues in crop and soil. As a result of the studies, a system of measures for clover from pests has been developed; alfalfa diseases and pests and measures to combat them in the Non-Chernozem zone were studied. Pests and pathogens of corn, root crops, peas, lupine and other fodder crops were identified; their biology, ecology and harmfulness have been studied. A set of protective measures has been developed to combat the main pests and diseases of fodder crops, including soil cultivation techniques, early sowing dates, the use of resistant varieties, micro- and macrofertilizers, pre-sowing treatment of seeds with combined preparations, etc. Plant Protection Department carried out work with herbicides. As a result of research begun in 1950, a method was developed to clean the meadows from weedy herbaceous vegetation with the help of preparations 2,4-D and 2M-4X. A chemical method for the destruction of woody and shrubby vegetation with the help of the same preparations in the Non-Chernozem zone of the European part of the USSR has been developed. Methods of using herbicides on crops of almost all fodder crops have been developed: perennial and annual legumes and cereal grasses for green mass and seeds, corn, fodder beets, rapeseed, etc. The theoretical issues of the mutual influence of fodder crops and weeds are studied, the substantiation of the effectiveness of the use of herbicides on different types of soils is given.

Plant diseases and pests may seriously affect the yield of crops and even threaten the survival of human beings. The characteristics of plant diseases and insect pests are mainly reflected in the occurrence of lesions on crop leaves. Machine vision disease detection is of great significance for the early detection and prevention of plant diseases and insect pests. A fast detection method for lesions based on a single-channel gravitational kernel density clustering algorithm was designed to examine the complexity and ambiguity of diseased leaf images. Firstly, a polynomial was used to fit the R-channel feature histogram curve of a diseased leaf image in the RGB color space, and then the peak point and peak area of the fitted feature histogram curve were determined according to the derivative attribute. Secondly, the cluster numbers and the initial cluster center of the diseased leaf images were determined according to the peak area and peak point. Thirdly, according to the clustering center of the preliminarily determined diseased leaf images, the single-channel gravity kernel density clustering algorithm in this paper was used to achieve the rapid segmentation of the diseased leaf lesions. Finally, the experimental results showed that our method could segment the lesions quickly and accurately.

Goal. To perform innovative developments for the protection of grain crops in Ukraine and on this basis to generate the investment and innovation database.
 Methods. Analysis of innovation developments of Institute of Plant Protection of National Academy of Agrarian Sciences of Ukraine and other institutions of Scientific and Methodological Center “Plant Protection” during 2001—2018. Distinguishing of these, which are connected with grain crop protection from pests, diseases and weeds. Grouping of innovations on grain crop protection due to different fields.
 Results. Created investment and innovation database for the protection of grain crops in Ukraine consists of 155 scientific developments, which are grouped in the following areas: forecasting of phytosanitary condition of crops; providing scientific breeding of crops for resistance to pests and diseases; biological method of plant protection; advanced environmentally friendly technologies to protect crops against harmful organisms; chemical method of plant protection; plant quarantine. The effect of the transfer of innovation may be as follows: net profit from 3367—7950 till 12644,5 UAH per 1 ha (under irrigation), profitabi­lity — from 84.1 to 131—152%.
 Conclusions. The result of the transfer of the created innovation is the effective protection of major crops (wheat, rye, barley, peas, buckwheat, millet, corn, soybeans) from pests in different soil-climatic zones of Ukraine and with all this obtaining a significant part of additional production of improved quality and increased profitability. This will be the basis for the successful solution of a number of problems of strengthening of grain farming and agricultural sector and the economy as a whole.

According to the legislation of Ukraine, one of the requirements of organic crop production is the use of organic seeds and organic planting material. High productivity and quality of sowing material for organic production of agricultural products can only be obtained with the full supply of plants and soil to nutrients and the protection of plants from diseases, pests and weeds. The purpose of the work was to study the technologies of protection and nutrition of legumes (peas and soybean) with the use of domestic biopreparations in seminal organic agrophytocenoses. The research was carried out in the right-bank forest-steppe of Ukraine. The influence of technologies of the use of complexes of biological products of natural origin on the productivity of the seed material of peas and soybeans, its seed quality and phytosanitary condition of crops were studied. The study evaluated the potential of legume crops by main economic characteristics in the conditions of use of organic production technologies in different phases of ontogenesis of plants. Positive influence of technologies of complexes of biological preparations on growth and development of cultivated plants, which was reflected on their biometric indices, is established, finally forming the yield of peas and soybeans and high crop quality. In general, the use of all investigated technologies using biopreparations on peas and soybeans ensured obtaining quality organic seed material that meets the requirements of DSTU 2240-93 for reproductive seed.

The study of ecological adaptability of different economic and biological indicators of intensive varieties of grain and leguminous crops for use in feed grain-grass crop rotation is aimed at increasing the production of high-quality concentrated feed. Objects of research: intensive varieties of spring wheat, barley, lupine (yellow, narrow - leaved and white), peas (sowing and field-PELs) and soybeans. In 3 experiments 13 varieties of spring wheat, 7 varieties of spring barley and 16 varieties of 6 types of legumes were studied. It was found that the adaptability of spring wheat, barley and peas against the background of intensive technology on a set of indicators above other cultures. The main stressor wheat varieties in the experiments, the deficiency of moisture and heat in the initial period of the growing season, spring barley - diseases (rust, leaf spot) pea pests (pea moth), Lupin, weeds and diseases, soy - sensitivity, lack of heat, weeds and disease.. On intensive soil fertility varieties of spring wheat «Lyubava», «Kamenka», «Madam», «Zlata» and «Rook» shaped grain crop at 7.3-8.0 t/ha, spring barley «Reliable» - 7.0 t/ha and peas «Before-100”-3,4 t/ha. the results of the comparison of the chemical composition and nutritional value of grain of different crops varieties have confirmed a special feeding value of soybean (14.5 and 15.3 MJ of energy; of 37.8-42.8 % of crude protein; The 17.8 was 23.0 crude fat in 1 kg DM), high contents of certain nutrients in the grain, other kinds: crude protein in yellow lupine (41,0 %) and white (of 37.3 and 39.9 %, respectively), starch - in cereals and peas (38,5 vs. 50.6 %), crude fiber - blue lupine (14,5-22,1 %), especially in determinantal varieties (of 20.9-22.1 per cent). Leguminous cultures were allocated by the greatest maintenance in grain of nitrogen, phosphorus and potassium, and grain cultures - carrying out them with a crop. The grain of all kinds of lupine calcium content of the highest (3.8-5.5 g/kg), the lowest - in peas and wheat (0.8-1.1 g/kg BW).

In order to solve the problems of many kinds of crop diseases and pests, fast diffusion speed, and long time of manual identification of diseases and pests, a crop disease and pest identification model based on deep learning from the perspective of ecological and environmental protection is proposed. Firstly, crop images are collected by field sampling to collect data set, and image preprocessing is completed by using nearest neighbor interpolation. Then, the network structure of the AlexNet model is improved. By optimizing the full connection layer, different neuron nodes and experimental parameters are set. Finally, the improved AlexNet model is used to identify crop diseases and pests. The experimental analysis of the proposed model based on the constructed data set shows that the average recognition accuracy and recognition time of fragrant pear diseases and insect pests are 96.26% and 321 ms, respectively, which are better than other comparison models. And, the recognition accuracy of this method on other data sets is not less than 91%, which has good portability.

This paper implies current and economically significant diseases and pests of an apple and pear, i.e. problems of integral protection of these species of fruits in our country. Measures for their prevention are recommended regarding an adequate period. Special consideration is given to the diseases such as Venturia pyrina, Venturia inaequalis, Monilinia fructigena, Podosphaera leucotricha and Chondrostereum purpureum, as well as to pests such as Cydia pomonella, Cacopsylla pyri, Cacopsilla pyrisuga, Eryiophidae, Panonychus ulmi and Aphididae. The demand and importance of mass implementation of the concept of integral production in terms of obtaining biologically more valuable and ecologically safer fruits, i.e. preservation of the environment and health have been implied.

Thirty-four cultivars of pea (Pisum sativum) were assayed for tumorigenesis after inoculation with Agrobacterium tumefaciens strain B6. The response of the 34 cultivars fell into 3 significantly different groups based on tumor weights: high, medium, and low susceptibility. The least susceptible cultivar, Sweet Snap, also formed the smallest tumors in comparison to 5 other cultivars when inoculated with 5 other strains of Agrobacterium. Preliminary experiments indicate that neither chemotaxis, binding, vir-gene induction, nor T-DNA expression are limiting factors in Sweet Snap's reduced susceptibility. In an inheritance study, the F1, F2, and F3 progeny from an initial cross between Sweet Snap and Wando (a more susceptible cultivar) formed tumors that were intermediate in weight between the two parents.

Copies of author's previously published articles inserted. Bibliography: leaves 128-143. This thesis describes the development of serological and nucleic acid based diagnostic methods for pea-seed borne mosaic virus (PSbMV), the isolation of specific effects on infected pea plants, the collection and biological comparison of new PSbMV isolates from Pakistan, the cloning and sequencing of specific parts of the genome of selected isolates, nucleotide and amino acid sequence comparisons between selected isolates, and the development of a ribonuclease protection assay (RPA) for identifying genomic differences among the PSbMV isolates. It is the first comparison of a range of geographically different isolates of PSbMV on the basis of both biological and molecular properties.

In this study, surveys were conducted in pea and potato fields in North Dakota and Central Minnesota to investigate the incidence and abundance of plant-parasitic nematodes in these fields. Moreover, the effect of the pin nematode, Paratylenchus nanus, on plant growth and yield of six field pea cultivars was determined under greenhouse conditions. Similarly, the influence of lesion nematode, Pratylenchus penetrans, and wilt fungi, Fusarium oxysporum alone and together on growth and yield of potato cultivar ‘Red Norland’, was evaluated in microplots under field conditions. The results indicate Paratylenchus spp. and Pratylenchus spp. are the most frequent nematodes, respectively, in pea and potato fields. Pin nematodes reproduced on field pea cultivars and caused up to 37% reduction in plant height and 40% reduction in yield. Additionally, both P. penetrans and F. oxysporum alone, and together had significant negative effect on growth and yield of potato.

Copies of author's previously published articles inserted. Bibliography :leaves 65-80 Ice nucleation active (INA) bacteria were detected in a pea field in South Australia. They were identified as strains of Pseudomonas syringae and Pseudomonas flourescens biotype 1. Some chemical agents were tested on the two ice nucleating species, as cryoprotectants.

Includes bibliographical references (leaves 82-92). Five isolates of pea seed-borne mosaic virus were compared by host range and symptomatology on 16 pisum sativum cultivars lines, 21 lines of Lathyrus and Lens spp. and several indicator species

Corrigendum inserted at the back. Includes bibliographical references (leaves 133-158). Ch. 1. General introduction -- ch. 2. General materials and methods -- ch. 3. Biological characterisation of Australian PSbMV isolates -- ch. 4. Developing nucleic acid based diagnostics for PSbMV -- ch. 5. Detection of PSbMV isolates by RT-PCR and RFLP analysis -- ch. 6. Developing an internal control for PSbMV RT-PCR -- ch. 7. Molecular analysis of the PSbMV VPG -- ch. 8. PSbMV sequence and phylogenetic analysis -- ch. 9. General discussion Sixteen pea seed borne mosaic virus (PSbMV) isolates were collected between 1995 and 1998. These isolates were biologically distinct yet serologically indistinguishable. The conclusion is that PSbMV is widespread and occurs at a low incidence in Australia. Reports sequence information on new isolates of PSbMV which has allowed genomic regions to be identified which distinguish PSbMV pathotypes and isolates; and, to the development of PSbMV nucleic acid hybridisation and RT-PCR assays.

Thesis (MSc)--Stellenbosch University, 2015.<br>ENGLISH ABSTRACT: The codling moth, Cydia pomonella (Lepidoptera: Tortricidae), is the key pest of apples and pears worldwide. The withdrawal of certain fundamental chemicals from codling moth management spray programmes, due to concerns about human, environmental and ecosystem health, has resulted in the search for softer, more environmentally friendly, and safer control measures. Entomopathogenic nematodes (EPNs), naturally occur in the soil, and actively search for hosts. The interest in using EPNs from the families Heterorhabditidae and Steinernematidae as a control measure was sparked in 1953, when an EPN was discovered in an insect. The aim is to incorporate EPNs in an integrated pest management (IPM) programme, to ensure minimal residue and eventually residue-free pome fruit production in South Africa. In order to ensure EPN success, both the environmental and technical factors influencing their efficacy, were investigated in this study. The biocontrol potential of three imported EPN isolates, being Steinernema feltiae and two isolates of Heterorhabditis bacteriophora (Hb1, Hb2), as well as a local isolate, Steinernema yirgalemense, were evaluated for the control of the codling moth under local conditions. All concentrations of S. yirgalemense, applied by immersion in a suspension of nematodes, gave > 98% control. The two formulated isolates of H. bacteriophora, Hb1-f and Hb2-f, gave < 30% control. When using the same nematode isolates, produced in vivo, S. yirgalemense still resulted in a higher codling moth control of > 90%, compared to 54% and 31% control of the H. bacteriophora Hb1 and Hb2 isolates, respectively. In follow up field trials, S. feltiae resulted in ≥ 80% control, and was thus more effective than both S. yirgalemense and the H. bacteriophora (Hb1) isolates, with 66% and 24%, and 24% and 9% control, for two separate trials, respectively. To validate the data obtained from the field trials, subsequent laboratory bioassays were conducted evaluating temperature regimes, following the same cycle as under natural conditions, with a constant humidity of 100%. Steinernema feltiae proved to be most effective, causing > 90% mortality, followed by S. yirgalemense, with 78% mortality. The two H. bacteriophora isolates (Hb1, Hb2) under the above-mentioned laboratory conditions, resulted in 73% and 59% control, respectively. Humidity thus seems to be the most important factor affecting EPN efficacy during above-ground applications. Steinernema feltiae proved to be a better candidate than S. yirgalemense for the control of the codling moth. The efficacy of different EPN isolates in controlling diapausing codling moth larvae at different temperatures was also evaluated, under local conditions, using spray application. Steinernema feltiae and two isolates of H. bacteriophora Hb1 and Hb2, including two local isolates, S. yirgalemense and Steinernema jeffreyense, were evaluated. The use of S. jeffreyense resulted in the most effective control, with 67% mortality, followed by H. bacteriophora (Hb1) with 42%, and then by S. yirgalemense with 41%. Laboratory bioassays simulating field conditions revealed that S. feltiae was most virulent to codling moth larvae, with 67% mortality by infection, followed by S. yirgalemense with 58%, the H. bacteriophora strain Hb1 with 48%, and the Hb2 strain with 24%. A comparison of the infection and penetration rate of two isolates of H. bacteriophora (Hb1, Hb2), S. feltiae and S. yirgalemense, which was carried out in multiwell plates at 14°C and 25°C, respectively, confirms the dramatic effect of temperature on EPN efficacy. At 14°C, all treatments with EPN species resulted in slower codling moth mortality than they did at 25°C, as after 48 h, < 15% mortality was recorded for all species, whereas at the warmer temperature, > 98% mortality was recorded for all species. After the exposure of washed, cool-treated larvae to 25°C for 24 h, the application of both S. feltiae and S. yirgalemense resulted in 100% mortality, whereas the application of the two H. bacteriophora isolates, Hb1 and Hb2, resulted in 68% and 54% control, respectively, over the same time period. At 14°C, S. feltiae had the highest average penetration rate of 20 IJs/insect, followed by S. yirgalemense with 14 IJs/insect, whereas S. yirgalemense had the highest penetration rate at 25°C, with 39 IJs/insect, followed by S. feltiae, with 9 IJs/insect. The two H. bacteriophora isolates had higher average penetration rates at the higher temperature. This study has highlighted the biocontrol potential of S. jeffreyense, as well as showing that S. feltiae is a cold-active nematode, whereas the other three EPN isolates prefer warmer temperatures. Stacked wooden fruit bins are regarded as preferred overwintering sites for codling moth diapausing larvae. Control strategies against the codling moth in South Africa have been hampered by the reinfestation of orchards by nearby stacked infested fruit bins or by the movement of bins between orchards. Worldwide, wooden fruit bins are systematically being replaced with plastic bins, which, in South Africa, will only be phased out over a few years. The objective of this study was to evaluate the potential of H. bacteriophora, S. feltiae, and S. yirgalemense, to disinfest miniature wooden fruit bins under controlled conditions in the laboratory. After dipping minibins in a suspension of 25 IJs/ml of all three EPN species, under optimum conditions of temperature and humidity, the highest percentage of control was obtained using S. feltiae (75%) followed by S. yirgalemense (57%), and then by H. bacteriophora (Hb1) (27%). The addition of adjuvants significantly increased (p < 0.001) S. feltiae infectivity to > 95%, whereas it did not result in a significant increase in H. bacteriophora or S. yirgalemense infectivity. The results indicated that H. bacteriophora would not be a suitable candidate to use for the control of the codling moth larvae in wooden fruit bins. The current preferred candidate for control would be S. feltiae, whose efficacy could be increased by means of the addition of an adjuvant. During winter, when the whole codling moth population are larvae and in diapause, no control measures are applied in orchards. This study has shown that EPNs can be sprayed in orchards to lower the codling moth cohort emerging after winter, as well as be included in an IPM programme. EPNs can act as a second line of defence, through supplementary control, and ensure effective control of the codling moth larvae which survived chemical spray applications, to safeguard against resistant codling moth populations in the next season.<br>AFRIKAANSE OPSOMMING: Kodlingmot, Cydia pomonella (Lepidoptera: Tortricidae), is ‘n belangrike plaag van appels en pere wêreldwyd. Die onttrekking van sekere fundamentele chemikalieë vanuit die kodlingmot beheerprogram weens die kommer oor menslike, omgewings en ekosisteemgesondheid, het gelei tot die soektog na sagter, meer omgewingsvriendelike en veiliger beheermaatreëls. Entomopatogeniese nematodes (EPNs) kom natuurlik in die grond voor en soek aktief na gashere. Die belangstelling in die gebruik van EPNs van die families Heterorhabditidae en Steinernematidae as 'n beheermaatreël is te danke aan die ontdekking van 'n EPN in ‘n insek in 1953. Die doel is om EPNs in 'n geïntegreerde plaagbeheerprogram (GPB) te inkorporeer om sodoende minimale residue te verseker en uiteindelik residu vrye produksie van kernvrugte in Suid-Afrika. Ten einde die sukses van EPNs te verseker, is beide die omgewings- en tegniese faktore wat hul doeltreffendheid beïnvloed in die studie ondersoek. Die biologiese beheer potensiaal van drie ingevoerde EPN isolate, Steinernema feltiae en twee Heterorhabditis bacteriophora (Hb1, Hb2) isolate, sowel as 'n plaaslike isolaat, Steinernema yirgalemense, is vir die beheer van kodlingmot onder plaaslike toestande geëvalueer. Alle konsentrasies van S. yirgalemense, wat deur indompeling in ‘n suspensie van nematodes toegedien is, het > 98% beheer tot gevolg gehad. Die twee geformuleerde isolate van H. bacteriophora, Hb1-f en Hb2-f, het < 30% beheer gegee. Met die gebruik van dieselfde nematode isolate, wat in vivo geproduseer is, het S. yirgalemense nog steeds 'n hoër kodlingmot beheer van > 90% opgelewer, in vergelyking met die 54% en 31% beheer van die H. bacteriophora Hb1 en Hb2 isolate, onderskeidelik. Steinernema feltiae het in opvolg veldproewe ≥ 80% beheer tot gevolg gehad en was dus meer effektief as beide S. yirgalemense en die H. bacteriophora (Hb1) isolate, met 66% en 24% en 24% en 9% beheer onderskeidelik in twee afsonderlike veldproewe. Om die resultate van die veldproewe te bevestig, is daaropvolgende laboratorium biotoetse uitgevoer en temperatuur regimes is geëvalueer deur die selfde siklus as onder natuurlike toestande te volg, met 'n konstante humiditeit van 100%. Die studie het bewys dat S. feltiae die mees doeltreffende isolate was met > 90% mortaliteit, S. yirgalemense het gevolg met 78% mortaliteit. Die twee H. bacteriophora isolate (Hb1, Hb2) het onderskeidelik onder bogenoemde laboratorium toestande 73% en 59% beheer tot gevolg gehad. Humiditeit blyk dus die belangrikste faktor te wees wat EPN se doeltreffendheid tydens bogrondse toediening affekteer. Die studie het bewys dat S. feltiae 'n beter kandidaat as S. yirgalemense vir die beheer van kodlingmot is. Die doeltreffendheid van verskillende EPN isolate vir die beheer van diapause kodlingmot larwes sowel as EPN se aktiwiteit by verskillende temperature is ook onder plaaslike toestande, deur bogrondse bespuitings, geëvalueer. Steinernema feltiae en twee isolate van H. bacteriophora (Hb1, Hb2), S. yirgalemense en ‘n ander plaaslike isolaat, Steinernema jeffreyense, is geëvalueer. Die gebruik van S. jeffreyense, het tot die mees effektiewe beheer gelei, met 67% mortaliteit, gevolg deur H. bacteriophora (Hb1) met 42%, en dan S. yirgalemense met 41%. Laboratorium biotoetse wat veldtoestande simuleer, het bewys dat S. feltiae die mees doeltreffend teen kodlingmot larwes is, met 67% mortaliteit tydens infeksie, gevolg deur S. yirgalemense met 58%, die H. bacteriophora Hb1 isolaat met 48%, en die Hb2 isolaat met 24%. 'n Vergelyking van die infeksie- en penetrasie tempo van twee isolate van H. bacteriophora (Hb1, Hb2), S. feltiae en S. yirgalemense wat in 12-put plate teen 14°C en 25°C uitgevoer is, het die dramatiese effek van temperatuur op EPN doeltreffendheid bevestig. By 14°C het alle EPN spesies behandelings stadiger kodlingmot mortaliteit as by 25°C na 48h tot gevolg gehad. ‘n Mortaliteit van < 15% is vir alle spesies aangeteken terwyl by die warmer temperature is > 98% mortaliteit vir alle spesies aangeteken. Na die blootstelling van afgespoelde, koel behandelde larwes aan 25°C vir 24 uur, het die toediening van beide S. feltiae en S. yirgalemense, 100% mortaliteit van larwes tot gevolg gehad terwyl die toediening van die twee H. bacteriophora isolate, Hb1 en Hb2, onderskeidelik 68% en 54% beheer tot gevolg gehad, oor dieselfde tydperk. By 14°C, het S. feltiae die hoogste gemiddelde penetrasie tempo van 20 ILs/ larwe, gevolg deur S. yirgalemense met 14 ILs/ larwe tot gevolg gehad, terwyl S. yirgalemense die hoogste penetrasie tempo getoon het by 25°C met 39 ILs/ insek, gevolg deur S. feltiae met 9 ILs/ insek. Die twee H. bacteriophora isolate (Hb1 en Hb2) het ook hoër gemiddelde penetrasie tempo by die hoër temperatuur getoon. Hierdie studie het die biobeheer potensiaal van S. jeffreyense beklemtoon, asook weereens bevestig dat S. feltiae ‘n koue-aktiewe nematode is, terwyl die ander drie EPN isolate warmer temperature verkies. Hout vrugtekratstapels, word beskou as ‘n ideale oorwintering skuiling vir kodlingmot diapause larwes. In Suid-Afrika word beheerstrategieë teen kodlingmot in die wiele gery deur die herbesmetting van boorde deur nabygeleë besmette hout vrugtekratte of deur die beweging van kratte tussen boorde. Hout vrugtekratte word wêreldwyd stelselmatig vervang met plastiek kratte. Dit sal egter eers oor ‘n aantal jare in Suid-Afrika uitgefaseer word. Die doel van hierdie studie was om die potensiaal van H. bacteriophora, S. feltiae, en S. yirgalemense te evalueer deur miniatuur hout vrugtekratte onder gekontroleerde toestande in die laboratorium te disinfekteer. Na die onderdompeling van die mini vrugtekratte in 'n nematode suspensie van 25 ILs/ml van al drie EPN spesies, onder optimale toestande van temperatuur en humiditeit, is die hoogste persentasie van beheer met die gebruik van S. feltiae (74,85% ± 3.64%) verkry. Die byvoeging van toevoegings middels het S. feltiae se vermoë om te infekteer betekenisvol (p <0,001) tot > 95% verhoog, maar dit het nie tot 'n betekenisvolle toename in die infektiwiteit van H. bacteriophora of S. yirgalemense gelei nie. Die resultate dui daarop dat H. bacteriophora nie 'n geskikte kandidaat is om te gebruik vir die beheer van kodlingmot larwes in besmette hout kratte nie. Die voorkeurkandidaat tans vir beheer is S. feltiae, waarvan die doeltreffendheid verhoog kan word deur middel van die byvoeging van 'n bymiddel. Gedurende die winter wanneer die hele kodlingmot populasie as larwes in diapause is, word geen beheer in boorde toegepas nie. Hierdie studie het getoon dat EPNs in boorde gespuit kan word om sodoende die opkomende kodlingmot populasie na die winter te verlaag en kan ook ingesluit word in 'n GPB program. Die EPNs kan as 'n tweede verdedigingslinie optree en doeltreffende beheer van kodlingmot larwes verseker wat chemiese bespuitings oorleef het, en sodoende beskerming teen weerstandige kodlingmot populasies in die volgende seisoen bied.

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Thesis (MScAgric)--Stellenbosch University, 2012.<br>ENGLISH ABSTRACT: Botrytis cinerea Pers. Fr. [teleomorph Botryotinia fuckeliana (de Bary) Whetzel] causes serious losses of over 200 crops worldwide, including rooibos seedlings and pears. This pathogen is characterized by morphological, physiological and genetic diversity. The genetic diversity and population structure have not been investigated for B. cinerea populations in South Africa. Botrytis cinerea collected from rooibos seedlings and in pear orchards in the Western Cape of South Africa were investigated in the present study. The study was done with the aid of microsatellite markers, the amplification of mating type alleles MAT1-1 and MAT1-2 and determination of resistance towards various fungicides. Population dynamics was inferred and a similar picture emerged in both production systems. Botrytis cinerea annually causes severe losses of rooibos seedlings (Aspalathus linearis) in nurseries situated in the Clanwilliam region. Sampling was done in five nurseries and the cryptic species status of the isolates obtained was determined through restriction enzyme digestion of the Bc-hch gene. All but one (206 out of 207) of the isolates belonged to Group II or B. cinerea ‘sensu stricto’. Analysis of the B. cinerea Group II population, using seven microsatellite loci, was performed to assess the genetic population structure. Total gene diversity (H) was high, with a mean of 0.67. Two of the nurseries populations’ sample sizes were severely limited after clone correction, yet 100 genotypes were discerned among the 206 isolates genotyped. The percentage of maximal genotypic diversity (G) ranged between 16 and 68 for the five populations, with a total value of 17 for the 100 genotypes. One genotype, represented by 27 clones, was isolated from four nurseries. Relatively low but significant population differentiation was observed in total between nurseries (mean FST = 0.030, P = 0.001). The distribution of mating types MAT1-1 and MAT1-2 differed significantly from the ratio of 1:1 for the total population plus two of the nurseries’ populations. Three nursery populations had an equal mating type distribution. The index of association (IA) analyses suggests that the populations are asexually reproducing. Analysis of molecular variance (AMOVA) indicated that 97% of the total genetic variation is distributed within subpopulations. Fungicide resistance frequency against iprodione for 198 of the genotyped isolates displayed highly varying levels of resistance amongst the five nurseries. The mean total incidence of resistance towards iprodione was 43%, ranging from 0% to 81% for the five nurseries. Baseline sensitivity towards pyrimethanil yielded an average EC50 value of 0.096 mg/L. Botrytis cinerea isolates were collected from pear blossoms (Pyrus communis) in four orchards. Two orchards in the Ceres area and two in the Grabouw area were sampled from. A total of 181 isolates were collected from the four orchards. Incidence of blossom infection in the orchards ranged from 3% to 17%. Overall, there was a high incidence of isolates that had only the Boty transposable element (74%) compared to those harbouring both (Boty and Flipper), simultaneously (transposa, 24%). One isolate examined had the Flipper element only. Cryptic species status according to restriction enzyme digestion of the Bc-hch gene indicated that all the isolates belonged to Group II or B. cinerea ‘sensu stricto’. Analysis of the Group II population, through the use of seven microsatellite loci, was performed to assess the genetic population structure. Total gene diversity (H) was high, with a mean of 0.69 across all populations. Although two of the subpopulations displayed a high clonal proportion, overall 91 genotypes were discerned among the 181 isolates. The percentage of maximal genotypic diversity (G) ranged between 18 and 33 for the four populations, with a total value of 14 for the 91 genotypes. One genotype, represented by 27 clones, was isolated from all orchards. Moderate, but significant population differentiation was present in total among orchards (mean FST = 0.118, P = 0.001). The distribution of the mating types, MAT1-1 and MAT1-2, did not differ significantly from a 1:1 ratio for the total population as well as the subpopulations. Index of association (IA) analyses, on the other hand, suggests that the populations reproduce asexually. Analysis of molecular variance (AMOVA) indicated that 88% of the total genetic variation is distributed within subpopulations, 9% between subpopulations and only 3% between production areas. Fungicide resistance frequency against fenhexamid, iprodione and benomyl varied, with the highest levels of resistance present against benomyl and low levels of resistance seen towards iprodione and fenhexamid. In conclusion, this study has shown that there exist within the studied populations of B. cinerea, obtained from rooibos nurseries and pear orchards, an adaptive capacity to overcome current means of control. The use of population genetics to further our understanding of how plant pathogens interact and spread throughout a given environment is of cardinal importance in aiding the development of sustainable and integrated management strategies. Knowledge of the dispersal of B. cinerea in the two studied cropping systems has shed light on the inherent risk that it poses, and this together with knowledge of the levels of resistance that occurs should serve as an early warning to help divert possible loss of control in future.<br>AFRIKAANSE OPSOMMING: Botrytis cinerea Pers. Fr. [teleomorf Botryotinia fuckeliana (de Bary) Whetzel] veroorsaak ernstige verliese van meer as 200 gewasse wêreldwyd, insluitende rooibossaailinge en pere. Hierdie patogeen word deur morfologiese, fisiologiese, asook genetiese diversiteit gekenmerk. Die genetiese diversiteit en populasie-struktuur van B. cinerea populasies wat in Suid-Afrika voorkom, is nog nie ondersoek nie. Botrytis cinerea verkryg vanaf rooibossaailinge en in peerboorde in die Wes-Kaap van Suid-Afrika is ondersoek. Hierdie studie is met behulp van mikrosatellietmerkers, amplifikasie van die twee paringstipe gene (MAT1-1 en MAT1-2), asook die bepaling van weerstandsvlakke teenoor verskeie swamdoders, uitgevoer. Populasie-dinamika is afgelei en ‘n soortgelyke tendens is in beide produksie-sisteme waargeneem. Botrytis cinerea veroorsaak jaarliks ernstige verliese van rooibossaailinge (Aspalathus linearis) in kwekerye in die Clanwilliam-area. Monsters is in vyf kwekerye versamel en die kriptiese spesiestatus van die verkrygde isolate is deur restriksie-ensiemvertering van die Bc-hch geen bepaal. Almal behalwe een (206 uit 207) isolaat het aan Groep II of B. cinerea ‘sensu stricto’ behoort. Analise van die B. cinerea Groep II populasie, deur middel van sewe mikrosatellietmerkers, is uitgevoer om die genetiese populasiestruktuur te bepaal. Totale geendiversiteit (H) was hoog, met ‘n gemiddelde van 0.67. Alhoewel twee van die kwekerye se monstergrootte erg ingeperk is ná kloonverwydering, is daar nogtans 100 genotipes onder die 206 isolate wat geïsoleer is, waargeneem. Die persentasie van maksimale genotipiese diversiteit (G) het tussen 16 en 68, vir die vyf populasies, gewissel, met ‘n totaal van 17 vir die 100 genotipes. Een genotipe, verteenwoordig deur 27 klone, is uit vier kwekerye geïsoleer. Relatief lae dog noemenswaardige populasie-differensiasie is in totaal tussen kwekerye waargeneem (gem. FST = 0.030, P = 0.001). Die verspreiding van die twee paringstipes (MAT1-1 en MAT1-2) het beduidend verskil van ‘n 1:1 verhouding vir die totale populasie, asook twee van die kwekerye se populasies. Die drie oorblywende kwekerye se populasies het egter ‘n gelyke verdeling van die twee paringstipes getoon. Die indeks van assosiasie (IA) analises toon dat die populasies ongeslagtelik voortplant. Analise van molekulêre variasie (AMOVA) het aangedui dat 97% van die totale genetiese variasie binne die subpopulasies versprei is. Hoogs variërende vlakke van weerstand tussen die vyf kwekerye teenoor die swamdoder iprodioon, is vir die 198 isolate wat getoets is, gevind. Die totale gemiddelde frekwensie van weerstand teenoor iprodioon was 43%, wat tussen 0% en 81% vir die vyf kwekerye gevarieer het. Fondasie-vlak-sensitiwiteit vir pyrimethanil het ‘n gemiddelde EC50 waarde van 0.096 mg/L opgelewer. Botrytis cinerea isolate is ook vanuit peerbloeisels (Pyrus communis L.) vanuit vier boorde versamel, twee uit elk van die Ceres- en Grabouw-areas. In totaal is 181 isolate vanuit die vier boorde versamel. Die frekwensie van bloeiselinfeksie het tussen 3% en 17% gewissel. Oor die algemeen was daar ‘n hoë frekwensie van isolate wat slegs die Boty transponeerbare element teenwoordig gehad het (74%) in vergelyking met dié wat tegelykertyd beide (Boty en Flipper) teenwoordig gehad het. Een isolaat het slegs die Flipper element gehad. Bepaling van die kriptiese spesiestatus met behulp van restriksie-ensiemvertering van die Bc-hch geen het aangedui dat alle versamelde isolate tot Groep II of B. cinerea ‘sensu stricto’ behoort het. Analise van die Groep II populasie, deur middel van sewe mikrosatellietmerkers, is uitgevoer om genetiese populasie-struktuur te bepaal. Totale geendiversiteit (H) was hoog, met ‘n gemiddelde van 0.69 oor alle populasies. Alhoewel twee subpopulasies ‘n hoë klonale fraksie getoon het, is 91 genotipes tussen die 181 isolate wat verkry is, onderskei. Die persentasie van maksimale genotipiese diversiteit (G) het tussen 18 en 33 vir die vier populasies gewissel, met ‘n totale waarde van 14 vir die 91 genotipes. Een genotipe, verteenwoordig deur 27 klone, was in al vier boorde teenwoordig. Gematigde dog beduidende populasie differensiasie was in totaal tussen boorde teenwoordig (gem. FST = 0.118, P = 0.001). Die verspreiding van die paringstipes (MAT1-1 en MAT1-2) het nie betekenisvol van ‘n 1:1 verhouding vir die totale populasie, insluitende die subpopulasies, verskil nie. Indeks van assosiasie (IA) analises het egter aangedui dat die populasies ongeslagtelik voortplant. Analise van molekulêre variasie (AMOVA) het aangedui dat 88% van die totale genetiese variasie in subpopulasies te vinde was, 9% tussen subpopulasies en slegs 3% tussen produksie-areas. Frekwensie van swamdoder weerstandbiedendheid vir fenhexamid, iprodioon en benomyl het gewissel, met die hoogste vlakke teenoor benomyl waargeneem, maar baie lae vlakke teenoor fenhexamid en iprodioon. Samevattend het hierdie studie getoon dat die populasies van B. cinerea wat in hierdie twee produksie-sisteme, op rooibossaailinge en in peer boorde, ondersoek is, ‘n aanpasbaarheid toon om huidige metodes van beheer te oorkom. Die gebruik van populasiegenetika as ‘n hulpmiddel om ons kennis van patogeen-interaksies en -verspreiding te verbreed, is van kardinale belang in die ontwikkeling van geïntegreerde en volhoubare beheermaatreëls. Kennis van die verspreiding van B. cinerea in die bestudeerde gewasproduksiestelsels, werp lig op die inherente risiko wat dié patogeen inhou. Dít, tesame met kennis van die weerstandsvlakke wat voorkom, kan as ‘n vroegtydige waarskuwing dien ten einde moontlike verlies van beheer in die toekoms te help teenwerk.

Thesis (MScConsEcol (Conservation Ecology and Entomology))--University of Stellenbosch, 2009.<br>ENGLISH ABSTRACT: Pseudococcus viburni (Signoret) (Hemiptera: Pseudococcidae) (obscure mealybug), is a common and serious pest of apples and pears in South Africa. Consumer and regulatory pressure to produce commodities under sustainable and ecologically compatible conditions has rendered chemical control options increasingly limited. Information on the seasonal occurrence of pests is but one of the vital components of an effective and sustainable integrated pest management system needed for planning the initiation of monitoring and determining when damage can be expected. It is also important to identify which orchards are at risk of developing mealybug infestations while development of effective and early monitoring tools for mealybug populations will help growers in making decisions with regards to pest management and crop suitability for various markets. It is also essential to determine the presence and efficacy of naturally occurring biological control agents in orchards so as to ascertain the potential of biological control as a viable alternative in orchards. However, under the current integrated pest management protocol, it has been difficult to determine this, due to the sporadic and relatively low incidence of mealybug infestations in some orchards, or by simply relying on naturally occurring field populations of biocontrol agents. Knowledge of the environmental conditions under which P. viburni population levels may become destructive is also essential for timing the release of insectary reared natural enemies as well as understanding the population ecology of this pest and its natural enemies. Information was gathered regarding the seasonal phenology of P. viburni and its natural enemies in pome fruit orchards in the Western Cape Province during the 2007/08 and 2008/09 growing seasons. Seasonal population studies showed that P. viburni has multiple overlapping generations with all life stages present throughout the year. The highest orchard infestations occurred during the summer period until early winter (January to early June). This was followed by a decrease in population from late June to November, before another increase in December. Presence-absence sampling of mealybugs on the host plant revealed that woody parts of the tree, such as the trunk and old stems were the most preferred sites for mealybug habitation, due to the availability of protected refuge sites. Migration of mealybug populations to newer growth and the upper sections of the tree crown, such as the new stems, leaves and eventually the fruit, was observed from December throughout the summer period until the early winter in June. Fruit colonization in both apples and pears commenced in January, when the fruit had developed a size sufficient for P. viburni to penetrate and occupy spaces such as the fruit core, calyx and stem end. There was no evidence of P. viburni occurring beneath the soil surface or on the roots of host trees. Two natural enemies of mealybugs, namely Pseudaphycus maculipennis (Mercet) and Coccidoxenoides perminutus (Girault), were found to be active in apple and pear orchards in the Western Cape. However, the status of C. perminutus as a parasite of P. viburni still needs to be verified despite evidence of emergence from P. viburni mummies, which was not sufficient enough to suggest that it is a useful biological control agent. Seasonal abundance trends of the two natural enemies revealed that their lifecycle is synchronized with that of the host. However, there was no evidence of P. maculipennis activity in Ceres. No predators were found during the course of this study. The rate of P. viburni parasitism at harvest was 46.52%, with P. maculipennis and C. perminutus constituting 98.966% and 1.034% of the parasitoids recovered from mealybug mummies, respectively. Studies on the use of pheromone traps as early monitoring tools for P. viburni showed that there was a positive and significant relationship between the fruit infestation and number of P. viburni adult males caught in pheromone-baited traps (r2 = 0.454). The action threshold level was estimated to be 2.5 male P. viburni caught per trap per fortnight at an economic threshold of 2% fruit infestation.<br>AFRIKAANSE OPSOMMING: Pseudococcus viburni (Signoret) (Hemiptera: Pseudococcidae) (ligrooswitluis), is ‘n algemene en ernstige plaag van appels en pere in Suid-Afrika. Druk deur verbruikers en regulasies om kommoditeite onder volhoubare en ekologies verenigbare toestande te produseer het chemiese beheeropsies toenemend beperk. Inligting oor die seisoenale voorkoms van plae is een van die essensiële komponente van ‘n effektiewe en volhoubare geïntegreerde plaagbestuurprogram. Dit is in die aanvanklike beplanning van monitering en om te bepaal wanneer skade verwag kan word. Dit is ook belangrik om boorde vroegtydig te identifiseer wat die risiko het om witluisbesmettings te ontwikkel. Die ontwikkeling van effektiewe en vroeë moniteringstegnieke vir witluisbevolkings sal produsente help met besluitneming rakende plaagbestuur en die geskiktheid van gewasse vir verskeie markte. Dit is ook noodsaaklik om die teenwoordigheid en effektiwiteit van biologiese beheer agente wat natuurlik in boorde voorkom te bepaal ten einde die potensiaal van biologiese beheer as ‘n lewensvatbare alternatief vas te stel. Onder die huidige geïntegreerde plaagbestuurprotokol was dit egter moeilik om laasgenoemde te bepaal weens die sporadiese en relatiewe lae voorkoms van witluisbesmettings in sommige boorde of deur bloot staat te maak op die veldpopulasies van biologiese beheer agente wat natuurlik voorkom. Kennis van die omgewingstoestande waaronder P. viburni bevolkingsvlakke skadelik raak is ook noodsaaklik vir die beplanning van vrylating van biologiese beheer agente, asook om die bevolkingsekologie van hierdie plaag en sy natuurlike vyande te verstaan. Inligting oor die seisoenale fenologie van P. viburni en sy natuurlike vyande in sagtevrugte boorde in die Westelike Kaapprovinsie is gedurende die 2007/08 en 2008/09 groeiseisoene versamel. Seisoenale bevolkingstudies het getoon dat P. viburni verskeie oorvleuelende generasies het met alle stadia teenwoordig regdeur die jaar.

Cocoa farmers in Ghana face increasing challenges. In the past, many of them could make a living from cocoa thanks to the advantages – ‘forest rents’ – that initially apply when forest is cleared to create cocoa farms: fertile soils, few pests and diseases. With time, however, weeds invade, pests and diseases build up, and trees age. To maintain production requires more labour, more inputs and more skill. In the past, farmers would often abandon older groves and seek new forest to clear. As they did so, the frontier for cocoa farming moved westwards across Ghana to the remaining high forest. But by 2000 or so, no new forest was available. Farmers now have to manage aging stands of trees, clear weeds and parasites, and combat pests, fungi and diseases. In Suhum District in the east and in Juaboso District in the far west of Ghana, we talked to farmers. They understood the challenges they faced, and knew how to deal with some of them. But many were not farming their cocoa as well as they could, losing yields and income as a result. This brief provides a basis for policymakers to move forward in responding to the current challenges facing cocoa farmers.

Date palm (Phoenix dactylifera L.) is the major fruit tree grown in arid areas in the Middle East and North Africa. In the last century, dates were introduced to new regions including the USA. Date palms are traditionally propagated through offshoots. Expansion of modern date palm groves led to the development of Tissue Culture propagation methods that generate a large number of homogenous plants, have no seasonal effect on plant source and provide tools to fight the expansion of date pests and diseases. The disadvantage of this procedure is the occurrence of off-type trees which differ from the original cultivar. In the present project we focused on two of the most common date palm off-types: (1) trees with reduced fruit setting, in which most of the flowers turn into three-carpel parthenocarpic fruits. In a severe form, multi-carpel flowers and fruitlets (with up to six or eight carpels instead of the normal three-carpel flowers) are also formed. (2) dwarf trees, having fewer and shorter leaves, very short trunk and are not bearing fruits at their expected age, compared to the normal trees. Similar off-types occur in other crop species propagated by tissue culture, like banana (mainly dwarf plants) or oil palm (with a common 'Mantled' phenotype with reduced fruit setting and occurrence of supernumerary carpels). Some off-types can only be detected several years after planting in the fields. Therefore, efficient methods for prevention of the generation of off-types, as well as methods for their detection and early removal, are required for date palms, as well as for other tissue culture propagated crops. This research is aimed at the understanding of the mechanisms by which off-types are generated, and developing markers for their early identification. Several molecular and genomic approaches were applied. Using Methylation Sensitive AFLP and bisulfite sequencing, we detected changes in DNA methylation patterns occurring in off-types. We isolated and compared the sequence and expression of candidate genes, genes related to vegetative growth and dwarfism and genes related to flower development. While no sequence variation were detected, changes in gene expression, associated with the severity of the "fruit set" phenotype were detected in two genes - PdDEF (Ortholog of rice SPW1, and AP3 B type MADS box gene), and PdDIF (a defensin gene, highly homologous to the oil palm gene EGAD). We applied transcriptomic analyses, using high throughput sequencing, to identify genes differentially expressed in the "palm heart" (the apical meristem and the region of embryonic leaves) of dwarf vs. normal trees. Among the differentially expressed genes we identified genes related to hormonal biosynthesis, perception and regulation, genes related to cell expansion, and genes related to DNA methylation. Using Representation Difference Analyses, we detected changes in the genomes of off-type trees, mainly chloroplast-derived sequences that were incorporated in the nuclear genome and sequences of transposable elements. Sequences previously identified as differing between normal and off-type trees of oil palms or banana, successfully identified variation among date palm off-types, suggesting that these represent highly labile regions of monocot genomes. The data indicate that the date palm genome, similarly to genomes of other monocot crops as oil palm and banana, is quite unstable when cells pass through a cycle of tissue culture and regeneration. Changes in DNA sequences, translocation of DNA fragments and alteration of methylation patterns occur. Consequently, patterns of gene expression are changed, resulting in abnormal phenotypes. The data can be useful for future development of tools for early identification of off-type as well as for better understanding the phenomenon of somaclonal variation during propagation in vitro.

Since APHIS was formed in 1972, it has evolved into a multi-faceted Agency with responsibilities that include protecting and promoting U.S. agricultural health from foreign pests and diseases, regulating genetically engineered organisms, administering the Animal Welfare Act, and carrying out wildlife damage management activities. It has been 15 years since APHIS compiled a history of its mission and activities. This year, 2012, marks both the 40th anniversary of the Agency and the 150th anniversary of USDA, providing a unique opportunity to put that history in context. This retrospective briefly examines the history of animal and plant health regulation within USDA, assesses APHIS'&#x0D; development over four decades, includes biographies of the Agency’s Administrators, and provides snapshots of some of the milestone issues and events that define the Agency’s history and its accomplishments.

For Plant Protection and Quarantine (PPQ) and our partners, 2016 was a year of remarkable successes. Not only did we eradicate 10 fruit fly outbreaks, but we also achieved 4 years with zero detections of pink bollworm, moving us one step closer to eradicating this pest from all commercial cotton-growing areas of the continental United States. And when the U.S. corn industry faced the first-ever detection of bacterial leaf streak (Xanthomonas vasicular pv vasculorum), we devised a practical and scientific approach to manage the disease and protect valuable export markets. Our most significant domestic accomplishment this year, however, was achieving one of our agency’s top 10 goals: eliminating the European grapevine moth (EGVM) from the United States. On the world stage, PPQ helped U.S. agriculture thrive in the global market-place. We worked closely with our international trading partners to develop and promote science-based standards, helping to create a safe, fair, and predictable agricultural trade system that minimizes the spread of invasive plant pests and diseases. We reached critical plant health agreements and resolved plant health barriers to trade, which sustained and expanded U.S. export markets valued at more than $4 billion. And, we helped U.S. producers meet foreign market access requirements and certified the health of more than 650,000 exports, securing economic opportunities for U.S. products abroad. These successes underscore how PPQ is working every day to keep U.S. agriculture healthy and profitable.

The Center for Plant Health Science and Technology (CPHST) was designed and developed to support the regulatory decisions and operations of the Animal and Plant Health Inspection Service’s (APHIS) Plant Protection and Quarantine (PPQ) program through methods development work, scientific investigation, analyses, and technology—all in an effort to safeguard U.S. agriculture and natural resources. This 2008 CPHST Annual Report is intended to offer an in-depth look at the status of its programs and the progress it has made toward the Center’s long-term strategic goals. One of CPHST’s most significant efforts in 2008 was to initiate efforts to improve the Center’s organizational transparency and overall responsiveness to the needs of its stakeholders. As a result of its focus in this area, CPHST is now developing a new workflow process that allows the customers to easily request and monitor projects and ensures that the highest priority projects are funded for successful delivery. This new system will allow CPHST to more dynamically identify the needs of the agency, more effectively allocate and utilize resources, and provide its customers timely information regarding a project’s status. Thus far, while still very much a work in progress, this new process is proving to be successful, and will continue to advance and expand the service to its customers and staff. The considerable and growing concern of homeland security and the management of critical issues drives CPHST to lead the methods development of science-based systems for prevention, preparedness, response, and recovery. CPHST is recognized nationally and internationally for its leadership in scientific developments to battle plant pests and diseases.