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Grain legumes play an important role in community livelihood and in the national economy in Kenya. Unfortunately, in many African countries, production doesn't satisfy the demand in grains due to various constrains. Understanding farmers practices and behavior in the management of grain legume pests is a crucial step in the development of sustainable management strategies. A total of 216 farmers were surveyed in eight districts of eastern Kenya to evaluate farmers' knowledge and perceptions of grain legume pests; to examine current pest management practices, and to identify other production constraints. Grain legumes are grown by a wide age-group of farmers, with both genders equally represented. Chemical control remains the main pest management strategy, and, to ensure pesticide effectiveness, farmers also use increased application rates, chemical alternation, frequent application and mixtures of chemicals. While farmers used other control measures, they showed only limited interest in biological control. The majority of the farmers had experience in grain legume farming and were able to identify the major pests, which were the legume flower thrips Megalurothrips sjostedti Trybom, the cowpea aphid Aphis craccivora Koch and the legume pod borer Maruca vitrata Fabricius. Our survey revealed that education and proximity to extension services contributed significantly to farmers' knowledge of grain legume pests, suggesting the need to provide continuous training and capacity building on integrated pest management in grain legume farming. The study also suggests integration of other pest management strategies such as the use of early maturing varieties, biopesticides and biofertilizer to reduce the use of chemical for sustainable pest management. 相似文献
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核桃多用种子或嫁接繁殖,嫁接后2 a~3 a挂果,4 a~5 a进入丰产期,实生苗需8 a~10 a挂果,15 a进入丰产期.核桃营养丰富、用途广泛、价值高、需求量大,价格稳升,栽培前景十分好,栽培技术与管理是关键. 相似文献
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谈园林植物病虫害防治 总被引:1,自引:0,他引:1
随着社会经济的发展,园林绿化工作取得了前所未有的成绩,园林植物的生态效益、经济效益、观赏效益日益凸现。与此同时,园林植物病虫害的发生也出现了复杂化、危险化的趋势,对绿地和风景区危害较大。病虫害常常导致园林植物生长衰弱和死亡,影响植物的生长、发育、繁殖及其观赏价值,甚至引起整株死亡,使绿化树种、风景林等林木大片衰败或死亡,从而造成重大的经济损失。在园林生态里,由于人类、植物、有害生物、环境条件和天敌等各组分之间存在着相当复杂的关系,所以其中任何一因子的变动,都会直接或间接地影响整个的城市园林生态系统。那么,在防治上要从生态学观点出发,在管理上创造不利于病虫害发生的条件,减少或不用化学农药,保护天敌,提高自然的控制能力,保持园林生态的稳定和可持续性发展。 相似文献
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优化的VHb基因和GFMcryIA基因构建的双价基因在烟草中的表达 总被引:1,自引:0,他引:1
利用人工合成的、密码子优化后的透明颤菌血红蛋白(VHb)基因与人工合成的GFMcryIA基因构建成双价基因植物高效表达载体。通过根癌农杆菌介导转化烟草,获得了36株卡那霉素抗性植株。经转基因植株的PCR及Southern blot检测,证实了双价基因在35株烟草基因组中的整合。Western blot检测证实了VHb基因的表达,杀虫实验证实GFMcryIA基因也表达出活性毒蛋白。且转基因烟草平均每株干重比非转基因烟草植株高7%。本研究结果表明转基因育种技术在培育出既高产又具抗虫性的作物或经济作物新品种方面具有良好的应用前景。 相似文献
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Amnon?LeviEmail author Claude?E.?Thomas Alvin?M.?Simmons Judy?A.?Thies 《Genetic Resources and Crop Evolution》2005,52(4):465-472
A cucurbit species named Praecitrullus fistulosus (Stocks) Pangalo, which thrives in India, is considered to be a distant
relative of watermelon. Recent experiments indicated that it has mild resistance to whiteflies (Bemisia tabaci). However,
our attempts to cross various US plant introductions (PIs) of P. fistulosus with watermelon or other Citrullus PIs have not
been successful. Thus, to determine genetic relatedness among those species, phylogenetic analysis [based on simple sequence
repeat (SSR)–anchored (also termed ISSR), and randomly amplified polymorphic DNA (RAPD) markers] was conducted among PIs of
P. fistulosus, Citrullus lanatus var. lanatus (watermelon), C. lanatus var. citroides and the wild Citrullus colocynthis.
Phylogenetic relationships were also examined with Cucumis melo (melon), Cucumis sativus (cucumber), and wild Cucumis species
including C. africanus, C. metuliferus, C. anguria, C. meeusei, and C. zeyheri. Wide genetic distance exists between Citrullus
and Cucumis groups (8% genetic similarity). Phylogenetic relationships among Citrullus species and subspecies are closer (25–55%
genetic similarity) as compared with those among most Cucumis species (14–68% genetic similarity). P. fistulosus appeared
to be distant from both Cucumis and Citrullus species (genetic similarity between P. fistulosus and Cucumis or Citrullus groups
is less than 3%). Although wide genetic differences and reproductive barriers exist among cucurbit species examined in this
study, they are still considered as potential germplasm source for enhancing watermelon and melon crops using traditional
breeding and biotechnology procedures. 相似文献
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Integrated pest management in field vegetable crops in northern Europe — with focus on two key pests
Improvements in (1) insecticide application, (2) supervised control, and (3) pest forecasting systems have each helped to reduce considerably the amounts of insecticides required to control fly, caterpillar and aphid infestations in vegetable crops in northern Europe. By growing plants that are partially resistant to certain major pests, it is now possible to apply even less insecticide than the dose recommended for the crop. In crops where only small amounts of insecticides are applied, natural predators should prevent large increases in pest insect populations and natural parasitoids should reduce the numbers of pest insects entering subsequent generations. The possible impact of introducing transgenic plants and the use of physical (crop covers), cultural (crop rotation, undersowing) and microbial (e.g. fungi, bacteria and nematodes) methods of control are also discussed. The withdrawal of certain insecticides, as a result of environmental and commercial pressures, means that some crops may soon be without appropriate insecticides for controlling one or more of the major pest species. Whether such systems will be sustainable, remains to be seen. 相似文献