Control of the cowpea aphid, Aphis craccivora Koch (Homoptera: Aphididae), in cowpea, Vigna unguiculata (L.) Walp.     

THOMAS I. OFUYA 《Integrated Pest Management Reviews》1997,2(4):199-207

Cowpea, Vigna unguiculata (L.) Walpers, is a major dietary staple in tropical Africa where it is most often cultivated. The production is, however, greatly hampered by severe infestation and damage by insect pests including the cowpea aphid, Aphis craccivora Koch. The damage and bionomics of the aphid are briefly introduced. Chemical, cultural, physical and biological methods, and use of plant resistance for A. craccivora control in cowpea are reviewed. Finally, prospects for integrated pest management are discussed  相似文献   

Effect of Planting Sequence and Time, and Nitrogen on Maize Legume Intercrop Yield     

W. B. Bryan  S. A. Peprah 《Journal of Agronomy and Crop Science》1988,161(1):17-22

Productivity of maize ( Zea mays L.) legume intercrops is determined by soil, management, and environment. Planting sequence and time and N fertilization are easily controlled management factors but their effects on intercrop yields are not well understood. Maize grown in monoculture or intercropped with polebean ( Phaseolus vulgaris L.) or cowpea ( Vigna unguiculata [L.] Warp.) was studied for two growing seasons at Morgantown, WV. Crops were seeded in the following sequences: maize before legume, both at the same time, and legume before maize. Planting times were early May or mid June. Nitrogen was applied at 0 or 160 kg ha⁻¹. Maize grain and forage, legume grain and forage, and total forage production were determined on a dry matter basis. Intercropping (average of all treatments) reduced maize grain and forage yields compared to maize in monoculture but had no effect on total forage production. However, total forage production was greatest when the seeding sequence was maize intercropped at the same time or before cowpea. Cowpea never produced grain, but forage production was almost double that of polebean. Maize produced most forage when seeded before the legumes, and the legumes produced most forage when seeded before maize. Early planting increased maize production and decreased legume production. Nitrogen increased maize grain, maize forage, and total forage yields but had not effect on legume forage production. It is concluded that maize/legume intercrops show promise for increasing forage production in temperate areas and more research on planting times and densities, weed control, harvesting and management is needed.  相似文献   

不同颜色防虫网覆盖栽培对豇豆生长发育的影响   总被引：1，自引：0，他引：1  

许如意  李劲松  袁廷庆  吴乾兴  肖日升 《热带农业科学》2011,31(8):46-50

研究了不同颜色（白色、黑色、红色、蓝色、绿色、银灰色）防虫网覆盖对栽培豇豆生长发育的影响。从豇豆的生育期、株高、茎粗、叶面积及叶绿素含量指数、产量和病虫害等方面综合考虑,在三亚地区绿色防虫网是较适合豇豆栽培的覆盖材料。  相似文献   

Effect of Relative Sowing Time on the Growth and Yield of the Component Crops in Okra/Maize and Okra/Cowpea Intercropping Systems     

C. O. Muoneke  J. E. Asiegbu  A. C. C. Udeogalanya 《Journal of Agronomy and Crop Science》1997,179(3):179-185

The effects of variations in the relative sowing time of component crops in okra/maize and okra/cowpea intercropping systems were examined in 1990 and 1991 cropping seasons. Okra was either sown the same day as, or two weeks before or after maize or cowpea. Intercropping reduced the growth and yield of okra, maize and cowpea relative to their sole crops. However, okra yield was depressed more by maize than by cowpea, especially when okra was sown two weeks after maize. Comparative assessment of okra/maize and okra/cowpea mixtures suggests that it is better to grow okra and cowpea together than intercropping okra and maize because yield advantages were always higher in okra/cowpea (67% and 59% in 1990 and 1991 respectively) than in okra/maize (15% and 29%). The results were discussed in light of competitive abilities of the various components in the mixtures.  相似文献   

Agroforestry systems and soil surface management of a tropical alfisol:     

R. Lal 《Agroforestry Systems》1989,8(2):97-111

Field runoff plots, 70 x 10 m each, were established on a tropical Alifisol in southwestern Nigeria to monitor water runoff, soil erosion and nutrient loss in water runoff. The non-agroforestry control treatment (A) was established at two levels: plow-till and no-till systems of seedbed preparation. There were two agroforestry systems based on contour hedgerows of (B) Leucaena leucocephala and (C) Gliricidia sepium established at 4-m and 2-m spacings. Field plots were established in 1982 and hydrological measurements were made for uniform maize-cowpea rotation for 12 consecutive growing seasons from 1982 through 1987. Once established hedgerows of Leucaena at 2-m spacing were extremely effective in reducing water runoff and controlling erosion. Runoff, erosion and nutrient losses were generally more from maize grown in the first season than from cowpea grown in the second. Mean seasonal erosion from maize was 4.3, 0.10, 0.57, 0.10, 0.64 and 0.60 t/ha for plow-till, no-till, Leucaena-4m, Leucaena-2m, Gliricidia-2m treatments, respectively. Mean runoff in the first season from treatments listed in the order above was 17.0, 1.3, 4.9, 3.3, 4.3, and 2.4 percent of the rainfall received. There were high losses of Ca and K in water runoff from the plow-till treatment. In contrast to runoff and erosion, losses of bases in water runoff from agroforestry treatments were relatively high, high concentration of bases in runoff was probably due to nutrient recycling by the deep-rooted perennials.  相似文献   

不同颜色防虫网对豇豆生长特性、产量及蓟马发生量的影响     

罗丰  袁廷庆  柯用春  王爽  吴乾兴  刘勇  黄国宋  孔祥义 《广西农业科学》2014,45(9):1584-1588

[目的]比较不同颜色（白色、绿色）防虫网设施大棚栽培对豇豆生长特性、产量及豇豆主要害虫蓟马发生量的影响,为绿色防虫网栽培技术在海南的推广应用提供科学依据.[方法]2012年冬季～2013年春季,以露地栽培为对照,对白色、绿色防虫网设施大棚下豇豆生育期、株高、茎粗、节间长、叶片叶绿素指数、豆荚性状、商品产量及蓟马发生量等指标进行调查.[结果]与露地栽培相比,豇豆在绿色防虫网覆盖条件下,抽蔓期提前5d,结荚期提前1d,采收期延长7 d;而白网覆盖下豇豆的生育期推迟;同一时期内,绿网覆盖下豇豆的株高、叶绿素指数均最高;白网、绿网覆盖和露地栽培在豇豆采摘盛期的荚长、荚横径和单荚重没有差异,但绿网覆盖下豇豆商品产量比白网覆盖提高8.63％,比露地栽培提高30.87％;不同颜色防虫网覆盖栽培下豇豆蓟马发生量达显著差异（P＜0.05）,且绿网内蓟马发生量低于白网和露地栽培.[结论]绿色防虫网覆盖栽培能增加豇豆产量,减少蓟马危害,建议在海南南部冬季豇豆种植区推广绿色防虫网.  相似文献   

Comparing the Impact of a Neonicotinoid and Biorational Agroneem on Herbivorous and Beneficial Arthropods on Cowpea and Tomato     

Jude Akamu Ewunkem  ;Louis Ernest Ndiva Jackai  ;Henry Osofuhene-Sintim  ;Beatrice Nuck Dingha 《农业科学与技术》2014,(7):585-596

Cowpea （Vigna unguiculata L. Walp.） and tomato （Lycopersicum esculentum L. Karst） are attacked by a wide range of insect pests worldwide. In many cases, pesticides are used to control the pests. In 2010 and 2011, we conducted field experiments to evaluate and compare the effectiveness of a biorational （Agroneem~） and conventional pesticide （imidacloprid or thiamethoxam） on insect pests of these crops. In the first year, two varieties of cowpea （Mississippi Silver and Pinkeye Purple Hull） and two of tomato （Mariana and German Johnson） were used; in the second year, the better performing of each group （Mississippi Silver and Mariana） were used for the study. A split-plot design with four replications in Year 1, and a randomized complete block design with six treatment combinations in Year 2. In the first year, both pesticide groups were applied following manufacturer＇s recommendation （10-14 d cycles）; and in the second year, the application of the pesticides was driven by economic thresholds level （ETL） of insect pests. The most prevalent species of insects recorded in both crops were in the families： Chrysomelidae, Pentatomidae, Cicadellidae, Vespidae, Sarcophagidae, Thripidae and Sphingidae. In both years, the diversity of insects on cowpea was greater than on tomato and more insects were observed in the second year compared to the first, despite the absence of significant difference （P 〉 0.05） between varieties in the treated plots. The yield of cowpea and tomato was comparable in all sprayed plots.  相似文献   

Diseases of Rubber and their Control     

R. L. Wastie 《国际虫害防治杂志》2013,59(3):268-288

Abstract

Most of the major diseases of Hevea brasiliensis are of worldwide distribution (with the notable exception of South American leaf blight, against which strict quarantine regulations are enforced by rubber-growing countries outside the Americas to prevent the unauthorised import of Hevea) but their local severity and importance vary from one region to another. Root diseases are a serious problem nearly everywhere and regular rounds of inspection and treatment are essential while the trees are still young in order to prevent serious losses. The recently introduced prophylactic collar protectant dressings specific to each of the three main diseases are valuable aids to control.

Diseases of the tapping panel may prevent tapping or hinder bark regeneration; black stripe in particular (Phytophthora palmivora) can be very persistent and is often eradicated only by repeated therapeutic fungicidal treatment of the bark. Stem diseases, chiefly pink disease (Corticium salmonicolor), are important in certain areas in wet weather, and can lead to severe damage and even dieback in the absence of effective treatment.

Four major leaf diseases can have a debilitating effect on the tree. Abnormal leaf fall (Phytophthora spp.) is severe in India, causing the abscission of mature leaves during the monsoon rains; treatment necessitates the application of a pre-monsoon prophylactic copper spray. Secondary leaf fall, caused both by Oidium heveae and Colletotrichum gloeosporioides which infect the flushes of new leaves produced after the annual leaf change (wintering), varies greatly in severity according to local weather and cultivar. It can be controlled by repeated rounds of an appropriate prophylactic fungicide or, under certain conditions, by artificially hastening the onset of wintering (and thus of refoliation) by removing the old leaves with a contact herbicide. By far the most important leaf disease is South American leaf blight (Microcyclus ulei); it is largely responsible for the lack of a vigorous rubber industry in South America, the home of the rubber tree. It can only be effectively countered by the use of resistant cultivars.

The economic importance of the above diseases is discussed and current control measures described.  相似文献   

Virulence characteristics of a new race of the parasitic angiosperm,Striga gesnerioides,from southern Benin on cowpea (Vigna unguiculata)     

J. A. Lane  T. H. M. Moore  D. V. Child  K. F. Cardwell  B. B. Singh  J. A. Bailey 《Euphytica》1993,72(3):183-188

An in vitro growth system was used to determine the virulence of two samples of Striga gesnerioides from Zakpota in southern Benin. Cowpea variety B301, previously considered resistant to all races of S. gesnerioides, was susceptible to both samples of the parasite. Two other cowpea varieties, 58–57 and IT81D-994, were totally resistant. Resistance in 58–57 was associated with a hypersensitive necrosis of infected roots, whilst IT81D-994 supported production of small S. gesnerioides tubercles with stems which failed to develop. Striga gesnerioides from southern Benin is the fourth race of the parasite to be identified, and the first with virulence on variety B301. The implications for breeding cowpeas with resistance to S. gesnerioides are discussed.Abbreviations IITA International Institute of Tropical Agriculture - LARS Long Ashton Research Station - SAFGRAD Semi-Arid Food Grain Research and Development  相似文献   

Evaluation of yield stability of cowpea under sole and intercrop management in Nigeria     

S. F. Blade  D. E. Mather  B. B. Singh  D. L. Smith 《Euphytica》1991,61(3):193-201

Summary Nine cowpea (Vigna unguiculata (L.) Walp.) breeding lines were grown in 13 experiments under sole crop and intercrop management, with and without insecticide application, in Nigeria. Cowpea was intercropped with cassava (Manihot esculenta Cranz), maize (Zea mays L.) and maize-cassava in the forest zone and with sorghum (Sorghum bicolor Moench.) and millet (Pennisetum glaucum (L.) R.Br.) in the savanna zone. Line by cropping system interactions were significant in 5 of 13 experiments and line by insecticide treatment interactions were significant in 2 of 13 experiments. Cowpea yield was severely depressed in intercropped plots and in plots to which no insecticide was applied. Among-environment variation in cowpea yield was greater when no insecticide was applied. Within each management treatment, the yield performance and stability of the cowpea lines was examined. Stability was assessed both by examining among-environment coefficients of variation and by regression analysis. Several of the breeding lines evaluated appeared promising under different levels of management and in a diversity of environments.  相似文献