大豆品种（系）对根潜蝇抗性的研究

１９８５－１９８９年田间鉴定４９份当地主栽的大豆品种（系），结果表明：不同品种的抗虫性有显著差异，共筛选出高抗材料两份，抗虫材料２０份。抗虫材料表现受害率低，受害根部幼虫蛀道小，对大豆苗期生育影响较小。初步认为品种抗虫性属于多基因控制的水平抗性。     

Pest status and ecology of bean stem maggot (Ophiomyia spp.: Diptera: Agromyzidae) on the Niassa Plateau,Mozambique

Research was carried out on the Niassa Plateau, northern Mozambique, with the aim of determining the phenology and importance of bean stem maggot (BSM) (Ophiomyia spp.: Diptera: Agromyzidae) on common beans. The objective of the study was to gather information in order to develop elements of an integrated control programme against BSM for use by farmers in the local cropping system, characterized by limited access to external inputs. Date of sowing trials were used in six consecutive rainy seasons to determine infestation rate of BSM during the main bean growing season and to determine damage due to the pest. These trials were also used to evaluate insecticide treatments against BSM and, at the same time, to undertake a survey of BSM parasitoids and the rates of parasitism from puparia collected at each sowing date. It was observed that infestation rates of BSM increased with delay in date of sowing in each of the two growing periods during the season and that percentage plant loss and yield decrease was correlated with number of BSM per plant. Insecticide seed treatmentwas effective in reducing infestation rates. BSM has two main parasitoids that probably play a role in limiting BSM population towards the end of the first growing period.     

Weeds and Shifting Cultivation

Abstract

Traditional labour-intensive methods of weed control which are normally associated with shifting cultivation are evaluated and compared with the use of herbicides and improved cultural practices. Problems occurring in shifting cultivation, such as weed seed dormancy, erosion and changing weed population; and methods of reducing the weed problem are discussed.     

Genotypic response of common bean to natural field populations of bean fly (Ophiomyia phaseoli) under diverse environmental conditions

Bean fly is a significant pest of common bean in semi-arid areas of East Africa. Apart from inadequate moisture in the dry land, bean fly simultaneously contributes negatively thereby adversely affecting bean productivity. The objectives of this study were to (1) identify sources of resistance to bean fly available in landraces, (2) confirm stability of host plant resistance in drought stress and (3) determine the effect of drought stress and seasonal variation on common bean genotypes in relation to bean fly attack for adaptability to the semi-arid areas of East Africa. Sixty four genotypes including landraces, bean fly resistant lines and local checks were evaluated for seed yield, 100-seed weight, days to maturity, plant mortality and pupae in stem in an alpha lattice design with two replications. This was under drought stressed (DS) and non-stressed (NS) environments and two treatments (insecticide sprayed and natural infestation) for three cropping seasons between 2008 and 2009. Genotypes differed in their reaction to natural bean fly attack under drought stressed (DS) and non-stressed (NS) environments over different cropping seasons. However, the effect of bean fly appeared to vary between the long rains (LR) and short rains (SR). It was observed that an increase in number of pupae per stem resulted in a higher plant mortality. The range of seed yield was from 345 to 1704 kg ha⁻¹ under natural infestation and from 591 to 2659 kg ha⁻¹ under insecticide protection. Seed yield loss ranged from 3 to 69%. The resistance of most of the bean fly resistant lines seemed to break down in presence of DS owing to their dismal performance. Screening of genetic resources in common bean to breed for host plant resistance to bean fly offers high potential of success if researchers take full advantage of the diversity available within the landraces.     

大豆重迎茬对大豆根潜蝇种群数量的影响

在黑龙江省的黑河、安达、密山、汤原等9个市县,对大豆根潜蝇的种群数量与大豆重迎茬年数之间的关系进行了系统调查研究和防治试验。结果表明重迎茬加剧了大豆根潜蝇的危害,重茬1,2,3年的有虫株率分别比正茬高14．8％,23．5％和25．5％。在大豆根潜蝇的防治中,采用呋多福、甲多、大豆种衣剂、叶喷剂、绿肥和大豆硼肥等药剂进行防治,较对照明显降低了危害株率和有虫株率,对大豆根潜蝇防治效果达7．7％～88．5％。     

枝孢属的一个国内新记录

报道枝孢属一新记录种:马缨丹枝孢C lad osporium lantanae。其形态特点是:分生孢子梗直立,稍弯曲,淡褐色;枝孢顶具2~3个孢痕,淡褐色,无隔膜。分生孢子顶生或侧生,形成短孢子链,椭圆形,0~1个隔膜,大多数无隔膜,基部有孢痕,淡褐色,平滑。另报道6种枝孢的8种国内新寄主植物、2个已知种的地理新分布和4个已知种。研究标本存云南农业大学真菌标本室(MHYAU)。     

Production of cotton varieties with resistance to Fusarium wilt with special reference to Tanzania

Abstract

Fusarium wilt caused by Fusarium oxysporum f. sp. vasinfectum (Atk.) Sny. & Hans. is an important disease of cotton in several developing countries where the use of resistant varieties continues to be the most practical method of control. The inheritance of resistance to wilt is complex, involving several major and minor genes. In order to identify resistant genotypes in segregating populations large numbers of plants must be screened using inoculation methods which minimise disease escape. Wilt incidence is increased when plants are attacked by the rootknot nematode (Meloidogyne acrita Chitwood, 1949) Esser et al. 1976. In areas where both organisms occur together, the wilt resistance‐potential of a variety cannot be realised unless it also has resistance to root‐knot. Problems of breeding for wilt resistance are discussed with reference to Tanzania, and methods are described for their application to a wilt‐resistance programme.     

Seed dressing insecticides for bean fly [Ophiomyia phaseoli (Tryon) (Diptera: Agromyzidae)] control in Ethiopia

Abstract

Six seed dressing insecticides were tested for efficacy against Ophiomyia phaseoli (BF) in 1987 and 1988 at two locations in south‐central Ethiopia. Endosulfan and aldrin, at 5 g a.i./kg of seeds, were the least phytotoxic and the most effective. The rest gave variable results; BF control with some insecticides (e.g. furathiocarb) was comparable, but they showed varying degrees of phytotoxicity. The maximum seed yield loss was 36.5%. The results suggest that aldrin be replaced with endosulfan, which is less persistent.