ISSN:0030-7793    

DOI:10.1080/09670877309412724

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

ISSN:0030-7793    

DOI:10.1080/09670877309412725

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

ISSN:0030-7793    

DOI:10.1080/09670877309412726

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

ISSN:0030-7793    

DOI:10.1080/09670877309412727

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

ISSN:0030-7793    

DOI:10.1080/09670877309412728

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

Mildew problems on cucurbit vegetable crops in Malawi are reviewed and suggestions made for their control on commercial cultivars.

ISSN:0030-7793    

DOI:10.1080/09670877309412729

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

ISSN:0030-7793    

DOI:10.1080/09670877309412730

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

Farmers in Africa often have only one or two hectares of cotton and use conventional knapsack sprayers to apply insecticides in 56–224 1 water/ha; in Malawi farmers have obtained yields averaging 1000 kg seed cotton per hectare. As water supply is a major problem ultra-low-volume application with a small battery-driven spinning disc sprayer is being evaluated with encouraging results although costs are slightly higher than for conventional spray application. 25% carbaryl and 40% DDT to controlDiparopsis castaneaHmps andHeliothis armigeraHbn respectively are applied according to assessments of insect populations by routine scouting, with dimethoate added as required as aphicide-acaricide. Spray is fed to the spinning disc at 0.5 ml/sec and swath width decreased from six to two rows during the season. On a two-row swath (1.8 m) when plants exceed 50 cm height, 2.5 1 of spray are applied per hectare.

ISSN:0030-7793    

DOI:10.1080/09670877309412731

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

ISSN:0030-7793    

DOI:10.1080/09670877309412732

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

Mobility results in movement of insects from their birth place (emigration) to another site (immigration). The scale, both in time and in space, on which such migration occurs may determine rates of increase or decrease in numbers in a fixed geographical area or plot. This is self evident in the case of mobile insects, such as locusts. Other documented examples include the spruce budworm in Canada and the Queensland fruit fly.

ISSN:0030-7793    

DOI:10.1080/09670877309412733

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor