ISSN:0030-7793    

DOI:10.1080/09670877309412751

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

ISSN:0030-7793    

DOI:10.1080/09670877309412752

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

The toxicity of a number of topically applied pyrethroids has been tested in the laboratory against three species of locusts and parathion-resistant and susceptible strains of the Egyptian cotton leafworm. Bioresmethrin, resmethrin and 5-benzyl-3-furylmethyl (+)-cis-chrysanthemate (NRDC 119) proved to be extremely active against one or more of these pests and there were small but noteworthy improvements with the synergists sesamex and TBTP. The field potential of the pyrethroids is discussed against the background of environmental problems associated with some of the insecticides in current use.

ISSN:0030-7793    

DOI:10.1080/09670877309412753

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

ISSN:0030-7793    

DOI:10.1080/09670877309412754

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

ISSN:0030-7793    

DOI:10.1080/09670877309412755

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

Leafspot is one of the major factors which limits the yield of the groundnut crop in Malawi. The most effective and economical uses of fungicidal dusts and water-based sprays to control the disease, are described. Data are also presented to show how the use of such fungicides affects parameters of yield such as numbers, size, weight and quality of kernels, and weight and quality of haulms.

ISSN:0030-7793    

DOI:10.1080/09670877309412756

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

ISSN:0030-7793    

DOI:10.1080/09670877309412757

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

Use of the chain scythe for aquatic weed control in irrigation canals in developing countries is described. Each weeding operation involves comparatively little effort and cost, although regular weeding rounds are necessary to maintain control. The optimum interval between operations depends on local conditions. On the basis of a calculation given in the paper, the costs of cleaning canals can be estimated.

ISSN:0030-7793    

DOI:10.1080/09670877309412758

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

A review is made of some crucial stages in the life-cycle of the water hyacinth (Eichhornia crassipes) as points towards which control programmes might be directed.

ISSN:0030-7793    

DOI:10.1080/09670877309412759

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

ISSN:0030-7793    

DOI:10.1080/09670877309412760

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor