摘要:

Manipulation of ground cover vegetation in apple orchards and vineyards had a substantial impact on the abundance of soil dwelling and foliage inhabiting arthropods. Systems with cover crops were generally characterized by lower densities of phytophagous insects, less fruit damage caused by insects on the trees, larger populations and more species of natural enemies and increased predation of artificial prey. Cover crops that remained in full bloom throughout the season, that produced more biomass and supported higher numbers of alternate prey, seemed to harbor the largest complex of predators and parasites. Apparently, cover crop manipulation can directly affect colonization of insect pests which discriminate among trees with and without cover beneath, and can also help retain populations of soil and foliage inhabiting natural enemies through the provision of alternate food and habitat. The design of proper cover crop-orchard mixtures can result in enhanced biological control of specific pests in existing orchards and vineyards.

ISSN:0144-8765    

DOI:10.1080/01448765.1985.9754453

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Twenty-one organic waste materials were collected from different locations in five states located in south western Nigeria. The organic wastes were evaluated for their fertilizer value.

ISSN:0144-8765    

DOI:10.1080/01448765.1985.9754454

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Field studies in a traditional bean cropping system (“Frijol tapado”) showed that an average of 8% of thePhaseolus vulgarispods harvested were attacked byZabrotes subfasciatus.Levels of attack observed on wildPhaseolus lunatusvines also present in the agroecosystem were comparable (x=9%)

ISSN:0144-8765    

DOI:10.1080/01448765.1985.9754455

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

摘要:

Growth traits and yields of maize (Zea mays) are described for varying fertilizer treatments (fresh cow manure, composted manure, inorganic NPK). Relative N-uptake is 9, 28, and 46% for compost, fresh manure and NPK, respectively. Growth rate and yields are correlated significantly with plant tissue nitrate at 30 days, which diminished in the order NPK>fresh manure>control> compost. Similarly, leaf nitrate at silking stage of maize decreases in the same order, with compost giving lowest soluble N levels. Total-N in grain at harvest does not differ significantly between the treatments, however. It is concluded that rapid early nitrogen release contributes to a high yield but elevated plant nitrate and nitrate remaining in soil after harvest are consequences which must be weighed against it. The difficulties inherent in estimating N-release from organic sources are discussed.

ISSN:0144-8765    

DOI:10.1080/01448765.1985.9754456

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

ISSN:0144-8765    

DOI:10.1080/01448765.1985.9754457

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

ISSN:0144-8765    

DOI:10.1080/01448765.1985.9754458

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

ISSN:0144-8765    

DOI:10.1080/01448765.1985.9754459

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

ISSN:0144-8765    

DOI:10.1080/01448765.1985.9754460

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

ISSN:0144-8765    

DOI:10.1080/01448765.1985.9754461

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor

ISSN:0144-8765    

DOI:10.1080/01448765.1985.9754452

出版商:Taylor & Francis Group    

年代:1985

数据来源: Taylor