摘要:

All fifteen insecticides tested significantly reduced pest levels. Permethrin 25 e.c. @ 150ga.i./ha proved significantly superior than other insecticides during both the years when observed 3 days after treatment but was at par with deltamethrin 2.8 e.c. and fenvalerate 20 e.c. when observed 7 and 15 days after spraying. Isofenphos was least effective, however, it did not differ significantly from phosalone during 1981–82 and fenitrothion, triazophos and phosalone during 1982–83. Maximum and the minimum cost benefit ratios of 1 : 10.6 and 1 : 4.0 were obtained in gamma BHC and fenvalerate treated plots respectively.

ISSN:0143-6147    

DOI:10.1080/09670878909371408

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Field trials were conducted during the aman season to understand the dissipation rate, half‐life and TMRLvalues of endosuifan 35e.c. in soil, green foliage and green grain following application in the flowering stage of paddy with the recommended dose (005% @ 500 litres/ha) and double the recommended dose (0.10% @ 500 litres/ha). The maximum residues on soil after 7 days of application (0.029 and 0.092 ppm) were well below the tolerance limit of endosuifan (0.1 ppm for rice in husk). The initial deposits varied from 4.571 to 11–671 ppm for green foliage and from 1.778 to 4.274 ppm for green grain. Dissipation followed a first order reaction in all cases and the half‐life values varied from 3.3 to 3.4 days for green foliage and from 5.6 to 5.7 days for green grain. Calculated waiting periods (TMRL) varied from 19.3 to 23.7 days for green foliage and from 22.5 to 29.9 days for green grain. The terminal residues of endosuifan at harvest in different substrates varied from 0.007 to 0.042 ppm, well within the prescribed tolerance limit.

ISSN:0143-6147    

DOI:10.1080/09670878909371409

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

10.8% of 1300 coconut seedlings surveyed in 1985 in the nursery at the Nigerian Institute for Oil Palm Research, Benin City, were attacked by termites. The main termite implicated in the attack wasMacrotermes bellicosusSmeathman. The whole body of coconut seednuts damaged were either fullyorpartially excavated by termites, including the plumule or growth region.

ISSN:0143-6147    

DOI:10.1080/09670878909371410

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

About a hundred insect pests attack millets in the field and during storage. Some are common throughout the millet growing areas. Stem borers and grain midge are of regular occurrence. White grubs are important in India. Spike worms have recently become serious in the sub‐Sahelian zone of West Africa. Sporadic attacks of blister beetles, armyworms, grasshoppers, chinch bugs, leaf beetles, head caterpillars and head bugs result in severe yield losses in certain seasons. There is a higher incidence of storage pests in the rainy season. Research on pest management needs to be intensified. The tactics differ with the pest complex and the agroecosystem. However, a combination of cultural practices and resistant cultivars have proved to be effective. Multiple pest resistance has become more important in order to reduce insecticide use, common in pest endemic areas and during outbreaks. The exchange of genetic material and research information can provide an interdisciplinary approach to pest management in millets.

ISSN:0143-6147    

DOI:10.1080/09670878909371411

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Atherigona orientalis(Schin.) is a dipterous pest of pepper fruit in Nigeria. Field and laboratory observations showed that available local varieties of pepper were infested by the developmental stages during the rainy season in Port Harcourt. The fruits were contaminated with pupae and larval frass. The population of the various stages are primarily related to the availability of susceptible pepper fruits, itself determined by rainfall. Of four local varieties, Nsukka Yellow(Capsicum annum)was most preferred and Bird's eye chilli(C. frutescens)the least preferred byA. orientalis.

ISSN:0143-6147    

DOI:10.1080/09670878909371412

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The biology of rice thrips,Stenchaetothrips biformiswas studied on different ages of variety TN1 seed/ings [10‐,20‐30‐day‐old] and the weedEchinochloa colona.The total life span was 20.1, 24.2, 26.2 and 32.5 days on 10‐, 20‐ and 30‐day‐old TN1 seedlings and the weed respectively. The fecundity was 21.4, 21.6, 28.7 and 15.1 eggs respectively on 10‐, 20‐, 30‐day‐old TN1 plants and the weed host. There was lower larval survival, reduced adult longevity, less fecundity and low population growth on the resistant rice variety Ptb 33 compared to the susceptible TN1.

ISSN:0143-6147    

DOI:10.1080/09670878909371413

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

The adult mortality ofCallosobruchus chinensisL. was 100% within 24 h after artificially infesting seeds pretreated with inert clay and stored for 12 months under ambient conditions. Pre‐treatment with thiram and delsan‐30 (TCMTB) were also effective in controlling the adults by impairing oviposition. The seeds maintained over 80% germination up to 12 months of storage under all the treatments.

ISSN:0143-6147    

DOI:10.1080/09670878909371414

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

In an attempt to find the optimum time of sowing for lucerne to manage insect pests to achieve a maximum yield of green fodder, sowing in early November, yielded the maximum, related to the least damaging intensity of leafhoppers, lucerne weevil and aphids, the optimal time for vegetative growth and the temperature and humidity. Other sowings gave a poor yield. Variety IGFRI‐244, was less attractive to these pests than variety, S‐932, and yielded more green fodder.

ISSN:0143-6147    

DOI:10.1080/09670878909371415

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Insect colonization of cowpea,Vigna unguiculatain contiguous weedy and weed‐free plots was monitored in the early and late seasons of 1986 in Akure, Nigeria. The cowpea aphid,Aphis craccivoraKoch preferentially invaded weed‐free plots and developed higher densities thereon. Numbers of predatory coccinellid and syrphid larvae were higher in weedy plots despite lower aphid densities.

ISSN:0143-6147    

DOI:10.1080/09670878909371416

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Effects of damage caused by the American bollworm,Heliothis armigera(Hbn.), on yield of tomato,Lycopersicum esculentumMill., transplanted at different times were studied in 1985–6 by treatment with some insecticides against this insect. Fruit damage was highly but negatively correlated(P =001) with the number (r= ‐0.69, 1985; ‐0.98, 1986); weight (r = ‐0.78, 1985; ‐0.64, 1986); and yield(r= ‐0.74, 1985; ‐0.90, 1986) of harvested fruits. Fruit damage was significantly reduced and yield increased by spraying thus showing serious damage was caused byHeliothis.Cypermethrin suppressed fruit damage by 70.4 and 52.2% in 1985 and 1986 and increased yield by 1150 and 67.6%, respectively.

ISSN:0143-6147    

DOI:10.1080/09670878909371417

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor