ISSN:0143-6147    

DOI:10.1080/09670878009414274

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Trials carried out during 1976 and 1977 have demonstrated the high insecticidal activity of decamethrin againstHeliothis armigera, one of the major pests of the tomato crop in the Cap Vert region of Senegal. Acephate, carbaryl and tetrachlorvinphos also gave acceptable levels of control, whereasBacillus thuringiensis, dichlorvos and dimethoate were unsatisfactory. The effectiveness of all the products was diminished when tomatoes were irrigated by means of overhead rotary sprinklers.

ISSN:0143-6147    

DOI:10.1080/09670878009414275

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Wodlly apple aphidEriosoma lanigerum(Hsm.) is widely distributed in India. It reproduces all year round on apple and crab apple. Alates are produced from July to November and lay nymphs with degenerate mouth parts. The infestation is spread by nursery plants and air currents. The pest is controlled in the nursery either by dip-treatment with fenitrothion (0.025%) or dichlorvos (0.088%) or by soil application of phorate granules (2.5–3.0 g a.i.) during spring. Subterranean populations can be controlled with granules of dimethoate (15 g a.i.), aldicarb (5.0 g a.i.) or carbofuran (3.0 g a.i.). Aerial populations are controlled by autumn sprays of fenitrothion + dichlorvos + demeton-methyl (0.05%), vamidothion (0.025%), phosophamidon (0.035%) or dimethoate (0.03%). Banding of the trunk base with granules has been found useful in reducing reinfestation by checking the first instar nymphs, which migrate between the aerial and subterranean parts. Resistant root stocks of the ‘M.M.’ series are recommended against the pest.

ISSN:0143-6147    

DOI:10.1080/09670878009414276

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Insect and bird pests infesting pearl millet in India have been listed and research work reviewed. White grubsHolotrichiaspp. and shootfly,Atherigona approximateare most important pests, besidesMyllocerusspp. (grey weevil),Marasmia trapezalis(leaf roller),Autoba (Eublemma) silicula(earhead worm) andPeregrinus maidis(plant hopper).Rhinyptiaspp. (adults) andHeliothis (Helicoverpa) armigerain the north-western arid zones and earhead midge in the south are becoming important pests. New pests as a result of host cross over are continuously being recorded.

ISSN:0143-6147    

DOI:10.1080/09670878009414277

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Antibiotics, Agrimycin 100, Agrimycin 500, Agric. Terramycin 17, A.S. 50 and Streptocycline, and fungicides, Brestanol, Fytolan and Vitavax, were evaluated under field conditions for control of bacterial leaf blight of rice caused byXanthomonas oryzae. Agric. Terramycin 17, Brestanol, Agrimycin 500 and a combination of Agrimycin 100 + Fytolan gave effective control of the blight phase of the disease. The combination of Agrimycin 100 + Fytolan spraying gave good control of the disease and an economic return on susceptible varieties like Sona.

ISSN:0143-6147    

DOI:10.1080/09670878009414278

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Diseases are among the most important limiting factors in maize production in the American tropics, and ‘maize (corn) stunt’ has long been recognised as one of the major problems of the crop in this area. For several years the etiology of the disease was poorly understood, and several different symptoms were associated with maize stunt, which is now known to involve viruses and spiroplasmas. Rayado fino (Spanish for fine striping) virus (RFV) is presently recognised as a distinct pathogen within the maize stunt complex and has been shown to be responsible for the rayado fino disease, which is widespread and increasingly important in the American tropics. Symptoms, which are characterised by a fine chlorotic stipple striping of the leaf veins are generally mild, but reductions of yields are frequently appreciable. The cicadellid leafhopperDalbulus maidisDelong & Wolcott, is the most important vector of the virus in the American tropics, although other species of leafhoppers have been indicated in North America. Virus particles are icosahedral, 30 nm in diameter and contain single-stranded RNA. The virus is not serologically related to other isometric plant viruses. Both virus and vector possess a restricted host range, limited to maize and teosinte. Rayado fino is frequently found under widely different ecological conditions. The disease may be controlled through the use of tolerant genetic material.

ISSN:0143-6147    

DOI:10.1080/09670878009414279

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The improved cassava mosaic-resistant cassava variety TMS 30395 produced significantly higher root yields under field conditions than its susceptible parent Isunikakiyan, irrespective of whether it was established from mosaic-free or mosaic-infected planting material. Significant reductions in fresh root yield, root number, root size, top fresh weight and starch content in both varieties resulted from plants established from CMD-infected planting material. For the variety Isunikakiyan, yield reduction was greater in plants established from clonal CMD-infected cuttings than in those established from disease-free cuttings but which later became infected through vector transmission.

ISSN:0143-6147    

DOI:10.1080/09670878009414280

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Records of the pine needle pathogensMeloderma desmazieriiandScirrhia acicolaare reported fromPinusspp. in Colombia. These are believed to be first records for the region and, in the case of S.acicola, for South America. The records of S.acicolaoutside North America are discussed and some are reported to be mis-identifications ofS. pini. There is evidence, however, that S.acicolamay have been established on Balkan pines for at least 25 years. The threat of S.acicolato exotic pine plantations in the southern hemisphere, now it has reached South America, is discussed.M. desmazieriidoes not appear to be a potentially important pathogen for exotic pine plantations.

ISSN:0143-6147    

DOI:10.1080/09670878009414281

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Different herbicides were tested for effective weed control in a seed crop of onion at Punjab Agricultural University Ludhiana, during 1975–76 and 1976–77. Oxadiazon (2.00 and 3.00 kg a.i./ha post-emergence), fluchloralin (0.90 and 1.20 kg a.i./ha pre-plant), fluchloralin + chloroxuron (1.20 + 1.50 kg a.i./ha pre-plant and pre-emergence, respectively) and fluchloralin + propanil (1.20 + 0.68 kg a.i./ha pre-plant and post-emergence, respectively) proved to be the most promising treatments controlling the weed population and leading to significantly higher seed yields. No residual effect of any of the herbicides was observed on succeeding crops of okra, bottlegourd, squashmelon and muskmelon.

ISSN:0143-6147    

DOI:10.1080/09670878009414282

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The occurrence of weeds in jute fields, from the time of land preparation to harvest of the crop for fibre or seed under various agroclimatic and edaphic conditions has been studied. The habitat and preponderance of the major weeds is summarised. The growth pattern of selected major weeds in relation to jute grown for fibre or seed and their behaviour in jute fields was also examined. The predominant weeds observed were annual grasses and sedges, including nutsedge. Broadleaved weeds occurred in smaller numbers and were not a serious problem. The weed seeds germinate along with the jute, compete with the crop and mature before the crop is harvested. The graminaceous and cyperaceous weeds exhibit the greatest frequency, dry matter accumulation and production of seeds by individual plants although great variation exists between different weed species and among the same species.

ISSN:0143-6147    

DOI:10.1080/09670878009414283

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor