摘要:

Soil samples including plant roots, were taken from areas with plants suspected of being damaged by nematodes. Analysis and identification was carried out. The most common and widespread nematode wasRotylenchulus reniformiswhich had fifteen hosts. There was a consistently high build-up of this nematode in experimental plantings of passion fruit and chemicals have to be used for control. Two species of root-knot nematode,Meloidogyne incognitaandM. javanica, were widely found although infestation seemed to be confined to a few plants in a crop. OnlyMeloidogynespp. andRotylenchulus reniformisare of economic importance. The main crops, i.e. rice and citrus, have no nematode problems under current practices. However, nematodes may become a problem as larger intensive farming schemes are developed.

ISSN:0143-6147    

DOI:10.1080/09670878009414924

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Field trials were carried out over a three year period in an alfisol in a subhumid tropical environment to evaluate the effectiveness of hand-weeding frequencies and several herbicides for weed control in cassava (Manihot esculentaCrantz). Uncontrolled weed growth caused 40% reduction in root yield of short, profusely branching cassava cultivar while a 68% reduction in root yield was observed in separate studies involving a tall non-branching cultivar. Two or three properly timed hoe weedings gave crop yields that were as good as keeping the plots weed free throughout the growing season. Although pre-emergence application of fluometuron at 2.0 to 3.0 kg a.i./ha or diuron at 2.0 kg a.i./ha used singly gave good weed control and crop yield, the efficacy of these herbicides was greatly improved by tank mixing each of them with alachlor or metolachlor at 3.0 and 2.0 kg a.i./ha respectively. Excellent crop yield was also observed where atrazine and metolachlor was applied pre-emergence at 2.5 kg a.i./ha. At current labour rates in Nigeria, it is cheaper to practise chemical weed control in cassava than to rely on hand-weeding even if the labour is readily available and the weeding can be carried out on time.

ISSN:0143-6147    

DOI:10.1080/09670878009414925

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

A field experiment was conducted for two years during 1977–78 and 1978–79 to evaluate the efficiency of methabenzthiazuron, terbutryn and metoxuron in controlling weeds in peas (Pisum sativum) at the Punjab Agricultural University, Ludhiana, India. Pre-emergence application of methabenzthiazuron at 1.05 and 1.40 kg a.i./ha gave efficient weed control and gave comparable yields to two hand hoeings. Post-emergence application of methabenzthiazuron proved inferior. Terbutryn pre-emergence showed promise but as a post-emergence application it was ineffective. Metoxuron both pre- and post-emergence showed phytotoxic effects on the crop.

ISSN:0143-6147    

DOI:10.1080/09670878009414926

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

SeveralSporobolusspecies are useful range plants in the Western United States. Two of them, however,S. poiretii(Roem. and Schult.) Hitch. andS. indicus(L.) R. Br. have become important weeds in improved sub-tropical and tropical pastures, the former in the South-eastern United States, the latter in tropical America. This paper briefly reviews the distribution, plant characteristics and forage quality of these weeds. Non-chemical and chemical methods of control are also discussed.

ISSN:0143-6147    

DOI:10.1080/09670878009414927

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0143-6147    

DOI:10.1080/09670878009414928

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0143-6147    

DOI:10.1080/09670878009414929

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0143-6147    

DOI:10.1080/09670878009414930

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0143-6147    

DOI:10.1080/09670878009414931

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0143-6147    

DOI:10.1080/09670878009414932

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0143-6147    

DOI:10.1080/09670878009414933

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor