摘要:

Comparative field observations of pest incidence on five selected varieties each of Japonica, Indica, and Japonica × Indica rice types indicated that tungro incidence was relatively higher on Japonica varieties, while stem borer incidence at heading stage was higher on Indica varieties. No differences in the relative abundance of other pests on these rice types were observed. Insecticide treatment and caging of plants reduced pest incidence on all varieties. Plant growth and yield of insecticide‐treated plants were significantly higher than unprotected plants. Caging reduced the number of tillers but the yields remained higher than unprotected plants. Yield loss estimated by the insecticide protection method was higher at 39% than that by the caging method at 25% overall. There was a significant positive correlation between yield loss estimated by the two methods in Indica and Japonica × Indica varieties and no such relationship in Japonica varieties.

ISSN:0143-6147    

DOI:10.1080/09670879109371601

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Extraction of nematodes from 36 root samples of tannia (Xanthosoma sagittifolium)collected from three locations in Morogoro region, Tanzania, revealed thatMeloidogynespp. were the dominant nematodes associated with the crop. A frequency of 100% was recorded in all three areas where high densities of up to 6570Meloidogynejuveniles and of up to 7.1Meloidogynefemales per gram of root tissues were recorded. TheMeloidogyne specieswere identified asM. arenariaandM. javanica.No external galls were visible on infected roots, but the nematodes were in sufficient numbers to cause damage to tannia.

ISSN:0143-6147    

DOI:10.1080/09670879109371602

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

Rodents damaged 6.32–8.15% wheat tillers in three districts of Himachal Pradesh,viz.Kangra, Sirmour and Solan. Maximum damage was recorded when the crop was at maturity stage. Lesser bandicoot rats hoarded 0.486 kg ear‐heads per burrow system on an average. Two treatments of 2.5% zinc phosphide at 45 days interval significantly reduced the damage from 7.16% to 1.25% in the experimental fields, thereby increasing the yield of grains by 56 kg/ha. A net gain of Rs.105.88 per hectare with cost‐benefit ratio of 1:18.3 was achieved.

ISSN:0143-6147    

DOI:10.1080/09670879109371603

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:0143-6147    

DOI:10.1080/09670879109371604

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:0143-6147    

DOI:10.1080/09670879109371580

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor