No abstract

The research was conducted during kharif seasons of 2008 and 2009. Nineteen genotypes comprising of seventeen Bt hybrids, one conventional hybrid and one variety were evaluated for their reaction to sucking insect pests, under unsprayed condition. Observations on sucking pests were recorded at weekly intervals. The highest population of leafhopper was recorded during 28 th and 32 nd standard weeks. The highest mean incidence was recorded in H-1226. Whitefly population remained below economic threshold level (ETL) during 2008 while during 2009 it crossed ETL in RCH 134 BG-II (6.00-6.23 adults/leaf). Mean highest population was recorded in IT-905 Bt and RCH-134 BG-II. Leafhopper and whitefly population were significantly and positively correlated with temperature while negatively correlated with rainfall. Among the genotypes, it was observed that there was no significant difference in population of the sucking pests.

No abstract

A pronounced residual effect of organic and inorganic fertilizers, applied in maize crop was observed on yields of maize-gobhi sarson cropping system. The experiment was conducted with 10 treatments of N, P, K, FYM, crop residue and zinc sulphate nutrients. The highest growth, yield and yield components of maize crop were recorded with 100% recommended fertilizer dose-RFD + ZnSO4 20 kg/ha and the grain yield (2409 kg/ha) was about 101% higher over the control. In case of gobhi sarson, the highest seed yield (1081 kg/ha) was observed as a pronounced residual effect of 10 t/ha FYM in preceding maize crop; which was about 81% higher over the control. The treatments where 50% N was substituted by FYM and crop residue in maize crop had the best reflection in enhancing the seed yield of gobhi sarson to the tune of 74 and 70% over the control and 16 and 13% over farmer’s practice. The highest rain water use efficiency (RWUE) and heatuse efficiency (HUE) was recorded in treatment 100% RFD + ZnSO4 20 kg/ha in maize crop and 10 t/ha FYM in gobhi sarson. DOI: http://dx.doi.org/10.3329/bjb.v43i2.21666 Bangladesh J. Bot. 43(2): 147-155, 2014 (September)