Search

The effect of different modes of pollination on quantitative and qualitative parameters of Egyptian clover, Trifolium alexandrinum L. was studied at Forage Section, Department of Genetics and Plant Breeding, CCS, Haryana Agricultural University, Hisar during 2012 and 2013. Maximum seed setting (81.5%) was recorded in A. mellifera pollination with an 8 frame colony (BP-8F) followed by 4 frame colony (BP-4F) (75.1%), open pollination (OP) (73.8%) and 2 frame colony (BP-2F) (71.5%). Maximum seed yield (2662.3 seeds) was observed in treatment BP-8F followed by BP-4F (2373.8), OP (2316.3) and BP-2F (2235.5). Still lower yield of 2103.0 seeds was found in hand pollination (HP) treatment that was significantly higher than the without insect pollination (WIP) treatment (1114.2). Minimum 1000-seed weight was observed in WIP (2.64 g). The seed weight of BP-4F (3.30), HP (3.20), BP-2F (3.17) and OP (3.03), the heaviest seeds were recorded in BP-8F (3.62 g/1000 grains) and it was at par with the treatment BP-4F (3.30 g). Highest seed germination per cent was recorded in BP-8F (94.7) followed by OP (90.7%). Lowest germination was found in WIP (84.7%). Though some work has been done on this aspect in India but comprehensive pollination studies has not been worked out.

The present study on the effect of variety and planting date of rice on population of natural enemies of brown planthopper, Nilaparvata lugens (Stal) showed that during August, the mean population of spiders was statistically on par on CSR 30 and PR 114. The population differed with dates and was significantly (p=0.05) higher (9.0/10 hills) in D2 during 2011 only. There was no significant difference in the population of spiders on two varieties and dates of transplanting during September 2011 only. However, significantly higher population of spiders was recorded in variety PR 114 (21.65/10 hills) and D2 (20.52/10 hills) than on CSR 30 (13.67/10 hills) and D1 (14.80/10 hills) during September, 2012. The mean population of spiders did not differ significantly with the dates during October, 2011 and 2012. However, it was significantly higher on variety PR 114 (27.65/10 hills) than on CSR 30 during both the crop seasons. Mirid bugs did not appear in the month of August, 2011 and 2012 whereas during September 2011, the variety CSR 30 and D1 registered significantly higher population than other variety and date. However, a reverse trend was observed with varieties and dates during 2012. The mean population of coccinelid, carabid and staphylinid beetles remained very low on both the varieties in the month of August during 2011 and 2012. However, the population of these predators was influenced significantly by the varieties and dates during 2012. The population of nymphal-adult parasitoids also remained very low during both years and was not influenced by varieties and dates.