Studies were undertaken to evaluate the rice genotypes of Sikkim and Tripura for their resistance against brown planthopper (BPH) under glasshouse conditions. Among 74 rice genotypes phenotyped, a genotype (AC-39843) was considered as resistant and two other genotype (AC-39842 and AC-39877) of Tripura were categorized as moderately resistant to BPH. To understand their mechanism of resistance, resistant genotypes were evaluated for different parameter of antixenosis and antibiosis. The antixenosis and antibiosis studies in terms of nymphal setting preference, per cent unhatchability of eggs, nymphal survival and development, honeydew excretion, probing mark test, plant dry weight loss and defence enzymes (Peroxidase, polyphenol oxidaseand catalase) indicated that these genotypes showed confirmation of resistance to BPH compared to susceptible check TN 1. Among resistant genotypes, AC-39843 recorded lowest sugar content followed by AC-39842 and AC-39877 compared to TN1. Total phenol content in AC-39843 was highest followed by AC-39877 and AC-39842. Resistant genotypes found in the study could be used as new resistant donors and utilized in resistance breeding programme against brown planthopper in rice.

ABSTRACT

The foraging activity of Apis cerana indica was found higher in first week of November 2011 and 2 nd week of December 2012 (33.83 bees/5min/m 2). Its maximum visitation was found at 1100hrs (66.06 bees/5min/m 2). The maximum foraging activity of Apis dorsata was observed at 1100hrs (11.75 bees/5min/m 2) whereas, the lowest was observed at 1700hrs (0.50 bee/5min/m 2).The higher foraging activity of Apis florea was noticed at 1300hrs (4.00 bees/5min/m 2) and was found least at 0900hrs (0.56 bee/5min/m 2).

An automated micro-malting unit for quality evaluation of lines from a barley breeding programme, with the capacity to process 87 samples of 15 g grain or up to 129 samples of 5 g grain each weekly batch, is described. Aspects of the design of the equipment, in particular the malting chamber and sample con tainers, are discussed. The malting unit provided a relatively uniform environment within a batch when tested by malting replicates of one cultivar. There were very small gradients within the malting chamber during steeping and modification which resulted in small differences in the hot water extract of malts depending on container position. However, replicate samples within a batch gave mean extract values with good overall precision with a coefficient of variation of 0-6%. Furthermore, the equipment gave reproducible malting conditions from batch to batch. Hot water extract values of six barleys did not differ significantly between three successive malting batches and the major contribution to variance for all the malting characters measured in this case was attributed to differences between cultivars.

A field study was conducted at Tennessee State University's research station to evaluate the effect of hardwood bark mulch on the winter survival of garden mums. A randomized complete block design was used. Cultivars used were adorn, encore, grandchild, jackpot, legend, minnautumn, minnwhite and triump. At the end of the flowering season the tops were removed leaving a four inch stubble in the mulch. The number of mum plants that resumed growth the following spring were counted for each cultivar. There was a difference in the winter survival of the different cultivars as well as a significant difference in the mulch treated and the control. Grandchild and jackpot were most cold hardy followed by encore, minnwhite, minnautumn, triump, legend, and adorn. Grandchild and jackpot with four inches of hardwood bark mulch had an 88 percent survival while the control had a 44 percent survival. Adorn. had a 51 percent survival with four inches of mulch and a 20 percent survival in the control. This data shows that hardwood bark mulch holds a great potential for providing excellent winter protection for garden mums.