EFFECT OF NANOSCALE ZINC OXIDE PARTICLES ON THE GERMINATION,GROWTH AND YIELD OF PEANUT

An investigation was initiated to examine the effects of nanoscale zinc oxide particles on plant growth and development. In view of the widespread cultivation of peanut in India and in other parts of the globe and in view of the potential influence of zinc on its growth, this plant was chosen as the model system. Peanut seeds were separately treated with different concentrations of nanoscale zinc oxide (ZnO) and chelated bulk zinc sulfate (ZnSO₄) suspensions (a common zinc supplement), respectively and the effect this treatment had on seed germination, seedling vigor, plant growth, flowering, chlorophyll content, pod yield and root growth were studied. Treatment of nanoscale ZnO (25 nm mean particle size) at 1000 ppm concentration promoted both seed germination and seedling vigor and in turn showed early establishment in soil manifested by early flowering and higher leaf chlorophyll content. These particles proved effective in increasing stem and root growth. Pod yield per plant was 34% higher compared to chelated bulk ZnSO₄. Consequently, a field experiment was conducted during Rabi seasons of 2008–2009 and 2009–2010 with the foliar application of nanoscale ZnO particles at 15 times lower dose compared to the chelated ZnSO₄ recommended and we recorded 29.5% and 26.3% higher pod yield, respectively, compared to chelated ZnSO₄. The inhibitory effect with higher nanoparticle concentration (2000 ppm) reveals the need for judicious usage of these particles in such applications. This is the first report on the effect of nanoscale particles on peanut growth and yield.     

Stress mitigating and immunomodulatory effect of dietary pyridoxine in Labeo rohita (Hamilton) fingerlings

A 60‐day experiment was carried out to delineate stress mitigating and immunomodulatory role of dietary pyridoxine (PN) in Labeo rohita fingerlings exposed to endosulfan. Two hundred and seventy fingerlings were randomly distributed into six treatments in triplicates. Five iso‐caloric and iso‐nitrogenous purified diets were prepared with graded levels of pyridoxine. Six treatment groups were T₀ (10 mg PN+without endosulfan), T₁ (0 mg PN+endosulfan), T₂ (10 mg PN+endosulfan), T₃ (50 mg PN+endosulfan), T₄ (100 mg PN+endosulfan) and T₅ (200 mg PN+endosulfan). The role of pyridoxine on stress mitigation and immunomodulation was assessed by biochemical and haemato‐immunological parameters like aspartate aminotransaminase, alanine aminotransaminase, lactate dehydrogenase, malate dehydrogenase, superoxide dismutase and catalase were significantly (P<0.05) lower while acetylcholinesterase was significantly (P<0.05) higher in pyridoxine‐fed groups. Erythrocytes count, haemoglobin content and total serum protein, albumin, globulin, nitroblue tetrazolium and lysozyme activity were significantly (P<0.05) higher while cortisol and blood glucose were decreased significantly (P<0.05) in pyridoxine‐fed groups. Percentage survival after challenge with Aeromonas hydrophila was highest in T₀ group. The results obtained in present study indicate that dietary pyridoxine supplementation at 100 mg PN kg^?1 diet reduces the endosulfan‐induced stress and triggers immune response in L. rohita fingerlings.     

Optimum timing of insecticide applications against diamondback moth Plutella xylostella in cole crops using threshold catches in sex pheromone traps

Field trials were conducted in cabbage (Brassica oleracea var capitata), cauliflower (B oleracea var botrytis) and knol khol (B oleracea gongylodes) crops at two different locations in Karnataka State (India) to optimize the timing of insecticide applications to control the diamondback moth, Plutella xylostella, using sex pheromone traps. Our results indicate that applications of cartap hydrochloride as insecticide during a 12–24 h period after the pheromone traps had caught on average 8, 12 and 16 males per trap per night in cabbage, cauliflower and knol khol, respectively, were significantly more effective than regular insecticide sprays at 7, 9, 12 or 15 days after transplantation. This was demonstrated by estimation of the mean number of eggs and larvae per plant, the percentage of holes produced, as well as the marketable yield of the three crops at each location. A good correlation between the immature stages, infestation level, the estimated crop yield and the number of moths caught in pheromone traps was also found, indicating the usefulness of pheromone‐based monitoring traps to predict population densities of the pest. © 2001 Society of Chemical Industry     

Controlled-environment and field evaluation of heat stress induced genetic variability on translocation efficiency and grain filling traits in rice

Journal of Crop Science and Biotechnology - The grain filling of rice is gets weakened by heat stress due to reduced spike photosynthesis at high temperature stress. An alternate source of carbon...