Performance of Wheat as a Relay Crop with Transplanted Aman Rice at Different Dates of Sowing and Control of Leaf Blotch Organism Bipolaris Sorokiniana by Biocides

Abstract

The experiment was conducted at the experimental field of Agrotechnology Discipline of Khulna University during Rabi Season, 2005 to study the appropriate time of sowing for wheat in relay cropping system with Transplanted Aman (T. aman) rice and also the performance of wheat as a relay crop in Khulna region. The experiment was laid out in Randomized Complete Block Design (RCBD). There were five different dates of sowing (22 November, 30 November, 8 December, 16 December and 24 December, 2005) as treatment with three replications. The data of plant height (cm), panicle length (cm), number of grain panicle⁻¹, thousand grain weight (g), grain yields (t ha⁻¹), biological yield (t ha⁻¹) and harvest index (%) were collected. The different dates of sowing had significant effect on plant height (cm), panicle length (cm), number of grain panicle⁻¹, thousand grain weight (g), grain yield (t ha⁻¹) biological yield (t ha⁻¹) and harvest index (%). The longest plant height, panicle length, the highest number of grain per panicle, grain yield (t ha⁻¹), and biological yield (t ha⁻¹) were found in 22ⁿᵈ November sowing. But the harvest index (%) was highest in 24ᵗʰ December sowing and 1000-grain weight (g) was highest in 30ᵗʰ December sowing. The lowest plant height (cm), number of grain per panicle, grain yield (t ha⁻¹) and biological yield (t ha⁻¹) were found in 24ᵗʰ December sowing. But the harvest index (%) was lowest in 30ᵗʰ December sowing and panicle length was lowest in 8ᵗʰ December sowing. Depending on the first experiment another experiment was conducted in the Plant protection Laboratory at Agrotechnology Discipline of Khulna University to evaluate the effect of different plants extracts namely rhizome of ginger, rhizome of turmeric, garlic bulb, neem leaf, nishindha leaf, datura leaf, marigold leaf, tobacco leaf, banyan leaf and cows urine at different concentrations (20%, 30%, 40%, 50%, 60%, and 70%) on the mycelia growth and formation of spore of Bipolaris sorokiniana, causal agent of leaf blotch disease of wheat. The experiment was conducted in Completely Randomized Design (CRD) with five replications. Mycelial growth and formation of spore of B. sorokiniana were recorded. Mycelial growth inhibition percentage was calculated thereafter. In all the cases, the mycelial growth inhibition percentage was found to be increased with the increase of concentration of all the treatments. Highest mycelial growth inhibition percentage was observed in case of tobacco leaf in cow’s urine (100%), tobacco leaf and banyan leaf in cow’s urine for 24 hours (100%), tobacco leaf and banyan leaf in cow’s urine for 7 (seven) days (100%) and cow’s urine (100%) at 70% concentration. In the case of 60% and 50% concentration the highest mycelial growth inhibition percentage (100%) was found in tobacco leaf and banyan leaf in cow’s urine for 7 (seven) days (100%). The highest mycelial growth inhibition percentage (86.62%) was found in case of 40% concentration in tobacco leaf in cow’s urine, in 30% concentration the highest growth inhibition (70.07%) was found in cow’s urine and in 20% concentration the highest growth inhibition (64.62%) was found in turmeric rhizome extracts. In all the cases the number of spore production was zero in all the concentration of cow’s urine and tobacco leaf and banyan leaf in cow’s urine for 7 (seven) days. The number of spore production was high at lower concentration of all the treatment and the mycelial growth inhibition percentage was higher at the higher concentration of all the treatment.