K. Nandini Devi

Critical Limits of Phosphorus in Relation to the Growth and Dry Matter Yield of French Bean (Phaseolus vulgaris L.) in Acid Soils of Thoubal District, Manipur (India)

Plants appear to face severe problems in getting phosphorus at early stage in their development. So, phosphorus deficiency symptoms most often occur in seedlings and young plants. Phosphorus is mobile within the plants and its translocation is from the older tissue to the growing points. This causes the deficiency symptoms appeared on the lower International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 7 Number 10 (2018) Journal homepage: http://www.ijcmas.com

Evaluation of Some Soil Test Methods for Available Phosphorus and Critical Level of French bean in Acid Soils of Thoubal District, Manipur (India)

Phosphorus is the second most important plant nutrient after nitrogen for agricultural production in most regions of the world. Phosphorus is used in the plant for energy storage and transfer, maintenance and transfer of genetic code and is structural component of cells and many biochemicals. Phosphorus deficiencies results in poor root growth, stunted top growth, reduced yield and crop quality along with delayed maturity (Mishra, 2012). In severe cases, phosphorus deficiency can cause yellowing and senescence of leaves. In many acidic soils in developing countries, phosphorus deficiency is the main limiting factor for crop production and therefore, requires the phosphorus fertilization for optimum plant growth and production of food and fibre (Attar, 2014). Phosphorus also reduces the harmful effect of excess nitrogen and imparts resistant to plant against disease. Supply of phosphorus to leguminous crops increase the numbers and size of root nodules and nitrogen fixing potentiality of Rhizobium, so it is essential for obtaining the higher yield of crop (Patil and Jadav, 1994).

Vertical Distribution of Micronutrient Cations in Imphal East and West District, Manipur (India)

Micronutrients play various important role in plant is well established. It plays an active role in plant metabolism i.e. cell wall development, respiration, photosynthesis, chlorophyll formation, enzyme activity, hormone synthesis, atmospheric nitrogen fixation, etc. The requirement of micronutrients for crop plants are relatively very small, however, if any deficiencies of it, the crop yield is drastically reduced. Micronutrients are very important for maintaining soil health and also increasing productivity of crops (Rattan et. al. 2009). However, exploitive nature of modern agriculture involving use of high analysis NPK fertilizers couple with limited use of organic manure and less recycling of crop residues are important factors contributing towards accelerated exhaustion of micronutrients from the soil (Sharma and Choudhary, 2007). Continuous negligence of micronutrient application and avoidance of organic manures are the major causes of International Journal of Current Microbiology and Applied Sciences ISSN: 2319-7706 Volume 7 Number 08 (2018) Journal homepage: http://www.ijcmas.com

Seasonal incidence of insect pests on soybean in relation to weather parameters

An experiment was carried out at ICAR Entomology Farm at Umaim, Meghalaya in kharif season during 2011with the aim to study seasonal incidence of insect pests on soybean (Glycine max (L.) Merrill).Six insects species, viz., stem fly (Ophiomyiaphaseoli Tryon), soybean leaf folder (NacoleiavulgalisGuen.), white spotted flea beetle (MonoleptasignataOliv.), jassids (EmpoascakerriPurthi), aphids (Aphis glycines Matsumura) and southern green stink bug (Nezaraviridula Linn.) were recorded. Among them stem fly and soybean leaf folder were found to be major pests.The population level of these insect pests was fully observed during 2nd week after sowing with a peak during July and August. Correlation studies indicated that only stem fly and soybean leaf folder were significantly correlated with abiotic factors viz., the minimum temperature and rainfall that favoured the development of stem fly whereas sunshine hours for the leaf folder.

Profile distribution of micronutrient cations in citrus orchard of Ukhrul district, Manipur (India)

Profile distribution of DTPA-extractable micronutrient cations (Zn, Cu, Fe and Mn) and their relationship with various soil properties were studied in eighteen profiles of citrus orchard of Ukhrul district of Manipur. The content of DTPA-extractable Zn, Cu, Fe and Mn were higher in surface horizons and decreased with depth in most of the profiles and ranged from 0.08 to 0.76, 0.01 to 0.34, 8.0 to 54.0 and 1.6 to 20.4 mg Kg−1, respectively. Surface horizons contain sufficient amount of DTPA-extractable micronutrient cations except Zn. Distribution of Mn was influenced positively with EC in the first (0–20 cm) and second layer (20–40 cm), Cu was influenced inversely by organic carbon and positively by EC, Zn was influenced positively with CEC and Fe was influenced by clay content of the soils. Multiple regression analysis indicated that DTPA-extractable Zn, Cu, Fe and Mn were influenced by CEC, EC, clay and EC to the level of 0.25, 0.63, 0.25 and 0.41, respectively. However, only clay and EC contributed significantly towards these nutrient cations.