Chlorophyll Content, Dry Matter Accumulation, Marketable Bulb Yield, Quality and Post Harvest Nutrients Status of Soil as Affected with N Levels and Varieties in Kharif Onion (Allium cepa L.)

The present experiment was conducted with the objectives: (i) To evaluate the performance of onion varieties (ii) To study the effect of N levels (iii) To find out the interactive effect of varieties and N levels on chlorophyll content, dry matter accumulation, marketable bulb yield, quality and post-harvest available NPK content in soil. Field experiment was conducted during kharif 2011-12 at Research field, Department of Vegetable Science, College of Horticulture, Mandsaur a campus of Rajmata Vijayaraje Scindia Krishi Vishwa Vidyalaya, Gwalior (Madhya Pradesh), India. Fifteen treatment combinations comprising of three varieties (V1 - Agrifound Dark Red, V2 - Bhima Super, V3 - Bhima Red) and five N levels (N1- 0 kg ha-1, N2 - 60 kg ha-1, N3 - 90 kg ha-1, N4 - 120 kg ha-1 and N5 - 150 kg ha-1) were laid in factorial randomized block design with three replications. Uniform doses of P (80 kg ha-1) and K (60 kg ha-1) were applied in each plot of the experiment. N doses (0, 60, 90, 120 and 150 kg ha-1) were applied to the plots as per the treatment. The sources of nutrients viz., N, P and K were Urea, Single Superphosphate and Muriate of Potash, respectively. Half dose of N and whole dose of P and K were applied as basal dose before transplanting of seedlings. While the remaining half dose of N was applied in 2 equal split doses, first at 30 and second at 45 days after transplanting. The findings of the experiment revealed significant effect of varieties and N levels on chlorophyll content in leaves, dry matter accumulation, marketable bulb yield and pyruvic acid content in bulb and post-harvest nutrients status of soil and NPK content in plant. However, interactive effect of varieties and nitrogen levels was non-significant on marketable bulb yield, post-harvest available K content in soil. Highest chlorophyll content, dry weight of bulb and marketable bulb yield were recorded with Agrifound Dark Red. Variety Bhima Super had highest pyruvic acid content and lowest number of doubles. Post-harvest analysis of plant showed highest NPK content with Agrifound Dark Red. Post-harvest analysis of soil indicated highest available NPK under Bhima Super. Among N levels, highest chlorophyll content, dry weight of bulb, number of doubles, marketable bulb yield, pyruvic acid content in bulb and NPK content in plant were found with application of 150 kg N ha-1. Highest available N in soil was determined with 150 kg N ha-1. Highest P and K were found with 0 kg N ha-1.