Differential response of short‐ and long‐duration cassava cultivars to applied mineral nitrogen |
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| Authors: | G Byju M Haripriya Anand |
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| Institution: | Central Tuber Crops Research Institute, Sreekariyam, Thiruvananthapuram 695 017, Kerala, India |
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| Abstract: | The differential response of two contrasting cassava cultivars to different rates of soil‐applied nitrogen (N) on the number of tuberous roots, harvest index, yield, nitrogen uptake, and fertilizer‐nitrogen‐use efficiency was studied over a period of 2 years on a typic Plinthustults in Kerala state in Southern India. The experiment was laid out in a split‐plot design with two popular cultivars of cassava, namely Sree Vijaya (6 months) and M‐4 (10 months) in the main plots, and eight urea‐N rates (0, 12.5, 25, 50, 75, 100, 150, and 200 kg ha–1) in subplots. Half of the N was applied at the time of planting and the other half 60 d later. The study revealed significant differences between the two cultivars regarding their response to fertilizer‐N application. The tuberous‐root yield of the short‐duration cultivar Sree Vijaya increased significantly up to 100 kg N ha–1 whereas the yield of the long‐duration cultivar M‐4 increased significantly only up to 50 kg N ha–1 rate. Also the N‐use‐efficiency parameters (i.e., agronomic, recovery, and physiological efficiencies) were higher in Sree Vijaya than in M‐4 but declined at N rates beyond 100 kg ha–1. The more efficient N use in the short‐duration cultivar was associated with a higher N uptake and a more efficient internal use. |
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| Keywords: | India Kerala Manihot esculenta nitrogen‐use efficiency Ultisols |
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