Abstract

Field experiment was conducted at Tamil nadu Agricultural University, coimbatore during 1986-87 to evaluate the performance of multi-tier crop combinations under rainfed conditions. The results revealed that the physiological parameters viz., Net Assimilation Rate, Relative Growth Rate and Crop Growth Rate were more influenced by nitrogen levels than by crop combinations. Introduction of tall third tier crop was not found to be advantageous because of completion for resources particularly moisture, which was reflected in plant water relations. The highest yield in terms of cotton equivalent was recorded in cotton + redgram, the major contributing factors being the negative temperature differential, reduced transpiration rate and high temperature water content. The fertilizer level of 60-30-0 kg NPK / ha was found optimum.

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