Impact of organic nutrient management practices on growth dynamics and economics of short-duration cassava (Manihot esculenta crantz.)

A series of field experiments were conducted at the Tapioca and Castor Research Station (TCRS), Tamil Nadu Agricultural University, Yethapur, Salem from 2022 to 2023. The purpose was to investigate the growth dynamics and economics of shortduration cassava under different nutrient management practices including both integrated and organic approaches.

Twelve treatments were carried out consisting of various combinations of organic manures, liquid organic foliar sprays, integrated nutrient management treatments and a control treatment (no manures/fertilizers/sprays). The experiments were carried out in a randomized block design (RBD) with three replications at the same location.

The results revealed that the different nutrient management practices had a significant impact on the physiological response throughout the various stages of plant growth. Based on the average data from two experiments, the INM treatment (FYM@ 25 t ha^-1 + 100% recommended dose of fertilizers andcassava booster spray) showed the highest physiological response during the final phase of growth. This treatment showed superior performance in terms of leaf area index (LAI), crop growth rate (CGR), relative growth rate (RGR), net assimilation rate (NAR), tuber bulking rate (TBR) and mean TBR. The organic treatment (wood ash @2 t ha^-1 and 3% panchagavya foliar spray) recorded comparable performance to the INM treatment in major parameters such as LAI, CGR, RGR and NAR. However, it followed the INM treatment in terms of mean TBR. Economic analysis revealed that the INM treatment yielded the highest net income and benefit-cost ratio (BCR), followed by the organic treatment. The control resulted in the least returns. In conclusion, the findings highlight the effectiveness of the INM treatment and the promising performance of the organic treatment which can contribute to sustainable and profitable cassava cultivation.