Longitudinal Growth Curve of Elephant Foot Yam under Extreme Stress and Plant Sensitivity III

Abstract

We investigate yield of Elephant-foot-yam with seed weight, plant height, canopy radius and girth at the top of stem as main variables in three dimensional studies on proliferation rate. Studies on plant sensitivity under extreme stress and minimal survival environment in yam growth experiments to maximise yield were undertaken in Dasgupta (2017a). Detaching underground yam around four and half month from sprouting for plants with seed weight 800 g, and replanting the remaining stem structure with some roots attached to it and continue experiment till final harvest on maturity, was seen to have significantly increasing effect in two stage harvest, when only a few irrigations were given in the peak summer temperature and little manure was administered at start. We compute proliferation rates modifying a technique of Dasgupta (2015). We consider weighted average of raw rates on proliferation, estimated at a time point with smooth weight function that down weights rates from distant points. Variations of proliferation rates with seed weight in continuous scale over time indicates that plants with seed weight 500 g, if properly nourished to have an extended lifetime, could have produced much higher yield than observed in the experiment, as the proliferation rate is high towards the end of lifetime; in contrast to downward trend of rates towards zero over time in plants with higher seed weights. Plant height, girth at the top of stem and canopy radius may also provide information on growth status in three dimensional figures, in place of seed weight of yam.