Fertilizer Management of minor tuber crops in Coconut based cropping system

Abstract

An investigation was carried out to evolve the fertilizer management practices of minor tuber crops in coconut based cropping systems during the years 1985-86 and 1986-87. This investigation was carried out as two experiments. In experiment I, screening of minor tuber crops under varying intensities of shade was done adopting a split plot design with 4 replications. In experiment II the fertilizer management of minor tuber crops in coconut based cropping system was studied. The experiment II was conducted in randomised block design with 3 replications. While experiment I was taken up at the Instructional Farm, College of Agriculture, Vellayani, experiment II was conducted at Coconut Research Station, Balaramapuram. Shade had significant influence on the length of vine/height of plant, LAI, NAR, CGR, dry matter production chlorophyll content of leaves, starch and protein content of tubers and yield of tuber of greater yam, lesser yam, tannia and elephant footyam. With increase in shade intensity, the yield declined proportionately in greater yam and elephant footyam reocrding highest yield under open condition. The tuber yield of lesser yam under open and 25 per cent shade levels were statistically on par, beyond which a drastic reduction in yield was observed with increase in shade intensity. Tannia recorded highest yields under 25 per cent shade, with an almost equal yield under 50 per cent shade. Fertilizer levels did not significantly influence the growth and yield characters of lesser yam, elephant footyam and tannia. But for greater yam there was significant increase in plant height in the first year and tuber yield in the second year with increase in fertilizer level. Greater yam responded linearly to fertilizer levels recording maximum yield with full recommended dose of fertilizer, although the variation was significant only in the second year. Lesser yam had maximum yield at medium fertilizer level and elephant footyam at lowest level, though not significant. The general performance of tannia was very poor. The economics worked out for the fertilizer management practices of greater yam, lesser yam, tannia and elephant footyam revealed that among the four crops tried, elephant footyam gave the maximum net profit followed by greater yam and lesser yam. However, tannia resulted in a loss.