EFFECT OF MYCORRHIZAL INOCULATION AND DIFFERENT PRUNING REGIMES ON FRESH ROOT YIELD OF ALLEY AND SOLE CROPPED CASSAVA (MANIHOT ESCULENTA CRANTZ) IN NIGERIA

摘要

The effect of mycoirhizal fungus inoculation on fresh root yield of cassava (Manhot esculenta crantz) cv TMS 4 (2) 1425 as influenced by two hedgerow tree species and their mixtures, subjected to two-and three-months prunning regimes were investigated in alley cropping experiments at three different sites within the same eco-climatic region in Nigeria.Mixture of the prunings of the two hedgerow tree species (Gliricidia sepium and Senna siamea) with mycorrhiza gave higher fresh root yield than the sole hedgerow tree with mycorrhizal inoculation. Gliricidia sepium prunings were found to give higher fresh root yield than the prunings from the Senna siamea. The 2-month prunings of G. sepium recorded higher yield than its 3-month prunings while 2-month prunings of Senna siamea recorded higher yield than its 3-month prunings. However, mycorrhiza inoculation with 2-and 3-months prunings in the two hedgerow species used were found higher than their counterparts without mycorrhizal inoculation in all the three sites. Mycorrhizal inoculation without the hedgerow prunings recorded the lowest fresh root yield but was still higher than the fresh root yield from the sole without mycorrhizal inoculation. Thus, inoculation with mycorrhiza increased alley-cropped cassava fresh root yield over uninoculated plants under both pruning regimes. Generally, this study shows that inoculation of cassava with mycorrhiza alone without mulching with prunings significantly increased cassava fresh root yield.