Evaluation of manihot glaziovii scion-cassava understock grafting for cassava growth and root yield during rainy and dry seasons

ABSTRACT Grafting of cassava (Manihot esculenta Crantz) understocks with scions from Manihot glaziovii was proposed to improve the cassava root yield and as a temporal approach to overcoming the problem of cassava mosaic disease (CMD). This work compared performance of nongrafted KU50 with M. esculenta grafted as understock with M. glaziovii, KU50 or HB80 scions. KU50 and HB80 are released M. esculenta varieties. Work was conducted in the field using a randomized complete block design (RCBD) with four replicates in two seasons (rainy and dry seasons) in Thailand. The M. glaziovii grafted plants were larger than nongrafted controls. Grafting also increased fresh root yield by 25% (dry season) and 37% (rainy season) and dry matter content by 19% (dry season) and 42% (rainy season) over the nongrafted controls. Net photosynthesis (Pn), stomatal conductance (gs) and growth parameters indicated that the grafted plants had a higher photosynthetic capacity and more vigorous growth than nongrafted controls during the dry season. Correlation coefficients of Pn and gs with growth and productivity parameters at different ages of the plant were highly significant during the dry season but not in the rainy season. This study demonstrated that M. glaziovii–cassava grafting improved cassava growth and root yield.