Yield components of the new seedless table grape ‘BRS Ísis’ as affected by the rootstock under semi-arid tropical conditions

Abstract

The new seedless table grape cultivar BRS Ísis has high bud fertility, yield and tolerance to downy mildew; its planted area is rapidly increasing in the Vale do São Francisco region in the Northeast of Brazil. The aims of the present study were to evaluate the yield performance, yield components, physical and chemical characteristics of the fruit of the cultivar BRS Ísis grafted onto different rootstocks in irrigated growing in the semi-arid region of Brazil. The experiment was conducted in a commercial vineyard in Petrolina, Pernambuco, over six production cycles in the period 2015-2018. The treatments were represented by the rootstocks IAC 572, IAC 766, IAC 313, Freedom, Harmony, Paulsen 1103, and SO4 in a randomized block design with four replications. There was a greater effect of the production cycle than of the rootstock on all the variables studied, with significant differences between rootstocks in some cycles and/or in the overall mean of the production cycles. Mean production of the six cycles was greatest for IAC 572, at 27 Kg (45 ton/ha/cycle) and 100 clusters per grapevine. The physical characteristics of the clusters and berries and chemical composition of the grape achieved the standards described for the cultivar BRS Ísis and market demands for all the rootstocks.