Performance of Two Very Early-Season Clementines, 'Clemenrubi' and 'Orogros' Mandarins on Three Rootstocks in Spain: Yield and Quality Study

The yield and fruit quality performances of Clemenrubi and Orogros mandarins were evaluated in the Mediterranean climate of Valencia, Spain, from 2009 to 2016. The cumulative yields and tree growth of both varieties' mandarins over this 8-year production period were lower in Clemenrubi. Fruit size was affected by the rootstock being the control rootstock (CC), which induced the smallest fruit, although yield efficiency and alternate bearing behaviour were not affected. Although C-35 was highlighted for delaying fruit maturity (lower RI and CI indices), no significant differences in TSS were obtained compared to the other rootstocks. CC also presented strong granulation disorder and C-35 the highest tree mortality. In conclusion, all the rootstocks for Clemenrubi and Orogros mandarins gave good fruit quality for fresh fruit markets in the eastern Mediterranean region. Nevertheless, long-term studies are needed to determine the exact effects of multibud galls on tree survival and the granulation problem on the CC fruit.