Resumo:
Grafted young coffee trees were observed in a greenhouse to study the effect of different scions and rootstocks on plant growth. Four Coffea arabica L. genotypes were used as scions: the cultivars Catuaí Vermelho IAC 15 and Oeiras MG 6851, and the progenies H 419-10-3-1-5 and H 514-5-5-3. They were also used as nongrafted control plants. Four genotypes were used as rootstocks: ‘Apoatã IAC 2258’ (C. canephora), ‘Conillon’ (C. canephora), ‘Emcapa 8141’ (C. canephora), and ‘Mundo Novo IAC 376-4’ (C. arabica). ‘Mundo Novo IAC 376-4’ and ‘Apoatã IAC 2258’ were classified as good rootstocks, while ‘Oeiras MG 6851’ and “H 419- 10-3-1-5” performed well as non-grafted plants. The diallel analysis statistical model was efficient to evaluate the general combination ability of the rootstocks and, therefore, recommended for rootstock selection procedures in breeding programs.