There is a worldwide tendency for planting apples at high density system onto the so called dwarf apple rootstocks, which have a strong effect on controlling the vigor of the trees. The most used is the M-9 due to its efficiency on vigor control, precocity of flowering, high productivity and also good fruit quality it induces to the scion varieties. In South of Brazil more vigorous rootstocks, as MM-106, M-7 and MM-111, have been widely used because worldwide tradition, lower initial cost as they require less trees/ha, and their facility of propagation The objective of this work was to compare the dwarf M-9 with the semi-dwarf M-7 and the semi-vigorous MM-111 concerned to vigor control, precocity of flowering, productivity and fruit quality of the apple cultivar Fuji. The statistical design was on completely randomized blocks, with 4 replications of three trees on each plot. The main cultivar was Fuji, pollinated by cv. Gala. The experiment was established in 1996 in Fraiburgo, the main apple producer area in the country. The layout of planting was 2,0 m within row by 5,0 m between rows. The study was carried out for four years. The parameters evaluated were precocity (n0 of flower buds per cm² of trunk cross sectional area), production (kg/tree), productivity (t/ha), fruit weigh (g) and distribution of fruit size (%). The results obtained on the 3rd season showed that M-9 was the most precocious, producing 1.94 times more flower buds per cm² of trunk cross sectional area than on M-7 and 2.7 times more than on MM-111. Concerned to production on 3rd season, M-9 produced 2.5 times more than M-7 and 2.7 times more than MM-111. On the 4th season M-9 produced 1.28 times more than M-7 and 1.26 times more than MM-111 (Table 2). The fruit weight was 159,2 g, 135,5 g and 131,2 g for M-9, M-7 and MM-111, respectively. In terms of distribution of fruit weight, M-9 produced 90,8% of fruits In the class > 62 mm, against 79,5% on M-7 and 70,9% on MM-111, showing that M-9 is not only the most precocious, but it is also the most productive and produces fruits of larger size than M-7 and MM-111.
Vigor; precocity; productivity; fruit size
