Identification of Potential Bud Fertility Parameters of Grapevine Cultivars Bolgar and Mavrud in the Autumn-Winter Period

V. ROYCHEV and D. BRAYKOV
Agricultural University, BG-4000 Plovdiv, Bulgaria

Abstract

ROYCHEV, V. and D. BRAYKOV, 2001. Identification of potential bud fertility parameters of grapevine cultivars Bolgar and Mavrud in the autumn-winter period. Bulg. J. Agric. Sci., 7: 381-392

The parameters of potential bud fertility of cv. Bolgar and cv. Mavrud were identified in the period 1994-1997. It was established that necrosis of primary buds in the wintering eyes of the first variety is significant and should be always kept in mind when defining bud load and collecting cuttings for grafting. The potential coefficients and high percentage of fruitful wintering eyes make Bolgar a cultivar of good fertility. Grape yield is formed mainly from buds with initiated 2 and 1 racemes of 550 μm to 750 μm and 350 μm to 550 μm. Mixed pruning is mandatory, fruiting cane should be 9 buds long at least. Cv. Mavrud is characterized with low percentage of primary bud necrosis and good potential fruitfulness of wintering eyes. Grape yield is formed by the high percentage of fruit buds and mainly by initial shoots with 1 and 2 racemes. Good quality wine production requires to prune back knots and suckers.

Key words: buds, potential fertility coefficient, raceme dimensions, grapevine cultivars