Changes in Potential Yield Parameters of the Grapevine Cultivars Bolgar and Mavroud over the Growing Season

D. BRAIKOV and V. ROICHEV
Agricultural University, BG-4000 Plovdiv, Bulgaria

Abstract

BRAIKOV, D. and V. ROICHEV, 2002. Changes in the potential yield parameters of the grapevine cultivars Bolgar and Mavroud over the growing season. Bulg. J. Agric. Sci., 8: 527–532

Particular dynamics and development aspects were examined in the potential yield parameters of wintering eyes at the 5th node of grapevine scions cv. Bolgar and Mavroud. The specific feature found in the parameters of potential yield coefficient consisted in the earlier attaining of peak values in cv. Bolgar than in cv. Mavroud. The primordial shoots, leaflets and first inflorescences in the wintering eyes formed at the same time in both cultivars, while the second inflorescences were set at a later time in cv. Mavroud. The dynamics of change in the inflorescence number in both cultivars followed similar pattern. The percentage of the smallest, up to 350 μm long inflorescences tended to decrease over the period and thus their share in the cultivar productivity was negligible. However, the changes in the number of inflorescence up to 550 μm and 750 μm long produced a parabolic curve, while the largest ones exceeding 750 μm, grew continually till the end of the growing season. The yield of the first variety will be formed mainly by the larger inflorescences over 750 μm in length, and in the second one – by those up to 550 μm and 750 μm long.

Key words: potential yield parameters, primordial inflorescence and wintering eyes sizes, dynamics of their development over the growing season, grapevine cultivars