Abscition and fruit falling dinamics in grapes

Abstract

One of the most critical stages which determines the production and quality of grapes is flowering and fruit falling. There are cultivars of Vitis vinifera L. which have an excessive falling of flower sprouts as well as small fruits apparently filled. All these seems to be influenced by different varieties and climates where vineyards are exploited. In this work it is intended to know the dynamics of fruit falling in different positions of the plant, as well as the percentages of fruit settling in each case. Evaluations were made in the phenologic orchard of Universidad Autónoma Agraria Antonio Narro at Buenavista, Saltillo, Coahuila, Mexico, with wine cultivars as follows: Grenache, Palomino, French Colombard, Rubired and Alicante Bouschet. Bags were placed covering the grape clusters before calipters ́ detachment; fallen fruits were collected along the development stage of clusters which were finally cut in order to know the settling percentage of fruit. No statistical differences were found among cultivars as far as settling percentage is concerned, but differences (P<0.05) among positions were found, mainly for cluster height in a sprout, being settling percentage higher for the superior clusters. Cultivars F. Colombard and Rubired were the only ones which showed differences (P<0.05) among its respective positions for each one of them in the plant's branch.