Resumen

ZERMENO, Alejandro et al. Effect of the entire whitewashing and TDZ application on budbreak, yield and quality of apple cv. Golden Delicious. Bioagro [online]. 2010, vol.22, n.1, pp.75-80. ISSN 1316-3361.

The apple production in northern Mexico shows problems related to the occurrence during the winter time of sunny and warm days followed by cold nights; those temperature fluctuations have a negative effect in the bud dormancy that results in a late bud break, lack of uniformity, bud detachment, and abort of embryos. The objective of this research was to analyze the effect of whitewashing (with calcium hydroxide) of entire apple trees (Malus domestica Borkh), at the beginning of the winter season, on vegetative and floral bud break, fruit yield and quality, and its relationship to the use of thidiazuron (TDZ) as bud break promoter. The study was conducted during the winter of 2005-2006, in an apple orchard cv. Golden delicious of nine year-old at Jame, Arteaga County, Coahuila State, Mexico. The vegetative budbreak of the whitewashed trees was 25 % higher than those of the control treatment and 21 % more than  the trees receiving TDZ .The combined use of whitewash and TDZ retarded floral bud break as compared to the control tress (no whitewashing, no TDZ). Likewise, such a combination did not improve floral budbreak. The whitewashing increased up to 27 % the fruit yield per tree as compared to the application of TDZ. No statistical differences in the variables of fruit quality were observed between whitewashing and the application of TDZ.

Palabras clave : Malus domestica; chill units; lime; plant growth regulators.