Resumen

ZERMENO-GONZALEZ, A. et al. Effect of total white washing of apple tree on its internal temperature, fruit yield and its relation to use of thidiazuron. Rev. Chapingo Ser.Hortic [online]. 2009, vol.15, n.3, pp.289-296. ISSN 2007-4034.

This study was conducted during the 2004-2005 winter to analyze the effect of whitewashing (with calcium hydroxide) entire apple trees (Malus domestica Borkh) at the beginning of the winter season, on the branches and trunks internal temperature (under the bark), the accumulation of chill units (CU), its effect on fruit yield and quality and its relation to the use of thidiazuron (TDZ) to induce budbreak. The results of this study indicated that at the hours of highest incidence of solar radiation, total tree whitewashing decreased the internal temperature of the branches up to 4 ^oC and of the trunks up to 9 ^oC. The accumulated CU during the time of the study, calculated with the internal temperature of the whitewashed branches, were 27.9 % higher than those recorded on the branches with no whitewashing, while the CU lost at the hours of highest solar radiation were up to 37.2 % lower. Total whitewashing increased the yield per tree up to 20 % more than application of TDZ. No statistical difference in fruit quality parameters was observed between total whitewashing and the application of TDZ to induce budbreak.

Palabras llave : Malus domestica Borkh; chill units; whitewashing; calcium hydroxide; budbreak.