IMPROVEMENT OF APPLE AND PEAR PRODUCTIVITY BY UREA SPRAY UNDER TEMPERATURE STRESS CONDITIONS

S. Zilkah, I. David, Y. Yeselson, S. Shamian, H. Hupert, O. Ribak
Influence of canopy applied urea (low-biuret) on bud break, yield and fruit size of 'Golden Delicious' apple and 'Spadona' pear has been studied for 3 years (1994–1996). Urea has been compared to the bud dormancy breaking chemical DNOC that commonly used in those species. Spray timing at beginning of green bud swell. In 1994, under climatic conditions of insufficient accumulation of chilling units in winter and high-temperatures in early spring, 8% urea treatment advanced the initial bud break, elevated total number of reproductive buds and significantly increased yield by 48% over the untreated apple controls. In spite the increased yield, average fruit size was not reduced. At same year, in pear, urea did not affect bud break, but increased yield by 65% over the controls. Improved productivity in pear could be attributed to the protective effect of urea that reduced fruit abscission under high temperature stress. In non-problematic environmental conditions (1995, 1996), such an urea effect has not been clearly shown.
Zilkah, S., David, I., Yeselson, Y., Shamian, S., Hupert, H. and Ribak, O. (1998). IMPROVEMENT OF APPLE AND PEAR PRODUCTIVITY BY UREA SPRAY UNDER TEMPERATURE STRESS CONDITIONS. Acta Hortic. 463, 279-286
DOI: 10.17660/ActaHortic.1998.463.34
https://doi.org/10.17660/ActaHortic.1998.463.34
Bud break, dormancy, Malus sylvestris, nitrogen, nutrition, Pyrus communis

Acta Horticulturae