Jl. Petri, INDUCTION OF APPLE TREE BUDDING BY HYDROG ENATED CYANAMIDE AND MINERAL-OIL UNDER INFLUENCE OF TEMPERATURE, Pesquisa agropecuaria brasileira, 32(1), 1997, pp. 71-75
Dormancy breaking in apple (Malus domestica B.) orchards with chemical
s is a very common practice in regions with mild winter. When mineral
oil and dinitro-ortho-cresol (DNOC) are recommended, they are used at
temperatures above 20 degrees C. The effect of other temperatures on t
he efficiency of hydrogenated cyanamide and mineral oil is not known.
In this work the effect of temperature on hidrogenated cyanamide and m
ineral oil on dormancy breaking of apple trees was evaluated. Apple sc
ions of cultivars Gala and Fuji received a treatment with mineral oil
at 4% plus hydrogenated cyanamide at 0.25% and were submitted to diffe
rent combinations of temperature before and after having received the
chemical treatment. The trial was carried out during three years. Perc
entage of bud breaking was evaluated at 40 and 60 days after treatment
s were performed. This breakage strongly increased when mineral oil tr
eatment (4%) and hydrogen cyanamide (0.25%) were used. Temperatures of
4 degrees C three days before or after application did not reduce the
efficiency of mineral oil plus hydrogenated cyanamide. This aspect al
lows concluding that the efficiency of mineral oil plus hydrogenated c
yanamide is not related to the temperature.