Response of Peach [Prunus persica (L.) Batsch] Trees Composed by Two Cultivars in An Environmental of Frost Incidence: Bloom and Fruit Set and Fruit Set
In Mexico, the frosts matching with the blooming and fruit set of peach plants [Prunus persica (L.) Batsch] affect their productivity; nevertheless the use of early cultivars grafted on late ones (bi-cultivar composition) can reduce the frost damages on flowers and fruits, unlike early unicultivar trees alternated with late cultivars. Because of this, two early (CP-Precoz and Puebla) and two late (Supremo and Zacatecas) peach cultivars were evaluated regarding their tree cultivar composition and their fertilization (NPK and poultry manure) during the blooming and fruit set in an environments with recurrent frost. The study was carried out in the Campo Experimental Valle México (Experimental Field in Mexico Valley) during 2005, and in the winters of 2011 and 2012 blooming and fruit set were evaluated again. When using the bi-cultivar tree blooming was delayed 8 d in Supremo, as compared with the unicultivar one. When using 90-30-90 g fertilization formula (N-P2O5-K2O) per tree per year blooming was delayed 12 d. Supremo as inter-stock increased 15.3 % anthesis of early varieties, with a higher effect in the CP-Precoz with 3 kg poultry manure per tree and per year. In Puebla the first and last bloom were delayed 16 to 22 d, and the end of the blooming period was further delayed 22 d. In CPPrecoz the last bloom was delayed 5 d. With the exception of the Zacatecas cultivar, all treatments increased and delayed blooming, and increased fruit-set when submitted to peaches of the bi-cultivar composition, suggesting that this practice is helpful in reducing frost damage.