ISHS Acta Horticulturae 199: II International Workshop on Temperate Zone Fruits in the Tropics and Subtropics
APPLES AND PEACHES IN TROPICAL LOWLANDS OF THE PHILIPPINES |
| Authors: | R. Llanes, E. Otomo, R.A. De Las Alas, G.R. Edwards |
| Abstract:
The feasibility study of apple, peach and nectarine cultivars in the highlands (Hermano et al., p.) was repeated at five lowland sites - Cuyapo, near Tarlac 15°30'N, Newtown, near Manila 14°35'N, Silang 14°14'N in Luzon and at 2 sites near General Santos, 6°07'N in Mindanao. The same approach was utilized namely:-
Close spacing, 3m x 1m, growth restriction, defoliation, branch bending and chemical dormancy - break treatments were combined. For apples, the Indonesian system of bi-annual defoliation and bending of long shoots produced similar results at all lowland sites as in the highland site at Baguio. There was little difference in growth periodicity and the same cultivar differences occured at all sites. The third growth cycle was induced by the second defoliation 10 months after planting. At the best managed site thirty plants of c.v. Beverly Hills carried 143 partly grown fruit 12 months after planting. H2CN2 (Alzodef) at 2% a.i. was effective in forcing buds which failed to burst following defoliation. Mg (C103)2 (Mag 40) at 0.76%a.i. caused partial defoliation. In contrast to apples, peaches showed quite remarkable differences between lowland sites and between lowland and highland. At all sites vegetative growth was extremely vigorous. At the hottest site growth continued unabated for 10 months, flower bud formation was minimal and growth retardation with PP333 was spectacular. At cooler lowland sites growth cessation did occur naturally but was hastened by PP333. Flower buds formed on laterals which ceased elongation. Bud-burst following hand defoliation was high, leaves preceded and exceeded flowers which were adequate but sparse and confined to sub-terminal positions. Dormancy breaking treatments had only slight effects. Flowers appeared normal, set fruit initially, but these were not retained. Only one fruit matured on the many cultivars compared at 5 lowland sites. This was half size, highly coloured and flavoured but partheno carpic. Mg (C103)2 0.76% a.i. defoliated mature leaves. A third growth cycle and second crop of flowers was induced within 12 months of planting. Ratooning was very effective in tree replacement. Fruit set is the limiting factor. | |
