Study of alternate bearing in 'Salustiana' orange [Citrus sinensis ( L).OSB.] in different productive situations

Abstract

The behavior of' Salustiana' orange was studied during three years in Spain and Uruguay in order to evaluate its alternate bearing. Irrigated adult trees in production grafted on sour orange and trifolia were used in Spain and Uruguay respectively. Sprouting and flowering increased in the flush of growth after year oflow production, with an increase in the percentage of multi or single inflorescences in the Spain trial; the flowering density showed an alternate pattern, with minimum values of 2.4 and maximum of 40 flowers every 100 nodes. Nevertheless, the number of harvested fruits and yield did not follow the same pattern, reaching 282 and 345 fruits per tree respectively. In Uruguay, sprouting and flowering did not show a defined pattern in two plots with different productivity, even though flowering density was always higher in Paysandú compared with Montevideo. This higher flower density did not result in a larger number offruits harvested, which suggest the existence of some kind of regulative mechanism during fruit set, being the sequence of yields one year oflow and two consecutive of high productivity in both conditions. According to the results, no typical alternate bearing was registered in 'Salustiana' , specially in the Uruguayan conditions.