Relationship between production of 'Baianinha' sweet orange trees, age and monthly rainfalls at the plateau of Botucatu, Brazil

Abstract

This paper deals with the existence of empirical relationship between the production of a sweet orange orchard planted at the plateau of Botucatu, SP, Brazil, with the orchard age and rainfalls that occurred before the picking season. The plants were of sweet orange 'Baianinha' variety, budded on 'Rangpur' lime (Citrus limonia Osbeck) rootstock, planted on "Terra Roxa Estruturada" soil, at an altitude of 810 m above sea level, where the climatic type Cwb, according to the Koppen climatic classification, occurs. The orchard was conducted by conventional ways and no irrigation was applied. The production of the crop was correlated with the age of the orchard and with rainfalls that occurred in the sixteen months before the picking season. Regression equations involving one or more values of rainfall were estimated. These equations could explain up to 82% of the orange yield variation. They showed that yield forecasting could be done at the anthesis and at the fruitset.