The objective of this work was to evaluate the effect of the amount of rainfall on nutrition status and the fruit yield of the orange 'Valencia' according to rates of applied N. The orange grove was planted in 1994, in a Typic Haplorthox (Rhodic Ferralsol), on Cfa climate with rainy season from November to March, northwestern Paraná, Brazil. The experimental design was of random blocks with four replicates. Four N rates, 30, 100, 170 and 240 kg ha-1, were assessed in two periods: smaller amount of rainfall (first fortnight of August, first fortnight of October and second fortnight of March) and larger amount of rainfall (second fortnight of September and November, and first fortnight of February). In the 1999/2000 and 2001/2002 season, fruit yield and leaf N were evaluated. The absorption of N is not enough for the fruit yield at the period of smaller amount of rainfall. The appropriate nutrition and fruit yield of orange with reduction of the rate of applied N is obtained on the period of lager amount of rainfall. Nitrogen fertilization must be divided into three times, between September 15 and February 15, coinciding with the rainy season.
Citrus sinensis; nutritional status; fertilization period
