Results of eight field experiments carried out in irrigated areas of the Submédio São Francisco River Valley, Northeast Brazil, from 1988 to 1993, were statistically analysed to evaluate the response of processing tomato (Lycopersicon esculentum, Mill) to phosphorus fertiliser, in soils with different available phosphorus contents by the methods of Mehlich - 1 or Bray - 1. The analysis showed that in soils where available P content was equal to or lower than 2 mg.dm-3, the mean increment in tomato yield due to P fertilisation was 190.8%, while in soils where the P content was 8 mg/dm³, the increment was only 21.7%. However, in soils with P content equal or higher than 14 mg dm-3, there was no response of the tomato crop to phosphorus fertilisation. In the two experiments where a quadratic response was observed, the maximum economical yields of 56.47 and 69.35 ton. ha-1 of tomatoes were obtained with 143 and 182 kg.ha-1 of P2O5, respectively.
Lycopersicon esculentum; irrigation; fertilisation; soil phosphorus; residual phosphorus
