THE INFLUENCE OF IRRIGATION CUT-OFF TIME ON THE YIELD AND QUALITY OF PROCESSING TOMATOES

Water management during the growth and ripening of tomato fruit can affect crop yield and quality. This study was conducted in the Ribera region of Navarra (Spain) on tomatoes grown for paste production using drip irrigation and plastic covering. The objective of the study was to manipulate irrigation cut-off during the last stage of crop development, to maximise commercial yield without affecting the processing quality of the fruit. This paper describes results from a field experiment, carried out in the 2001 season using the Perfectpeel variety. All plots were irrigated at 100% crop evapotranspiration (ETc) until cut-off treatments were applied 6, 5, 4, 3, 2, and 1 week before harvest. The state of maturity was defined for the dates on which cut-off took place so as to analyse ripening progress in the different control plots and later determine total and commercial yield, as well as other industrial quality parameters. While yield was not affected significantly by cutting off irrigation earlier, the fruit were considered better in terms of harvest grouping and quality when irrigation was cut off at the beginning of the ripening process.