Effect of irrigation and potassium application in melon (Cucumis melo L.) production. II: Quality

The influence of different watering regimes and of potassium applications on the quality of the melon cultivar «Pielde Sapo» was studied over a two-year period (1995 and 1996). The statistical design was a split-plot with four replications,where irrigation was the main factor and applied potassium was the secondary factor. Water levels were determinedaccording to the watering needs (NRc) calculated on the basis of crop evapotranspiration. Four irrigationtreatments were tested: 1.25 NRc; 1.00 NRc; 0.75 NRc and 0.50 NRc. Two potassium treatments were applied: K0 (0UF) and K1 (375 UF K2O in 1995 and 2 L ha–1 of a commercial product for spraying 20% of K2O in 1996). The potassiumdoses tested did not significantly influence any of the quality parameters studied except for flesh firmness inthe placenta area in 1995. Both in 1995 and 1996, the water deficit significantly reduced fruit size and flesh thickness.The severe water restriction caused a strict decrease in the percentage of fruits with recorded weight above 2.5kg. However, the weight percentage of the placenta plus the seeds in relation to the whole fruit, and the sugar content,both increased significantly in water deficient treatments. In 1995, skin thickness decreased with less irrigation whileflesh firmness increased. Following quality concerns, and in order to obtain large fruits with appropriate levels ofsugar, it is advisable to provide water amounts that meet the crop’s watering needs