Effect of the application of jasmonic acid and benzoic acid on grafted watermelons yield under greenhouse conditions in the southeast of Spain for mitigation of stress

One of the main problems of watermelon crops in Southeast Spain is the thermal difference because of climatic conditions that appear during the first stages of the crop. The objective of this work was to evaluate the effect of inducing the systemic acquired resistance (SAR) and the induced systemic resistance (ISR) through the application of jasmonic acid (JA) and benzoic acid (BA), respectively, to counter the abiotic stress. We assessed two treatments of JA and BA, T-1 (500 mg.kg(-1) + 500 mg.kg(-1)) and T-2 (2000 mg.kg(-1) + 2000 mg.kg(-1)), as well as a control test using an experimental design of randomized blocks with four replications. The results obtained for kg.m(-2), fruits/m(2), kg/plant and fruits/plant did not show statistically significant differences. However, we obtained statistically significant differences in the average fruit weight compared with the control test in the two experiments carried out in 2009 and 2010. The results showed that there was no metabolic cost in the plants when applying the assessed treatments of JA and BA.