The aim of this study was to evaluate the damage caused by PRSV-W and ZYMV on zucchini squash (Cucurbita pepo cv. Caserta) under greenhouse and field conditions. Plants were inoculated with the two viruses in singly and mixed inocula at 12 and 22 days after emergency (DAE) for the test in the greenhouse, and at 5, 15 and 25 DAE in the field. Plants inoculated with PRSV-W + ZYMV, PRSV-W e ZYMV, at 12 DAE, under greenhouse conditions showed 39.6, 36.8 and 12.1% of reduction on leaf area, respectively, as compared to the control. Fresh and dry weight biomasses were also affected by virus infection at 12 DAE. In the field test, plants inoculated with both viruses, single or mixed, at any stage, did not yield marketable fruits. However, the amount of unmarketable fruits produced by these plants varied from 14 to 861 g/plant, according to the age plants were infected. Control plants, treated only with buffer, at 5, 15 and 25 DAE, yield on average 573 g, 937 g and 1172 g of marketable fruits and 282 g, 221 g and 192 g of unmarketable fruits, respectively. Fresh weight biomass of plants infected with both viruses, single or mixed, at 5 and 15 DAE showed an average reduction of 60.7 and 22.7%, respectively, compared to the control. No reduction on fresh weight biomass was observed for plants infected at 25 DAE.
Cucurbita pepo; Potyvirus
