Yellow Squash and Zucchini Cultivar Evaluation in Georgia

Ten yellow squash (Cucurbita pepo) and nine zucchini (C. pepo) cultivars were evaluated in southwest Georgia during spring and fall growing seasons in 2014 and 2015. Plants were grown using plastic mulch and drip irrigation following standard production practices for squash in Georgia. Plants were harvested 10 to 13 times during each study season. Fruit were graded into fancy, medium, and culls. Virus pressure was low during the trials. For yellow squash yields, there were significant cultivar by season interactions; however, Solstice, a straightneck yellow squash, and Gentry, a crookneck cultivar, were consistently among the highest yielding yellow types. Despite having no documented virus resistance, 'Gentry' performed well during the fall season. However, 'Precious II', a yellow straightneck cultivar with the presence of the precocious yellow gene, experienced high cull rates in the fall due to virus effects on the fruit. There was a year by season by cultivar interaction for zucchini yield. Despite this interaction, 'Respect' was ranked among the highest yielding cultivars in all four seasons of the trial. Differences were also observed between seasons for yellow and zucchini squash, with fall yields generally being lower than those in the spring. The results of this study suggest significant differences in the adaptability of squash cultivars for spring and fall production in Georgia. In addition, virus resistance, while important, should not be the exclusive factor for determining cultivars for fall-planted squash in Georgia.