Field Performance Comparison of Two Transgenic Summer Squash Hybrids to Their Parental Hybrid Line

'Pavo', a commercially grown, virus-susceptible squash (Cucurbita pepo L.) hybrid, and two experimental virus-resistant transgenic squash hybrids, XPH-1719 and XPH-1739, were tested for field performance. The two transgenic squash hybrids possess the desired fruit and plant characteristics of their parental line, 'Pavo', plus resistance to zucchini yellow mosaic virus and watermelon mosaic virus 2 (XPH-1719), and resistance to zucchini yellow mosaic virus, watermelon mosaic virus 2, and cucumber mosaic virus (XPH-1739). Percent emergence and days to flowering were similar among the three hybrids. XPH-1719 and XPH-1739 were equally effective in producing a high percentage of quality marketable fruit and yields with 90% and 13,800 kg.ha -1 and 87% and 16,500 kg.ha -1 , respectively. XPH-1719 and XPH-1739 demonstrated their outstanding virus resistance over 'Pavo' by producing only 3% and 14% symptomatic plants, respectively, compared to 53% for 'Pavo'. They also produced the lowest percentage of infected fruit, 0% and 7%, respectively, with 'Pavo' at 26%.