Yields, Postharvest Storage, and Response to Pruning of Eggplant Cultivars Grown in High Tunnels in New Hampshire, USA

Abstract

We grew eight cultivars of eggplant (Solanum melongena) over 2 years in four experiments conducted in high tunnels located in Durham, NH; North Haverhill, NH; and Ossipee, NH, USA. The marketable yields of eggplant harvested over 14 to 15 weeks ranged from 925 to 3269 g per plant (2.5–8.8 kg⋅m–2), depending on year and cultivar. Significant differences in marketable yield among cultivars were observed in three of the four experiments, but trends were not consistent. Parthenocarpic cultivars developed for greenhouse production, including Angela, Annina, Aretussa, Jaylo, and Michal, did not produce significantly greater yields than the cultivars developed for field production (Nadia, Traviata, and White Star). In two experiments, using a subset of cultivars, we explored the effects of training plants to four leaders compared with the standard practice of no pruning. Pruning treatment did not impact significantly the number or weight of marketable fruit, or the percentage of cull fruit, and there was no cultivar-by-pruning treatment interaction. In three separate experiments in Durham NH, USA, weight loss, browning, and softness were evaluated after 2 weeks of storage in one of three conditions: within the ideal range of temperatures (average of 50–64 °F), too warm (63–73 °F), and too cool (38–49 °F). Overall, responses to conditions that were warmer or cooler than ideal were as predicted, and weight loss, softness, and browning were all minimized when fruit were stored at 50 or 60 °F. We did, however, see some differences among cultivars in susceptibility to common postharvest storage problems. In conclusion, we found that cultivar choice can be important for high-tunnel eggplant producers, especially if postharvest storage conditions are not ideal. We also found that pruning and parthenocarpy did not enhance marketable yields, allowing growers to reduce labor and seed costs without impacting yield or fruit quality negatively.