Work

Auxin-induced parthenocarpy as an alternative to pollination of trellised sweet acorn squash grown under protection in fall and early winter

Year: 2026

Type: article

Abstract: Sweet-fruited acorn squash are a premium-priced vegetable in Israel and are produced under field conditions in the spring and summer. They are also produced from plants grown trellised in screenhouses in the fall, for marketing after storage during the winter months. Ordinarily, in these screenhouses, bumblebees are introduced for pollination when the plants begin to flower. However, viability of pollen and activity of bees are subject to the vagaries of environmental factors. Our objective was to determine if spraying the plants with auxin during flowering to induce parthenocarpic fruit set could act as a viable alternative to the bees. Sweet acorn squash seedlings were transplanted into a screenhouse in the fall and subjected to three treatments, spraying with auxin to induce parthenocarpic fruit set, pollination by bumblebees, or spraying with auxin plus bee pollination. The treatments were then compared for yield, and fruit quality, including physical traits, carbohydrates and antioxidant contents, and several taste parameters, at harvest and after one, two, or three months of storage at 15C, 95% RH. The fruits produced by the auxin-sprayed plants were heavier and had a larger circumference, and had noticeably thicker mesocarp and undeveloped seeds. Yields of auxin-treated plants were comparable to those subjected to bee pollination. Total soluble solids (TSS), sugar, and antioxidant contents of auxin-treated and bee-pollinated derived fruits were similar. However, fruits developing from the auxin treatment contained more starch at harvest and retained more starch during storage, suggesting that auxin delayed fruit ripening and aging

Source: Scientia Horticulturae

DOI: 10.1016/j.scienta.2026.115184