Flower Development and Yield of Cucurbita in Four Locations Differing in Temperature

• Published in: HortScience Vol. 33; no. 3; p. 543
• Main Authors: Wien, H.C, Cady, S, Maynard, D.N, McClurg, C, Riggs, D
• Format: Journal Article
• Language: English
• Published: 01.06.1998
• ISSN: 0018-5345; 2327-9834
• DOI: 10.21273/HORTSCI.33.3.543d

Preliminary greenhouse experiments indicated that Cucurbita pepo , when grown at high temperatures, shows a high incidence of female flower bud necrosis, preventing those flowers from reaching anthesis and thus delaying fruit set. This can lead to reduced yield in areas with short growing seasons. To determine if delayed fruit set also occurred under field conditions, replicated cultivar trials were conducted during the summer seasons of 1996 and 1997 in Ithaca and Albany, N.Y.; Wye, Md., and Bradenton, Fla. Mean growing season air temperatures were 20, 21, 24, and 28 °C, respectively, at the four locations. Delay in fruit set was indicated by the main stem node number at which the first fruit formed. In Ithaca and Albany, the six cultivars grown in both years formed their first fruit at node 17, while this was shifted to node 24 at Wye, and to node 26 or more at Bradenton. Fruit yields among the C. pepo cultivars ranged from 45 to 85 mt·ha –1 in all locations except Bradenton, where they ranged from 7 to 35 tons. Among C. pepo cultivars, `Appalachian' showed least yield decrease at Bradenton, and `Howden' and `Baby Bear' the most, in the hotter 1996 season. The C. maxima `Prize Winner' yielded well in all locations. The results indicate that delayed fruit set occurred most often in the highest temperature locations. There is scope for selecting for improved high temperature female flower development among C. pepo cultivars.