Harvest Date and Size Distribution of Peach Fruit Are Altered with Fall-applied Ethephon

Abstract

Ethephon was applied at 100 mg·liter -1 to peach [ Prunus persica (L.) Batsch., cvs. Jerseydawn and Cresthaven] trees in Oct. 1987 and 1988 to increase flower bud hardiness and delay bloom the following spring. Flower bud survival after exposure to -26C in Jan. 1988 was enhanced with fall ethephon application in both cultivars. Ethephon delayed bloom by 7 (1988) and 3 (1989) days in `Jerseydawn' and by 10 (1988) and 4 (1989) days in `Cresthaven'. Total fruit production per tree for `Jersey-dawn' was not affected by ethephon treatment in 1988; however, yield was enhanced with ethephon treatment in 1989. For `Cresthaven', yield was enhanced by ethephon treatment in both years. Most fruit from the untreated trees were harvested on the first harvest dates and were in the largest size categories, while most fruit from the treated trees were harvested on the last harvest dates and were in the smaller size categories both years in both cultivars. Smaller pistils and heavier prethinning crop loads lead to smaller fruit and a later harvest date. Chemical names used: 2-chloroethylphosphonic acid (ethephon).