Shoot Growth and Fruit Development as Affected by Warming the Soil in Forcing Culture of 'Tonewase' Persimmon under Restricted Root Volume

Abstract

Effects of warmed and non-warmed soils on shoot growth and fruit development were compared by using in seven-year-old 'Tonewase' persimmon (Diospyros kaki L.) in forcing culture under restricted root volume condition. The warmed soil was maintained at 20°C by circulating warm water in the pipes laid in the ground from Jan.12 to Apr.15. The time of bud burst and anthesis by warming was advanced slightly, compared with plants in the non-warmed treatment. Warming the soil increased shoot growth and accelerated maturation and TSS accumulation of fruit, but the yield was reduced because of low fruit set and small fruit size.