FACTORS OF SUDDEN HOLLOW DEPRESSION FRUIT DISORDER IN JAPANESE APRICOT
The sudden hollow depression of Japanese apricots (Prunus mume) differed from sunscald in that it initiated suddenly in the flesh toward the fruit apex well before any disorder symptoms occurred in fruit skin. Only at the advanced stage did this disorder show the similar symptoms found in the fruits with sunscald. Later, fruit skin was depressed toward the hollow, reaching frequently to the stone. This disorder developed rapidly from late May. The disorder developed when fruit temperature exceeded 29°C in Gojiro and 30°C in Nankou. As the temperature increased above this threshold, so did the percentages of the fruits that developed the disorder. Soil moisture affected the percent occurrence of the disorder. The percentages of fruits with the disorder increased as soil moisture decreased. When soil moisture was maintained at -10, -30 and -50 kilopascals, the percentages of the fruits with the disorder were 10.3, 15.0 and 23.2%, respectively. Fruits with the disorder were characterized by low calcium concentrations in flesh and seed. Nitrogen concentration within fruit tended to be high in disordered fruits, thereby significantly increasing the nitrogen-calcium ratio. The results suggested that any strategies aimed to regulate soil moisture to an appropriate level and to increase calcium concentration of the fruits should help to reduce the occurrence of sudden hollow depression of Japanese apricot fruits.
Chong, B.M., N.D. Kang, , K.K. Seo, , G.M. Shon, , C.W. Rho, and S.M. Kang, (2008). FACTORS OF SUDDEN HOLLOW DEPRESSION FRUIT DISORDER IN JAPANESE APRICOT. Acta Hortic. 772, 333-337
calcium, Prunus mume