Scientific Reports of the Faculty of Agriculture, Okayama University
Published by the Faculty of Agriculture, Okayama University
ONLINE ISSN : 2186-7755


In order to clarify the factors that cause fruit pit-spilitting and physiological fruit drop in peach (Prunus persica cv.'Shimizu-hakuto'),the effects of fruit thinning on fruit development were investigated.In addition,the characteristics of fruit development in 'Shimizu-hakuto'were compared with those in early-ripening cultivars which cause heavy pit-splitting but low physiolofical fruit drop,and in 'Yamao-hakuto'which hardly cause any pit-splitting or physiological fruit drop.Pit-spilit and fallen fruits genarally show a rapid enlargement at the end of stage Ⅰof fruit growth than normal fruits.At completion of pit splitting the percentage dry weight content of the pit reached 30%. Fruit with relatively less increase in length that of diameter and width,at the early stage of the fuit development,showed low pit-splitting occurrence in all the cultivars.Early in the stage of fruit development, we observed two vascular bundles attached to the seed of the early-ripening cultivars,but only one in 'Shimizu-hakuto'and'Yamato-hakuto'.Embryos in pit-spilit fruit were smaller than in normal fruit,and their length in fallen fruit was less than 5mm.The development of endosperm was also delayed in fallen fruit.
embryo development
physiological fruit drop