Effect of early environments on the flower formation in tomato. I

Abstract

The present study was carried out to investigate the effects of night temperature and soil moisture during four weeks immediately after cotyledon expansion on the growth and flower formation of tomato. The studies consisting of Exp. 1 and 2, gave the results on night temperature and soil moisture as presented in Tables 1 to 4 on Exp. I. and in Tables 5 to 12 on Exp. 2, respectively.1.The number of nodes to the first flower cluster (leaf number) was found to be greatly affected by night temperature during the first two weeks after cotyledon expansion; it was minimized at low temperature and maximized at high one.Vegetative growth as measured by plant height and leaf number was also found to be greatly affected by temperature during the second two weeks after cotyledon expansion; it was minimized at low temperature and maximized at high one.2.The experiment with varied night temperatures which enabled the sensitive phases for leaf and flower numbers to be defined more accurately proved that, from the fifth to tenth day after cotyledon expansion, the tomato seedling was sensitive to the night temperature in the leaf number but not of the flower number. On the contrary, from the tenth to fifteenth day, it was sensitive in the flower number but not of the leaf number.3. The leaf number was greatly affected by soil moisture during two weeks after cotyledon expansion; it was minimized in its optimum condition. and maximized in dry condition.The interaction of night temperature and soil moisture was observed in the leaf number; when the soil moisture was kept in optimum condition, the leaf number was minimized at low night temperature and maximized at high one; but no significant difference was found when kept in dry condition. Moreover, the duration of dry soil moisture treatment also greatly affected the leaf number and it was minimized with two-weeks duration and maximized in three-weeks duration.