Studies on the Flower Formation in Tomatoes and Eggplants

III. Effect of Temperature Regimes, Light Intensities and Fertilizer Levels on the Flower Bud Differentiation in Tomatoes

Abstract

1) Tomatoes, cv.‘Shin-Hogyoku No. 2’were grown under constant temperature regimes of 17, 24, and 30°C, of two light intensities of natural sunshine and shaded with three cloths and at two levels of N, P and K during two growing seasons (1962, 1963) to study the interaction among those factors on flower bud differentiation and its subsequent development. In 1963, the soil at the level 2(NPK) was used as bed soil.
2) The effect of the levels of fertilizer on the plant growth was light at high temperature of 30°C and hard at low temperature of 17°C. Especially, in 2(NPK) plot where bed soil was used at 17°C in 1963, the growth of seedlings was very high and remarkably different from the previous results, but it was very small at the low level of fertilizer (NPK). The difference between bed soils at 2(NPK) and NPK level was very large.
3) The influence of the levels of fertilizer on the time of flower bud differentiation was low at high temperature of 30°C and remarkable at low temperature of 17°C. Especially, the plot of 17°C, using bed soil at 2(NPK) level, in 1963 was flower bud differentiation at the earliest stage, in 19 days from sowing time, but NPK plot was remarkably late. The difference between bed soils at 2(NPK) and NPK level was very large.
4) The influence of light intensities on flower bud differentiation was remarkable in order of 30°C and 24°C. Especially, in 1963, in the shaded plots of those temperatures, the time of flower bud differentiation was late and lacked uniformity, but the shade influence at the low temperature of 17°C was the lowest.
5) The time of flower bud differentiation was the earliest in the bed soil 2(NPK) of 17°C among all plots, but the length of flower bud was rather larger at 24°C than at 17°C.
6) The effect of the levels of fertilizer on the number of flower buds was low at 30°C, but it was remarkable at 17°C. In 1963, the number of flower buds at 17°C in the bed soil at 2(NPK) level was very large, but it was very few at 17°C at NPK level. The difference between bed soils at 2(NPK) and NPK level was very large.
7) The effect of light intensities on the number of flower buds was remarkable at 30°C, but it was lower at 17°C than at all others.