Studies on the Flower Formation in Tomatoes and Egg-plants

I. Effect of Temperature Regimes 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 and at two levels of N, P and K during two growing seasons (1960, 1961) to study the interaction of those factors on flower bud differentiation and its subsequent development.
2. In 1960 the following results were obtained:
a) The height and fresh weight of seedlings in 2(NPK) and NPK plots were: 24°, 30°, and 17°C in decreasing order. However, seedlings in 2(NPK) plots grown at the same temperature were larger than those in NPK plots.
b) The time of morphological differentiation of flower buds and their subsequent development in both 2(NPK) and NPK plots in order of earliness were: 30°, 24°, and 17°C. Under the same temperature regime, seedlings in 2(NPK) plots differentiated flower buds earlier than those in NPK plots.
c) The number of flower buds per seedling was 24°, 30°, and 17°C in decreasing order, that of 2(NPK) plots being consistently higher than that in NPK plots.
3. In 1961 the following results were obtained: The results in 1961 were essentially the same as those in 1960 except that in the second year, temperature had no influence on the development and the number of flower buds. This inconsistency with respect to the time of flower bud differentiation is attributed to the large difference in the amount of solar radiation as the sum total of the duration of sunshine per day and per growth period, between the two seasons. Total sunshine hours per growth period were 85.3 hours in 1960 and 116.4 hours in 1961.