EFFECTS OF THE SEASON AND TEMPERATURE ON THE GROWTH AND DEVELOPMENT OF YOUNG TOMATO PLANTS
Tomato plants were raised at two temperature regimes which differed by 5°C during the winter season of 1978/79. The periods of time from sowing until the plants reached a fresh weight of 10 g, and until the 15th leaf and the first truss were initiated, were determined. The results were plotted against the middle of the growing period concerned. For all the growth characteristics, the growing periods increased linearly from the autumn into the winter and they decreased linearly from the winter into the spring. The points of intersection of the functions were very close to the shortest day. This phenomenon also occurs in other crops. Apparently, natural radiation determines to a large extent the rate of weight increase and the development of the growing point. Over the season, the total variation in the growing periods for the different growth characteristics is about 25 times as great as the effect of a 1°C temperature change. With regard to the weight increase and the rate of leaf initiation, no interaction was found between the effects of the season and the temperature. The leaves of tomato plants are smaller in winter, but more leaves are initiated below the first truss. This is why truss initiation takes place at a more or less constant fresh weight.
Klapwijk, D. (1981). EFFECTS OF THE SEASON AND TEMPERATURE ON THE GROWTH AND DEVELOPMENT OF YOUNG TOMATO PLANTS. Acta Hortic. 115, 49-58