Influence of Night Temperature and Nitrogen Nutrition on the Growth, Sucrose Accumulation and Leaf Minerals of Sugar Beet Plants.

Open Access
Publisher Website
Google Scholar
Abstract
Sugar beets (Beta vulgaris) of the variety GW 304 were grown in pots containing vermiculite to which nutrient solutions were added and allowed to drain off daily. Representative plants of the high N series grown at a night temperature of 17[degree] C had sucrose concentrations after 28 and 56 days (8.3 and 8.8%) similar to those of the initial growth period (8.8 and 9.2%). At a night temperature of 10[degree]C the sucrose values at the end of 28 and 56 days were 10.5 and 11.0%, and at a night temperature of 4[degree]C, 11.3 and 12.1%, respectively. The corresponding values for the plants deficient in N were 15.4 and 15.4% for nights at 17[degree]C, 16.3 and 18.3% at 10[degree]C, and 16.6 and 18.3% at 4[degree]C. N deficiency and low night temperatures retarded the growth of tops and storage roots. Nevertheless, maximum sugar storage occurred in the N deficient plants, primarily at the low night temperatures of 4-10[degree] C. Leaf mineral concentrations were modified by N nutrition and night temperature, e.g. the petioles of high N plants at a high temperature were always higher in nitrate than petioles of plants at a low night temperature. Likewise phosphate-phosphorus and K values of the petioles for both the low and high N plants were higher at the high night temperatures. These mineral increases were associated with decreases in per cent petiole dry matter as night temperatures were increased. Phosphate-phosphorus values of the blades and not of the petioles were increased tremendously by a N deficiency.
Keywords