The Study of Drought Stress in Sugar Beet and the Ways of its Minimization

Abstract

The article presents peculiarities of drought stress identification in sugar beet and the alternatives for the use of additional components of cultivation technology aimed at increasing tolerance to water deficiency at the early stages of growth and development, namely: (i) soil amendment with moisture-retaining polymers; (ii) seed treatment with a growth regulator contributing to a better formation of the root system; and (iii) foliar application of micro fertilizers. The study of the state of the plant photosynthetic apparatus was carried out with the use of the devices for measuring chlorophyll fluorescence FLORATEST, developed at the Institute of Cybernetics of the National Academy of Sciences of Ukraine. The measurements were performed according to the guidelines on Determination of the Fluorescence Induction of plant Chlorophyll: Theoretical and Practical Bases of the Method. For better representativeness of the sampling, the measurements were performed at the same time of day and with the same intensity of illumination of the plants. As a result of the studies, the ratio of variable to maximum fluorescence (F v /F m ) of the plant photosystem obtained with the use of a portable fluorometer was found to be the most effective method of rapid diagnostics of drought stress in plants. A high level of correlation was found between the concentration of free proline and the Fv/Fm ratio, with the correlation coefficient for sugar beet r = -0.96, which corresponds to a very strong relationship.