Обґрунтування критичних періодів росту помідора за різних способів поливу на основі аналізу ростової функції

Abstract

Specifying the degree of dependency of variability of growth plant indexes on crop productivity is an urgent task which enables to determine the optimum parameters of the regulatory factors that facilitate to increase the productivity when efficiently using resources. The aim of the study was to make a mathematical model that describes the growth for tomatoes, and based on its analysis, specify critical growth phases, duration of critical periods when using different irrigation methods, and determine the degree of impact of growth indexes varying in critical growth phases on the yield of tomato plants. The growth processes were simulated using the B. Gompertzian function based on the dynamics of leaf-area duration obtained during the study of different irrigation methods in the period of 1993-2010 years at the Institute of Irrigated Agriculture of NAAS of Ukraine. The calculations of the duration of critical periods have shown that it is within the 31st day and doesn’t significantly differ by the irrigation methods. The maximum growth rates of leaf apparatus can be observed when using drip irrigation in 52 days starting from the beginning of vegetation, that is 8,7-19,1% higher than for the options with typical irrigation or micro irrigation. Accordingly, the yield when using drip irrigation is 12,8-17,9% higher when compared to the other irrigation methods. Based on the correlation and regression analysis it has been determined a close dependence between the growth rates of leaf apparatus in the critical phases of growth and productivity, which shows that in 92% of cases the variability of growth plant indexes of tomato plants in critical periods of growth is the reason of yield varying.