Modelling of grains’ shoots formation
The processes of seed germination and shoots formation of crops caused by environmental factors are investigated. Also existing approaches to the modelling of this period, modelling of processes taking place in a seed during its germination, shoots formation are investigated, the structure of the developed model of the period of sowing - rise of shoots is described, as well as the results of numerical experiments. The specified model is aimed at overcoming the disadvantages and improving previous models of the period of sowing - rise of shoots. Development of this model is based on the achieved level of modelling of shoots formation with introduction of certain modifications. The model takes into account both physical processes taking place in a seed prior to germination of shoots and physiological and biochemical processes such as hydrolysis of endosperm reserves, respiration, distribution of hydrolysis products within axial organs and their growth. The model is implemented on a PC using Microsoft Office Excel. Many numerical experiments were carried out in order to investigate sensitivity of the model to changes of environmental conditions during germination of seeds. It was found that main agrometeorological factors affecting the time of emergence and completeness of germination are temperature, humidity and soil density. Influence of soil moisture becomes the most apparent at the stage of absorption and accumulation of moisture by a seed starting from sowing to beginning of growth process. Provided that there are optimum moisture and temperature, density of soil appears to be limiting factor affecting shoots formation: if soil density increases duration of shoots emergence increases as well. Developed dynamic model allows determining the date of shoots emergence, their field germination rate, distribution of particular number of plants of with different depth of seeds covering and a number of plants per particular unit of area.
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