Distribution corn medium early maturity group for agronomic characteristics

Purpose. The aim of the research was to estimate corn hybrids in terms of the main agronomic characteristics, such as protein content and starch yield. Methods. Field trials, laboratory tests, and cluster analysis. Results. It was found that the hybrids under investigation had differences in morphology, including the form of leaf plate, the size, and shape of corncob, shape of grain and number of grain rows. The best hybrid in terms of yield in the Steppe zone proved to be ‘HS 2632’, which had a high protein content of 9.60 %. In Polissia zone, the best hybrid for yield and starch content was ‘Zdobutok’ with the yield of 11.38 t/ha and starch content of 76.35%, which significantly exceeded the values of the characteristics in the Steppe zone, as well as in other hybrids in the area. Two hybrids, which had high yields in Polissia zone (9.83 and 9.85 t/ha) were defined, namely ‘Svitoch 38’ and ‘Danubio’, with the last one characterized by a high protein content (9.40%) and the lowest value of the starch content (73.25%). It was determined that the closest in terms of the characteristics under study hybrids entered the same cluster. This distribution was caused by the peculiarities of inheritance of agronomic characteristics of crops. Conclusion. Based on these studies, four clusters of corn hybrids were determined in terms of a complex of agronomic characteristics as follows: ‘SI Tiptop’ and the ‘NS 2632’, ‘SI Arios’ and ‘Zdobutok’, ‘Enigma’ and ‘SI Аmplitude’, ‘MAC 24H’ and ‘Danubio’. It is recommended to grow different hybrids on a farm because they realize their genetic potential based on environment, which allows reducing the effects of unfavorable factors.

Dynamic pattern of chlorophyll content in the leaves of sugar beet

Purpose. To determine the patterns of change in the content of the green pigment in plant chloroplasts of sugar beet and their relationship, to identify the features of pigment complex during the growing season. Methods. Field, laboratory, analytical, and statistical. Results. The peculiarities of changes in chlorophyll content in the leaves of sugar beets during the growing season are presented. It was found that the most intense green pigments synthesis occurs in the stage of closing leaves when their content reaches the maximum value: chlorophyll а of 8.620 mg/g and chlorophyll b of 4.15 mg/g. Using the ratio of chlorophyll a and b in their total weight the accumulation of a pigment depending on the stage of plant development is determined. Thus, in the first half of the growing season (the 8-true leaves stage and the stage of leaf closure between rows) the synthesis of chlorophyll b dominates, while in the second (the stage of closure leaves in rows and the technical maturity stage) chlorophyll a. Conclusions. It was established that the least intensive synthesis of chlorophyll occurs in the early stages of plant growth and development due to small leaf surface area and low assimilation of the photosynthetically active radiation. Thus, at the beginning of the growing season crops (the 8-true leaves stage and the stage of leaf closure between rows), chlorophyll b dominates in the structure of the green pigment. Reduction of chlorophyll content 1.3 times the end of the growing season (in the stage of technological maturity – 6.3 mg/g) compared with the stage of leaf closure in rows occurs due to the accumulation of sufficient sugar supply in the roots resulting in slowing physiological processes and the dying off old leaves.