The thesis deals with the study of the peculiarities of yield formation and quality of sugar beet seeds and planting material of Miscanthus under drip irrigation and application of MaxMaryn absorbent.
It was established that the growing of sugar beet seeds under the conditions of drip irrigation with the simultaneous application of nitrogen fertilizers under irrigation regime, when during the interstage period “leaf rosette-formation of flowering shoots” the soil moisture was maintained at the level of 60%, and during the interstage period, “the beginning of flowering-seed maturity” – 80% of AR caused the increase in the height of plants by 25–35 cm, the formation of a greater number of flowering shoots (8–9), where the bulk of the seeds is forming, as well as the significant increase in the number of leaves and leaf area, compared with the control 1 – without irrigation and without fertilization.
It was found that under drip irrigation and simultaneous nitrogen fertilizers application there were 4.8–8.4% of 100% germs more than under absolute control.
Drip irrigation contributed to a significant increase in the content of total and bound water in the seed cells. The free water content of the seed cells was greater than the content of bound one but the significant decrease or increase of such water content in plants doesn’t depend from the seeds growing conditions.
Under drip irrigation, the content of chlorophyll in the leaves increased by 0.12–0.13% and was 1.85–1.86% on a completely dry – matter basis, compared to the absolute control – without irrigation and without fertilizers. Depending on irrigation regimes, there is no significant difference in the content of chlorophyll. In the conditions of drip irrigation with the nitrogen fertilizers application the intensity of flower formation increased under both regimes: on the central shoot 1,4 times more, and on the primary shoots – in 1,5 times more flowers were formed in comparison with the absolute control. Seed yields increased by 1.6 times compared to the absolute control and by 1.3 times compared to the variant where only nitrogen fertilizers were applied without the drip irrigation.
Under growing the sugar beet seeds in rainfed conditions, the application of absorbent during the period of seedlings planting provided an increase in the number of flowers per 10 – cm segments of the shoots of one plant at the lowest consumption rate by 3,0%, and at the rate of 1,5 g per plant – by 11,2%. compared to control. The application of absorbent provided a significant increase in the size of pollen grains compared with the control – without absorbent both without irrigation, and in conditions of drip irrigation. The largest dimensions of pollen (22.3–22.4 microns) were due to the application of absorbent at the rate of 1.0–1.5 g per plant under drip irrigation conditions.
In the conditions of drip irrigation, the amount of free water in the leaves was significantly influenced by the factor “irrigation”, and on the content of bound water during the budding development stages and flowering of seedlings the factor “absorbent” in the stage of seeds maturity, the influence of this factor was less, and influence of the factor “irrigation” was greater
In the conditions of drip irrigation and application of an absorbent by the consumption rate of 1.5 g per plant during all the stages of seed plants development, a significant increase in the chlorophyll content in the leaves was obtained in comparison with the control. The application of drip irrigation provided a significant increase in seed yield. On average, over three years in control without the absorbent application, the yield of seeds under drip irrigation increased by 0.65 t/ha compared with control – without irrigation.
Peculiarities of growing the planting material of Miscanthus in conditions of drip irrigation. The application of absorbent in rainfed conditions both without irrigation, and in conditions of drip irrigation did not contribute to an increase in biometric indices of plants. The content of chlorophyll in the leaves was affected both by absorbent and drip irrigation.
The drip irrigation has significantly influenced the mass of mother rhizomes of Miscanthus, while at the same time under the absorbent application only a tendency to its increase was observed.
The use of drip irrigation both with and without the application of absorbent has provided, on average over the years of the research the increase of yield of one mother plantation of rhizomes weighing 15–20 g in 1,5 and rhizomes weighing 25–30 g – in 1,4 times compared with growing of mother plantations without irrigation.
Key words: drip irrigation, absorbent MaxMaryn, sugar beets, Miskanthus, pollen quality, seed yield, seed quality.
