Effects of sowing time and seeding rates on the field germinability and survival of winter wheat

Abstract

The aim and tasks of the study. The study purpose was to determine the integrated effect of sowing time, seeding rates, and weather conditions during the growing season on the field germinability and survival of bread winter wheat plants, variety Astet.

Material and methods. The study was carried out in the eight-field fallow-grain-tilled crop rotation in the experimental field of the Chair of Plant Production of the KhNAU nd. a. VV Dokuchaev. The experiment was laid out by the conventional split plot method. The first order plots were the following sowing time variants: (1) – September 5–7; (2) – September 15–17; (3) – September 25–27. The second order plots were seeding rates of 4.0, 4.5, 5.0 and 5.5 mln seeds/ha. The cultivation technology, except for the issues under investigation, was conventional for the study region. The experiment was conducted in four replicas; the total number of the second order plots was 48. The area of the elementary registration plot was 45 m².

Results and discussion. Of the studied agrotechnical factors, the sowing time had the greatest effect on the variability of the field germinability of winter wheat seeds. The shares of seeding rates were negligible: 0.5% after bare fallow steam and 2.7% after buckwheat. The effect of anthropogenic factors was more pronounced on the total survival of plants. This was observed on winter wheat crops sown after buckwheat. Thus, the shares of the seeding rates and sowing time in the total variability of the survival of winter wheat sown after bare fallow were 6.0% and 2.5%, respectively, and after buckwheat – 21.4% and 6.0%, respectively. There was no significant effect of interaction between any of the agrotechnical factors under study. A tendency of the interaction effect was only noticed.

Conclusions. We proved the influence of the seeding rate and sowing time on the variability of the total survival of bread winter wheat plants during the vegetation period. The best field germinability of seeds and the plant survival in most of the study years were achieved with sowing time (2) (September 15–17).

To plant survival to a greater extent depended on the seeding rate, with the share in the change in this index of 21.4% after bare fallow and 6.0% after buckwheat.

The increase in the seeding rate from 4.0 mln seeds/ha to 5.0 mln seeds/ha did not significantly reduced the plant survival after the both predecessors, which gives grounds to consider the seed rate variations within this range as possible without significant reduction in the plant survival, that is, without significant aggravation of competition between them.