Heat resistance of winter wheat seeds depending on growing conditions

Abstract

The research was conducted in the Department of Seed Growing and Agrotechnologies of the V. M. Remeslo Myronivka Institute of Wheat during 2016–2018 on new winter wheat varieties MIP Valensiia, MIP Vyshyvanka, MIP Kniazhna, Myronivska slava, Trudivnytsia myronivska that are put in the State register of plant varieties suitable for distribution in Ukraine. The soil of the experimental field where the research was conducted is deep, low-humus, slightly leached chornozem and has the following agrochemical characteristics: 3.6–4.5% of humus, 55–64 mg of hydrolyzed nitrogen per 1 kg of soil, 190–271 mg of mobile phosphorus per 1 kg of soil, 112–180 mg of exchangeable potassium per 1 kg of soil, 5.3–6.4 salt pH, 23.1–28.6 mg-eq of absorbed bases per 100 g of soil, the base saturation degree 86.2–94.4%. When seeds of winter wheat varieties were thermal tested, it was found that the in seeds grown after green manure as a preceding crop after 5 minutes of heating the sprouting activity increased (by 1.2–5.6%), while the seed vigor and laboratory germination on the contrary – decreased (by 7.6–8.8% and 7.8–8.4% respectively). When the seeds were heated for 10 min, these indices decreased significantly. Namely sprouting activity by 36.4–44.0%, seed vigor by 40.4–52.6% and laboratory germination by 35.4–38.2%. For the soybean as a preceding crop when heating the seeds for 5 min, there was also found an increase in the sprouting activity (by 2.6–12.4%) and when heating for 10 min this index decreased significantly (by 34.0–41.0%). When heating seeds for 5 and 10 min, the seed vigor and laboratory germination indices decreased (by 5.2–57.2% and 6.4–41.8% respectively). On average for the years of the research (2016–2018), when heating for 5 minutes the seeds of the varieties MIP Vyshyvanka, Trudivnytsia myronivska, MIP Valensiia, MIP Kniazhna, and Myronivska slava grown after the preceding crops green manure and soybean, the sprouting activity increased (by 2.6–6.2%), but the germination energy and laboratory germination decreased (by 8.0–7.8% and 8.2–8.6% respectively) compared to control (with no heating). On average for 2016–2018, the results of thermal testing showed the highest indices of laboratory germination for both preceding crops when heating for 5 and 10 min, as compared to the control in the variety MIP Vyshyvanka (90% and 72% for green manure, 88% and 67% for soybean) and the lowest indices in the variety Myronivska slava (86% and 48%, 84% and 45%, respectively). It was established that the influence of preceding crops on the indices of laboratory germination during thermal testing seeds of winter wheat varieties was insignificant.