The spread of pests and the productivity of winter wheat for permanent cultivation

Abstract

Goal. To determine the influence of prolonged action of natural and anthropogenic factors on the phytosanitary condition (pests) of winter wheat and the dynamics of its performance for permanent cultivation. Methods. Field, statistical, laboratory. Results. The obtained results show that anthropogenic and natural factors have a certain influence on the distribution of pests in crops of winter wheat and the level of its performance. By the results of the monitoring of pests in the crops, it was found out that the greatest damage was done to them by Agrotis segetum and the larvae of grasshoppers. The average number of insects of Agrotis segetum for the duration of the study was 4.3 ins./m2, and of grasshoppers — 8 ins./m2. Among grasshoppers, the dominant species was Agriotes gurgistanus Fald. — 52,5% in the species composition. Correlation link between the presence of pests in crops of winter wheat and the weather conditions and years of observation have shown their inverse relationship. The correlation coefficient between the number of pests and temperature and water regimes during the growing season were respectively –0,78...–0,62. Fertilization has a positive effect on the productivity of winter wheat even for permanent cultivation. So, on average for years of researches, the yield increase due to fertilizers was 8.3–9.5 t/ha. However, the imbalance of nitrogen and weather conditions (particularly soil moisture) can lead to lower yields. Therefore, before the application of fertilizers, it is recommended to carry out diagnostics of soil and plants as to the content of macro-elements. Conclusions. The correlative relationship is determined between the presence of pests in crops of winter wheat and weather conditions, which indicates their inverse relationship. It is established that the productivity of winter wheat over the years, not decreased. It is proved that the culture by its genetic characteristics can adapt to long cultivation in the same place. However, the study confirms the feasibility of compliance with science-based crop rotations.