Productivity and resistance to infection by biotic factors of lines - parental components of mayz hybrids when using biopreparations under irrigation

Abstract

Purpose and objectives. The purpose was to improve the existing technology of growing parents of innovative maize hybrids on irrigated lands by evaluating the impact of new biologicals on plant diseases, pest infestation and seed yield under irrigation in the Southern Steppe.

Materials and methods. The study was conducted in the experimental field of the Institute of Irrigated Agriculture of NAAS in 2019–2020. Factor A – parental lines belonging to various ripening groups (DK 445, DK 411, DK 281, and DK 247) included in the pedigree of hybrids Stepovyi, Skadovskyi, Azov, Arabat, Chonhar, Vira, Oleshkivskyi, Hileia and others bred at the Institute of Irrigated Agriculture of NAAS and the Institute of Grain Crops of NAAS. Factor B - treatment of maize parents with innovative biologicals – Fluorescein BT, Trichopsin BT, Biospectrum BT. The methods were conventional for irrigation conditions and maize breeding studies.

Results and discussion. The studied biologicals had positive effects on resistance to fungal diseases. The development of blister smut (Ustilago zeae Beckm.) on early-ripening line DK 281 was influenced by all the biologicals. Fluorescein BТ reduced the disease incidence by 1.9%; Trichopsin BG – by 3.0%; Biospectrum BT – by 3.2%. The incidence of Fusarium head blight was also decreased by biologicals. Biospectrum BT was the most effective agent. The incidence of Fusarium head blight in the lines decreased by 2.8–4.0%. The lowest incidence of Fusarium wilt was recorded in line DK 247 treated with Biospectrum BT – 8.9%. Corn borer infestation was reduced by Trichopsin BT and Biospectrum BT, which have both insecticide/fungicidal and growth-stimulating effects. The reduction in the incidence was 2.3–2.8%, depending on the genotype of the lines. Treatment with biologicals improved the cob structure of the studied lines. Trichopsin BT and Biospectrum BT had the greatest effects on the cob parameters. Due to Biospectrum BT, the cob length increased by 5.2–6.7%, the cob diameter – by 2.0–4.9%, and the cob grain weight – by 3.0–7.1%. The results of measurement of the yields from the parents (maize lines) showed that under irrigation the average performance of the studied maize lines ranged 3.75 to 6.11 t/ha, depending on the genotype of the lines (factor A) and the use of biologicals.

Conclusions. It was found that biologicals Fluorescein BT, Trichopsin BT, and Biospectrum BT reduced the damage to maize lines induced by blister smut, Fusarium wilt, and corn borer by 0.9–4.2%. Treatment with Biospectrum BT ensured the highest grain yields from the maize parent, which averaged 4.63 t/ha, the gain in the yield was 0.44 t/ha or 10.5%. Treatment with Trichopsin BT had a positive effect on the yield, which averaged 4.54 t/ha, providing a gain in the yield of 0.35 t/ha or of 8.4%. Treatment with Fluorescein BT increased the yield by 0.14 t/ha or by 3.3%. Biospectrum BT was the most effective agent, which provided a significant reduction in the damage to the maize lines caused by fungal diseases and pests