Розвиток фузаріозу початків кукурудзи на гібридах різних груп стиглості та його шкідливість в умовах Правобережного Лісостепу України

Abstract

Maize ( Zea mays L. ) is one of the most strategically and economically important crop in worldwide together with wheat and rice. But, as the rest of the other grain crops maize is suffering from different diseases which affect almost all plant’s parts. Among of maize diseases – ear rots are supposed as the most widespread and harmful. The most common disease of maize ears in most regions of maize cultivating in Ukraine is fusarium ear rot (dominant causative agent - the fungus Fusarium verticillioides (Sacc.) Nirenberg; Teleomorph: Giberella moniliformis Wineland; synonym: F.moniliformis ). Every year maize disease cause yield losses which in some years can reach 30.0% and more. Fusarium ear rot can cause serious damage to all types of corn. The incidence of the disease largely depends on weather conditions and occurrence of maize plants damaged by European corn borer ( Ostrinia nubilalis ). The main damage from the disease are direct losses of grain at the start and hidden, affecting the yield and quality. Besides developing at the beginning period of storage (humidity exceeding 18%), the pathogen of Fusarium verticillioides , producing toxins (fumonisins) can cause poisoning effect on humans and animals. The aim of the research was to analyze the interrelation of maize hybrids of various maturity to Fusarium ear rot intensity and to study disease harmfulness in terms of Right bank Forest Steppe zone of Ukraine Maize pathology monitoring of research plots of maize with different maturity group showed that hybrids four maturity terms were affected by Fusarium pathogen in different degrees. Weather conditions also had a significant impact on the severity of Fusarium ear rot. Figures 1,2,3,4 image average air temperature and amount of rainfall in the growing seasons of maize in 2015 and 2016. Per the weather conditions were more favorable for the disease in 2016. In addition, setting experiments in isolated areas of forest belts planting corn in monoculture (4-5 years) contributed to the accumulation of European corn borer which promote the incidence of Fusarium infection. According to received research data the most Fusarium incidence was seen on hybrids of middle-early and mid-season groups of maturity, which respectively accounted for 28.3 and 27.0% (2015) and 30.1 and 30.3% (2016). Similarly, the disease severity was 2.9 and 5.0% (2015) and 3.2 and 10.0% (2016). On average, for two years of Fusarium intensity these variants are accounted for 29.2 and 28.7%, and growth of 3.1 and 7.5% respectively. The remaining maize hybrids from other maturity groups occupy an intermediate position of the disease intensity. The maize yield according to Fusarium ear rot harmfulness in 2016 was lower on middle-early and average-late hybrids by an average of 0.5 t/ha relative to 2015, and the early- and mid-season yield respectively was lower by an average of 0.3 t/ha. In the 2015-2016 dominant role among the major maize ear diseases had Fusarium ear rot (dominant causative agent - the fungus Fusarium verticillioides (Sacc.) Nirenberg). The most favorable weather conditions for the development of Fusarium ear rot were in 2016. Found that most Fusarium ear rot intensity was observed on average-late maize hybrids, which incidence were 20 to 27% level, and severity from 5% and higher. Yield losses depending on the degree of disease intensity were varied from 0.3 to 0.5 t/ha.