engleski

Factors influencing first generation European corn borer abundance and damages

European corn borer (ECB) is one of the most significant maize pests in the world and also in Croatia. ECB causes yield reduction from 2 to 25%, even more in years favorable for its development. According to estimations, these losses are around 7%. Overwintering success, together with climatic conditions, are the key factors determining the abundance and intensity of the attack of the 1st generation. Additionally, the tolerance to the 1st generation ECB infestation is very often connected with maize FAO maturity group. The main aim of this work was to establish the differences among FAO maturity groups and among different climatic regions in damage caused by ECB larvae. Altogether 32 different FAO hybrids belonged to four FAO maturity groups (eight hybrids per group) in the two-year field trials located at four sites with different climatic conditions (Adriatic coast, North West, East and Central Croatia) were investigated. The damage caused by moth larvae on different FAO maturity groups significantly differ but might be correlated with climatic conditions as well. The analysis showed a strong positive correlation between the average monthly air temperature and the first generation attack (r = 0.6306 to 0.7386) in both research years. Additionally, the analysis showed a strong negative correlation between the total amount of rainfall in June and first generation attack (r = 0.7105 to 0.758). The maize of the higher FAO groups has high and robust stems with large number of big leaves. That intensive vegetative growth is a biological characteristic that attracts first generation of ECB to intensifying egg lying. However, the weather conditions are a crucial factor influencing moth activity in June and egg laying. For egg laying warm and dry June is the most favourable conditions. High population level of the first generation may lead to high level of second ECB generation which ultimately causes yield reduction.

european corn borer, maize, FAO maturity groups

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