Weather Conditions and Maturity Group Impacts on the Infestation of First Generation European Corn Borers in Maize Hybrids in Croatia.

Renata Bažok,Ivan Pejić,Maja Čačija,Helena Virić Gašparić,Martina Kadoić Balaško,Darija Lemić,Zrinka Drmić

doi:10.3390/plants9101387

Renata Bažok, Ivan Pejić + Show 5 more

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https://doi.org/10.3390/plants9101387

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Abstract

Overwintering success and weather conditions are the key factors determining the abundance and intensity of the attack of the first generation of European corn borers (ECB). The tolerance of maize to the 1st generation of ECB infestation is often considered to be connected with the maize maturity time. The aims of this research were (I) to examine the reactions of different maize FAO maturity groups in term of the damage caused by ECB larvae, (II) to analyze the influence of four climatic regions of Croatia regarding the damage caused by ECB larvae, and (III) to correlate observed damage between FAO maturity groups and weather conditions. First ECB generation damage has been studied in the two-year field trial with 32 different hybrids divided into four FAO maturity groups (eight per group) located at four locations with different climatic conditions. The results showed a lack of correlation between the FAO maturity group and the percent of damage. The percent of damage was positively correlated with the average air temperature in June (r = 0.59 for 2017 and r = 0.74 in 2018, p = 0.0001) within the range from 20 to 24.5 °C and was negatively correlated with the relative air humidity (r = −0.58 in 2017 and r = −0.77 in 2018, p = 0.0001) within the range of 50% to 80%. Our results provide a better understanding of the different factors that influence ECB damage. The obtained data could be used to predict the damage from the first generation of ECB under the weather conditions of different regions.

Highlights

The European corn borer (ECB) (Ostrinia nubilalis Hübn.), is a serious pest of maize (Zea mays L.)in Europe and the United States (US) as well
The aim of this research was to (I) determine the differences among FAO maturity groups regarding the damage caused by ECB
Statistical analysis of the weather conditions recorded in May and June showed that the temperatures in May and June significantly differed between years (Table 1)

Summary

Introduction

The European corn borer (ECB) (Ostrinia nubilalis Hübn.), is a serious pest of maize (Zea mays L.)in Europe and the United States (US) as well. The European corn borer (ECB) (Ostrinia nubilalis Hübn.), is a serious pest of maize (Zea mays L.). The pest is native to Europe [1] and was accidentally introduced in the US in 1917 and spread around the country causing serious damage. The losses are estimated at $1 billion per year [2]; ECB is one of the most important pests from an economic point of view. The preferred host plant of this pest is maize [3]; ECB is a polyphagous insect and attacks many different plants, including sorghum, pepper, hemp, millet, chrysanthemums, and some weeds [4]. The extent of losses in maize caused by this pest depend on the degree of the infestation, the year, the yield averages and can range from 250–1000 kg/ha [3].

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