The impact of the sowing time on the European corn borer (Ostrinia nubilalis Hubner) attack
in some romanian hybrids

Adina-Daniela Tărău, Camelia Urdă, Ana Maria Vălean, Laura Şopterean,  Andrei Varga,
Roxana Călugăr, Alina Șimon, Florin Russu

 ARDS Turda

Keywords: maize, hybrids, sowing seasons, Ostrinia nubilalis Hubner, incidence of the attack on ear. 

 Abstract: European corn borer (Ostrinia nubilalis Hubner) it is the most representative maize pests, for the conditions in the Transylvanian Plateau and is the most important pest after the emergence of the tassel, attacking all the aerial organs of the maize plant. The damages are made by mature larvae which tunneling in stalks, tassels and ears. The attack on stalks affects plant developmental causing their breakage and, implicitly, the decrease in maize yield. The attack on ears favors the installation of pathogens, which depreciates the quality of the kernels.
The reaction of maize hybrids to European corn borer attack can be influenced by several factors, including the time of sowing. Certain corn hybrids show variable susceptibility to this pest. In these sense, the aims of this study were to (i) evaluate the influence of sowing date (season) of maize on the natural attack incidence of European corn borer larvae on ear; (ii) determine the reaction of hybrids from different FAO maturity groups regarding the natural attack on ear of this pest.
The research was carried out in the experimental fields at ARDS Turda, using 12 maize hybrids as biological material (Turda 248, Turda 165, Turda 201, Turda Star, Turda 332, Turda 344, Turda 335, Turda 2020, Turda 380, HST 148, HST 149, Sur 18/399 HST). Observations and determinations on the natural attack of the European corn borer on ear were carried out in the period 2021-2023.
The timing of sowing influences the susceptibility of maize hybrids to the attack of Ostrinia nubilalis larvae. Earlier sowing seasons favor natural European corn borer attack on ear. The hybrids Turda 248, Turda 165, Turda Star, Turda 344 and Sur 18/399 hybrids are the most susceptible to European corn borer attack on ear and the most tolerant Turda 380, Turda 2020, HST 149 and HST 148. The choice of the optimal sowing season, in combination with other agricultural practices and the use of hybrids tolerant to the attack of Ostrinia nubilalis, can significantly reduce the damage caused by this pest.