Impact of selected agrotechnical factors on the occurrence of pests in maize cultivation (Zea mays L.)Wpływ wybranych czynników agrotechnicznych na występowanie szkodników w uprawie kukurydzy (Zea mays L.)

The objective of presented in this paper the results of the 4-year field research was an evaluation of effect of two-component (NP) fertilizer placement depth, the type of nitrogen fertilizer and the date of its application on the occurrence of pests in maize cultivation. Changing weather conditions in the years of performing the field studies significantly differentiated the percentage of maize plants damaged by pests. The depth of NP fertilizer application did not have a significant impact on the number of plants damaged by the European maize borer [Ostrinia nubilalis (Hübner)], frit fly (Oscinella frit L.) and cereal leaf beetle (Oulema melanopus). Frit fly damaged plants fertilized with ammonium nitrate at higher degree than the plants fertilized with urea. In-season sidedress nitrogen application at the BBCH 15/16 growth stage increased the percentage of plants damaged by cereal leaf beetle compared to the pre-sowing N application. Regardless of the years of research and the NP fertilizer placement depth, significantly the smallest damage to plants caused by cereal leaf beetle was recorded for pre-sowing application of ammonium nitrate or urea and significantly the greatest when ammonium nitrate was applied in season at the BBCH 15/16 growth phase.