Author:
Liaska Y.,Stryhun O.,Honcharenko O.,Kravchenko V.
Abstract
Goal. Determine the damage to modern corn hybrids by the caterpillars of the cotton bollworm, develop a point scale for assessing the damage of kernels on the cob, and calculate the direct losses of grain yield.
Methods. Field. The studies were carried in the research fields of the Cherkasy Research Station of Bioresources of the NSC «Institute of Agriculture of NAAS» 2017—2019. The cultivation of corn was carried out in accordance with the cultivation technology recommended for the Forest-Steppe zone of Ukraine, Cherkasy region. Plot size — 56 m2, in four replicates. Placement of plots — randomized. The number of damaged corncobs of cotton scoop was determined per hectare. To calculate the number of damaged kernels per corncobs, each damaged corn cobs was opened and the number of eaten and damaged kernels was counted. To calculate the direct yield losses for each corn hybrid, the total number of kernels eaten and damaged by the caterpillars of the cotton bollworm (per hectare) was calculated, which was multiplied by the mass of 100 kernels, respectively.
Results. The degree of harmfulness of cotton bollworm caterpillars on maize hybrids of different maturity was investigated. In 2017—2019 The corncobs are most damaged in hybrids of the mid-maturing group — 58.4%, less — in early-maturing hybrids — 41.1%, and in the middle-early ones — 47.8%. For the first time, a nine-point scale was developed for assessing the defeat of caryopses on the cob by Helicoverpa armigera Hbn. caterpillars direct losses of grain yield are calculated. It was found that significant yield losses were observed in all mid-season maize hybrids (0.185—0.280 t/ha).
Conclusions. In the Left-Bank Forest-Steppe of Ukraine, the cotton bollworm turned out to be a dangerous pest of the generative organs of corn. Therefore, the selection of resistant hybrids to attack by caterpillars of the cotton bollworm is a key element in the protection of this crop. And the nine-point scale developed by us allows us to assess the degree of damage to caryopses by the caterpillars of Helicoverpa armigera Hbn.
Publisher
Institute of Plant Protection of NAAS
Subject
General Earth and Planetary Sciences,General Environmental Science
Reference16 articles.
1. Demenko V.M., Vlasenko V.A., Yemets O.M. (2012). Obgruntuvannia chyselnosti osnovnykh shkidnykiv zernovykh kultur v umovakh pivnichno-skhidnoho Lisostepu Ukrainy. [Substantiation of the number of the main pests of grain crops in the conditions of the north-eastern Forest-steppe of Ukraine]. Visnyk SNAU. 9 (24). Vyp. 9 (24). Seriia «Ahronomiia i biolohiia». Р. 14—18. (in Ukrainian).
2. Shevchenko O.V. (2017). Problema hlobalnoi zminy klimatu v konteksti mizhnarodnoi bezpeky. [The challenge of global climate change in the aspect of international security]. Aktualni problemy mizhnarodnykh vidnosyn. [Actual problems of international relations]. Vyp. 130. P. 24—38. (in Ukrainian).
3. Dolia M.M., Pokozii Y.T., Mamchur R.M. (2004). Fitosanitarnyi monitorynh. [Phytosanitary monitoring]. Kyiv: NNTs IAE. 294 p. (in Ukrainian).
4. Prohnoz fitosanitarnoho stanu ahrotsenoziv Ukrainy ta rekomendatsii shchodo zakhystu roslyn u 2012 r. [Forecast of phytosanitary condition of agrocenoses of Ukraine and recommendations for plant protection in 2012]. Ministerstvo ahrarnoi polityky ta prodovolstva Ukrainy. Natsionalna akademiia ahrarnykh nauk Ukrainy, Holovna derzhavna inspektsiia zakhystu roslyn. Kyiv. 2012. (in Ukrainian).
5. Kuzmynskyi A.V. (2013). Stiikist hibrydiv kukurudzy do luskokrylykh shkidnykiv. [Resistance of corn hybrids to lepidopteran pests]. Biuleten Instytutu silskoho hospodarstva stepovoi zony. № 4. Р. 132—135. (in Ukrainian).