Шкодочинність бур’янів у посівах соняшнику

Abstract

Проведено дослідження з визначення шкодочинності автотрофних та гетеротрофних бур’янів у посівах соняшнику в умовах Лівобережного Степу України. Встановлено динаміку зміни врожаю залежно від типу засмічення посівів, найбільш шкодочинні види бур’янів, ступені шкодочинності різних видів: Amaranthus retroflexus, Xanthium strumarium, Chenopodium album, Lactuca tatarica, Orobonche cumana.

Проведены исследования по определению вредоносности автотрофных и гетеротрофных сорняков в посевах подсолнечника в условиях Левобережной Степи Украины. Определены динамика изменения урожая в зависимости от типа засорения посевов, наиболее вредоносные виды сорняков, степени вредоносности таких видов: Amaranthus retroflexus, Xanthium strumarium, Chenopodium album, Lactuca tatarica, Orobonche cumana.

Alongside with the decrease of biological productivity, weeds are inflicting technological damage, deteriorating the quality of crop and economical effectiveness of growing crops. The quality of mechanical cultivation and planting is falling significantly. The authors conducted the research on determination of harmfulness of autotrophic and heterotrophic weeds in sunflower sowings in the conditions of Left-Bank Steppe of Ukraine. It was established the dynamics of crop variation depending on the type of crowding of sowings, the most harmful species of weeds, degrees of the harmfulness of different types: Amaranthus retroflexus, Xanthium strumarium, Chenopodium album, Lactuca tatarica, Orobonche cumana. It was found out that regardless of weather and agronomic conditions of growing sunflowers, seedlings of weeds appeared in the period from the beginning of field works and to the closing of dominant agrophytocenosis. In the modeled research the authors determined the loss of crop from the presence of certain segetal species and degrees of their harmfulness in sowings depending on quantity. The results of the study showed that the greatest crop loss was experienced by sowings of sunflower where Lactuca tatarica grew. In the presence of it 10 pc. / m2 the loss of crop was 0.37 t / ha, at 20 pc / m2 - 0.65 t / ha, and in case of 30 pc / m2 – 1.04 t / ha. It was found out that unlike non-parasitic green weeds, heterotrophic weeds are more closely connected with host-plants. In agrophytocenosis of sunflower the following parasitic weeds were found: Orobanche cumana, O. Ramose, which parasitized on cultivated plants. Such root parasites as Orobonche cumana were more commonly found on the roots of sunflower. Thus, parasite-weeds as well as autotrophic, have significant effect on the decrease of sunflower crop, since sunflower is a cultivated crop, it is possible to exercise control over segetal plants in its sowings for a rather long time. Therefore permanent control over the purity of agrophytocenosis concerning the presence of segetal species is a necessary component of a set of measures aimed at obtaining high and sustainable crops.