Field Performance of Some Soybean [Glycine max (L.) Merr.] Cultivars Sown on Different Dates

Abstract

Soybean [Glycine max (L.) Merr.], with high oil and protein content, is one of the world's main nutritional sources and millions of hectares are given over to its cultivation. Intensive farming and producing multiple crops per year (such as second-crop soybean cultivation), can improve natural resource exploitation and productivity. The objective of this study was to examine the effects of some soybean cultivars on yield and yield components in lowland conditions in the Mardin province over the main-crop and second-crop seasons. This research was carried out in the lowland conditions of Mardin province in Türkiye in 2018 and 2019. The A-3127, Arısoy, Ataem-7, Blaze, Bravo, Cinsoy, Gapsoy-16, Lider, May-5312, Nova, SA-88, and Umut-2002 cultivars were used as plant material in this research. Since the region is suitable for growing double crops per year, soybean field trials were carried out both as a main crop and as a second-cropped. Sowing dates and 12 different soybean cultivars were taken as factors in the research. The first sowing took place on April 16, the second on April 25, the third on June 15, and the fourth on June 30 in both years of the research. Two sowings were the main crop, while the other two were second-crop. According to the results, the A-3127 (3700 kg ha-1) and Gapsoy-16 (3694 kg ha-1) cultivars produced the highest seed yield. The Arısoy (676 kg ha-1), Gapsoy-16 (676 kg ha-1), A-3127 (662 kg ha-1), and Cinsoy (662 kg ha-1) cultivars produced the most oil yield. The study determined that early sowing increases overall yield while late sowing decreases seed yield significantly (on average by 30%). For this region and in areas with similar agricultural environments where double-crop can be grown each year, early cultivars for a second crop may be recommended to reduce the vegetable food and oil deficit.