Condições hídricas do solo e a emergência da soja em diferentes épocas de semeadura

Abstract

The present work was carried out to evaluate the influence of different planting times on the percentage of soybean emergence in cropping systems with and without irrigation. Two soybean cultivars (BRS Bônus IPRO and BRS Foco IPRO) were evaluated in four soybean planting times (28/09, 02/10, 07/10 and 13/10/2021) in an environment with and without irrigation, with the plots being subdivided by the four seasons and sub-subdivided for the two cultivars. These assessments were carried out until the last season completed 20 days after sowing (DAS). Comparing the final stand

of plants from the 4 seasons, it was noted that when planting was carried out in mid- October (4th season), the stand obtained was formed with a greater speed associated

with a higher percentage of emergence, this is due to the regularization of rains occurred later. However, the planting carried out in the first half of October (2nd and 3rd seasons) showed regular values, showing that anticipating the planting of soybeans aiming at the corn off-season can be viable, even with the plants showing a smaller stand when compared to those that were sown later. For the season sowed at the end of September (1st season), early planting resulted in a low germination speed and a low germination percentage. For all planting times, the irrigated soybean condition ensured a faster seedling emergence and a better final stand when compared to the rainfed condition, which for irrigated cultivation shows a possibility of anticipating planting with a view to a second crop. For non-irrigated crops, the best time for planting was October 13th, with late planting being more favorable for seedling emergence and development.