Rain advances soybean planting in central Brazil but delays southern winter crops

Conab published its October Agricultural Monitoring Bulletin on 23 October, assessing weather and crop development from 1 to 21 October. It describes uneven rainfall: moisture supported summer planting in the Center-West, while excess water hindered field work and affected winter crops in the South. Lower rainfall, in turn, constrained soybean planting in parts of the North and Northeast.

For the 2026/27 season, Mato Grosso had planted more than 60% of its planned soybean area. Planting also advanced in Paraná, where most established fields were developing well, although Conab said excess moisture could cause germination failures, weeds and greater pest and disease pressure. Progress varied across Goiás: work in the southwest was moving ahead, with completion expected during October, while rainfed planting in other areas remained limited or temporarily paused.

Conditions differed in Mato Grosso do Sul, where high soil moisture had temporarily halted planting in most production regions. In Rio Grande do Sul, growers awaited drier soils and rain-free days; in São Paulo, wet fields restricted machinery access. Conab reported vegetation indicators above the historical average across monitored regions but found differences from the previous season: higher readings in southern Goiás and southwestern Mato Grosso do Sul, and readings near the prior season in northern Mato Grosso and western Paraná.

For 2025/26 wheat, rainfall harmed grain quality in São Paulo and Paraná. São Paulo’s harvest was nearing completion, with much of the harvested grain below the quality expected by milling industry. In Paraná, hectolitre weight was also below expectations and harvest had reached 75% of planted area. Progress was slow in Rio Grande do Sul because of heavy rain and lower solar radiation; much of the crop was filling grain or maturing, stages sensitive to ear diseases.

Figures for summer crops show how one weather pattern can affect different crops and growth stages differently. Rice sowing had reached about 40% of planned area in Rio Grande do Sul and slightly more than half in Santa Catarina by the first half of October; rain and saturated soil raised field costs and hindered early crop development. First-crop corn planting was nearing completion in Paraná, some eastern Goiás municipalities were between 50% and 70%, and Rio Grande do Sul exceeded 80% of planned area. These percentages measure planting progress, not final output or yield.