Canopy and Root growth: The canopy reaches its full size, maximizing light interception for photosynthesis. Vegetative growth slows to a stop on indeterminate varieties; the last new flowers and pods at the top of the plant appear by the R5 stage. Root growth also changes. Primary and lateral roots grow vigorously up to the R5 stage, but after the R5 stage, the shallow roots begin to senescence while deeper roots continue growing until roughly R6.5, i.e., R5+3^{rd} to 4^{th} week. By about R6.5, root growth is completed.

What changes can be seen in soybean pods and seeds as they mature?

▶ Pods and seeds gradually change color and moisture content.

▶ At R6 (full seed), the pods are green, and the seeds moisture is ~70-75%.

▶ By R6.5, seeds have accumulated most of their dry weight, and moisture drops to sim60-65%.

▶ By R7 (beginning maturity), pods turn yellow-brown and seeds have <50% moisture (shows physiological maturity). At this stage, seeds have lost much of their moisture, and pods turn brown.

▶ After R7 stage to R8 stage, seeds continue to dry down (to~13% for harvest), seed dry weight reaches its maximum.

At the R8 stage, marked by dry pods and mature color, indicates full maturity. At this point, no additional dry weight is added.

▶ After the R8 stage, with the pods and stems fully dry, the plant is ready for harvest.

Indeed, this farmer's old adage provides wisdom on how to be careful in seed filling months, August and September, which coincide with the mid-seed filling phase, during which the final seed size is determined. As the plant reaches peak physiological and structural development, different practices that enhance the assimilate supply – maintaining green leaf area, avoiding defoliation, and supplementing nutrients – can extend seed filling, improve seed composition, and maximize soybean yield potential. Farmers can make timely, yield increasing decision by understanding these dynamics.

Remember, what you do in August and September shapes the soybean harvest in October/November.