With the planting season coming up, we thought it would be a good time to share a simple guide on soybean growth stages! It is sure to come in handy this growing season.<\/p>\n\n\n\n
Germination<\/strong> begins when a soybean seed absorbs 50 % of its weight in water. This is known as imbibition. Next up is the vegetative<\/strong> (V) stages, followed by the reproductive<\/strong> (R) stages. <\/p>\n\n\n\n Cotyledons appear on the surface of the soil<\/p>\n\n\n\n The first two leaves are unifoliolate and are produced on opposite sides of the stem. This is the first leaf node.<\/p>\n\n\n\n Nitrogen-fixing nodules begin to form on the root system. At this step, it’s important to assess the population to determine if re-seeding is required. Of course, you’ll need to evaluate your soybean stand visually, but you’ll also need concrete evidence for a good idea of where things are. Get your shovel out to search for the seedlings!<\/p>\n\n\n\n Nodules have probably started actively fixing nitrogen. If you cut a nodule in half and see a pinkish colour on the inside, you’ll know that it’s in good health and fixation is taking place. Dig up a few plants with a shovel to confirm active nodulation.<\/p>\n\n\n\n Floral buds start to develop from stages V4 to V6. Plants can recover from 100 % defoliation from hail at this stage with a minimal risk of yield loss. <\/p>\n\n\n\n At least one flower (purple or white) will have bloomed between the bottom third and sixth nodes of the main stem. <\/p>\n\n\n\n There is an open flower at one of the two uppermost nodes on the main stem. Flowering will continue for 3 to 5 weeks. From 20 % to 80 % of flowers will abort.<\/p>\n\n\n\n Pods are around 6 mm long (1\/4\u201d) at one of the four uppermost nodes on the main stem. The rate of potassium uptake peaks shortly after R2. <\/p>\n\n\n\n Pods are around 20 mm long (3\/4\u201d) at one of the four uppermost nodes on the main stem. Seeds start to develop and flowering continues. Nitrogen uptake reaches its peak between R4 and R5. <\/p>\n\n\n\n Seeds are around 3 mm long (1\/8\u201d) in a pod at one of the four uppermost nodes on the main stem. Seed growth picks up speed and root growth gradually slows down. <\/p>\n\n\n\n Green seeds fill a pod on one of the four uppermost nodes on the main stem. There is still significant nitrogen uptake from the soil, which then travels to the seeds. <\/p>\n\n\n\n Most pods are yellow and at least one pod on the main stem has reached its mature colour (reddish brown). Seeds at the R7 growth stage are at 60 % moisture. <\/p>\n\n\n\n 95 % of pods have reached their mature colour (reddish brown). 5 to 10 days of drying weather are generally required after R8 to obtain grain moisture below 15 %. <\/p>\n\n\n\nVE Emergence<\/strong><\/h2>\n\n\n\n
VC Unrolled unifoliolate leaves<\/strong> <\/h2>\n\n\n\n
V1 First unrolled trifoliolate leaves<\/strong><\/h2>\n\n\n\n
V2-V3 Second and third unrolled trifoliolate leaves<\/strong><\/h2>\n\n\n\n
V4-V5 Fourth and fifth unrolled trifoliolate leaves<\/strong><\/h2>\n\n\n\n
R1 Beginning flowering<\/strong><\/h2>\n\n\n\n
R2 Full flowering<\/strong><\/h2>\n\n\n\n
R3 Beginning pod<\/strong><\/h2>\n\n\n\n
R4 Full pod<\/strong><\/h2>\n\n\n\n
R5 Beginning seed<\/strong><\/h2>\n\n\n\n
R6 Full seed<\/strong><\/h2>\n\n\n\n
R7 Beginning maturity<\/strong><\/h2>\n\n\n\n
R8 Full maturity<\/strong><\/h2>\n\n\n\n