What stage is your crop in?
All too often, agronomists provide crop recommendations according to stages of crop growth. For corn and soybeans, this is referred to as the “V” stage. While a plant’s progression through these stages can’t be determined by days on the calendar (due to varying hybrid types, environments, planting dates and location,) they are standardized by visual plant development.
The V stage of the corn plant is determined by the number of collars present on the plant. The leaf collar is the light-colored collar-like “band” located at the base where every leaf blade connects to the stem of the plant. Leaves within the whorl, (those not fully expanded to allow for a visible leaf collar) are not included. For example, the photo at left has three collars so it’s considered a “V3 plant”, even though there are 6 leaves present. If this example were to be converted to a whole-field recommendation, the field would be considered at stage “V3” when 50% of the plants are determined to show three fully developed collars.
The soybean version of this identification system divides plant development into vegetative (V) and reproductive (R) stages. With the exception of the first two stages, the (V) stages are designated numerically as V1, V2, V3, through V(n), where (n) represents the total number of nodes that develop (fluctuates by variety and environmental influence). The V stages following VC are numbered according to the uppermost fully developed leaf node. To determine the correct stage, start with the unifoliolate leaf node. A leaf node is fully developed when the leaf above it has fully unrolled, meaning the leaflet edges are no longer touching. The eight R stages are simply designated numerically and describe the stages of flowering, pod production, pod fill and maturity.
Click the photo below for an expanded and printable visual of all growth stages in both corn and soybeans. We’d love to hear how the crop is progressing on your farm. What stage are your crops currently in?