The dissected V3 plant, fig. 8, is shown with the leaves laid alternately (from side to side) in succession as they naturally appear on the intact corn plant. This same manner of display was used for all subsequent stages presented. Notice from the dissected V3 plant the stem apex (growing point) is still below the soil surface, and that very little stalk (stem) elongation has occurred.
Root hairs are growing from the nodal roots by this time, and growth of the seminal root system has virtually ceased.
All leaves and ear shoots that the plant will eventually produce are being initiated (formed) now. At about V5, leaf and ear shoot initiation will be complete and a microscopically small tassel is initiated in the stem apex tip. The stem apex at tassel initiation is just under or at the soil surface, although total above-ground plant height is about 20 cm (8 inches).
Management Guides - V3 Stage
The below-ground growing point during the very early leaf stages is especially affected by soil temperatures. Cold soil temperatures may increase the time between leaf stages, increase the total number of leaves formed, delay tassel formation. and reduce nutrient availability.
Destructive hail, wind or frost which damages the exposed leaves at V3 will have little or no effect on the below-ground growing point or final seed yield.
Flooding at any time when the growing point is below the water level can kill the corn plant in a few days, especially if temperatures are high.
Weed control reduces competition by weeds for light, water and nutrients. The use of chemicals, mechanical cultivation, and management practices such as higher plant densities or crop rotations, or combinations of these are effective weed control practices. Cultivation too deep or too near the plant after V2 will destroy some of the nodal root system; so cultivate cautiously.
figure 7 |
figure 8 |
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