Weeds: when corn pops up, so do weeds. Now is the time toget a handle on what else is in your fields.
V3 (Third Vegetative Leaf)
GDU’s to V3: 330
Days after emergence: 19 days
Height: about 5 inches
What’s happening in the plant at V3?
At V3 the plant depends less on seed nutrients.
Nodal and Seminal roots supply more and more moisture and nutrients.
Fertilizer deficiencies: the plant is looking for nutrients outside of itself. Small developing root systems need the fertility close by. For this reason, I am a big fan of starter fertilizers.
You may be able to tell at this point if you didn’t have enough fertilizer up front.
V4 (Fourth Vegetative Leaf)
GDU’s to V4: 390
Days after emergence: 24 days
Height: about 8 inches
What’s happening in the plant at V4?
Roots continue to expand.
3 sets of nodal roots should be visible.
Stalk will start to elongate, putting on height.
Growing point is still under the ground.
Fertilizer deficiencies, especially incorn–on–corn fields. (Yellow anemic looking fields). Like V3 a small root system still may not reach most of the broadcast fertilizer applied.
You will really start to notice in V4 if you’re short on nitrogen.
If short, amendments can be made but you will need to do it soon before yield loss occurs.
V5 (Fifth Vegetative Leaf)
GDU’s to V5: 450
Days after emergence: 28 days
Height: about 12 inches
What’s happening in the plant at V5?
Starch has been converted to sugar and the seed no longer contributes to the plant’s growth. Your baby can now feed itself!
The growing point moves above ground and the plant is susceptible to the elements: hail, frost (not that we’d get that), etc.
This is when corn will go from looking a little awkward to looking awesome! That’s because the root system is now big enoughto utilize the fertilizer throughout the profile.
If you split the stalk, you can find the ear!
The first leaf that appeared during emergence shrivels up and dies off.
Greensnap: If temps are warm and the plant is growing nicely, you can start to have greensnap issues. Rapidly elongating cells tend to be more brittle and with high wind can be a problem starting at V5.
Stay tuned for part 2 of this series where we look at stages V6 to VT.
Rick is a true agronomist at heart. He gets excited about the ins and outs of product performance and helping growers (or as many come to be known, friends) find the very best products for their acres. When he isn’t thinking about the next greatest products for the Peterson Farms Seed lineup, he’s busy with wife Erin and son Leland growing monster pumpkins (like, 1200+ lbs) on their land near Underwood, MN.