Green snap, also called brittle snap, occurs when corn is in the vegetative state between V5 to V18 and strong winds cause stalk breakage at or below the growing point of the plant. Plants broken by green snap will not produce grain.
Corn that has reached V5 (5 leaf collars) is at or above the soil surface, making it vulnerable to green snap. During the rapid growth stage the internodes of the corn plants are elongating at a fast pace and new leaves can emerge every two days. As more leaves emerge, the plants are increasingly susceptible to experiencing wind and stalk breakage.
What causes green snap?
Temperature fluctuations are hard on corn stalks
When temperatures are hot, corn plants are somewhat capable of bending and are less susceptible to wind damage. But when cool temperatures occur during a wind event, they make corn plants increasingly rigid and subject to increased likelihood of green snap.
During the rapid growth stage, corn plant cells contain more turgor pressure (the water pressure within each cell). As turgor pressure increases, so does the probability of stalk breakage in strong gusty wind scenarios.While corn varieties can vary in brittle stalk ratings, the bottom line is that all corn is subject to breakage during high wind situations.
Chem applications can cause brittleness
An application of a Group 4, Growth Regulator herbicide can increase the probability of green snap. Growth regulator herbicides, such as 2,4-D and Dicamba are auxins that promote rapid abnormal growth in plants, which cause corn plants to develop more brittleness. Broadleaf weed resistance to many herbicides has increased the usage of these growth regulators in recent years, according to the USDA.
High nitrogen levels can favor green snap, too. When corn plant growing conditions are aligned for high yields that rapid growth can make corn plants brittle and subject to breakage.
High corn plant populations compete for resources
High corn plant populations also favor green snap because competition for nutrients, water and sunlight increases plant height while stalk girth decreases; however, yield loss from green snap is not directly proportional to stand loss. (Most hybrid corns planted today are capable of increasing individual plant yield by adding more dry matter or weight per kernel.)
The most serious loss of yield occurs when large areas of the corn field are broken off from green snap, rendering that area non-productive for grain.
Check with your crop insurance company provider to examine your policy to find if you are insured for wind damage in green snap situations.
EVI satellite imagery from the FBN network helps spot problem areas in your fields.
Satellite imagery is now accessible directly within FBN Maps and is included with FBN membership at no extra charge. Any member who has field boundaries draw in FBN will receive satellite images.