Brittle Snap in Corn
What is Brittle Snap?
This is the condition where rapidly growing stalks are broken by strong, sudden winds, associated storms and similar related weather activity. During rapid growth, the cell walls are extremely fragile and stalk tissue may be at a greater risk of brittleness compared to other growth stages.
What Factors Affect Brittle Snap?
Many factors affect brittle snap severity. The timing and velocity of the wind are the most obvious, coupled with the hybrid involved. Heavy winds during cool morning hours will cause more brittle snap than if the wind occurred during the heat of the day when plants are more flexible. Strong-rooted hybrids with less give at the base will have more brittle snap than a shallow-rooted variety. Conditions that favor rapid growth will increase the incidence of brittle snap; some of these conditions include adequate nitrogen, high temperatures, good soil moisture and the use of growth stimulator herbicides such as 2,4-D, dicamba, and clopyralid. Field geography, soil type and crop management practices also influence brittle snap severity.
When is a Corn Plant Most Susceptible to Brittle Snap?
During a corn plant's vegetative growth phase, rapidly elongating internodes are often brittle and susceptible to breakage. The two most common periods for brittle snap are the V5 to V8 stage, or when the growing point is just emerging from the soil line, and the V12 to R1 stage, which is about the two weeks prior to tasselling, until just after silking.
The V5 to V8 Stage?
When the growing point is just emerging above the soil line, the corn plant is entering a period of rapid change. The nodal root system is beginning to expand rapidly so the plant's ability to take up water and nutrients is increased dramatically which enhances faster leaf and stalk growth in the plant. Fast growth means the cell walls become thinner or are more fragile. Also at this stage of growth, the many nodes and internodes are arranged together in a small area. This concentration may make the plant less flexible and more susceptible to breakage. Brittle snap at this stage usually occurs below the growing point so snapped plants usually do not recover.
V12 to Tasselling?
At this time the corn plant is going through its most rapid stage of growth. This is the 21 to 28 day time period when the corn plant increases in size from about 3 feet to its mature.