Back Wind Damaged Maize Crops

Date: 23 February 2018

With the recent weather events some maize crop have gone down largely as a result of extreme winds. In general, maize is a reasonably resilient plant and often survives serious wind events.

Where plants have gone over, damage assessment before any action is taken is key. It is important to categorise how much of the paddock is affected and severity of the damage. In any event, it is important that you take your time to make the assessments and not panic. 

Crop growth stage will have an impact on how the crop quality and yield will be affected. Plants affected at later stages of grain filling development may not be affected as much as if it was during early grain filling.

When plants are leaning over with or without bent stems the first thing to do is assess the leaning angle. If stems are bent but upper plant parts have straightened vertically (aka goose necking) plants will likely still be able to transport water and nutrients and should continue to mature, albeit at a slower rate, and should hence be monitored.

Where maize has a significant lean (>30°), leaf shading can significantly reduce photosynthesis. In the worst case scenario, plants could eventually shut down and die as they are unable to supply carbohydrates required for kernel growth.

If plants are broken above the cob yield loss could occur to a level depending on how far the crop is further from reaching maturity. Where necessary, crops should be left to mature, but will mature slowly and may need to be harvested earlier than normal. Crop should be monitored and harvested when they get as close as possible to a good harvest maturity preferably at least 30% whole plant drymatter. 

Crops broken below the cob or are flat on the ground will result in either all or a substantial amount of the plant dying.  Kernels on the ears (cobs) will likely abort due to reduced grain filling as a result of poor photosynthesis.

The key when harvesting these crops is to slow down, harvest in the opposite direction to how the plant is lying and increase the amount of material that is picked off the ground.  It should also be noted that if the crop is wetter than normal, chop length should be adjusted, i.e., plants with a drymatter (DM) of <30% should be chopped at around 18-20mm. A good quality inoculant, such as 11C33 will help with the fermentation process, especially given the likely soil contamination and lower DM. Good stack management with good compaction are even more critical.

Talk to your local Pioneer area manager, contractor or merchant representative for advice and support.