Fall Armyworm in NZ Maize: Four Years of Research
Four years since it was first detected in New Zealand, researchers and growers now know much more about management of maize pest fall armyworm (FAW).
Good quality maized silage is best made when whole plant dry matter is between 30-40%. If harvested at less than 30% dry matter, the silage stack will be too wet, resulting in stack leachate, which in turn, represents nutrient loss. In contrast, if dry matter is above 40%, stack compaction and air exclusion will be much more difficult, typically leading to aerobic bacterial losses.
An important maturity indicator is the maize kernel milk line, where the milky liquid changes into the harder darker starch line. By snapping a cob in two and examining the upper portion's kernels, the milk line can be easily seen. When the milk line is one third of the way up from the bottom of the kernel, the plant is in the 28-32% DM range.
Milk line is only indicative that harvest time is near and there are other indicators needing consideration. In-field estimation of crop DM requires considerable experience, which most contractors and technical advisors have experience in harvest scheduling and can offer advice on harvest maturity.
As the maize harvest season proceeds, North Island Velvetleaf coordinator Sally Linton reminds farmers, growers and contractors that machinery hygiene is critical in the prevention of the spread of unwanted weed pests including velvetleaf.
