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).
In this he summarised quotations from some of the most respected dairy nutritionists and academics in the USA. The article makes fascinating reading and many of the points raised are very relevant to local dairy farmers.
I've followed Dr Mahanna's example and using the same headings, have summarised some of the key issues my colleagues and I see with maize silage management in New Zealand.
Paddock
There is a sizeable gap between those farmers who consistently grow high yielding, high quality maize silage crops and those who don't. The most frequent issues we see in the field are poor ground preparation resulting in uneven plant populations, later than ideal planting dates, inadequate weed control and maize crops which are chopped too soon or too late.
Aim for a fine, even seed-bed. This will allow more accurate planting and good seed-to-soil contact. Some of the worst seed beds we see are the result of either too short a time between spraying out and cultivating or soils being tilled when they are too wet.
Walk crops regularly and be prepared to spray seedling weeds if necessary. Weeds often look insignificant when they are very small, but when they grow even low populations can have a major impact on maize silage yield and quality.
Choose a reliable contractor and communicate with them regularly. A low price job could cost you a lot in the long-term.
Harvest and storage
This quote, from Dr Mahanna's article could easily be applied to New Zealand farmers:
A visitor from Europe recently told me, "You Americans waste too much feed", and I see too much of this going on with my clients. He went on to say "we soil sample, prepare the ground perfectly, spend a lot of time trying to decide what is the right seed and population; you fertilise it, plant it, spray for weeds, bugs, maybe even treat with a fungicide and cut or chop at what you think is the ideal time. Then right at the end you wreck everything you worked so hard for by chopping too wet or too dry, not packing it enough and not maintaining a good silage face".
The best operators apply an inoculant, cover their maize silage as soon as it is harvested and seal the edges thoroughly. We have seen excellent results from using oxygen-barrier film. Aim for no spoilage at the top of your stack or bunker.
Place rodent bait in stations around the silage stack and replenish them frequently.
Feeding
If you are feeding significant amounts of conserved feeds it is important to understand their quality and also the quality of the pasture you are feeding them with. Laboratory test results can help determine the best combination of feeds, how much to feed and what minerals should be added. Silage test results can also help pin point management issues so you can do a better job next season.
One of the most common issues we see is poor silage feed-out management. It takes skill to remove silage without loosening the face. Ensure all farm staff understand the importance of keeping the silage stack face tight. Always ensure new staff are adequately trained before you let them loose on your silage stack.
To read a full copy of Dr Mahanna's Feedstuff article "Nutritionists, other experts offer forage advice" visit www.pioneer.nz/news/2016-01-12/nutritionists-other-experts-offer-forage-advice.html
• Ian Williams is a Pioneer forage specialist. Contact him at This email address is being protected from spambots. You need JavaScript enabled to view it.
