Raewyn Densley heads up the team investigating the variation in germination that has been discovered across Northland, Waikato and Bay of Plenty in assorted hybrid varieties supplied by the seed company.
In affected crops the seed has germinated, put out a root and a small shoot but not emerged above the soil surface.
“At this stage there is not a lot we cannot say because we simply do not know all the answers yet. But what has just come to light is that within the crop there are some paddocks that are fine, some that are affected by patchy germination.”
Early investigations indicat the issue is in chemical treatments used on the seeds, rather than the seeds themselves.
“Aside from a small portion of seeds that are not treated at all and sold to organic growers, almost all seeds in New Zealand are treated.
“It depends on the growing conditions what they are treated with.
“Growers with no insect issues may use only a fungicide while some may also incorporate an insecticide and in some cases a bird repellent too.”
She said in 30 years of marketing maize seed in NZ this is the first time the company has experienced an emergence issue with seed.
“Not all the hybrids have been affected and some areas have more issues than others.
“Each hybrid is genetically different so not all hybrids will be equally affected by the problem.”
Densley said the issue is only now becoming more apparent as earlier maize crops start to emerge and the gaps in seed germination become obvious.
The company runs a replacement policy for growers who have experienced problems with crop germination and every year a small proportion require resowing.
But she said the problem became apparent when a higher than usual proportion of growers started reporting emergence problems in the past two weeks.
“In terms of having to resow, every situation will be different. We are encouraging all our growers who notice problems to contact our team and we will work with them to decide on the best course of action.”
The seed treatment uses two off-label (not formally approved) products. However, there are no conditions around the products’ off-label use and such application is not uncommon for agri-chemicals.
As the company gathers more data Densley hopes it will better determine a pattern to the problems experienced.
Several contractors said they had issues with some clients experiencing the problems reported and are working with Pioneer to determine the cause.
One Waikato report has been of a grower having 45ha of crop lost and another losing almost half of a 60ha plot.
Brook Nettleton of Waikato based BlueGrass contracting said he has the odd client with patchy germination but it is not overly alarming.
“It may be related to a hybrid but we are not sure how widespread that hybrid may be.”
Densley urged any growers experiencing problems to contact their Pioneer area manager.
