The new realities of using neonic seed treatments

Saturday, January 9, 2016

Agriculture is a science-based, evidence-based, technology-driven business. We have an innate desire to do the right things. If given enough lead time and research support, we can adapt

by DALE COWAN

Farmers, Ontario agriculture ministry research support staff and the crop inputs industry have been working together to understand and implement the requirements for complying with the new realities of using neonic seed treatments.

Far from a perfect situation, it does however bring Integrated Pest Management (IPM) to centre stage in demonstrating the need for using treated seed. The underlying principle in IPM is to take action when economic thresholds are breached by the pest in question and formulate an appropriate response, using all available mitigation practices to reduce economic loss with the smallest possible environmental footprint.   

Over the past two seasons, some farmers and crop input retailers have been conducting side-by-side seed treatment trials comparing neonic treatment to fungicide only. The results have been variable. Neonic treatments most often show increases in yield capture, with some heavier clay soils showing no economic benefit. In some cases, higher yield capture and greater net returns can be seen when no neonics are used and still other fields with sandy loam textures show significant yield capture.  

It all raises the question whether all fields and all acres in a field need a prophylactic treatment to control a pest – in this case, wireworms. Is wireworm severity predictable? Do they have a spatial component in so far as they are prevalent in certain areas each year? We know they tend to stay close to where they hatched and finish their life cycle in close proximity, moving up and down with soil temperature and food supply rather than laterally. They are attracted to CO²  release, which brings them to feed on germinating seeds. The use of bait traps that emit CO² is one of the scouting techniques to determine their presence.

Knowing where to place bait traps for pest assessments can be challenging. If tillage was done recently, we may have a situation where organic matter is breaking down, releasing CO² throughout the soil profile. Pests may not be attracted to the bait at all, resulting in no capture and a very good chance they would be missed in a scouting activity.

Precision ag technologies may be useful in setting up for scouting and bait placement and for mitigating damage. Drones with thermal imaging may detect areas with warm soil temperatures, increasing the likelihood of identifying favourable sites for bait placement.

With an appropriately equipped planter and yield monitor technology, coupled with a global information software system (GIS), a split planter test strip can be set up and responses measured in many replicated strips. It is as simple as taking half the planter rows and filling them with a neonic-treated seed and the other half with a check treatment of fungicide only. You can then harvest with a yield monitor and run a split planter script to see the results in a spatial context across the field in map form.

The following map illustrates the variable yield response to insecticide treatments. You can readily see that not all acres respond equally and some areas actually give higher yields without neonic treatments. This illustrates that the pest in question is not uniformly distributed.  It should also raise the question whether the treatment should be applied everywhere.  

The map also shows the T1 treatment with fungicide to compared to T2 treatment fungicide and insecticide, resulting in 14 more bushels of yield captured with neonics. What's interesting is that it doesn't show a uniform yield advantage as the areas in blue are where the fungicide-treated seed yielded more than the neonic-treated seed

This map then raises questions: Do we know enough about the questions? What else is being controlled? Can we set up an application system with an alternative treatment and apply where needed when we plant?

Agriculture, if anything, is adaptable, We are a science-based, evidence-based, technology-driven business. We have an innate desire to do the right things. If given enough lead time and research support, we can adapt.

We are beginning to see the development of LFR (liquid fertilizer ready) insecticides formulated to be compatible in liquid pop-up fertilizers that are already placed on the seed at planting. We could go so far as injecting them as needed into the pop-up fertilizer stream at the seed furrow without mixing up a whole tank of liquid fertilizer.

Within the next two seasons, we will see widespread availability of dual-hybrid corn planters and aftermarket retro fits with the ability to have two hybrids per row. With an appropriate mapping script, hybrids can be switched on the fly, depending on what we are trying to accomplish. One hopper could be neonic-treated and the other fungicide only. If indeed the wireworms are rather stationary year over year, then maps can be created to run the corn planter and drop the appropriate hybrid as needed.

We need to do some research to understand the pests better and to see if the technology is applicable long-term. As with most Precision ag technologies, the capability is built well ahead of the expert system to manage them effectively. Nonetheless, we have a challenge with pest management we have a technology but we need the research to go with it. BF     

Dale Cowan is a Certified Crop Adviser in Ontario and the Senior Agronomist and Sales Manager for Agris and Wanstead Co-operatives, located in southwestern Ontario.