10 March 2022
Planters’ progression means more care needed with fungicides, growers told.
PROGRESSION in machinery capability could have drawbacks as well as advantages when it comes to planting, according to an application specialist.
Speaking at a recent Syngenta Potato Science Seed & Soil Pathogen webinar, Syngenta Application Specialist, Harry Fordham, advocated new advice for in-furrow fungicide application during potato planting which he says will help growers achieve a more complete zone of protection around the mother tuber when using modern high-speed belt planters.
He pointed modern planters are capable of operating at far higher speeds, compared to traditional cup planters.
“That could compromise the consistent incorporation of spray in the soil target zone around the mother tuber with the original sprayer set up on the planter, along with potentially resulting in the risk of drift at the higher speed,” Harry said.
Syngenta trials had investigated new nozzle technology, water volume use and the set-up of nozzle orientation while looking at the role of its fungicide Amistar in control of both black dot and Rhizoctonia pathogens in the soil in trials spanning three years.
Harry pointed out the original brass AZ in-furrow nozzle – which is no longer available – did have a very small orifice producing fine droplets susceptible to drift. Some of the alternatives trialled included hollow cone technology to give a wide band of application to cover more of the soil at speed, along with larger orifice less prone to blockage and drift.
Results of the trials have shown the Lechler TR80 had performed consistently well over successive seasons. The set-up recommended was with two nozzles - one at the front and a second at the rear of the planter shoe, to spray the soil as it falls back in to cover the planted tuber.
With the research repeatedly showing application at 100 l/ha producing the best results for both crop yield and tuber quality, compared to 50 l/ha, the TR80 was operated with an 015 nozzle in both situations, Harry said.
The other combination which showed good promise from one year of trials was a set-up instigated in Germany, using two Lechler FT90 nozzles, set up to deliver 33% of the spray at the front of the shoe, by fitting at 01 sized nozzle, and 66% at the rear on the closing soil, through an 02 nozzle.
“The relatively large nozzle orifice would be unlikely to block. More interestingly it is a pre-orifice nozzle design, so offers some level of drift reduction and may be a combination to consider, especially with higher speed planters,” Harry said.
More details in the May issue of Potato Review. Click here to subscribe if you don't already receive a copy.