Spraying a fungicide requires contemplating the stage of plant a bit in another way than when spraying a herbicide. At herbicide timing, the cover of the crop is lots shorter and fewer dense.
“For fungicides, we’re now talking about a taller canopy, a canopy that’s probably closed in, and a canopy that’s a little bit diverse in its structure, where the top half might look completely different from the bottom half,” says Tom Wolf of AgriMetrix and Sprayers 101, on this Wheat College episode.
With respect to concentrating on a illness, it’s good to know the place the illness develops and the way it will journey by means of the cover, with a purpose to target it correctly. Wolf says that the spray must land the place the illness is, as most fungicides don’t translocate inside a plant very properly.
Water volumes in the tank combine performs into this by manipulating the place the spray goes, particularly deeper into the cover — it’s the strongest instrument accessible when making use of fungicides, says Wolf.
A wheat or cereal cover has roughly three layers, or target zones. The highest layer is the emerged head, for fusarium head blight timing, which is a comparatively straightforward target with twin nozzles for a directed spray, says Wolf.
Getting deeper into the cover to hit these backside two layers, for tan spot, or different ailments that come up from residue, the solely strategy to hit them is to extend water quantity, to extend the droplet density, which Wolf says is the “currency of fungicide performance.” (Story continues under video)
“What I often recommend is to look down, and ask yourself the question what part of the plant canopy do I have to target, based on the disease and the mode of action, and can I see that plant part?” Wolf says, and when you can’t see the plant half, that’s the place the water quantity aids.
In the case of temperature and spraying fungicides, the plant nonetheless must take that fungicide up, which is rather more environment friendly when the droplet continues to be moist, and in scorching, dry situations, that droplet may dry earlier than it’s absorbed by the plant.
Wolf suggests to look at the Delta T (which you’ll find extra information on on this Wheat College episode), enhance the water quantity, and contemplate the droplet dimension.
For aerial spraying, practicality comes into play as an plane has a smaller hopper that places down finer droplets, however they will’t spray on windier or hotter days.