Weather delays for seeding and spraying make it all the more important to have equipment ready to go and running smoothly when productive moments come along. Here are a few preparations to consider for the drill and sprayer.
Check for air flow through each opener. Look for air leaks and cracks that could reduce pressure or cause seed and fertilizer to dribble out from the wrong place. To do this, have someone walk around the drill as you crank product through. Check big and small hoses, especially where they connect with manifolds. You can often hear the hissing of air through crack. You can also feel air coming through. If you’re alone, run product through then do a walk around to look for seed and fertilizer laying where it shouldn’t be.
If the drill is new (or new to you), the learning curve required to work the kinks out will be extra frustrating if seeding is already late. Perhaps have the retailer help you check it over and give a heads-up on possible issues to watch for as you “ground truth” the technology.
Empty the fertilizer tank if seeding is delayed. In humid conditions — often the precise conditions that cause delays — fertilizer can start to clump together. This can lead to blockages in the bottom of tanks and metering systems. Emptying the tank if the drill sits idle for a day or more may prevent this. At the same time, check manifolds for build up that may reduce performance.
While the sprayer is idle, consider installing low-drift nozzles that can improve performance in reasonable (20 km/h or less) winds. Perhaps higher-flotation tires would be worthwhile if it looks like a wetter spraying season.
Try to avoid leaving the sprayer tank full. The longer a herbicide sits in a sprayer, the greater the risk that it is going to hang up in the tank OR that older herbicide residues in the tank and plumbing will be freed and added to the tank mix. Unwanted consequences can result.
The ideal is to assess conditions, then fill the sprayer if conditions are right for spraying. With a limited window, fill the sprayer just enough to spray it out within that window. If, due to an unforeseen reason, a spray tank has to be left overnight with herbicide sitting in it, (1) pull fresh water from the flush tank to rinse the booms before letting it sit – if the sprayer has that feature. (This is especially important for Liberty and glyphosate.) (2) Run the agitation frequently. (If the sprayer doesn’t have the feature described in point 1, potentially turn on booms occasionally to keep product from settling in screens.) (3) Check a few screens and filters before going again. (If they’re bad, all may need to be cleaned.) And (4) re-charge booms with around 15 gallons of product before starting spraying again. Have a sanitary location to do this (such as a biobed) where product will not run into streams, etc.
The recirculating boom: A useful design that helps flush and prime a boom quickly is the recirculating boom offered by some aftermarket boom manufacturers. Tank contents can be pumped through the entire boom assembly without actually spraying. This ensures that the boom is primed without any soil contamination. It also dilutes whatever residue there may be in the boom plumbing with the entire tank, likely reducing its concentration enough to be of little concern. An additional feature of recirculating booms is that many offer stainless steel tubing throughout most of their feed and return length, minimizing the black rubber hose products that often adsorb, and later release, herbicide contamination.
Daily cleaning. Empty sprayers should be cleaned at the end of every work day regardless if the same product or tank mix is being sprayed the following day. This will help to prevent serious contamination issues for those nights when you have to leave the sprayer full. This is especially important after spraying a herbicide to which a subsequent crop may be sensitive – the classic case being a Group 2 and moving to canola. Be extra diligent with cleaning and pay attention to the tank walls, all screens and boom ends.
The ideal tank cleaner has a detergent, a surfactant and a component to increase pH (i.e. ammonia) in one formulation. The detergent will cut any oils or fats found in current adjuvants, the pH increaser solubilizes the Group 2 herbicides and encourages chemical hydrolysis of some products, and the surfactant makes sure that droplets don’t hang on the sprayer surfaces. Think of the spot free rinse at the car wash. For more specific cleaning tips on page 9 at the Guide to Crop Protection.