Potato Review

www.potatoreview.com POTATO REVIEW JULY/AUGUST 2022 33 SPROUT SUPPRESSION anywhere between ve- and seven-weeks pre-desiccation. at said, waiting for ideal conditions at application is much more important than a strict calendar date, even if it means going later in your window,” said Simon. Certis Belchim Technical Specialist Harry Raley agrees that application conditions are paramount and leading up to application it is important to ensure that the crop is free from any stress. at could relate to disease, nutrient de ciency, or water supply, as a healthy, green canopy will provide the best vehicle for maximum uptake and translocation into the tubers. On timing, Harry acknowledges the desire to apply MH early, but he says it’s important to strike a balance, as going too soon can have a yield penalty. is is because the active substance stops cell division within the plant, halting tuber bulking. For its liquid formulation Crown MH, Certis Belchim recommends applying between three and ve weeks prior to desiccation and when 80% of tubers have reached a diameter of 25mm or more. Once the crop is in the right condition above and below ground, Harry says pick the time to apply carefully. “ e priority is to ensure the spray solution does not dry on the leaf too quickly, so the MH molecules are absorbed,” he adds. is means hot and dry conditions should be avoided, ideally spraying in the evening when temperatures are cooling down. Sprayers should only be moving when the mercury is below 25C. No rain No rain should be forecast, or irrigation scheduled, for at least 24 hours (ideally 48hours) and relative humidity should be above 75% and not expected to fall for a few hours after spraying. “Water rates should be at or above 400 L/ha,” said Harry. He adds that the criteria that need to be met for good uptake means getting the product on quickly and e ciently when a window presents itself is paramount. ere are two MH products on the market: Granular bagged formulation Fazor and liquid Crown MH which comes in 20-litre containers or 600-litre intermediate bulk containers (IBCs). E cacy of the two formulations is comparable, but Mr Raley points out that growers with a signi cant potato area can bene t greatly from ordering Crown MH in IBCs with a Fastran 850 closed transfer system. With some simple plumbing into the sprayer’s venturi system, the Fastran 850 enables operators to draw the liquid from the IBC straight into the sprayer tank at a rate of 25 L/min. Operator exposure is almost eliminated, lling is quick and easy and empty IBCs are collected free of charge for reuse, reducing waste packaging. “ e Crown MH formulation is also non-foaming, so ensures you are getting a full load and eliminates spills or waiting for foam to settle. All things combined, it means there is the potential to get an extra one to two loads into a shift and that could be the di erence between getting your MH on in the right conditions or not,” said Harry. Volunteer control While the importance of MH for sprout control is the area of focus since CIPC was withdrawn, Harry adds that it was originally marketed as a solution for volunteer control. At a time when growers’ solutions for crop protection issues, like soil-borne pests and diseases, aphids and foliar diseases are dwindling, it’s important to keep land free of volunteers as part of an integrated pest management strategy. “It’s a point which is now getting overlooked and further strengthens the case for using a product like Crown MH and doing everything within your control to get the best out of it,” said Harry “Using MH with ethylene does give you a more predictable crop to deal with, so there is less risk of losing control.” Simon Alexander, Independent Potato Specialist Simon Alexander, Independent Potato Specialist. Adrian Cunningham, Independent Storage Expert. Harry Raley , Certis Belchim Technical Specialist.