The time is approaching to apply Fazor (maleic hydrazide) to potatoes in the field, but recent temperatures have been high. Dow AgroSciences are advising potato growers to avoid applying Fazor when temperatures exceed 26ºC, but to consider spraying in the cooler conditions of the evening or early morning in irrigated crops. They explain that in order to ensure maximum uptake and translocation, the product should not be applied to stressed crops.
Alex Nichols of Dow AgroSciences advises growers to start their integrated programme for sprout suppression in store and minimising volunteer potatoes left behind from the previous year’s crop with an in-crop application of Fazor. “The timing and conditions of application for Fazor need to be spot on for best results. I would advise going back to basics to make sure that the key application criteria are met. The effectiveness of Fazor is a function of application timing, growing conditions at application, accuracy of application, variety and storage conditions.”
He explains that Fazor is applied to second earlies and maincrop potatoes around five weeks before harvest. ,“In terms of application timing, growers should calculate back at least three and ideally about five weeks from intended burn down date. This allows the chemical sufficient time to be taken up by the leaves and translocated to the tubers where it acts. The crop should be actively growing and the haulm mostly green, but with a few of the lower leaves turning yellow and, where relevant, most of the flowers fallen. Each field should be checked for maturity and tuber size, using test digs. The guidelines are that the smallest tubers required to reach marketable size should be greater than 25 mm across. Crops should not be stressed by drought, pests, diseases, high temperatures (in excess of 26ºC) or waterlogged.”
Alex says that potato growers have had to endure yet another challenging growing season, so potatoes may well be worth more and will need protection, especially for storage quality.
Fazor is included in the Assured Produce Protocol. It is recommended that growers check with their supplier before making an application.
Fazor contains 600g/kg maleic hydrazide, formulated as a water-soluble granule and packed in a 5 kg bag. It is recommended on second earlies and maincrop potatoes (not on seed or first earlies) at a dose rate of 5 kg/ha in 350-500 litres of water. It should be applied to actively growing foliage, typically around 3 to 5 weeks before burn down. It has a maximum number of treatments of one per crop and a latest time of application of 3 weeks before harvest. Fazor is fully approved for use on bulb onions and has specific off-label approvals for use in garlic, shallots, carrots and parsnips.
