Potato Review

www.potatoreview.com POTATO REVIEW MAY/JUNE 2021 37 NUTRITION use Hi-Phos® from FMC. Phosphorus at tuber initiation is important for both potato yield and quality. Most of the potatoes grown are for the pre-packed market and a small proportion go for processing, so yield and quality are both very important,” he said. According to Richard, relieving the stress of the plant with foliar feed is also important to alleviate disease pressures. “My farmers grow a lot of the potato variety Melody and if crops come under stress, they can become susceptible to Alternaria leaf blight and I believe that keeping on top of de ciencies can have many bene ts to overall plant health.” Application timings “Our main aim is to maintain the canopy during the hot summer months, which is especially important as most of the crops aren’t irrigated,” Richard said. “ e key to maintaining the canopy is having the right nutrition so that the crop doesn’t senesce early, which can cause lower yields.” Richard applies nitrogen, phosphate and potash in the seedbed, and then a foliar feed later in the season. “At just past the 100% ground cover stage, usually around early July, we apply ve litres of Hi-Phos® and around three or four weeks later, we apply ve litres again. is deals with any de ciencies, and the potash helps with root development and bulking.” Having balanced proportions of potassium, magnesium and phosphorus is the reason it delivers high e cacy explains Richard, who views it as a cost-e ective solution. “We have found Hi-Phos® to be very successful in getting the results we want on di cult to manage elds,” he said. Vital nutrients Phosphorus, magnesium and potassium, are essential nutrients for potato crops, and if applied strategically as part of a tailored programme, they can be very e ective at correcting micronutrient de ciencies. Commercial Technical Manager at FMC, Je Fieldsend, explained that phosphorus is a key element for energy utilisation within the plant. “It’s an important component of numerous cell structures and plays a vital role in establishing rooting in the early stages of plant growth. Magnesium helps to promote healthy green leaf area. It’s vital in early development of the plant tubers and is an integral nutrient for good yields,” he said. “Among many crucial uses, potassium helps with root development and water balance in the crop, which will be key at times of drought for Richard. An application of Hi-Phos® during rapid growth is bene cial as crops may not be able to access su cient phosphorus from the soil at these times of high demand. “As it has a high content of water-soluble phosphorus, this is quickly available to the plant and is useful when the root system is developing, during owering, and at tuber initiation. As Richard has done, we recommend applying foliar phosphorus at tuber initiation to stimulate tuber numbers and it can also be applied at bulking to boost tuber size.” TISSUE TESTING To understand where foliar nutrition is needed Richard routinely tissue tests the crops. “ ere isn’t enough tissue testing done on potato crops. If you tissue test, you can identify de ciencies early on, meaning you’re a step in front and able to correct it before seeing problems emerge,” says Richard. “We believe that it’s better to routinely test the newest leaves on the plant, at the same time of day, because levels can vary throughout the day naturally. We aim for early – mid morning.” “Our main aim is to maintain the canopy during the hot summer months, which is especially important as most of the crops aren’t irrigated.”