Potato Review

www.potatoreview.com POTATO REVIEW MARCH/APRIL 2021 39 CONFERENCE REPORT Plan ahead for nematode control e interest in Velum Prime Velum Prime ( uopyram), used to protect yields while actively managing nematode populations for the long term, has taken on added momentum in recent months. is is in part down to the authorisation of an alternative means of application in the form of broadcast spray up to 72 hours before planting which extends its versatility to situations where in-furrow application is not practical, while the loss of Vydate (oxamyl) in 2020 means growers are giving greater thought to management decisions, the conference heard. “Nematicides are only one component of programme for managing potato cyst nematodes and wherever possible should be used alongside a long rotation and resistant varieties. It is how the elements of a programme are combined that de nes the chances of success,” said Jack Hill, Bayer Roots and Horticulture Commercial Manager. To aid growers in their quest to bring PCN populations down to levels sustainable for the long-term, Bayer is promoting a three-point plan that incorporates all aspects of control. Central to this plan is matching nematicide use to the situation. Three-point control plan 1. Sample rst Accurate testing and analysis is the foundation of good PCN control. Sampling and testing not only shows if PCN is present, but also what species is causing damage. How this information is interpreted will depend on the situation in hand, for example, are you trying to detect an early-stage infestation or an established one? is information, coupled with the resistance and tolerance status of the available varieties, is the rst stage towards developing a PCN management strategy. “Once you have an understanding of the species involved and the level of infestation, a suitable programme can be devised. Delivering it may involve some di cult decisions, but if land is to be protected for the long-term, then growers need to nd a way to implement it fully wherever possible,” explained Amy King, Bayer Market Development Representative for roots and horticulture. 2. Choose your programme PCN is a complicated pest. As well as the initial population count other factors such as variety, soil type and eld/farm history all contribute to what could be described as PCN pressure in a particular eld. All these factors will need to be considered when making an informed judgement on treatment options, those at the conference were told. In higher pressure situations, a conventional nematicide applied at full rate typically produces a greater yield response than that of Velum Prime applied on its own. “In such situations, the advice is to apply Velum Prime at the full rate in sequence with a granular nematicide at half-rate. In our trials, the programme has been robust, consistent and, on average, at least as e ective as full rate granules used alone for yield protection,” Amy said. Where testing has indicated populations to be the lower end of the spectrum, Velum Prime applied alone can be e ective. “In lower pressure situations we see that Velum Prime provides yield protection in line with existing standards and population management better than that achieved with a granule,” Amy added. Velum Prime typically costs around half that of granular nematicides. 3. Follow application guidelines Velum Prime is the only nematicide that can be applied in-furrow at the time of planting or by broadcast spray up to 72-hours before planting. “Trials spanning several years and contrasting seasons, con rm that the e cacy of both application methods is broadly similar,” Amy said. For bothmethods, the application rate is 0.625 L/ha though the water volume to be applied depends on the applicationmethod. Where VelumPrime is applied as a broadcast spray it must be nomore than 72 hours before planting and at a water rate of 200-500 litres per hectare. It must then be incorporated to a minimumdepth of 10-20cm. e broadcast spray can be applied via a conventional boomsprayer or froman application systemmounted to the same tractor as the tilling machine. It must be applied to the whole eld after destoning but ahead of bed tilling Alternatively, VelumPrime can be applied as an in-furrow spray in 200-500 litres (reducible to 100 l/ha) of water per hectare using on-planter application technology. “It is important to direct spray into the planting furrow and not onto the seed tuber. Application should bemade using two nozzles per row; one at the front of the planting share and directed down into the furrow and the second at the rear of the share and directed so to spray the soil as it closes around the planted furrow,” Amy said. “A typical set-up is to apply using two nozzles per row: One at the front of the planting share and directed down into the furrowwith the second at the rear of the share and directed so to spray the soil as it closes around the planted furrow,” she added. “Once you have an understanding of the species involved and the level of infestation, a suitable programme can be devised. Delivering it may involve some di cult decisions.” Amy King, Market Development Representative for roots and horticulture Caligula, a new fungicide from Bayer containing 125g/L fluopyram and 125g/L prothioconazole in a suspo-emulsion (SE) formulation, was launched by Bayer at the conference. Velum Prime is the only nematicide that can be applied in-furrow at the time of planting or by broadcast spray up to 72-hours before planting.