Potato Review

www.potatoreview.com POTATO REVIEW JULY/AUGUST 2020 11 DESICCATION AND FLAILING W ith the loss of diquat, many growers will be concerned about in ated desiccation costs this year. Lead Analyst in AHDB’s FarmEconomics team, Mark Topli , has been assessing the likely costs of di erent approaches, while contractors and agronomists also have some tips for growers on how best to manage their expenditure. e two common regimes have been either ail and spray (2.5 l/ha diquat) or a split application of diquat (total 4 l/ha). is has been compared to an all-chemical treatment using two applications of Gozai (total 1.6 l/ha) and one of Spotlight (1 l/ha) and a regime where the ail is followed by an application of Spotlight (1 l/ha). For growers already using a ail and spray regime, the increase in cost isn’t felt to be as signi cant as for those moving to a ail and spray regime or sticking to a chemical approach. Mark said: “ ose growers moving from desiccating with diquat only to a ail and “Cost increase will depend on approach” Desiccation costs are looming following the loss of diquat. Experts from across the industry share their views on how growers can minimise the expense. PPO inhibitor will see a signi cant increase in costs per ha – anything from 150 – 210%. If the grower already uses a ail to top the haulm and continues to use in combination with a PPO inhibitor, then the cost increase is less signi cant – in the region of 13–15%.” Using the Gozai and Spotlight sequence works out at 151% higher than using diquat alone. If growers are moving to a ail and spray system from a diquat-alone system, then a two-section rear-mounted or three-section front and rear- mounted ail and Spotlight, will see a 205% or 211% increase in their costs. is is largely down to the additional cost of purchasing and using the ail equipment. Where a two-section ail and spray regime is already being used, then substituting the diquat for Spotlight costs around 13%more. Ultimately the regime growers use will depend on their circumstances and the market for the crop. Diquat gave more reliable desiccation than Spotlight/Gozai combinations and, because of the risk associated with relying totally on PPO inhibitors, many growers will use ail followed by spray, even when the soil is wet. · Application includes: Sprayer labour, fuel, water, repairs and depreciation · Flailing includes: Additional costs of labour and fuel, ail repairs, spares and depreciation · Flail equipment: 2 section rear mounted and 3 section front and rear mounted Equipment alternatives Investing up to £45,000 in a new six-row ail is a big cost to consider, particularly if the grower also has to invest in specialist row crop wheel equipment which could cost another £6,000. e costing does not include the tractor. For many, a cheaper option could be to use a contractor. Specialist grower and contractor, G&D Matthews, based near Spalding in Lincolnshire, has been providing a Scott six-row, Scott 3 section ailing service for the past two years. David Matthews of G & DMatthews Ltd said: Front and rear topper and press wheels, G & D Matthews flailing pre-desiccation in Lincolnshire. ➜