Emergency Approval of Maxcel – a much needed thinner for apples
The plant regulator for the chemical thinning of apples, Maxcel has been granted a 120 day emergency approval in the UK, starting on the 12th April 2010. This emergency approval will be welcomed by UK commercial apple growers, according to Mike Hutchinson of Hutchinsons.
"We have been looking forward to getting a reliable chemical thinner in the UK for the past few years, ever since carbaryl was withdrawn. Now we have access to Maxcel which will be a great help in terms of thinning the crop and creating the right balance of crop load and fruit size. Maxcel won’t negate the need for hand thinning altogether, but will make it quicker, more cost-effective and easier to manage in terms of staffing numbers," says Mike.
"All apple varieties can suffer from irregularity of cropping to some degree or another, with some worse than others. Quite a few of the newer varieties, such as Gala, Jazz, Braeburn and Kanzi, have a tendency to be precocious and to over crop and will benefit from the application of Maxcel. If a tree is left to over-crop, it not only affects this year’s crop in terms of fruit size and quality, but also next years as the tree tends to under-crop the following year. This biennial cropping pattern helps no-one, grower or end market," he says.
Mike says that Maxcel selectively thins by using inter fruitlet competition and, because it is used earlier than hand thinning, when the fruitlet is between 8 to 12 mm in size, it optimises fruit size and picking quality. "Hand thinning for misshapen or damaged fruits tends to be done later, after natural fruit drop has occurred."
Mike Hutchinson advises that Maxcel is applied at the correct growth stage of the crop and when the weather is suitable. "In a perfect world the fruitlet would be 10 mm and the weather warm and sunny. You have a good range of fruitlet sizes to go for, but make sure it is warm enough. I would advise that Maxcel is applied as a special treatment on its own."
In terms of timing, Maxcel should be applied when the king fruitlet has a diameter of 10-12 mm. The suppliers of Maxcel, Interfarm UK Ltd, will be supplying suitable measures to help growers with this assessment. Applications should be made at the start of the warming trend when maximum daily temperatures for the 2-3 days following application are expected to be at least 18° C. It should not be applied when temperatures are below 15° C. One application can be made per year.
Based on the active 6-benzyladenine, which is a naturally occurring compound, Maxcel is recommended at dose rates of 350-750 ml/per 100 litres of water. It is important to ensure adequate coverage of fruit and foliage without excessive run-off, with water volumes being adjusted according to tree size and spacing. It is also important to use a water volume that allows for sufficient Maxcel to be applied, depending on the variety and its ease of thinning.
Maxcel is being marketed in the UK by Interfarm UK Ltd, an associate company of Sumitomo Chemical Company. HL Hutchinson is a distributor of Interfarm UK Ltd. The product is being supplied under the terms of the emergency approval as instructed by The Chemicals Regulatory Directorate (CRD). It will be accompanied by the relevant documentation required by CRD for this type of approval, including the CRD emergency approval certificate, which will give growers all the necessary information for use.
