Best use of Fazor in root crops

UK - September 29, 2008

Carrot and parsnip growers are informed that the time for applying Fazor (maleic hydrazide) to root crops to suppress re-growth and thereby helping to maintain quality is approaching.  As part of the product stewardship responsibilities, it is confirmed that Fazor has SOLA's for use in all varieties of outdoor carrot and parsnip, issued on the 7th September last year and valid up to December 2013.

The new refined application rate for Fazor in both carrots and parsnips is 8 kg product/ha, with one application per crop.  The MRL for maleic hydrazide remains at 30 mg/kg in these crops.

To ensure good product stewardship and get the best from Fazor, it should be applied using a conventional hydraulic sprayer in 350-500 litres of water per hectare, when the crop foliage is mature, but not actively growing.  Green tops are essential for Fazor to be absorbed and translocated to the roots.  It is better that applications are made slightly later rather than earlier, as this can impact yield if the canopy is not mature.  This is typically from mid October onwards when the crop has 5-25% leaf yellowing or necrosis and when the crop begins to lean.  Application timing should be judged on a crop by crop basis but must be before the first frost.  Rain within 24 hours of application may reduce effectiveness, however.  If the crop is to be over-wintered, at least 4 days should be allowed after application before topping or covering the crop for frost protection.  Fazor should not be applied less than 3 weeks before harvest.  It can be used in conjunction with black polythene for in-field storage.

Fazor works by inhibiting sugar metabolism in the root crop.  There is evidence that suggests this helps to maintain the taste, tenderness and processing quality of the over-wintered root crop.  It also ensures that the flavour is maintained, especially sweetness of the roots.  Also by suppressing secondary rooting Fazor helps to maintain yield and quality.  In parsnips, Fazor reduces woody core and glazing in late-lifted crops, thereby optimising market value of the crop.

By helping maintain quality in field stored crops Fazor prolongs the time that carrots and parsnips can be left in the ground and extends the lifting period.  This means that harvest can be extended thus the season for locally supplied produce can be longer.  Supermarkets can source supplies of home grown UK root vegetables for longer, relying less on imports.  It will also reduce or eliminate the need for cold storage and washing, thereby reducing costs.

Growers need to obtain a copy of the new notice of approval to use Fazor in carrots and parsnips via the PSD web site, ADAS offices, the HDC or NFU.  The SOLA reference number is 2703 of 2007 (linked to MAPP 13679).

Fazor contains 60% w/w maleic hydrazide, formulated as a water-soluble granule and is packed in a 2.5 kg bag.  It is recommended on second earlies and maincrop potatoes and bulb onions.  It has SOLA's in carrots, parsnips, garlic and shallots.

For further information on these SOLA's, growers should contact the HDC.