Life after Chlorpyrifos

The loss of Chlorpyrifos is proving to be a real headache for many farmers – grassland and arable alike. The impact of Frit Fly and Leatherjackets on crops cannot be overstated.
The only solutions now are a combination of cultural control
methods currently used by many organic farms or seed treatments.

FRIT FLY control                                                                   

There are usually 3 generations of Frit fly during the year, the third generation in August/Sept is the most damaging as the larvae tunnel into the stems of grass and cereal plants causing dead hearts. Interrupting this hatching and feeding
cycle should give reasonable control.
This can be achieved by spraying out the sward with Glyphosate in late July/early August followed by ploughing in mid August. The ground should be left uncropped for several weeks although there is scope to establish a green crop eg forage rape, stubble turnips if required.


The Crane Fly lay eggs through mid-summer and early autumn into grass leys. The larvae hatch and will start grazing on the roots of plants.
This is a real issue in new leys and 1st cereals. As with FRIT FLY the main control method is to spray out the sward followed by the plough in late July/early August and leave uncropped for several weeks to starve the larvae. Roll any newly planted crops to encourage tillering – consider spring rolling as well where there is evidence of Leatherjackets.

Control in established grassland is more challenging, grazing swards as tight as possible in August and September can reduce the opportunity for Crane Flies to lay their eggs successfully. The use of early nitrogen in the spring where possible can help.

Obviously leaving ground open during this period leaves crops open to other risks including Wheat Bulb Fly and can cause soil loss issues in high rainfall events.


In cereals the addition of DETER seed treatment on
cereals can reduce the impact of Leatherjackets and Frit Fly in addition to Wireworm, Aphids (BYDV) and Slugs.

In all events please talk to an R.M.JONES
agronomist who will be able to provide further information and advice.




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