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Certis in potato turnaround
Jul03The range of Certis’ metaldehyde slug pellets, Trigger, Certis Metaldehyde and Certis Red, have had the use on potato crops re-instated allowing a harvest interval of just seven days.
The news follows the revocation of all metaldehyde-based slug pellets for use on potatoes in autumn last year.
Certis regulatory officer Sue Young said: “This was a result of EU harmonisation of maximum residue levels (MRLs). The MRL that was set for metaldehyde in potatoes was at a level for which no data was available that could prove use of the products would not exceed that MRL.
“We therefore had to conduct trials and produce data to show our products could be used within the label recommendations without exceeding the MRL. This has now been completed and the CRD (Chemicals Regulation Directorate) has granted approval for use of both three per cent and five per cent formulations of Trigger, Certis Metaldehyde and Certis Red, with a maximum total dose of 23.4kg per hectare for the three per cent and 14kg/ha for the five per cent pellets.”
The seven-day harvest interval for potatoes is a particular benefit, notes Certis, as other metaldehyde products currently registered for use in potatoes are all subject to a 21-day harvest interval
Science into practice: Controlling fruit midge pests naturally
Jun22by HDC
Horticulture Week
19 June 2009
For many horticultural crops, especially perennial fruit crops, attack by various species of leaf-curling or other gall midges can be serious - the blackcurrant leaf midge is particularly important commercially.
Some species are controlled with the broad-spectrum OPs or pyrethroid insecticides. However, using these insecticides is undesirable for a number of reasons but particularly because they disrupt integrated pest management. For other species, such as the apple and pear leaf midges, there are no effective control methods and they cause extensive damage, especially in nurseries and young orchards.
Alternative, non-pesticidal control methods need to be identified. An HDC project, CP 38, is funding cutting-edge research on midge pheromones to come up with some answers.
Typically, plant-feeding midges are short-lived as adults and highly specific for their host-crop. In several species there is evidence for production of highly potent sex pheromones by virgin female adults and strong attraction of mated females to volatiles from host plants. Identification of these attractants could provide the means of manipulating pest behaviour at critical stages in their life cycle. This is a challenge because of the difficulties of working with these small and delicate insects.
In world-beating research, the female sex pheromones of three midges of significance to the UK horticultural industry - the pear midge, pear leaf midge and blackcurrant gall midge - have been identified. Work is progressing to produce sex pheromone traps for use commercially. The traps can be used to determine the relative abundance of midges in crops and will be useful for timing insecticide sprays.
Restriction will hit use of slug pellets in July
Jun22Growers face big restrictions in the use of a key ingredient for controlling slugs at a crucial time of year, Bayer Crop Sciences has warned.
July is a key month for using slug pellets on potato crops - this will be extra challenging this year as growers cope with reduced metaldehyde rates.
Earlier this year some metaldehyde products were re-approved by pesticide chiefs, said Bayer Crop Sciences product manager Peter Stacey, but use on potatoes was restricted to a maximum individual dose of 350g of active ingredient per hectare and a maximum total dose per crop of 700g
The restrictions effectively rule out the “little -and-often approach” of applying mini metaldehyde pellets with every blight spray.
Trial group Scottish Agronomy said growers could probably improve results by switching to a methiocarb-based slug control strategy. “We have consistently seen greater activity from methiocarb,” said trialler Eric Anderson. “This overides the higher number of baiting points delivered by some methaldehyde produces.
“The optimum time to begin slug control is at 50 to 75 per cent canopy closure, which crops usually reach early in July. At this time the canopy is starting to create moist slug-conducive conditions on the soil surface but still allows uniform pellet distribution.
“Full rate application of methiocarb pellet, such as Draza forte at 3.75kg/ha will have the biggest initial impact on slug population at this timing.”
