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Prolectus® – a Botryticide with just the right pedigree

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Agrii fruit specialist Julian Searle expects a lot from any new chemistry and he says that Prolectus (based on the active ingredient fenpyrazamine) does not disappoint. “In fact, I would say that it has the right pedigree and performance we are looking for.”

Julian works in the southern counties and advises top fruit, soft fruit and grape vine growers. “Prolectus received UK registration late in 2015 and I have used it for two years now, mainly on grape vines. I think it is an important new addition to the fungicide armoury controlling Botrytis in grapes, strawberries and a number of protected crops. Prolectus is backed up with some strong scientific results on its performance, based in part on its mode of action which differs from many other products used in grape vines. Fenpyrazamine is a FRAC group 17 (ergosterol biosynthesis inhibitor) and so is ideal to integrate with other fungicides such as pyrimethanil and fludioxanil plus cyprodonil which are used in grapes for Botrytis control.”

Botrytis control usually requires a programme of 5 to 6 fungicide sprays (in strawberries up to 17 sprays according to the Pesticide Usage Survey) and so Prolectus will always form part of a programme and should be sequenced with products using a different mode of action to minimise the risk of resistance. To prevent or limit the development of less sensitive Botrytis strains, applications of any Botryticides should not be made consecutively and should be used in alternation with others that work differently.

Julian Searle explains how Prolectus works. “It is a strong protectant fungicide with excellent kickback and strong antisporulant activity – all of which is required to control Botrytis which can escalate rapidly in the right conditions. In free water or high relative humidity when germination is stimulated by the presence of exogenous nutrients from the crop and optimal temperatures 15-20° degC up to 30 deg°C. Other Botryticides may have less overall curative activity. It is a very capable material in my view. It won’t let you down.”

He is also pleased that it has a shorter Harvest Interval than some other grape vine fungicides. “Prolectus has a 14 day Harvest Interval in grapes compared with a 21 day Harvest Interval in other products. In strawberries and protected crops it has just a 1 day Harvest Interval which is very useful closer to harvest and when it comes to picking regimes.”

Nufarm’s National Key Account Manager, John MacInnes, reports that in trials and commercial usage in Italy, Prolectus showed excellent activity against Botrytis, and performed as well as or better than the standard fungicide treatments currently used.  “Growers welcomed this robust fungicide to integrate into their disease control programmes. In particular, Prolectus has strong curative activity which blocks the development of B. cinerea so that it not able to sporulate. Botrytis produces a huge number of spores so antisporulant activity is valuable.”

In grapes grown for wine, Prolectus is recommended at 1.2 kg/ha in a water rate of 300 to 1000 Litres per hectare. The higher water volumes are used where necessary to achieve good coverage. The timing for wine grapes is from the start of flowering until berries start to ripen. Prolectus can be sprayed until 14 days before harvest in wine grapes.

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