One of the principle topics for Euroworks 2014 Finland regarded the sea buckthorn fly. This little fruit fly has the capacity to reduce a crop into the realms of unprofitable enterprise. All crops have a break even point and most of those require a good crop in the first place – the profit only comes from doing the job well.
So it is important that the appearance of the fly is known, challenged and limited in its capacity to reproduce so that every year the population grows. The use of sticky fly traps was discussed, and there was some suggestion that flies can be more sensitive to different tones of yellow/orange in the type of trap. It seemed however that the trap that was brought to the conference with around 1000 flies on it was yellow and had done its job. But these traps are only there to indicate the presence of the flies and allow identification of different species. Once in the crop then the damage will be done.
It seems that most of European growers are organic and will maintain this status in order to deliver a natural product to the consumer. This means no sprays are an option in the control of fly. Some other fruit crops utilise netting for hail control which doubles as providing pest control as well. This is fine for small orchards, but in commercial terms I see mechanically harvested sea buckthorn as being larger orchards so netting becomes expensive both in capital purchase and labour. So vigilance in observation as with the arrival of caterpillar or bird attack sounds like the order of the day.
The suggestion from Germany that fleece under the trees will stop the viability of pupae also sounds an important option. Preventing the ability of one year’s generation to pass onto the following year must be critical if we are to control the fly. I have an uncomfortable feeling that the fly is present in our native environment although currently living off other hosts. It would be valuable to know if foragers have seen the tell tale signs of sea buckthorn fly damage.
It was suggested that the fly seems to like sweeter varieties , so maybe its willingness to eat some of our very sour native wild stock is less enthusiastic. Only time will tell.
So this coming week as I return to spreading compost under my plants I will be starting to consider when/how to place and secure fleece in this coming year. Of course it might be that the UK will not have the problem for a while yet, but that is no reason to be complacent. All crops have pests and sea buckthorn is clearly no different. The problem comes when one looks for natural solutions alone. But the solutions will be largely reliant upon timing, attention to detail, sharing information and a little innovation.
