Vine Talk: Plan to ‘hit hard and hit early’
By Dave Antrobus, Solutions Development Manager - Syngenta
Regardless of whether you are trying to control Light Brown Apple Moth, powdery mildew or downy mildew, the timing of sprays in your program is critical and there is no spray more important than the first application.
For Light Brown Apple Moth (LBAM), insecticide labels recommend targeting this pest soon after egg lay or when larvae are small. Countless trials have shown that this application timing, when LBAM is at its most vulnerable stage of its lifecycle, is when most products achieve their best results. If the larvae get too large, they can survive the insecticide spray.
Monitoring moth flights and working out predicted egg hatch dates has proven to be a valuable tool in planning when to spray. Last year, this strategy worked particularly well as LBAM were on the move much earlier than normal (up to 4 to 5 weeks earlier in some districts), as well as there being numerous flights. Growers who monitored frequently throughout the season and acted on information, such as moth flights, were able to remain in control of LBAM populations, rather than letting populations establish which required an increased effort to achieve good control of large larvae.
When it comes to controlling fungal infections, preventative or very early intervention is just as important.
Populations of fungal pathogens, like downy mildew and powdery mildew, are made up of individual isolates. Once these diseases establish the infection can release literally billions of spores. When talking about such large numbers, there is always the chance that some spores or isolates will have resistance or tolerance to the chemical you are applying.
Having a preventative spray program in place and applying good protectant fungicides ahead of rainfall events is critical to ensure the disease does not establish and to maintain a handle on resistance build-up. With resistance management it’s a numbers game.
Keeping populations of any pest or disease at low levels, or ideally absent, is the best approach.
Frequently monitoring the weather conditions as well as understanding the target pest or disease in its early stages can pay dividends time and time again. If the conditions are right for the disease or pest to multiply, it is best to act before it’s too late, and also ensure you have the right product on hand to spray before it becomes a problem.
Plan ahead, hit hard and hit early.