Build IPM into your vine program
In the June Vine Talk, I recommended using the dormancy period as a great opportunity to get amongst your vines and identify what pests you have and where they are hiding. Grapevine scale, Mealybugs and mites are among the many pests you are likely to encounter. This period of dormancy is where your insect control strategy for the coming season starts.
If you are on top of this, you may also have applied a targeted dormant spray and employed pruning techniques that have further reduced pest numbers. Infested vine material should also have been removed from the vineyard or destroyed.
Grape growers that have done these things are well prepared!
Even so, green growth, moisture and warm conditions can cause pest populations to escalate quickly, so we need to be conscious of what’s important for the coming weeks.
Insect pests are typically opportunists. They grow and reproduce quickly when conditions are right, which can sometimes lead to an explosion in pest populations. However, it can take a little longer for the beneficial species to multiply and help control these pests. During this lag-time, it’s important not to have a knee jerk reaction when you see insects in your vines. Before you reach for that insecticide you need to ask the question, ‘what impact will this product have on beneficial species’, and if so, ‘what are the longer-term implications for my vineyard’? An understanding of the IPM friendly-nature of the crop protection product you intend to use is important. With IPM, the idea is to selectively target insect pests and control the pest population sufficiently, while minimising harm to beneficial species. These beneficial insects (otherwise known as natural enemies) can help keep pest numbers below a threshold where spraying would be required.
Your local agronomist/viticulturist should be able to guide you in making well informed decisions about the best products to use and how to apply them when pest thresholds are reached. With the 2018-19 vintage approaching, an exciting new product has been released for mite control in wine grapes. Along with offering control of a broad range of other pests, this product is relatively soft on beneficial species and is IPM friendly. Growers should contact their reseller for more details.