|Version 2||Date January 2020||Reference 42|
Graph 1: Scores for % incidence, severity and sporulation of grapevine powdery mildew (Erysiphe necator) on leaves following treatment of cv Ruby Cabernet with various fungicides including BIOPEST®, Loxton North, South Australia, January 2011. (Source: Margarey & Hayes – Loxton 2011)
Controlling powdery mildew, mealybugs and scale is a serious problem for many grape growers, but with BIOPEST® they now have the option of using one product to control all.
SACOA’s BIOPEST® is a highly refined iso-paraffinic oil with biorational pesticidal properties, which make it different to other products which use synthetic chemistry.
BIOPEST® v. Synthetic chemistry
BIOPEST® acts on pests primarily by smothering and drowning, however newer research indicates that BIOPEST® can reduce the output of volatile compounds from plants making them less attractive for feeding.
BIOPEST® is also an effective stand-alone fungicide across a range of crops (i.e. powdery mildew in grapes) making it an organically certified alternative to sulphur.
BIOPEST® is similar to sulphur in that it is a protectant fungicide, but has the advantage of working effectively in cool weather, controls vine scale and mealybug and does not have the unpleasant odour of sulphur.
It’s a great product for growers looking to implement IPM programs as it is very soft on predatory insects. With this in mind, SACOA recently obtained certification with the Biological Farmers Association for the use of BIOPEST® in organic viticulture.
Graph 2: Using BIOPEST® as a trunk drench for post-harvest mealybug control in grapes. (Source: AHA Viticulture – SW WA April 2014)
BIOPEST® is registered for use up to E-L stage 31 (berries are pea size, formerly referred to as bunch closure), however trial work conducted with the Australian Wine Research Institute showed there were no significant impacts on winemaking or the sensory characteristics of resultant wine when BIOPEST® was used at twice the recommended rate up to one day before harvest.
BIOPEST® is not subject to resistance so there is no need to limit product applications as with some other chemical groups.
BIOPEST® is not a magic bullet and will only control diseases and pests when used correctly, particularly targeting the right pest stage. As BIOPEST® is a protective product, thorough application is essential and higher water rates will definitely assist with achieving good coverage. Spray intervals will also need to be tightened if disease pressure is high.
Caution is also needed when alternating between BIOPEST® and sulphur sprays with an interval of three weeks between applications preferred. With no obvious symptoms the crop will continue to grow but will have a reduced yield of up to 40%.
Figure 1: The mealybug lifecycle where SACOA recommends applying BIOPEST® in winter and spring.
(Source: UC DAVIS)
Graph 3: The number of longtailed mealybug per leaf and the proportion of leaves infested expressed as a percentage of all stages of mealybugs in untreated plots in a vineyard where an insecticide trail was conducted, Northcliffe, WA 2004/2005. Sizes of mealybug were classified as small (S), medium (M), large (L) or adult (A) depending on body length. (Source: S. Learmonth – GWRDC RT04/06-02)
o 1st Instar as post harvest trunk drench.
o 1st Instar as pre-bud burst trunk drench.
o 2-3 foliar applications at 10-14 day intervals from bud burst up to 15mm diameter fruit.