A Simple Adjuvant Solution - Rob Saunders - The Fruit Grower

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Adding an adjuvant to sprays has become more common practice and more so in horticulture, where there are fewer sprays registered and good coverage is essential. According to Jack Ingle of Oro Agri, use of an adjuvant need not be complicated. He recommends the use of Wetcit with most inputs, whether fungicides, insecticides or herbicides. “Many inputs can be improved through better spreading and faster uptake through the leaf cuticle and Wetcit does just that. It also degrades naturally in the environment.”

Jack says that Wetcit is used on millions of hectares in over 90 different countries on a wide range of crops and with most conventional agrochemicals and even biopesticides.” I think that our simple strategy appeals to some growers. Some prefer to  have only one or two adjuvants in their shed.  

Over a two-year period, herbicide studies at  University of Illinois have shown that Wetcit enhances greater uptake and faster translocation of systemic products. This means that there is less chance of the spray being adversely affected by environmental conditions such as rain showers, so improving rain ‘fastness’. More active ingredient is delivered to the target plant and so crop applications are improved. Wetcit performed better than methylated rape seed oil, silicone surfactants, non-ionic wetter and crop oil concentrates. It showed good spreading, wetting and fast penetration. For example,researchers showed movement of glyphosate going down to the target weed roots.

When it comes to insect control, Wetcit wets the exoskeleton of the insect and allows the insecticide to move through the protective waxy layer and into the insects’ respiratory organs.

Jack reports that in replicated trials in Hungary with the insecticide Calypso (thiacloprid), the insecticide alone gave 49% control of woolly apple aphid after three days and 67.2% after seven days. When Wetcit was applied with the Calypso, the control of woolly apple aphid went up to 75.8% after three days and 83.9% after seven days.

A thin, properly distributed leaf spray will dry off quicker. Wetcit users report reduced canopy wetness reducing susceptibility to fungus disease attack.

Regardless of whether you are spraying a contact or systemic pesticide or a foliar nutrient, Wetcit delivers it to the desired site – giving active ingredients the best chance of peak performance.

Hutchinsons specialist fruit agronomists say that Wetcit is straightforward and its use is comprehensive. Nigel Kitney, a specialist agronomist from Hutchinsons, says “I use Wetcit with mildewicides to improve their efficacy and also where low water volumes are called for where Wetcit enhances target coverage or where the target is difficult to get to, such as woolly aphid, mealy bugs and rosy apple aphid.  I used to apply it with scab fungicides but the new Delan Pro formulation (containing dithianon and potassium phosphonates)formulation has improved in this area.”

He says it has been used in trials by Dr. Angela Berrie, Research Leader at NIAB EMR with positive results. “In these trials in 2016 the level of mildew was 44.1% mildewed leaves with just the fungicide alone but when Wetcit was mixed with it, the level of mildewed leaves was reduced to 27.3%. In 2017 the fungicide only treatment resulted in 71.7% mildewed leaves but when Wetcit was added this dropped to 53.6%.”

Rob Saunders, also a Hutchinsons horticultural expert, says Wetcit is a useful product and he uses it where the target is difficult and where it is important to get good deposition and coverage. “For example for the control of woolly aphids,” says Rob. “Having one adjuvant to suit most inputs will allow some growers to simplify their programmes and storage. As a company we want to advise the most appropriate partner adjuvant for the job.”

Jack Ingle has also used Wetcit with downy mildewicides and miticides on grapes. “It enhances uptake and gets the product quickly into the plant. Wetcit is used at 100 to 250ml/100 litres (0.1 to 0.25%) to optimise pesticide efficacy. The higher dose rate should be used when there is high insect or disease population, where low water volumes are used, or where hydrophobic (waxy or hairy) plant surfaces or insects with waxy secretion are being targeted.  It does not increase drift and Jack has data from the University of Nebraska and Brazil showing that addition of Wetcit resulted in an average 25% reduction in drift.