BIOPEST in Cotton – Cotton Research Program

SACOA’s Cotton Research Program

The primary goal of SACOA’s Cotton Research Program is to test, validate and extend the use of spray oils in cotton IPM programs.

SACOA is currently spearheading this goal via research into their BIOPEST formulation. The premise underlying this research commitment is relatively
simple – that BIOPEST’s unique formulation can deliver improved pest control, reduce the negative effect of traditional chemistry on pest resistance and beneficial insects, and provide economic benefits in the form of reduced spray costs without any negative effect on yields.

But talk is cheap, and this belief is founded on precedent and evidence. Precedent from other commercial crops such as bananas and citrus and evidence from previous season’s research in cotton.

Cotton Research Program findings discussed on this page are:

• Spray Oil Efficacy is a Cumulative Effect
• BIOPEST (nC24) More Effective Than Canopy® in Aphid Mesh House Trials
  
• Aphid Mesh House and Laboratory Trials
  
• Green Mirid and Helicoverpa Trials

IMPORTANT NOTE: The content of this page does not in any way constitute a recommendation by SACOA to use BIOPEST outside of its registered use.

Spray Oil Efficacy is a Cumulative Effect

An oil’s efficacy is influenced by a number of factors. However, it is important to appreciate that no single factor will determine the performance of an oil. So whilst it is important to evaluate an oil based on its specifications, the evidence in the field should act as the final test. Key factors include:

• Paraffinic Content (%Cp): Paraffinic molecules in an oil are regarded as providing the most insecticidal value and plant safety. As a result, an oil with a high proportion of paraffinic content such as BIOPEST with a %Cp of 74% is preferable for either stand-alone sprays or as an insecticide carrier (for a spray oil to be a ‘paraffinic oil’ it must have at least 62% Cp).
• Surfactant: The surfactant can have a significant effect on mixing stability, plant coverage and rainfastness. It can also improve the insecticidal properties of the oil by assisting in coverage and ‘penetration’ of the insect. BIOPEST’s superior proprietary surfactant package has been shown to deliver unique efficacy and modes of action (refer ‘Future’ section).
• Purity (USR): Purity is assessed via UnSulphonated Residue (USR) – a measure of the absence of damaging ‘aromatics’ in an oil. BIOPEST’s base oil is of the same 99.8% USR standard and quality every time, meaning no fluctuations in ingredients and quality. This eliminates the need for a UV stabiliser to mask quality issues.
• ‘Weight’: An oil’s weight refers to its carbon number (such as ‘nC24’ or ‘nC27’). Whilst a heavier oil can have the ability to stay on the plant longer it does not significantly influence the insecticidal properties of the oil. Highlighting this important fact is the research results below.

BIOPEST (nC24) More Effective Than Canopy® (nC27) in Aphid Mesh House Trials

Mortality rates at Day 1 after exposure of aphids to oil deposits

Independent research conducted through the University of Queensland concluded that deposits of BIOPEST are more effective than those of an nC27 (Caltex Canopy®) for up to 5 days after treatment (refer graph below).

Even though the deposits of the nC27 oil persisted a few days longer, the cumulative mortality percentages inflicted on those aphid cohorts exposed to Canopy® were lower and statistically different (P=0.05) from those recorded for aphids exposed to the deposits of BIOPEST oil, at least on days 1 and 3 after treatment.

These results highlight that an oil’s efficacy is based on more than a single specification.

The superior efficacy can be explained by the proprietary surfactant package in BIOPEST providing superior coverage and penetration into and on the insect. This surfactant package, when combined with a unique quality base oil with a true USR of 99.8% and a paraffin content of 74% Cp equates to increased efficacy.

Aphid Trials

BIOPEST is registered for use in the control of cotton aphid.

A series of six field experiments (supported by mesh-house and laboratory tests) were conducted to assess the efficacy of BIOPEST oil against the cotton aphid, (Aphis gossypii Glover).

Aphid field trial results

Key Findings

• BIOPEST produced high levels of rapid mortality, with most mortality occurring within 15 minutes of spraying.
• Oil residues on leaves produced aphid mortality for up to 9 days after spraying.
• At low infestation aphid rates, BIOPEST oil alone at 2%, at a spray volume of 82 L/ha can control cotton aphid on cotton as well as chemical insecticides such as Regent®.
• At high aphid infestation rates, the level of control is moderate (approximately 85%) compared to that achieved by chemical insecticides (approximately 95%). However, by leaving a residue pest population, BIOPEST maintains some food source for beneficial predator insects.

Green Mirid and Helicoverpa Trials

Season-long field trials were conducted at Australian Cotton Research Institute, Narrabri during the 2003-04 season.

Mirid & helicoverpa field trial results

Key Findings

• The addition of 1% BIOPEST to the full-rate chemical regime significantly increased mortality over that for the full-rate chemical regime, with an additional 30% (mirids) and 29% (helicoverpa eggs, VS+S larvae) mortality being recorded.
• Estimated gross margin was increased by over 10% with the addition of 1% BIOPEST to the full-rate chemical regime.
• The two whole-of-season trials also demonstrated that a half-rate insecticide regime + 2% BIOPEST can produce control of green mirids and helicoverpa equivalent to a full-rate insecticide regime. (SACOA does not endorse reduced rate applications unless otherwise stated on the label).
• The full rate insecticide + BIOPEST results provide the cotton industry with a means to extend the mode of action of conventional insecticides, reduce resistance issues and increase kill % and profitability.