Plant Protection Chemistry NZ Ltd



R & D for specialty agrichemical providers

PPCNZ undertakes a wide variety of laboratory tests to measure and compare the performance of adjuvants and spray formulations, on a variety of plant species. Much of this confidential work contributes to the development of novel agrichemical adjuvants and innovative uses for existing products, and provides data for numerous patent applications by our clients.

Droplet Spreading
Droplet spreading compares how adjuvants spread on difficult-to-wet plant surfaces and determines the extent adjuvant addition can help improve agrichemical coverage of a plant target.

Droplet Adhesion
Droplet adhesion is a critical component of spray efficacy. Spray droplets can adhere, bounce or shatter on initial impact with a leaf surface. The spray droplet adhesion test measures differences among formulations in how well they benefit spray retention on target surfaces.

Dynamic Surface Tension (DST)
A Krüss Bubble Pressure Tensiometer is used to determine DST of surfactant solutions over surface ages up to 1000 msecs. The faster the reduction of surface tension, the better the droplet adhesion will be over short fall distances. Surfactant solutions with lowest surface tension at the time of impact will adhere best to plant surfaces.

Droplet Spectra
A Malvern laser is used to quantify the droplet spectrum of adjuvant sprays using different nozzles, pressures, pesticides etc. This study determines the distribution of droplet sizes in a spray swath, including the VMD and proportion of driftable fines produced.

Foaming is generally an undesirable property in agrichemical sprays. This test measures the amount of foam produced and the time it takes to break down in different adjuvant and spray formulations.

Foliar Uptake & Translocation
Foliar uptake and translocation of radiolabelled pesticide can be measured over time to determine how a formulation can be modified to provide the greatest activity for that pesticide. The effect of environment and differences between plant species and growth stages can be accurately compared. Both cuticular and stomatal penetration can be measured separately and the physical transport of a pesticide within a plant accurately determined.

Autoradiography provides qualitative visual representations of pesticide movement within a whole plant or plant portions.


We produce high quality videos of spray droplet impaction and coverage of plant surfaces that can be used for marketing purposes.

Tracksprayer Spray Retention, Rainfastness and Bioefficacy Trials
Spray application to a variety of crops can be accurately simulated with a moving head tracksprayer to determine spray retention on whole plants or different parts thereof, and to compare the bioefficacy of different spray formulations. This is useful in determining and comparing how sprays modified with adjuvants can increase retention and efficacy of pesticides on target plants. The rain-proofing properties of adjuvant/pesticide formulations can be determined using a rain simulator, with varying rain intensities and durations applied to pre-sprayed plants.

Microscopy (Light, Confocal, SEM)
Light microscope is used to examine droplet interactions with surfaces, while confocal laser scanning microscopy illustrates the penetration of chemicals into plant tissues via both surface stomata and intact cuticles. Scanning electron microscopy (SEM) illustrates in detail the micro-structure of leaf surfaces, such as waxes and stomata, and is also used to study the effects chemicals have on the micro-structure of plant surfaces. 

Bioassays and Pot Trials
Bioassays and pot trials are undertaken to determine and compare the efficacy of herbicide formulations and spray application techniques on a wide variety of plant species. Sprays are applied with a calibrated tracksprayer. Pest and disease assays to determine insecticide and fungicide efficacies are undertaken by research associates with established international reputations.


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