Effects of adjuvants on the characteristics of low drift flat fan nozzles

R.G. RichardsonA and J.H. CombellackB

A Keith Turnbull Research Institute, PO Box 48, Frankston 3199, Australia

B SpraySmart Enterprises, 27 Bedford Street, Box Hill 3128, Australia

Presented at the Fourth International Symposium on Adjuvants for Agrochemicals, Melbourne, Australia, 3-6 October 1995.


The effect of three adjuvants, an emulsified mineral oil (D-C-Trate), an emulsified canola oil (KTRI9) and an ethoxylated alcohol (BS1000), on lateral distribution, droplet spectra and operating pressure of low drift pre-orifice flat fan nozzles from five manufacturers was examined. Nozzles were operated at specific flow rates to measure lateral distribution using a 25 mm channel patternator. Lateral distribution varied with nozzle make, size, adjuvant and flow rate. On average D-C-Trate produced more even distributions with co-efficient of variation (CV) close to 10% than KTRI9 and BS1000 which gave CVs of around 14%. CVs for individual nozzles ranged from 5 to over 30%. Droplet spectra was measured with a Malvern 2600 particle sizer and varied with adjuvant, nozzle size and flow rate. BS1000 produced 1.9 to 2.7 times the volume of driftable droplets (<100 ┬Ám diameter) than the two emulsified oils. Spectra also varied between nozzles of the same size produced by different manufacturers. Operating pressures required to achieve specific flow rates also varied with adjuvant. Water required from 14 to 42 kPa less pressure than the adjuvants to achieve the same flow rate. The significance of these results is discussed.


Plant Protection Quarterly (1997) 12 (2) 39-45.