ABSTRACT
Trials carried out during 1988 and 1989 have clearly shown the benefit of two spray adjuvants in achieving more reliable results from a spray program in barley. In 18 trials in 1988 and 1989, over a range of sites and cultivars, the addition of a phospholipid adjuvant (PA) to a program of autumn- and spring-applied pesticides and growth regulators gave a mean yield increase of 0.39 t/ha. Yield increases were due to increases in ear numbers and mean grain weight, which varied with variety and site. This yield increase equated to a three-fold return on adjuvant cost. The addition of a synthetic latex (SL) to the first node spray in three trials significantly increased yield by 0.44 t/ha. This yield increase equated to a 20-fold return on adjuvant cost. The yield from plots which were artificially wetted to simulate heavy dew was higher than in untreated plots where no adjuvant was applied. In further trials, uptake of manganese was significantly increased by the addition of the PA from a mean of 65 ppm 10 DAT to 122 ppm 20 DAT.
These adjuvants offer hope for improving the reliability of targeting, increasing the window of opportunity for spray applications, and the possibility of reducing the rates of pesticides while maintaining yields and gross margin.
