Biosecurity, pests, weeds and diseases
Conclusions 1. The volume of application with water affected the results obtained. The visual results of Treatment 1 suggested it was not an acceptable commercial result and the plant counts support this conclusion. Treatments 2 and 3 looked very similar and were very similar and were very acceptable results. 2. The height of spraying affected the results in that where the plane had to start climbing to pass over trees, the effectiveness dropped off. 3. Spray drift could be a problem because of the risk of causing damage to trees and native vegetation. Severe damage was seen on trees at the end of the plots at Toodyay. However this effect also occurs with ground spraying operations. The greater risk with aircraft is due to the fact that the plane is actually flying over the trees whereas a ground spray drives around them. District office trial. 81M043 (A), 81M03 (B), 81M043 (C), 81M054, 80M050, Comments: At the first time of spraying, both the Glean treatment and diuron 350 MCPA 400 killed all radish plants. There was a substantial later germination of radish, but the wheat in the diuron 350 MCPA 400 treatment suppressed radish growth. Both Glean treatments severely retarded wheat growth and allowed germinating radish plants to develop and set seed. The Glean affected wheat recovered, but still appeared less vigourous than the other treatments at the dough stage. At the second time of spraying, both treatments failed to control the radish. The failure is attributed to showery conditions on the day of application, as better control was achieved using the same chemical mixes at tillering. At both the second and the third time of spraying, the effectiveness of the diuron mixes is directly related to the hormone concentration in the mix. At the third time of spraying, the ester and the amine treatment killed the radish, but both treatments took a month until all plants died. Visually, the first time of spraying would have given the best yield. The trial was not harvested, because of a patchy ryegrass infestation. Moora district office trial. 81KA57, Glean compatibility trial. Barrel herbicide trial. Hoegrass plus flowable linuron. 81M57 (B), Dicamba residual trial. 81A58 There was no obvious signs of damage in the various planting date, like there was in the 1980 trial. The size of the doublegee in the oats and barley nil plots was very large and provided strong
Number of Pages
Pearce, G A. (1981), Aerial spraying trial.. Department of Primary Industries and Regional Development, Western Australia, Perth. Report.