Browsing by Author "Milner, J"

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    Expanded registration for Metarhizium strains against canegrubs : SRDC final project report BSS246
    (BSES, 2002) Samson, P; Milner, J; Bullard, G
    Eight fungicides and three liquid insecticides are registered in Queensland for application to sugarcane at planting, and these may come into contact with Metarhizium during application from cane planters. Seven of the chemicals were tested for deleterious effects on two Metarhizium isolates, FI-147 and FI-1045 (BioCane?), in laboratory and field experiments.In growth studies on medium, the fungicides Cane Strike? and Sportak? were about 10 times more toxic than Shirtan? and Tilt?, while toxicity of the latter fungicides was about 100 times that of the three insecticides Lorsban?, Talstar? and Regent? (based on active ingredient). When the amount of active ingredient in each product and field application rates are considered, the expected order of harmfulness in commercial use would be Regent < Talstar < Lorsban < Cane Strike < Tilt < Shirtan < Sportak.In a field experiment where Metarhizium granules were sprayed with each chemical (except Regent) at very high rates and then covered with soil, only Shirtan showed any toxic effect on spore viability, with a reduction from 82% to 69%. No harmful effect of any chemical was detected in counts of colony-forming units in soil samples or in bioassays of treated soil using negatoria and greyback canegrubs. No reduction was found in viability of FI-1045 on nine farms, where BioCane granules were applied though commercial planters with fungicide, compared with granules buried in untreated soil. Thus, we believe that BioCane is compatible with these chemicals in practice, and a label change for BioCane to include application at planting has been drafted with Bio-Care Technology Pty Ltd.
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    Farming systems that optimise the control of greyback canegrubs by BioCane� : SRDC final report BSS226
    (BSES, 2002) Samson, P; Logan, D; Milner, J; Kettle, C
    The carry-over of BioCane from one crop to the next is likely to be affected by soil cultivation during seedbed preparation. Metarhizium spores were concentrated in the rows in ratoon crops, either as spores surviving from the original BioCane application or as new spores produced by cadavers that are likely to be aggregated beneath stools. Soil disturbance was analysed using plastic beads as a marker. There was surprisingly little lateral displacement of the beads after cultivation. However, the rows themselves are likely to be displaced when crops are replanted unless minimum tillage planting into the old rows is practiced. In one field site prepared conventionally, spore concentrations were much lower in the new crop than they had been in the old crop.There was no effect of a trash blanket on grub response to BioCane in bins. Death of grubs following contact with BioCane may be slower at lower temperatures (<24?C), but the apparent difference was small. Spore concentrations in soil were not significantly affected by trash blanketing in most experiments. Overall, we were unable to conclude that trash blanketing will influence the efficacy of BioCane in commercial fields.There was no deleterious effect of the insecticides suSCon Plus, Confidor CR (controlled release) or Confidor SC (liquid), or of the fertilisers sulphur, gran-am or urea, on the survival of spores on BioCane granules in PVC rings. This is in agreement with field observations, where there have been no complaints from farmers who have applied BioCane close to some of these other products in commercial practice. However, abnormally low concentrations of spores in the rings indicate technical problems with the product that reduce confidence in the results.