| Abstract | 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. |
