| Abstrakt: |
The potential of bacterial symbionts in suppressing T. squalida populations on cauliflower from transplanting to harvest was evaluated. Significant reductions in plant infestation percentage and population density (/m2) were recorded throughout the plantation seasons in 2005 and 2006 after spraying the plants. The percentage reduction in numbers/m2 was the highest in March for treatments with X. nematophilus and P. luminescens. The treatments also reduced the economic threshold of T. squalida on cauliflower in this experiment from 1.04 before spraying with X.nematophlius to 0.66 after spraying in 2005. In 2006, this threshold was reduced to 0.39 and 0.07, respectively. The economic threshold of T. squalida on cauliflower was 1.34 before and 0.98 after treatment with P. luminescens in the 2005 season and reduced to 0.17 before and after treatment in 2006. This indicates an increase in the marketability of heads harvested as a consequence of monthly treatments. In a comparison test with conventional insecticides Hostathion and Lannate, there were no signification differences in control resulting from treatments with X. nematophilus and Lannate. The percentage control in these trials reached 66, 63 and 63, 61% for treatments with X. nematophilus and Lannate respectively, for the 2005 and 2006 seasons. [ABSTRACT FROM AUTHOR] |
