Table 2.

Results of chi-square tests of independence computed for Dutch elm disease sanitation treatments as elm losses progressed during the 5 year study.

Comparison of sanitation treatments19741974 through —
Girdling plus prompt versus prompt removal1.532.031.586.26*3.19a
Girdling plus prompt versus conventional0.777.62**56.71**98.58**136.22**
Prompt removal versus conventional2.2210.31**38.67**52.40**92.65**
Methoxychlor spray versus conventional0.040.810.120.033.33a
  • aSignificant at 10-percent level.

  • *Significant at 5-percent level.

  • **Significant at 1-percent level.