minumun of 57.2 °F. Average rainfall of the site has been reported as around 60
inches a year, but in the last three years precipitation has been between 15 to 18
inches below the normal. Soil is a sandy loam. Planting spacing was lOxlO feet
between rows and trees.

Three plots were selected for the test. Each plot (treatment) was six rows by 16
seedlings (96 plants). One plot, the central one, was treated three times in 1988 (i.e.,
mid April, early June, and early July) with approximately 12 ounces (340 ml) of a 1%
solution of “Roots” (1:100 by volume) per tree. The treatment was only done in the
first year. No irrigation was used. *

In early March 1991, total height, and diameter (at the base of the trees) were
measured in all surviving trees. Comparative survival analysis was made for the
treated and untreated samples. Height and diameter data were analyzed with
Statview II for analysis of variance.

RESULTS AND CONCLUSIONS

Three years after transplanting to the field 85% of the initially treated
seedlings had survived, while only 43% and 77% of the two untreated plots of
seedlings survived (Table 1).

In all cases, the treated pines experienced significant growth improvement in
total height and diameter compared to the untreated control piots.

There was a location (plot) effect in height (Control C > Control A) but the
treated plants statistically significantly exceeded both control plots in height. The
case was even greater with respect to diameter growth where increase was 31 % and
18% over controls A and C, respectively. These results are specially important
because they demonstrate a residual effect that endured for two growing seasons
after treatment.