Click here to return to table of contents

5
 
Data were analyzed using STATVIEW II (Abacus Concepts, Inc., Berkeley, CA 94704, U.S.A. for the growth data and by a combination of the ImageMeasure software and STATVIEW II for the microscopic measurements. Specific analyses for each growth parameter will be described in the Results section below.
After four months of growth the seedlings were harvested and the following parameters measured: (1) fresh and dry foliar biomass, g (2) fresh and dry root biomass, g; (3) fresh and dry rooeshoot ratio; and (4) seedling height, an. These data were analyzed with the same statistical package described for the main experiment


RESULTS


After the ca 15 months there were very large and statistically significant differerences between the control and treated plants in all the properties that were measured (Table 1); The ratio of the means (SIR) indicates that stem fresh weight showed the greatest response followed by stem dry weight This suggests that the increase in cell wall formation induced by the metabolite predon-ünates. However, needle fresh weight was increased over 2-fold while needle dry was increased only 1.43-fold. In fact in every case the fresh weight ration increase was greater than the dry weight increase suggesting increased water uptake as another major effect of the OB. it is generally assumed that water uptake is entirely passive (e.g., Salisbury and Ross 1985) and if this is the case than this increase might be attributed to greater root biomass or increase in root hair surface. This could not be the answer in this experiment since the roots were pot bound and had to be trimmed periodically to keep the roots from harvesting resources from the gravel beds on which the pots resided. Increased membrane permeability would appear to be a plausible hypothesis.
Although we did not measure mineral nutrient content of the tissues, the fact that the treated plants grew so much more in the fifteen month lime period suggests that indeed the treated plants absorbed more nutrients. The treated plants were visibly greener and this visual observation along with our previous work suggests that the treated plants had more chlorophyll and since they grew faster they had higher total photosynthesis and/or a higher rate of photosynthesis. The data (Table 1.) indicate that fresh weight was affected more than dry weight and the order of effect was stem fresh weight
 

5