FIRST-YEAR FIELD PERFORMANCE OF 60 MICROPROPAGATED SILVER MAPLE CLONES IN SOUTHERN ILLINOIS.
Four selected clones from each of 15 provenances were clonally micropropagated and established in plastic mulch in both upland and lowland plantations in southern Illinois. Despite a severe drought, survival in the field was 95%. The plastic mulch controlled weeds, reduced erosion, and supplemental irrigation was not necessary. Although clonal differences in field mortality were statistically significant, the lower survival of some clones may be attributable to plantlet size and planting technique rather than to genetic differences among clones. There was a longer growing season for trees from the midwest and southern provenances as evidenced by date of bud set. As a group, trees from the IL, IN, KS, and MS provenances set bud 26 days later in the upland site and 19 days later in the lowland site than the trees from the northern provenances of MN, NH, Ontario, and VT. The shorter growing season resulted in reduced height and caliper growth of trees from the northern provenances.