Experiments were conducted to determine whether solid matrix priming (SMP)
enhanced germination of loblolly pine (Pinus taeda L.) seeds. Six solid mat
rices with suitable properties were tested for their water release characte
ristics and three had the desired characteristics of high water holding cap
acity and a small change in water potential for a given change in water con
tent. Among the suitable matrices, Carri-All which is a clay was chosen for
further study. SMP with Carri-All improved the rapidity of germination (me
dian germination day) and synchrony (time between 15 and 85% germination) f
or stratified seeds from five open-pollinated North Carolina and Oklahoma f
amilies. Total final germination was only slightly improved by SMP. The mos
t rapid, uniform germination was achieved with 6 d of SMP at 30 to 35% WC (
-1.5 to -0.9 MPa); longer treatments and higher WCs resulted in germination
during treatment. Seed/matrix ratios (dry weight) from 1:1 to 1:4 were equ
ally effective in stimulating germination. The optimum SMP treatment reduce
d differences in germination vigor among families. SMP has potential as a t
ool for nursery managers to increase the rapidity and synchrony of loblolly
pine seed germination and produce more uniform and vigorous seedling crops
.