Strobili and Conelet Losses In Four Species Of Southern Pines

Abstract

In a central Louisiana seed orchard, 27,677 female strobili were tagged on selected clones of 4 pine species (loblolly, slash, shortleaf, and longleaf) over 4 years. Only 41 percent deveioped into cones. Losses were tallied by date and, when possible, by cause. For lobloiiy, differences in losses were significant between years but not among clones. For slash there were significant differences both among clones and between years. Shortleaf showed no significant differences among clones or between years, but there were consistently higher losses for both shortleaf and iongieaf than for iobioiiy and slash. Insects were the largest single identifiable cause of mortality. Losses were greatest in early spring. Damage from birds, mechanical breakage, or weather was minimal. The only weather that caused any large loss was a hailstorm that caused a 20-percent loss of shortleaf coneiets and strobiii in 1974. If losses in the missing, unknown, and aborted stage-1 categories are included with known insect depredations, over 98 percent of ail losses can be attributed to insects.

Citation

McLemore, B.F. 1977. Strobili and Conelet Losses In Four Species Of Southern Pines. Res. Note SO-226. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station. 5 p.