Treesearch

Nymphs and females of the roach inquiline, Attaphila fungicola W. M. Wheeler, respond to odor-trail substances of Atta texana (Buckley) and Trachymyrmex septentrionalis (McCook).The ants are more sensitive than roaches to the pheromone.

The vegetation of southern Florida is poorly described in the literature, and the taxonomy and ecology of the pine-wiregrass type especially has been neglected by plant scientists. These deficiencies in plant knowledge were a serious obstacle when research commenced in 1956 on problems of grazing cutover pine flatwoods at the Caloosa Experimental Range. Since then, plant collection and identification has been a high priority project. This paper presents a checklist of 189 vascular plants identified over the past 8 years, with a brief introduction to their habitat, abundance, and forage value.

A survey of 8,005 acres of pulpwood-size pine plantations on eroded sites showed that survival was 38 percent in loblolly, 48 percent in shortleaf, and 29 percent in slash. Average annual growth per acre was 0.89 cord for loblolly, 0.58 cord for shortleaf, and 0.88 cord for slash. Form class was 2 to 3 percentage points better in loblolly than in shortleaf. Estimates of rough cord volume per acre of loblolly and shortleaf can be made with the regression equations and tables based on this sample. Case histories and observations suggest how plantations can be managed for timber as well as...

This note describes methods developed and practiced by the Institute of Forest Genetics to insure the high survival and thrifty seedlings needed for some types of research. The special care begins with seed extraction and extends through the early years in plantation. While the methods were developed primarily for longleaf, which in ordinary practice is notorious for poor survival and slow height growth, they are also applicable to other tree species or hybrids.

Cutting stems near groundline and spraying the fresh stumps with 2,4,5-T in diesel oil killed 99 percent of the plants within 2 years, but cost twice as much as a foliage spray with 2,4,5-T in water, which killed 66 percent.

Clipping the needles of longleaf pine seedlings immediately before planting reduced vigor and rate of early growth in three tests conducted in central Louisiana. Survival was unaffected in two tests, but was reduced in the third when seedlings encountered an early summer drought. The tests were part of a series whose purpose was to find ways of increasing long leaf survival, which is usually erratic and often low. Earlier work had shown that needle clipping reduces initial mortality on droughty sites.

Research on the chemical control of unwanted hardwood trees has been conducted at Alexandria, Louisiana, for nearly two decades. During this time, scores of silvicides have been tested by various methods of application, and southern landowners have used the findings to improve forest productivity on millions of acres.

At the 1962 Southern Weed Conference, I sunnnarized results from two studies that indicated the injection of undiluted phenoxy herbicides will kill upland scrub hardwoods more effectively and economically than diluted herbicides. Substantial·savings seemed possible through the use of cheaper chemicals, wider spacing of incisions, elimination of a carrier, and reduction of time spent in filling tools. A later and more comprehensive study, reported herein, substantiates earlier findings and provides additional information to guide landowners in their hardwood control programs.

In exploratory tests in central Louisiana, ' colonies of town ants, Atta texana (Buckley), have been destroyed with an experimental bait containing mirex, a chemical used for controlling the imported fire ant. The bait was formulated as small pellets and placed on the surface of the ground. It is safe to handle, requiring only the use of rubber gloves. The chemical compound is dodecachlorooctahydro- 1 , 3, 4-metheno-2H-cyclobuta [cd] pentalene

Juvenile longleaf pines vary considerably in their susceptibility to brown-spot needle blight. Under similar exposure to infection, a few seedlings may prove resistant while the rest are heavily attacked and many die within a few years. The extent to which resistance is genetically controlled, however, has yet to be determined.