Degree-day model for timing insecticide applications to control Dioryctria amatella (Lepidoptera: Pyralidae) in loblolly pine seed orchards

2002 ◽  
Vol 134 (2) ◽  
pp. 255-268 ◽  
Author(s):  
James L. Hanula ◽  
Gary L. DeBarr ◽  
Julie C. Weatherby ◽  
Larry R. Barber ◽  
C. Wayne Berisford

AbstractBecause Dioryctria amatella (Hulst) is a key pest in loblolly pine, Pinus taeda L. (Pinaceae), seed orchards in the southeastern United States, improved timing of insecticide applications would be valuable for its control. To time two fenvalerate (Pydrin® 2.4 EC) applications we tested four variations of a degree-day model that was developed to predicted when various proportions of D. amatella eggs would hatch during the spring generation. We compared reductions in Dioryctria spp. cone damage to unsprayed checks and a standard operational spray regime of four monthly applications of fenvalerate. In addition, we examined seeds from healthy cones to determine if sprays to control D. amatella also reduced seed damage caused by Leptoglossus corculus Say (Heteroptera: Coreidae) and Tetyra bipunctata (Herrich-Schäffer) (Heteroptera: Scutelleridae). Trials were conducted from 1984 to 1986 in two orchards in South Carolina and one in Alabama. Degree-day accumulations (threshold = 11 °C) were begun on the day when the cumulative number of male D. amatella equaled or exceeded five captured in 15 Pherocon 1C® traps baited with 100 μg of Z-11-hexadecenyl acetate. One application per year was insufficient to control D. amatella or reduced seed-bug damage. Two sprays based on D. amatella phenology significantly reduced coneworm and seed bug damage, and were as effective as four sprays applied monthly. None of the treatments reduce spring cone losses, which are primarily caused by Dioryctria merkeli Mutuura and Monroe. Several variations of the model performed well, but we suggest that the best, based on efficacy and ease of use, was when sprays were applied immediately after five males were caught (degree-day = 0) and again when the model predicted 50% of the spring generation eggs had hatched.

1981 ◽  
Vol 5 (2) ◽  
pp. 62-65
Author(s):  
John F. Kraus ◽  
Earl R. Sluder

Abstract Control-pollinated polymix progenies of 9 slash pine (P. elliottii Engelm.) and 10 loblolly (Pinus taeda L.) pine from some of the best clones in a South African tree improvement program were tested in Georgia. Overall, the progenies of the South African selections in both species have done well after five years in the field. One of the slash pine and three of the loblolly pine families were better than open-pollinated progeny from established seed orchards.


1980 ◽  
Vol 4 (3) ◽  
pp. 153-156
Author(s):  
John Talbert ◽  
Gordon White ◽  
Charles Webb

Abstract In a comparison of three diverse seed sources of improved Virginia pine (Pinus virginiana Mill.) planted at two locations in north Alabama and south-central Tennessee, only stem straightness differences were statistically significant at six years of age. Families and seed sources tended to maintain the same ranking relative to each other at both locations. A majority of families performed significantly better than a Virginia pine commercial check lot, indicating substantial improvement in growth and straightness characteristics in one generation of selection. Two improved loblolly pine (Pinus taeda L.) seed orchard mixes from the South Carolina Piedmont showed a 27-percent height advantage over the Virginia pine at age 6.


1998 ◽  
Vol 74 (2) ◽  
pp. 185-189 ◽  
Author(s):  
F. E. Bridgwater ◽  
D. L. Bramlett ◽  
T. D. Byram ◽  
W. J. Lowe

Controlled mass pollination (CMP) is one way to increase genetic gains from traditional wind-pollinated seed orchards. Methodology is under development by several forestry companies in the southern USA. Costs of CMP depend on the efficient installation, pollination, and removal of inexpensive paper bags. Even in pilot-scale studies these costs seem reasonable. Net present values from CMP in a sample of sixty-seven loblolly pine (Pinus taeda L.) seed orchards in the Western Gulf Forest Tree Improvement Program are conservatively expected to average $108 per acre of plantation established with seedlings from CMP among the best six parents in each of five breeding regions and $154 per acre for CMP among the best pair of parents in each breeding region. Key words: supplemental mass pollination, expected genetic gains, pollen contamination


1980 ◽  
Vol 4 (3) ◽  
pp. 118-121 ◽  
Author(s):  
H. E. Kodama ◽  
D. H. Van Lear

Abstract Prescribed burning of young unthinned plantations of loblolly pine (Pinus taeda L.) in the South Carolina Piedmont significantly reduced the quantity of individual nutrients in the L layer, but not the F + H layers of the forest floor. Burning reduced the weight of the L layer by 60 percent but the weight of the combined F + H layers was unaffected by the relatively fast-moving strip-head fires. Nutrient losses by ash convection from the L layer during the prescribed fire ranged from 3.6 lbs/ac for P to 23.1 lbs/ac for N. Some impaction of nutrients released in burning on pine canopies was detected by analysis of throughfall and stemflow. However, quantities of nutrients intercepted and released by the canopy are small when compared to nutrient transfer by leaf fall and precipitation. The canopy and stems markedly altered the nutrient concentrations of intercepted precipitation.


1982 ◽  
Vol 6 (1) ◽  
pp. 30-33 ◽  
Author(s):  
John L. Ruehle

Abstract Container-grown loblolly pine seedlings (Pinus taeda L.) with Pisolithus tinctorius, Thelephora terrestris, or no ectomycorrhizae (control) were outplanted on a South Carolina reforestation site. Two years after planting, seedlings initially colonized with Pisolithus or Thelephora had greater survival, height, and root collar diameter than control seedlings. Growth data were integrated into seedling volume indices (D²H). Seedlings with ectomycorrhizae at planting had nearly a three-fold greater D²H than seedlings initially without ectomycorrhizae. These results provided additional field validation for the hypothesis regarding benefits of ectomycorrhizae on this type of planting stock.


1991 ◽  
Vol 15 (1) ◽  
pp. 44-50 ◽  
Author(s):  
N. C. Wheeler ◽  
D. L. Bramlett

Abstract Flowering in conifer seed orchards may be sporadic and insufficient to meet reforestation needs at early ages. Consequently, considerable effort has been made to develop cultural treatments to enhance flowering in operational seed orchards. For a number of species, flower-promoting technology is well-defined. This study evaluated two known technologies, currently in use for other species, for flower-promoting effects in loblolly pine (Pinus taeda L.). A replicated experiment was installed in a 10-year-old, second-generation loblolly pine seed orchard at Lyons, GA. Overlapping, saw-cut girdles and stem-injected GA4/7 were applied alone, and in combination, to main boles of ramets of four clones. Timing of treatments was evaluated using four treatment dates. All treatments significantly enhanced female flower production, relative to controls, although girdling was clearly the most effective single treatment. There was no treatment effect on pollen production. Timing of treatment is important but may require evaluation on a site-by-site basis. Tree health 1 year after treatment was excellent, although clonal sensitivity to some treatments was noted. Use of flower stimulation techniques is recommended, particularly for younger loblolly pine orchards. South J. Appl. For. 15(1):44-50.


2002 ◽  
Vol 26 (3) ◽  
pp. 146-152 ◽  
Author(s):  
Donald M. Grosman ◽  
William W. Upton ◽  
Frank A. McCook ◽  
Ronald F. Billings

Abstract Three systemic insecticide treatments, emamectin benzoate alone, imidacloprid alone, and a combination of emamectin benzoate and thiamethoxam, were injected one or two times into loblolly pine,Pinus taeda L., during a 2 yr period in a seed orchard in east Texas. Single injections of treatments containing emamectin benzoate reduced coneworm (Dioryctria spp.) damage by 94–97% during the study period. A second injection after 1 yr did not improve protection. Imidacloprid also significantly reduced coneworm damage in 1999, but not in 2000. Significant reductions in damage from pine seed bugs (Tetyra bipunctata Say andLeptoglossus corculus Herrich-Schaffer) and an increase in the number of full seeds per cone resulted from imidacloprid and thiamethoxam treatments and to a lesser extent from emamectin benzoate. Yearly injections of imidacloprid or thiamethoxam were required to maintain protection against seed bugs. The best overall treatment, two injections of emamectin benzoate plus thiamethoxam, reduced cone and seed losses from insects by 86%. South. J. Appl. For. 26(3):146–152.


1984 ◽  
Vol 8 (1) ◽  
pp. 35-40 ◽  
Author(s):  
Thomas A. Waldrop ◽  
David H. Van Lear

Abstract Unthinned, pole-size loblolly pine (Pinus taeda L.) plantations in the South Carolina Piedmont were burned at different seasons under minimal wind conditions to evaluate the effects of fire intensity on crown scorch. Needle drop, an indicator of crown scorch, was significantly greater on areas burned with medium- to high-intensity fires than on unburned plots. There was a direct relation between bark char height, beyond a threshold value of 3 feet, and crown scorch. Scorched needles fell within three weeks following fire. Moderate crown scorch had no detrimental effects on survival and growth of trees in the upper crown classes. Complete crown scorch resulted in the death of 20 and 30 percent of trees in the codominant and intermediate crown classes, respectively.


1977 ◽  
Vol 1 (4) ◽  
pp. 8-10
Author(s):  
D. H. Van Lear ◽  
N. B. Goebel ◽  
J. G. Williams

Abstract The performance of adjacent unthinned plantations of loblolly (Pinus taeda L.) and slash pine (P. elliottii Engelm.) on three sites in South Carolina was evaluated after 16 growing seasons. Sites ranged from a noneroded Piedmont soil to an excessively drained sandy soil of the Sandhills physiographic region. Growth and survival varied widely among sites, with greatest productivity occurring in the Piedmont and the lowest in the Congaree Sandhills. Despite the droughty nature of the latter site, survival after 16 growing seasons was over 80 percent for both species. On a volume basis, loblolly pine outperformed slash pine at the upper Pidemont and Aiken Plateau sites, while slash pine was superior on the dry Sandhills site. Incidence of fusiform rust was much higher for both species at the Aiken Plateau than at the other sites.


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