Search Results

You are looking at 1 - 5 of 5 items for

  • Author or Editor: Luke T. Case* x
Clear All Modify Search

Herbicide-treated mulches can increase duration of efficacy; however, it is not known if the herbicide-treated mulches can reduce the amount of herbicide getting into the root zone or leachate water. The objective of this study is to examine herbicide movement and leaching potential using a bioassay between pine nuggets sprayed with oryzalin vs. a direct spray of oryzalin. Oryzalin-treated mulch and direct sprays were applied to 1-gallon pots at 2.0 lbs/acre a.i. (2.2 kg·ha-1 a.i.). The study was repeated in time, with trial 1 starting in Jan. 2004, and trial 2 starting in Nov. 2004. Both were conducted in a glass greenhouse in Columbus, Ohio. There were six dates of evaluation in each study: 0, 4, 8, 16, 32, and 64 DAT. An oat (Avenasativa) bioassay was conducted on three pot levels (0–2, 2–8, and 8–15 cm) and leachate to determine herbicide presence on each evaluation date. In trial 1, pots with direct sprays showed more herbicide presence in the top 2 cm than the oryzalin-treated mulch pots on each of the evaluation dates. In trial 2, results were much the same except for 32 DAT, where the oryzalin-treated mulch showed slightly more presence than the spray treatment at the 0-2 cm level. In both trials, there was a significant increase in herbicide presence in the oryzalin-treated pine nugget pots at the 0–2 cm level from 0 to 4 DAT, suggesting that the mulch does retain the herbicide. Also, results indicated more herbicide leaching into the 2–8 cm zone with the direct sprays compared to the pots containing oryzalin-treated pine nuggets. In trial 2, there was indication of the herbicide getting into the 8–15 cm zone from the direct spray treatment up to 8 DAT. There were no signs of herbicide presence in the leachates from any of the treatments.

Free access

Two experiments were conducted at the The Ohio State University Waterman Farm, Columbus, on efficacy and phytotoxicity with evalautions at 30, 60, 90, and 120 DAT using dry weights and visual ratings 0–10 with >7 being commercially acceptable for efficacy, and 1–10 with <3 being commercially acceptable for phytotoxicity. The herbicide-treated mulches and herbicide–mulch application methods were compared to sprays of the five chemicals applied directly to the surfaces of the plots [oryzalin (oryzalin), (AS) Surflan (aqueous solution) 2 lb/acre (a.i.), flumioxazin (SureGuard WDG), 0.34 lb/acre (a.i.), acetochlor 76% (Harness 2.5 lb/acre (a.i.), dichlobenil (Casoron CS) 4 lb/acre (a.i.) and a combination of oryzalin and flumioxazin], two untreated mulches (pine and hardwood) and a weedy. Mulches were applied untreated, over the top of soil surfaces sprayed with the different herbicides. Mulches were also applied untreated to untreated soil surfaces and then sprayed with the different herbicides. Pretreated bark mulches were also evaluated and prepared by placing the mulches on a sheet of plastic, as a single layer thick and sprayed and allowed to dry for 48 hours. Twenty of 38 treatments gave efficacy rating of >7, pooled over all evaluation dates. One was a direct spray, Surflan + SureGuard (7.6). Three were pretreated mulches, Surflan + SureGuard (8.2), Harness (7.8) and Surflan (7.4) treated pine. None of the pretreated hardwood barks provided ratings of >7. Nine were treatments with the herbicides applied under the bark. Seven of the nine provided ratings of >8 and only one involved hardwood bark, Surflan + SureGuard under pine (9.1), Casoron under pine (8.9), Surflan under pine (8.7), Harness under pine (8.3), Harness under pine (8.0) and SureGuard under hardwood (8.0).

Free access

DNA herbicides are the most commonly used preemergents in container nursery crops. The objectives of this study were: 1) to investigate differences between DNA herbicide applied as granulars, directed sprays, or in combination with mulch (pine nuggets and cypress) on Taxus, Azalea and and Ilex root development; and, 2) to compare efficacy of the above treatments on common groundsel (Senecio vulgaris), large crabgrass (Digitaria sanguinalis), and annual bluegrass (Poa annua). The granular formulations tested were Barricade 65 WG (prodiamine) at 2.0 lbs active ingredient per acre (a.i./ac) and Treflan TR10 (trifluralin) at 2.0 lbs a.i./ac. The liquid formulations that were used as direct sprays and to treat the mulches were Surflan 4 AS (oryzalin) at 2.0 lbs ai/ac and Pendulum 3.8 CS (pendimethalin) at 3.0 lbs a.i./ac. Evaluations of phytotoxicity and efficacy were taken as rated scores, dry weights, and leaf area measures. Evaluations were taken at 30, 60, 90, and 120 days after treatment (DAT). Efficacy ratings were based on a 0-10 scale with zero being no control, 10 perfect control and 7 commercially acceptable. By 120 DAT, none of the treatments were commercially acceptable. Root (1.52 g) and shoot (3.75 g) weights indicate that Ilex was stunted the most vs. the control (2.42 g roots and 4.87 g shoots) by the direct spray of Pendulum 2X. The Azalea was most effected by the granular application of Barricade at the 2X rate (1.72 g for roots, 4.44 g for shoots) vs. the control (2.23 g for roots, 5.83 g for shoots). Taxus roots were most stunted by Treflan 1X (0.81 g) vs. control (1.01 g). Shoot weights were the lowest with Cypress+1X Pendulum (0.90 g), vs. the control (0.96 g); however, the Treflan 1X treatment gave the second lowest shoot weight for Taxus (0.91 g).

Free access

As limitations on water used by container nurseries become commonplace, nurseries will have to improve irrigation management. Several ways to conserve water and improve on the management of irrigation water applied to container plants are discussed in this review. They include 1) uniform application, 2) proper scheduling of irrigation water, 3) substrate amendments that retain water, 4) reducing heat load or evaporative loss from containers, and 5) recycling runoff water.

Full access

The objective of this study was to evaluate the extent and duration of efficacy and phytotoxicity of two new formulations of dichlobenil (Casoron 50WP and Casoron CS), applied alone or onto two bark mulches, pine nuggets or shredded hardwood. The herbicide treated bark was compared to a control (weedy check), direct sprays of the herbicides and mulch alone. Three granular preemergent herbicides, dichlobenil (Casoron 4G) and two formulation of flumioxazin (Broadstar 0.17G, VC1351, and VC1453) were also evaluated for a total of 12 treatments. The trial started on May 23, 2003. Visual ratings and dry weights were evaluated for efficacy at 4, 8 and 16 weeks after treatment (WAT) and phytotoxicity 2, 4, 8, and 16 WAT. Ratings of efficacy were based on a 1-10 scale where, 0 represents no control, 10 represents complete control. Visual rating scores of 1 (no injury) to 10 (complete kill) were used for phytotoxicity on Salvia May Night. The two most efficacious treatments are Casoron CS as a directed spray (7.9) and treated on pine nuggets (9.0). The hardwood bark with Casoron CS also was providing an efficacy rating of 7.75 in the analyses of combined dates 4 and 8 WAT. The weed control provided by the untreated hardwood bark and pine nuggets was not significantly different from the control. Four treatments—Casoron CS and 4G, Casoron CS on pine, and CS on hardwood—provided ratings of 3 and above for phytotoxicity, in the analyses of combined dates 2, 4, 8, and 16 WAT. Although the Casoron CS was the second most efficacious treatment it had a phytotoxicity rating of 9.25 over combined dates. The CS on pine, however, had a significantly reduced phytotoxicity rating (3.5) and superior efficacy.

Free access