, Research Triangle Park, NC (FRAC code 11)], mancozeb [Mancozeb; Bonide Products, Oriskany, NY (FRAC code M03)], and ametoctradin + dimethomorph [Zampro 525F; BASF Corp. (FRAC code 45 and 40)]. A nonionic surfactant (Induce 90; Helena Chemical Co.) was used
Guirong Zhang, Mohammad Babadoost, Alan De Young, Eric T. Johnson, and David A. Schisler
Katie J. Kammler, S. Alan Walters, and Bryan G. Young
oil concentrate (COC) to a high-concentrate, oil-based adjuvant ( Jordan et al., 1989 ). A nonionic surfactant (NIS) is recommended for use with halosulfuron because the label states that the use of a COC will result in increased crop injury and
David G. Himelrick, Robert M. Pool, and Philip J. McInnis
Several cryoprotectant chemicals were tested for their ability to increase the freeze resistance of grapevine (Vitis labruscana Bailey) leaf and dormant bud tissue. DuPont Surfactant WK, ethylene glycol, and BRIJ 35 were effective in lowering the low-temperature exotherm (LTE) in `Concord' grape buds below controls by 5.4, 5.1, and 3.9C, respectively, in March. Measurements taken in April showed BRIJ 35 and Surfactant WK to be notably superior to the other products, giving LTEs 14.1 and 12.2C below controls, respectively. Ethylene glycol, Frostguard, and Frost Free were less effective. LTEs were also significantly decreased in grape leaf disks 4.1C by BRIJ 35, 2.1C by Frostguard, and 0.4C by Frost Free treatments. Chemical name used: trimethylnonylpolyethoxyethanol (DuPont Surfactant WK).
Sven E. Svenson, Robert B. McReynolds, and Wes A. Deuel
Field evaluation of meadowfoam (Limnanthes alba) seedmeal as a soil amendment to control clubroot caused by Plasmodiophora brassicae was conducted using cauliflower seedlings and seeded mustard grown in naturally infested soils. Ionic surfactant drench was applied as a comparative treatment. Meadowfoam seedmeal (MSM) incorporation at a rate of 15,000 kg·ha-1 resulted in greatest control of clubroot incidence and severity. This treatment also resulted in significantly greater fresh weight yield of cauliflower compared to controls and surfactant drench application. Some phytotoxicity symptoms were observed at high rate (30,000 kg·ha-1) of MSM treatment. MSM glucosinolate products may have an important role in regulating plant-pathogen interactions.
Durward Smith, Jay B. Fitzgerald, and George E. Meyer
Insect infestation of plant material is a serious problem to the greenhouse industry. Nonpesticidal destruction of insects on plant material before they are placed in the greenhouse would supply producers and growers with pest-free plant materials and decrease pesticide usage and exposure of workers and the environment to chemical insecticides. The efficacy of vacuum treating chrysanthemum (Chrysanthemum morifolium) and poinsettia (Euphorbia pulcherrima) plants for the reduction of insect pests (aphids and greenhouse whiteflies) was investigated. The effects of surfactants on insect elimination was determined. Properly controlled vacuum treatment in conjunction with surfactants was found to disrupt the physical integrity of the insects in all stages of their life cycle.
Chris B. Watkins, Randolph M. Beaudry, Terence L. Robinson, and Alan N. Lakso
ReTain™, a commercial plant growth regulator containing aminoethoxyvinylglycine, an inhibitor of ethylene production, was applied 4 weeks before normal harvest to `Jonagold' trees and the effects on fruit maturity and quality at harvest, and quality after air and controlled atmosphere storage was investigated. When fruit were harvested from 3 to 6 weeks after treatment, fruit ripening was inhibited as indicated by lower internal ethylene concentrations, delayed starch hydrolysis, and lower levels of skin greasiness. A number of factors indicated that other aspects of fruit metabolism were affected by the compound. Treated fruit were softer than nontreated fruit at the first harvest, and the benefits of ReTain on firmness appeared only at the later harvests. Also, at each harvest date, average fruit weight of ReTain-treated fruit was lower than nontreated fruit. We have investigated the possibility the ReTain and/or the accompanying surfactant, Silwet, inhibited leaf photosynthesis, thereby leading to altered carbon metabolism. Trees were unsprayed, or sprayed with surfactant, and ReTain plus surfactant. No treatment effects on photosynthesis were detected. However, leaf photosynthesis rates were generally low and quite variable. Measurements of fruit diameter confirmed that the increase in fruit volume following treatment was ≈2% less on the ReTain plus surfactant-treated fruit than nontreated fruit. The increase in fruit volume for the Silwet treatment was ≈1.5% less than in untreated fruit. The data indicates a rapid change in fruit volume as fruit changed in color. Inhibition of ethylene by ReTain may be an important factor influencing fruit size.
John F. Ahrens, Larry J. Kuhns, Tracey L. Harpster, and Todd L. Mervosh
In 1995, Monsanto Chemical Co. announced that they would replace Roundup herbicide with Roundup Pro for use in the ornamentals and turf markets. Both products contain 4 lb a.i./gal glyphosate, but Roundup Pro contains a more-active surfactant. Though Roundup was labeled as a nonselective herbicide, dormant conifers were found to have varying degrees of resistance to it. Directed sprays that hit the lower two-thirds of many dormant conifers became common practice in the industry. Because the surfactant in Roundup Pro increases the activity of the glyphosate, a series of trials were initiated in 1996 in Connecticut, Pennsylvania, and Vermont in which four glyphosate formulations were applied to a variety of dormant conifers. Roundup, Roundup Pro, Glyfos, and Accord (with and without surfactant) were applied either over-the-top or as directed sprays to the lower 18 inches of the plants at rates between 0.5 and 3 lb a.i./acre. Plants treated included globe arborvitae; upright yew; Canadian hemlock; Colorado, Norway and white spruce; Douglas fir; eastern white pine; and balsam, Canaan, and Fraser fir. In a preliminary study, injury to the spruces in the form of dwarfed and chlorotic new growth was primarily associated with fresh pruning wounds. Accord plus surfactant and Roundup Pro injured more spruces than Roundup, but injury was slight. No injury was observed in upright yew with any formulation at rates up to 0.75 lb a.i./acre. Injury to arborvitae was greatest with Accord plus surfactant, intermediate with Roundup Pro, and least with Roundup. Results are inconclusive at this time, but the results of additional studies available early in the next growing season.will be presented.
M. Fidanza, P. Colbaugh, H. Couch, M. Elliott, and S. Davis
Fairy ring has become a troublesome and persistent disease on golf course putting greens and other turf areas in most regions of the United States. Many basidiomycete fungi are associated with this destructive disease in turfgrass. Recent widespread epidemics of fairy ring have led investigators to examine possible management and control options. Curative approaches include topical flutolanil fungicide applications in conjunction with soil surfactants, the application of flutolanil under high-pressure injection, and the use of nitrogen fertility programs. These curative programs were effective at suppressing visual symptoms and turfgrass injury. A preventive approach evaluated repeat applications of flutolanil plus a soil surfactant prior to disease development. This preventive program was effective at eliminating visual disease symptoms on bermudagrass putting greens. Information presented will review results from field research studies conducted over the past 3 years in Florida, North Carolina, Ohio, Texas, and Virginia.
N.K. Dokoozlian, N.C. Ebisuda, and R.A. Neja
The effects of surfactants on the efficacy of hydrogen cyanamide (H2CN2) applied to `Perlette' grapevines (Vitis vinifera L.) grown in the Coachella Valley of California were examined in 1994 and 1995. Vines were pruned in mid-December in both years and treatments applied at 1000 L·ha-1 the following day to dormant spurs and cordons using a hand-held spray wand. In 1994, H2CN2 was applied at 0.5%, 1%, or 2% by volume in combination with 0%, 0.5%, 1%, 2%, or 3% by volume of the amine-based surfactant Armobreak. In 1995, H2CN2 was applied at 0.5%, 1%, or 2% by volume in combination with Armobreak at 0% or 2% by volume. In 1994, budbreak rate was highly dependent upon H2CN2 concentration when 0% to 1% Armobreak was used; budbreak was generally most rapid for vines treated with 2% H2CN2 and slowest for vines treated with 0.5% H2CN2. When 2% or 3% Armobreak was used, however, little effect of H2CN2 concentration was observed. Results were similar in 1995, but the budbreak of vines treated with 2% H2CN2 + 2% Armobreak lagged behind that of vines treated with 1% H2CN2 + 2% Armobreak. The number of days after treatment required for 70% bud-break generally declined as the concentrations of H2CN2 and Armobreak were increased. A separate experiment conducted in 1995 revealed that several surfactants varying in chemical composition, Armobreak, Activator 90 and Agridex, had similar effects on H2CN2 efficacy. The results indicate that the addition of surfactants to H2CN2 solutions can significantly reduce the amount of active ingredient necessary for maximum efficacy on grapevines. Chemical names used: hydroxypolyoxyethylene polyoxypropylene ethyl alkylamine (Armobreak); alkyl polyoxyethylene ether (Activator 90); paraffin petroleum oil (Agridex).
M.A. Fidanza, P.F. Colbaugh, M.C. Engelke, S.D. Davis, and K.E. Kenworthy
Fairy ring is a common and troublesome disease of turfgrasses maintained on golf course putting greens. Type-I fairy ring is especially destructive due to the development of hydrophobic conditions in the thatch and root zone, thus contributing to turfgrass injury and loss. The objective of this 2-year field study was to evaluate the application and novel delivery method of two fungicides and a soil surfactant for curative control of type-I fairy ring in a 20-year-old creeping bentgrass [Agrostis palustris (synonym A. stolonifera)] putting green. In both years, all treatments were applied twice on a 28-day interval. In 1998, flutolanil and azoxystrobin fungicides were applied alone and in combination with Primer soil surfactant by a conventional topical spray method, and fungicides without Primer applied via high-pressure injection (HPI). Acceptable type-I fairy ring control was observed in plots treated with flutolanil plus Primer, HPI flutolanil, azoxystrobin alone, azoxystrobin plus Primer, or HPI azoxystrobin. In 1999, treatments were HPI flutolanil, HPI flutolanil plus Primer, HPI azoxystrobin, HPI water only, and aeration only. Acceptable type-I fairy ring control was observed in plots treated with HPI flutolanil plus Primer or HPI azoxystrobin. HPI of fungicides alone or in combination with a soil surfactant may be a viable option for alleviating type-I fairy ring symptoms on golf course putting greens.