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  • Author or Editor: E.K. Nelson x
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Abstract

Success in presenting a paper at meetings of the Society requires that slides be of high quality and properly used. A paper has only one purpose- to inform. A slide has only one purpose- to portray information for quick understanding.

Open Access

Absorption of “C-labeled glyphosate by whole carrot (Daucus carota L.) plants infected or not infected by swamp dodder (Cuscuta gronovii Willd ex R & S) increased from 14% 1 day after treatment to 56% 14 days after treatment. Absorption of 14C-labeled glyphosate did not increase from 14 to 45 days after treatment. 14Carbon-labeled glyphosate appeared in the carrot root 1 day after application and its concentration increased with time in both infected and noninfected plants until 14 days after treatment. From 14 to 45 days after treatment, the concentration of 14C-labeled glyphosate in the roots decreased. At 1 day after treatment, dodder tissue contained as much 14C-labeled glyphosate as any physiological sink in the carrot. At 45 days after treatment, dodder tissue contained more 14C-labeled glyphosate than all other physiological sinks, except the petiole of the treated leaf. Swamp dodder stems had absorbed 14C-labeled glyphosate directly from a solution within 1 day after treatment. Chemical name used: N-(phosphonomethyl)glycine (glyphosphate).

Free access

Abstract

The effects of 10% carbon monoxide (CO) added to air or controlled atmospheres (2% O2 with or without 5% CO2) on quality and storage life of grapes (Vitis vinifera L. cv. Thompson Seedless) were compared with those of the conventional SO2 fumigation treatments for decay control. CO in air reduced respiration and C2H4 production rates, and retarded berry browning and softening, but was only partially effective in retarding decay beyond 2 months at 0°C. SO2 treatments were very effective in controlling the spread of decay, but brown discoloration of the berries increased, especially after 2 months at 0° or 1°. When combined with 2% O2 with or without 5% CO2, CO inhibited C2H4 production and retarded decay development, but the presence of CO2 increased brown discoloration of the berries. A combination of 2% O2 + 10% CO was as effective as SO2 in controlling decay of grapes held at 0° for up to 4 months and caused less browning and bleaching than SO2.

Open Access

Genetically transformed cultivars of creeping bentgrass (Agrostis stolonifera L. syn. Agrostis palustris Huds.) that are resistant to glyphosate have been developed by a collaboration of the Scotts and Monsanto companies. Prior to commercial release, we desired to determine if the transformed plants behave similarly to traditional creeping bentgrass except for the effects expected from the inserted gene, i.e., resistance to glyphosate. Therefore, studies were initiated on 23 June 2000 in Marysville, Ohio; 14 July 2000 in Middleton, N.J.; and 20 June 2000 in Gervais, Ore., to examine the relative lateral spread and competitive ability of several transformed lines of creeping bentgrass, non-transformed controls, and reference cultivars. Vegetative plugs of creeping bentgrass were transplanted into a mature stand of Kentucky bluegrass (Poa pratensis L.) or a uniform mixture of Kentucky bluegrass with perennial ryegrass (Lolium perenne L.). The plots were watered as needed to prevent moisture stress. Competitive ability of the transformed plants and reference cultivars were determined monthly by measuring the average diameter of the creeping bentgrass patch. On all observation dates, the transgenic lines, as a group, were smaller in average diameter (5.1-7.6 cm) compared to the reference cultivars (5.4-14.2 cm) and non-transformed control lines (5.9-10.2 cm). At the end of the observation period (Aug. 2001), no differences (P = 0.05) in lateral spread were observed between individual lines of transgenic bentgrass. Three lines of interest, ASR365, ASR368, and ASR333, had lateral spread rates that are similar to, or less than, that of their non-transformed parent and the conventional creeping bentgrass cultivars tested. Chemical names used: N-(phosphonomethyl) glycine (glyphosate).

Free access

Abstract

Sixty-three cultivars of carnation (Dianthus cary ophyllus L.) including 42 Sim types, 9 non-Sim standards and 12 miniature types, were tested for susceptibility to Fusarium stub dieback caused by Gibberella zeae (Schw.) Petch. All cultivars were assigned a numerical rating by comparing infection rates to ‘Improved White Sim’ (IWS) used as a standard assigned rating of 1.00. Sixteen cultivars had ratings significantly lower than IWS and 3 significantly higher. The range of the ratings was from 0.20 for ‘Maj Britt’ to 2.61 for ‘Orchid Beauty’. The range for Sim types was from 0.25 for ‘Yellow dusty’ to 1.67 for ‘California White’. It is suggested that sufficient variation exists in commercial cultivars for selection for resistance to Fusarium stub dieback.

Open Access

Plant establishment and lateral growth of glyphosate-resistant creeping bentgrass [Agrostis stolonifera (synonym A. palustris)] were assessed to determine if the insertion of the construct conferring herbicide tolerance affected establishment rate or aggressiveness characteristics in unmowed situations. Field studies were carried out in Michigan, Illinois, Ohio, and Oregon in 2000 and 2001 to examine the relative lateral growth of several transformed lines of creeping bentgrass, non-transformed controls, and cultivar standards. Vegetative plugs of creeping bentgrass were transplanted into replicated bare-soil plots and irrigated as needed to prevent moisture stress for an initial 6-week period. Measurements of maximum and minimum stolon spread, percent cover, and stand density for each entry were made in the field at all locations during 2000 and 2001. Few statistical differences (P = 0.05) in establishment and lateral growth were observed between individual lines of transgenic creeping bentgrass, non-transformed control lines, and standard cultivars and over a 15- to 18-month period. Overall, lateral growth and establishment rate of transgenic lines were similar to their non-transformed parent and the standard cultivars tested. Transgenic creeping bentgrass lines should have no greater potential for lateral growth than conventional creeping bentgrass cultivars currently in use.

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