Search Results
Abstract
Iron chelates, iron salts, and acid-treated mine tailings significantly increased turfgrass greening of Kentucky bluegrass (Poa pratensis L.) when compared to control plots. Turf treated with iron salts and acid mine tailings after 384 days were significantly darker green than those treated with chelates. There was a positive correlation between turf color, total leaf iron, and chlorophyll 17 days after treatment, but not after 384 days.
Fungicides, including Topsin M, Rovral, Ronilan, Ridomil/Bravo, TD 2350-1, CGA 219417, and a combination of Topsin M and TD 2350-1, were evaluated for control of Botrytis allii in a commercial field of hard, yellow, seed onions near Madras, Ore. The 10 × 25-ft split-plots were replicated three times in a randomized complete block design, with half the plot planted with Topsin M-treated seed prior to planting. Plots received a single fall fungicide application on 30 Sept. 1994, and two spring applications on 3 May and 13 May 1995. Stand counts were taken 4–6 Nov. 1994 and 21 Apr. 1995 to evaluate reduction in plant population over winter. Three row-foot of plants grown from untreated seed were removed and examined for lesions and sporulation 15–19 June 1995. Thirty-plant samples were taken from both plots with treated and untreated seed 17–21 July 1995. Botrytis was considered present if lesions plus sporulation were observed on the bulb at the time of sampling, or if sporulation developed on previously non-sporulating lesions within 3 days of storage in plastic bags at room temperature. A visual rating of plants that remained standing due to adequate root systems was conducted 24 July 1995. Bulb evaluation of non-seed-treated plots on 15–19 June indicated significant control of botrytis with TD 2350-1 over plots not receiving foliar fungicide application. Evaluation of non-seed-treated plots on 17–21 July indicated Topsin M, TD 2350-1, and a combination of the two fungicides provided significant disease control compared to plots without foliar application of fungicides. There were no significant differences between fall and spring stand counts, or between treated and untreated seed.
Abstract
The mineral composition of grasses commonly used for turf has received little study. This is especially so for the micronutrient elements. Some data are available for grasses grown under pasture conditions (7), however, most of these grasses and their method of culture are quite different from turfgrasses. The paucity of information on turfgrasses prompted this survey of the mineral composition of several grasses commonly used for ornamental purposes. The grasses studied were grown in the field under a maintenance program typical of that used for turfgrasses. The results should be of value for future comparisons where nutrient toxicities, deficiencies or imbalances are suspected.
Abstract
In a field test of 25 Kentucky bluegrass cultivars (Poa pratensis L.) “common types” were generally more drought tolerant than recently introduced turf types. ‘Code 95’, a common type, and ‘Merion’ exhibited high drought resistance and produced turf of good color, texture, and density. Turf mowed at 3.8 cm was more resistant to drought than turf maintained at 1.9 cm.
Abstract
There was no correlation between drought resistance and several plant characteristics of 12 Kentucky bluegrass cultivars (Poa pratensis L.) rated high, intermediate, or low in drought resistance on the basis of Visual response to drought stress.
Abstract
Significant differences in iron and chlorophyll content occurred between 25 cultivars and 5 blends of 3 year old, well-established Kentucky bluegrass (Poa pratensis L.). ‘Adelphi’, 111. 38-17, ‘Sodco’, ‘Sydsport’, ‘Windsor’, and blends of ‘Common’ + ‘Kenblue’ and ‘Windsor’ + ‘Merion’ received highest visual ratings for dark green color.
Abstract
Use of certain pesticides over a 3-year period caused a marked build-up of plant debris (thatch) of ‘Kentucky’ bluegrass (Poa pratensis L.) turf above the soil surface. Applications of the chlorinated hydrocarbon insecticides, dieldrin and chlordane, resulted in a thatch layer of 20 mm or more. The use of the carbamate insecticide, carbaryl, caused an average match thickness of 1.3 mm. The plots that received no insecticides or the mercuric fungicide, phenyl mercuric acetate (PMA), had no measurable thatch. The match depths were closely associated with plant debris wt.
As the no. of earthworm burrows increased, the amount of thatch decreased. Where earthworms were present to any extent, thatch was virtually non-existent.
Abstract
Seedlings of Kentucky bluegrass (Poa pratensis L.), perennial ryegrass (Lolium perenne L.), red fescue (Festuca rubra L.), and weeping alkaligrass [Puccinellia distans (L.) Parl.] were exposed to water stress prior to measuring heat tolerance of leaf blade segments. Heat tolerance was determined using an electrolyte leakage assay. Water stress pretreatments did not increase in vitro heat tolerance of turfgrass leaves.
Abstract
Field and laboratory tests of cold hardiness were conducted on 8 cultivars of bermudagrass (Cynodon spp.) and 2 cultivars of Paspalum vaginatum. The cultivars of bermudagrass were more cold hardy than those of Paspalum. ‘Brookings’ bermudagrass was the hardiest turfgrass.
Abstract
Injury to turfgrass leaf segments was measured as percent electrolyte leakage as affected by the duration and level of imposed heat stress. Species differences in heat tolerance were most apparent when injury was monitored over time at 50°C, using leaf segments which were obtained from heat-hardened plants and immersed in distilled water during the stress treatment. Quantitative differences in heat tolerance in vitro were consistent with qualitative descriptions of drought resistance for most of the species tested.