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Forage yields of five grass species: Agropyron cristatum (L.) Gaertn., A. smithii Rydb., Lolium perenne L., Poa pratensis L., and Puccinellia distans (L.) Parl., were studied in soil under greenhouse conditions with NaCl additions of 0; 5,000; 10,000; and 20,000 ppm. Forage yield of P. distans was reduced 23% by addition of 20,000 ppm NaCl, compared to a minimum reduction of 40% for the other grass species. Addition of 30,000 ppm NaCl to soil completely inhibited seedling survival of A. cristatum, A. smithii, Elymus triticoides Buckl., P. distans, Puccinellia lemmoni (Vasey) Scribn., and Sporobolus airoides (Torr.) Torr. Puccinellia airoides (Nutt.) Wats. and Coult. and P. distans were unusually toleran to foliar applications of NaCl in the field. Mineral analysis of leaf tissue by emission spectroscopy showed that Na concentrations increased as NaCl addition to the soil increased. However, there was no relationship between salt tolerance of the various grasses and amounts of Na in leaf tissue. Increased NaCl addition to the soil resulted in decreased leaf Ca and Mg, but no relationship existed between leaf K and NaCl addition. P. distans is of value for vegetating saline roadsides.

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.

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.

The cold hardiness of 6 cool season grass genera was compared in mid-winter under controlled freezing conditions. Creeping bentgrasses (Agrostis palustris Huds.) tolerated the lowest temperatures whereas perennial ryegrasses (Lolium perenne L.) was the least hardy. Kentucky bluegrass (Poa pratensis L.) readily loses cold hardiness when exposed to warm conditions and did not reharden when exposed to cool temperatures. Appreciable hardiness in Kentucky bluegrass was induced by simulating drought conditions.

Sixteen minilysimeters were used in a study to determine the effect of preconditioning to shade on evapotranspiration (ET) by Kentucky bluegrass (Poa pratensis L. var ‘Merion’). Grass that had been preconditioned to 100, 71, 51, and 27% of possible photosynthetically active radiation (PAR) was subjected to full sun (100% PAR) or full shade (2% PAR) for one day periods. Canopy temperature and ET were measured and compared for grass from differing preconditioning treatments. Live biomass was later clipped, dried and weighed. Dry weight increased by a factor of nearly 3 as pretreatment PAR increased from 27 to 100%. In spite of this difference in the 20 mm high canopy densities, ET and canopy temperature were equal for grasses from all preconditioning treatments when placed in full sun or full shade. It was concluded that ET is not influenced by preconditioning to shade as long as complete ground cover is maintained.

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.

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.

Color Variations of creeping bentgrass (Agrostis palustris Huds.) are correlated with the iron and Chlorophyll content in leaf tissues. The color value and Chlorophyll content of ‘Cohansey’, a light green cultivar, increases significantly 2 hours after the application of ferrous sulphate. However, ‘IaGreen 4-45’, a dark green cultivar, shows little response. Increases in Chlorophyll or color following iron treatment are temporary. Chlorophyll content of creeping bentgrass cultivars varied during the growing season, and peaked in August.

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.

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.

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.

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.

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.