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  • Author or Editor: J. L. Eggens x
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Abstract

Rooted cuttings of Anthemis nobilis, Arctostaphylos uva-ursi; Veronica officinalis and Houttuynia cordata were grown in the greenhouse and in nutrient solutions differing only in pH. The levels of pH were adjusted to 3 to 9 for A. nobilis and A. uva-ursi, to pH 4 to 9 for V. officinalis and to pH 4 to 6 for H. cordata. A. nobilis grew well at pH 4 to 7 but best growth was near pH 5. Arctostaphylos uva-ursi made best growth at pH 4 but not significantly better than at pH 5 to 7. V. officinalis grew well over a wide pH range (4 to 7 inclusive) and plants died gradually at pH 9. For the H. cordata trial a limited number of plants was available and at the imposed pH levels (4, 5 and 6) all plants grew uniformly and well.

Open Access
Authors: and

Abstract

Germination responses of creeping bentgrass (Agrostis palustris Huds.) and Kentucky bluegrass (Poa pratensis L.), and annual bluegrass (Poa annua L.) to elevated temperature were evaluated by germinating seed in sustained temperature regimes or by moving imbibed seed from high to intermediate or from intermediate to high temperatures. ‘Penncross’ creeping bentgrass germinated well at 40°/30°C (day/night) temperature or when moved from 40/30° to 25°/18° or from 25°/18° to 40°/30°. ‘Baron’ Kentucky bluegrass seed germination was decreased by 34°/28° and there was no germination at 40°/30°. Moving imbibed seed from 40°/30° to 24°/18° resulted in a high germination percentage, while imbibition for 12 or 24 hours at 25° resulted in some germination at 40°/30°. Annual bluegrass seed germination was significantly less at 34°/28° than at 25°/18° and was prevented at 40°/30°. Imbibition at 40°/30° prior to 25°/18° decreased germination and there was no annual bluegrass germination at 40°/30° regardlessf of pretreatments at 25° for up to 24 hours.

Open Access

Abstract

Annual bluegrass (Poa annua L.) and ‘Penncross’ creeping bentgrass (Agrostis palustris Huds.) were grown in monostand and polystand in silica sand and supplied with solutions in which 0%, 25%, 50%, 75% or 100% of the N was NH4 + and the remainder was NO3. In polystand, annual bluegrass was more competitive than ‘Penncross’, producing more shoot and root dry weight and more tillers. Competitive ability of annual bluegrass was decreased as the percentage of NH4 + increased in nutrient solution. The decrease in competitive ability was reflected by a decline in tiller number and root and shoot dry weight. ‘Penncross’ was less affected by N form than was annual bluegrass.

Open Access

Abstract

The effectiveness of ethephon for reducing the growth of annual bluegrass (Poa annua L.), when grown as single plants in pot culture in the greenhouse or outdoors, and within a Kentucky bluegrass (Poa pratensis L.) sod, was evaluated. Ethephon reduced the growth of annual bluegrass more than that of Kentucky bluegrass. Concentration was more important in reducing plant spread than the number of applications. Ethephon applied to field grown turf reduced the leaf area per tiller of annual bluegrass but not Kentucky bluegrass. Leaves per tiller and the shoot dry weight of field grown Kentucky bluegrass increased with increasing ethephon rates compared to nontreated plots. Although significant growth retardation occurred for both species in pot culture, only Kentucky bluegrass canopy height decreased in the field with increasing ethephon rates. Decreased Kentucky bluegrass canopy height resulted from reduced sheath length. Chemical names used: (2-chloroethyl) phosphonic acid (ethephon).

Open Access

Abstract

Five cultivars of creeping bentgrass (Agrostis palustris Huds. ‘Emerald’, ‘Penncross’, ‘Penneagle’, ‘Prominent’, and ‘Seaside’) and annual bluegrass (Poa annua L.), a weed, were grown in pot culture in silica sand and supplied with nutrient solutions in which 0%, 25%, 50%, 75%, or 100% of the N (210 mg·liter−1) was NH 4 + and the remainder was NO 3 - . Growth rate, as measured by new leaves and tillers, and final size, as measured by leaf width, leaf number, tiller number, and cover, were significantly different among species and cultivars and among N ratios. All species/cultivars produced their best growth with some mixture of NH 4 + -N and NO 3 - -N . Annual bluegrass grew better in high- NH 4 + conditions, while the bentgrass cultivars grew as well or better in high NO 3 - conditions. There were significant differences among the bentgrass cultivars in their sensitivity to N source, with ‘Penncross’ being the most sensitive and ‘Seaside’ the least.

Open Access

Abstract

The effect of mefluidide, a growth regulator, on the growth of annual blue-grass (Poa annua L.) was evaluated under pot culture and field conditions. In pot culture, mefluidide caused a significant reduction in shoot and root dry weight and tiller number of single annual bluegrass plants, and of annual bluegrass planted at high densities. In the latter case, mefluidide also increased the success of ‘Penncross’ creeping bentgrass (Agrostis palustris Huds.) overseeded into the annual bluegrass. Overseeding success of ‘Fiesta’ perennial ryegrass (Lolium perenne L.) in field trials increased significantly with increasing rates of mefluidide. No increase in success was noted in overseeding with creeping bentgrass in the field. There was a minimum detrimental effect of mefluidide to turf quality of the established turf species in the golf course fairway. Chemical names used: N-[2,4-dimethyl-5[[[trifluoromethyl] sulfonyl]amino]phenyl]acetamide (mefluidide).

Open Access