`Terom' globe artichoke (Cynara scolymus L.) plants were propagated vegetatively and grown for 2 years in soil-filled pots in the greenhouse under saline-sodic conditions. Plants were irrigated with water containing from 1 to 10 g NaCl/liter. Growth and yield responses were evaluated with a two-line response model. The aim of this work was to determine the salt tolerance threshold and slope for artichoke yield and growth expressed in terms of electrical conductivity (EC) of irrigation water (ECi) and saturated-soil extract (ECe). The thresholds for yield and plant fresh weight (PFW) were the same—2.7 and 4.8 dS·m-1 for ECi and ECe, respectively. The slopes for yield—14.4% and 10.7% per dS·m-1 for ECi, and ECe—were greater than those for PFW. These data indicate that PFW was less sensitive to soil and water salinity than yield. Plants survived and produced suckers at an ECe of 21.8 dS·m-1, but `Terom' yield was much more sensitive to saline-sodic conditions.
A. Graifenberg, M. Lipucci di Paola, L. Giustiniani, and O. Temperini
W.V. Welker and D.M. Glenn
Peach [Prunus persica (L.) Batsch] trees were planted in killed sod developed from five different grasses. Tree growth was evaluated within the killed-sod treatments, as well as between killed-sod and bare soil treatments. Canopy width, tree height, and trunk cross-sectional area were all greater in the killed-sod treatments than in the bare soil treatments. All five grasses tested were acceptable for developing a killed-sod mulch. Chemical names used: N-(phosphonomethyl) glycine (glyphosate); N1(3,4-dichlorophenyl)-N,N-dimethylurea (diuron); 5-chloro-3-(1-1-dimethylethyl)-6-methyl-2,4(1H,3H)-pyrimidinedione (terbacil).
The purpose of this study was to evaluate the effectiveness of soil-incorporated hydrogel to reduce irrigation requirements of transplanted Kentucky bluegrass (Poa pratensis) sod. The treatments included an untilled control, tilled soil, and tilled soil with incorporated hydrogel. Initial irrigation treatment were made daily, at various percentages of potential evapotraspiration (PET), to determine irrigation requirements of newly transplanted sod. Other irrigation treatments were later imposed on transplanted sod which had been established at 100% of PET, to determine irrigation requirements of established sod. Turf quality was measured weekly, and sod transplant rooting strength was also measured.
S.S. Barton and J. Mercer
Two focus group sessions were conducted to determine the market potential for a new horticultural product, wildflower sod. One session included homeowners with suburban lots and an interest in wildflowers. Another session included landscape professionals, property managers, and garden center operators. Participants viewed a slide presentation about the uses of wildflowers and wildflower sod; a videotape illustrating wildflower sod installation; and a demonstration plot with wildflower sod planted at different spacings (solid, 50%, 25%, or plugs at 1”, 18”, or 24” centers) and at different times of year (fall, spring). The discussion was conducted by an unbiased facilitator. Participants cited the instant effect of wildflower sod as a major advantage. The price was viewed as acceptable for small areas, especially if sod was broken apart and spaced as plugs. Comments from participants were also used to develop an ideal product description and a marketing plan.
Tara Auxt Baugher, Kendall C. Elliott, and D. Michael Glenn
Three growth suppression treatments were compared during 1991 to 1993 on `Stayman' apple (Malus domestica Borkh.) trees grown in the T-trellis and the MIA trellis systems. All treatments—root pruning, K-31 fescue (Festuca arundinacea Schreb.), and K-31 fescue plus root pruning—suppressed tree growth compared to the nontreated control, but results were inconsistent between years and systems. Sod or sod plus root pruning reduced terminal shoot length in both systems in 2 out of 3 years. Root pruning decreased shoot length in the T-trellis in 1992. Sod decreased trunk cross-sectional area in the T-trellis in 1993. Treatments did not affect 3-year average yield efficiency but did appear to increase biennial bearing. Sod, with or without root pruning, decreased fruit cracking in the T-trellis 69% and 42%, respectively, in 1992, and sod plus root pruning decreased cracking in the MIA trellis 50%. Sod reduced fruit diameter in the T-trellis in 1992. Secondary effects of growth suppression treatments included increased light penetration and improved fruit color. Sod decreased leaf N and Mg and increased leaf P, K, and Cu. The Oct. 1993 stem water potential gradient from root to canopy was more negative in the sod plus root pruning treatment, and the osmotic potential of rootsucker leaves in the combination treatment was greater than in the control, indicating that sod plus root pruning alters the distribution of water within a fruit tree.
C. A. Sanchez
Approximately 33% of all irrigated lands worldwide are affected by varying degrees of salinity and sodicity. Soils with an electrical conductivity (EC) of, the saturated extract greater than 4 dS/m are considered saline, but some horticultural crops are negatively impacted if salt concentrations in the rooting zone exceed 2 dS/m. Salinity effects on plant growth are generally considered osmotic in nature, but specific ion toxicities and nutritional imbalances are also known to occur. In addition to direct toxic affects from Na salts, Na can negatively impact soil structure. Soils with exchangeable sodium percentages (ESPs) or saturated extract sodium absorption ratios (SARs) exceeding 15 are considered sodic. Sodic soils tend to deflocculate, become impermeable to water and air, and have a strong tendency to puddle. Some soils are both saline and sodic. This workshop presentation will summarize various considerations in the management of saline and sodic soils for the production of horticultural crops.
Siyuan Tan and Garvin D. Crabtree
Competition between perennial ryegrass (Lolium perenne L. `Manhattan II') sod and wine grapes (Vitis vinifera L. `Chardonnay') for mineral nutrients was investigated with three methods of vineyard floor vegetation management (bare floor, mowed, and unmowed sod) and three rates of urea application (0, 137, and 274 kg N/ha). Sod decreased N concentration of grape leaves in both 1986 and 1987; Fe concentration in 1986; and S, Ca, B, and Mn in 1987. Sod also reduced total content of all measured nutrients in grape leaves. Mowing did not alleviate this reduction in leaf nutrient content. A high rate of urea (274 kg N/ha) compensated for N reduction in grape leaves caused by sod competition. Chemical names used: 2-[1-(ethoxyimino) butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2 -cyclohexen-1-one (sethoxydim); N,N-diethyl-2-(1-naphthalenyloxy)propanamide (napropamide).
Xunzhong Zhang, E.H. Ervin, and R.E. Schmidt
Decline of sod quality during the transportation, storage, and transplant stages of sale is a primary economic concern of sod producers. However, the mechanisms of extending sod quality during storage, transportation, and transplantation remain unclear. This study was conducted to investigate the influences of selected plant metabolic enhancers (PMEs) seaweed (Ascophyllum nodosum Jol.) extract (SWE), humic acid [93% a.i. (HA)], and propiconazole (PPC), on sod tolerance to stress during storage and posttransplant root growth of tall fescue (Festuca arundinacea Schreb.) sod. The SWE + HA, and PPC were applied alone, or in a combination, to tall fescue 2 weeks before harvest. Photochemical efficiency (PE) of photosystem II was measured immediately before harvest. The harvested sod was subjected to high temperature stress (40 °C) for 72 or 96 hours. The heated sod was replanted in the field and posttransplant injury and root strength were determined. On average over 1999 and 2000, application of SWE (50 mg·m-2) + HA (150 mg·m-2), PPC (0.30 mL·m-2), and a combination of SWE + HA with PPC (0.15 mL·m-2), enhanced PE of preharvest sod by 8.5%, 9.1%, and 11.2%, respectively, and increased posttransplant rooting by 20.6%, 34.6%, and 20.2%, respectively. All PME treatments reduced visual injury except SWE + HA and SWE + HA + PPC in 1999. Extension of heat duration from 72 to 96 hours caused significantly more injury to the sod and reduced posttransplant rooting by 22.9% averaged over 2 years. The data suggest that foliar application of SWE + HA, PPC alone, or in a combination with SWE + HA, may reduce shipment heat injury and improve posttransplant rooting and quality of tall fescue sod. Chemical name used: 1-(2-(2,4-dichloropheny)-4-propyl-1,3-dioxolan-2yl)methyl-1-H-1,2,4-triazole [propiconazole (PPC)].
Panayiotis A. Nektarios, Georgios Tsoggarakis, Aimilia-Eleni Nikolopoulou, and Dimitrios Gourlias
Two field studies (winter and summer) were performed to evaluate the effect of three different fertilizer programs and a urea formaldehyde resin foam (UFRF) soil amendment on sod establishment and anchorage. Fertilizer treatments involved were 1) a quick release (QR) granular fertilizer (12-12-17); 2) a slow release (SR) fertilizer (27-5-7); and 3) a foliar (FL) fertilizer (20-20-20). The application rate was 50, 30, 0.35 g·m-2 for QR, SR, and FL, respectively. The substrate consisted of sandy loam soil, and in half of the plots UFRF flakes were incorporated in the upper 100 mm at a rate of 20% v/v. The effects of the fertilizer and soil amendment on sod establishment were evaluated through measurements of the dry weight of clippings and roots and the visual quality of the turf. Sod anchorage was measured by determination of the vertical force required to detach a piece of sod. For each treatment the initial and final pH, EC, available P, exchangeable K, Ca, Mg, and Fe were also determined. It was found that FL reduced clipping yield but retained turf visual quality similar to the other fertilizer treatments except in winter, when it resulted in the worst quality ratings. However, FL fertilizer promoted root growth and provided high vertical detachment force values and therefore enhanced sod establishment. Slow release fertilizer resulted in moderate top growth and visual quality of the turf during winter, but delayed sod establishment. Quick release fertilizer increased top growth and improved turfgrass visual quality during the winter, but root growth and vertical detachment force were reduced, indicating poorer sod establishment. UFRF did not enhance sod establishment since there was a negative effect on root growth when temperatures were below 10 °C, without however affecting vertical detachment force. Differences in soil P, K, Ca, Mg and Fe between treatments were inconsistent between the two studies, except for final K concentration, which was higher for QR fertilization than SR and FL. Foliar fertilization can enhance sod establishment compared to QR and SR, by accelerating sod anchorage and root growth. QR can be used in late autumn to improve winter green up of the sod. UFRF does not improve or accelerate sod establishment and possesses a minimal capacity to improve soil properties of sandy loam soils.
The effects of single and sequential applications of currently available herbicides at 0.5X and lX rates on St. Augustinegrass sod production were investigated. single applications were made immediantely after the field was harvested, and remaining ribbons tilled and rolled, while sequential applications were applied approximately six months later. Sod was harvested one year after the initial application with tensile strengths and root core weight recorded. Data will be presented on the herbicide treatment rates and number of application effects on sod tensile strength and root mass.