Search Results

You are looking at 61 - 70 of 1,481 items for :

  • Refine by Access: All x
Clear All
Free access

Richard G. Snyder

Successful greenhouse tomato businesses are able to keep production and quality high while maintaining reasonable cost controls. One way of controlling costs is to use growing media that are locally available in good supply, and therefore of low cost. In Mississippi. as in other states in the southeast, pine bark is an available byproduct resource from the forestry industry; fines (<=95mm diameter) can be used as a growing medium following composting. Rice hulls are a readily available waste product from rice mills, especially in the Mississippi Delta region; these are suitable after being crushed and composted.

In comparison to plants grown in rock wool, yield from plants in pine bark fines, rice hulls, or sand were higher, while quality was not significantly different in the l-crop/year system. In a spring crop, yield and quality were higher from plants in pine bark, rice hulls, and rock wool than from those grown in sand. On a per plant basis, cost for the rock wool system, perlite system (pre-bagged), perlite (bulk), peat moss, sand, composted rice hulls, and pine bark lines are $1.50, $1.00, $0.35, $0.60, $0.24, $0.22 and $0.17, respectively. Pine bark and rice hulls are good choices for growing media for greenhouse tomatoes in areas where they are available.

Free access

Calvin Chong, R.A. Cline, and D.L. Rinker

Four deciduous ornamental shrubs [`Coral Beauty' cotoneaster (Cotoneaster dammeri C.K. Schneid); Tartarian dogwood (Cornus alba L.); `Lynwood' forsythia (Forsythia × intermedia Zab.); `Variegata' weigela (Weigela florida Bunge A.D.C.)] were grown in trickle-fertigated containers. There were eight media consisting of 25% or 50% sphagnum peat or composted pine bark, 25% sand, and the remainder one of two sources of spent mushroom compost; four media with 509″ peat or bark mixed with 50% spent mushroom compost; and a control medium of 10070 pine bark. Initially, higher than desirable salt levels in all compost-amended media were leached quickly (within 2 weeks of planting) and not detrimental to the species tested. Unlike cotoneaster, which showed no difference in growth (shoot dry weight) due to medium, dogwood, forsythia, and weigela grew significantly better in all compost-amended media than in the control. Growth of these three species was 20% greater in peat-based than in bark-based, compost-amended media. Dogwood and forsythia grew slightly more (+8%) with spent mushroom compost based primarily on straw-bedded horse manure than with one based on a blend of straw-bedded horse manure, wheat straw, and hay. The addition of sand (25%) to a mixture of 50% peat or bark and 25 % spent compost produced a medium with minimal compaction.

Free access

Ronald F. Walden and Alex X. Niemiera

The pour-through (PT) nutrient extraction method involves collection of leachate at the container bottom that results from displacement of substrate solution by water applied to the substrate surface. The PT is a convenient and effective means of monitoring the nutritional status of the soilless container substrates used in the nursery industry, but is less convenient for large containers, particularly those used in the “pot-in-pot” system of growing trees in production containers within in-ground socket containers. We describe a simple vacuum method of extracting solution from pine bark in containers using ceramic cup samplers. When N was applied to a pine bark substrate at 56–280 mg/L, extractable N was slightly higher for the PT than for the ceramic cup method. The correlation between applied and extractable N was 0.99 for both methods. Further comparison of pine bark extract nutrient and pH levels for PT and ceramic cup methods will be presented.

Free access

Yin-Tung Wang and Amy Ching-Jung Tsai

Vegetatively propagated plants (15-cm in leaf spread) of a white-flowered Phalaenopsis Taisuco Kaaladian clone were imported bare-root in late May and planted in a mix consisting of three parts of medium-grade fir bark and one part each of perlite and coarse Canadian peat (by volume) or in Chilean sphagnum moss. All plants were given 200 mg·L-1 each of N and P, 100 mg·L-1 Ca, and 50 mg·L-1 Mg. K concentrations were 0, 50, 100, 200, 300, 400, and 500 mg·L-1. After 7 months, plants grown in moss produced an average of two more leaves than those in the bark mix (4 to 5 vs. 2 to 3 leaves), regardless of K rates. In any given medium, K rate did not alter the rate of leaf production. The K rate did not affect the size of the top leaves when grown in the bark mix. However, plants grown in moss had increasingly longer and wider top leaves as K rate increased. The lower leaves on plants in the bark mix receiving no K showed deficiency symptoms of purple tinting, yellowing, necrosis, and even death. Yellowing and necrosis started from the leaf tip and progressed basipetally. The K at 50 mg·L-1 reduced and 100 mg·L-1 completely alleviated the symptoms of K deficiency. Plants grown in moss and receiving no K showed limited signs of K deficiency. Flowering stems started to emerge (spiking) from plants in the bark mix up to 4 weeks earlier than those planted in sphagnum moss. For plants receiving no K, all plants in the bark mix bloomed, whereas none planted in sphagnum moss produced flowering stems. Overall, at least 200 mg·L-1 K (∼250 mg·L-1 K2O) is recommended to produce quality plants with maximum leaf growth and early spiking.

Free access

Calvin Chong* and Adam Dale

Terminal stem cuttings of seven woody nursery species [boxwood (Buxus sempervirens L. `Green Mountain'), coralberry (Symphoricarpus × chenaultii Rehd. `Hancock'), lilac (Syringa velutina Kom.), Peegee hydrangea (Hydrangea paniculata Siebold. `Grandiflora'), purple-leaf sandcherry (Prunus × cistena N.E. Hansen), Rose-of-Sharon (Hibiscus syriacus L. `Lucy'), and winged spindle-tree (Euonymus alata Thunb.) Siebold. `Compacta')] were rooted under outdoor lath (50% shade) and mist in leached rooting media consisting of 0, 20, 40, 60 and 80% by volume of 2-year-old grape pomace amended in binary mixtures with sphagnum peat, perlite or composted bark. Rooting performance, expressed in terms of percent rooting, mean root number per rooted cutting, and length of the longest root per cutting, was regressed on level of pomace. When there were differences due to amendments, most species rooted better with perlite than with bark and peat, to a lesser degree, due in part to more favourable air-filled porosities with perlite (33% to 42%) than with bark (29% to 37%) or peat (24% to 35%). With boxwood, increasing level of pomace up to ≈60%, especially when mixed with perlite or peat, resulted in substantial increases in rooting percentage, root number and length. All three rooting parameters of winged spindle-tree decreased linearly with increasing level of pomace with perlite or bark. The effect of pomace level on other species varied between these extremes with little or no negative effect on rooting.

Free access

Russell S. Harris*, Edward W. Bush*, and Ronald J. Ward

Bifenthrin and fipronil are important pesticides used in the nursery industry for the control of imported fire ants. Our research measured the influence of irrigation frequency and time on the degradation of bifenthrin and fipronil in pine bark nursery medium. Pine bark media leachates were collected over a 180-d period. Levels of bifenthrin, fipronil, and metabolites of fipronil (MB 46513, MB 45950, MB 46136) were measured using gas chromatography and mass spectrophotometery. Bifenthrin leachate concentrations decreased from 60 ppb on day 1 to ≈1 ppb after 120 d. Fipronil leachate concentrations decreased from 40 ppb on day one to a low of 15 ppb after 120 d. In contrast, metabolites MB 45950 and MB 46136 gradually increased over the 180-d period. Metabolite MB 46513 was not detected during the experiment. Pine bark medium leachate concentrations of bifenthrin and fipronil were greater than previously reported levels in pure water. We theorize that organic compounds present in pine bark may have increased the solubility of these chemicals.

Full access

Nicole L. Shaw, Daniel J. Cantliffe, Julio Funes, and Cecil Shine III

Beit Alpha cucumber (Cucumis sativus) is an exciting new greenhouse crop for production in the southeastern U.S. and Florida. Beit Alpha cucumbers are short, seedless fruit with dark-green skin and an excellent sweet flavor. Beit Alpha-types are the leading cucumber types in the Middle Eastern market and have gained recent popularity in Europe. Beit Alpha cucumbers grown hydroponically under a protected structure have prolific fruit set, yielding more than 60 high-quality fruit per plant during one season. U.S. hydroponic vegetable production is generally associated with structure and irrigation investments which are costly as well as other inputs, such as the media, which must be replaced annually or with each crop. Beit Alpha cucumber `Alexander' was grown in Spring 2001 and 2002 in a passive-ventilated high-roof greenhouse in Gainesville, Fla. Three media types, coarse-grade perlite, medium-grade perlite, and pine bark, were compared for efficiency of growing cucumbers (production and potential costs). During both seasons, fruit yield was the same among media treatments [average of 6 kg (13.2 lb) per plant]. Irrigation requirements were the same for each type of media; however, leachate volume was sometimes greater from pots with pine bark compared to either grade of perlite suggesting a reduced need for irrigation volume when using pine bark. Pine bark is five times less expensive than perlite and was a suitable replacement for perlite in a hydroponic Beit Alpha cucumber production system.

Free access

Jennifer Green, Derald A. Harp, and Kevin L. Ong

Phytophthora diseases are economically important, requiring the use of chemical fungicides and, more recently, biological controls. Recent research suggests that composted bark products may lessen the impact of the disease, even in the absence of these chemicals. An experiment was conducted to compare chemical and biological fungicides to untreated pine bark compost. Impatiens wallerana plugs were transplanted from 288 trays into 1801 trays. All plants were planted into Berger BM-7, 35% composted bark mix (Berger Horticulture, Quebec, Canada). Media was prepared by premixing one of the five following fungicide treatments: 1) Control, 2) Banrot at 0.6 g/L, 3) Root Shield at 1.6 g/L, 4) Actino-Fe at 5.1 g/Ll, or 5) SoilGard at 1.6 g/L. Plants received no fertilizer. Three strains of Phytophthora were grown in 25 °C on clarified V8 media. Pathogenic inoculum was made by macerating the growth media and fungi in 100 ml H2O. Mixture was pulse-blended for 1 min, and an additional 200 mL dH2O was added. Inoculation was 5 ml per plant. Flats were kept on a misting bench, and misted twice daily for 15 min. The experiment was set up using a RBD repeated six times with three plants per rep. Plants were rated weekly for 5 weeks using a damage scale of 0 to 5, with 0 indicating no sign of disease and 5 being dead. Statistical analysis was conducted using a Chi-Square. Disease incidence between the biological, chemical, and composted bark treatments did not differ, with all treatments providing complete control. At least in this study, the use of composted pine bark media provided Phytophthora control equivalent to current chemical and biological fungicides.

Free access

Anne-Marie Hanson, J. Roger Harris, Robert Wright, Alex Niemiera, and Naraine Persaud

Newly transplanted container-grown landscape plants are reported to require very frequent irrigation. However, container nurseries in the U.S. commonly use growing substrates that are mostly bark, even though the contribution of bark-based growing substrates to water relations of transplanted root balls is unknown. Therefore, a field experiment was undertaken to determine water relations of a pine-bark substrate (container removed) within a drying mineral soil over a three week period. A range of common production container sizes—3.7 L (#1), 7.5 L (#2), 21.9 L (#7), 50.6 L (#15), and 104.5 L (#25)—was used. The fraction of substrate volume that is water [total volumetric water (TVW)] within the top and middle zones of substrate was compared to TVW at corresponding depths of adjacent mineral soil. The fraction of substrate and soil volume that is plant-available water [plant-available volumetric water (PAVW)] was calculated by subtracting the fraction of substrate or soil volume below where water is unavailable to most plants (measured with pressure plates) [plant-unavailable volumetric water (PUVW)] from each TVW measurement. The pine-bark substrate had a PUVW of 0.32 compared to a PUVW of 0.06 for soil. Top sections of substrate dried to near zero PAVW 6 days after irrigation for all containers. Larger container sizes maintained higher PAVW in middle sections than smaller container sizes, and PAVW was always higher in the adjacent soil than in the embedded substrate. Overall, very little PAVW is held by the embedded pine-bark growing substrate, suggesting the need for container substrates with greater water retention once transplanted to mineral soils.

Free access

A.M. Shirazi and G.H. Ware

The genus Ulmus contains numerous stress-tolerant species, especially those from areas of China with climates similar to various regions of the United States. Lace-bark elm, Ulmus parvifolia, the true Chinese elm, has an extensive temperature distribution range in China and offers great promise as a street tree. The high resistance of this elm to Dutch elm disease and other elm problems makes it an excellent tree for urban landscapes. Two new U. parvifolia cultivars, Athena® and Allee®, are not cold hardy for northern climates and there is a need for new cold hardy lace-bark elms. Screening thousands of seedlings for cold hardiness, upright form, beautiful bark characteristics, and larger leaves will bring the most desirable U. parvifolia cultivars into the green industry. We determined that seed dormancy and the percentage of seed germination of four selected lacebark elms after 2 and 4 weeks were >30% and >50%, respectively. There were significant differences in stem cold hardiness among new lace-bark elms from China (about –32 to –40 °C). Laboratory determination of cold hardiness can provide great advantages over years of field testing. Response to the outdoor temperature in December, January, and February on a seed cold hardiness freezing test showed significant reduction in seed germination, especially at –30 °C. Freezing test of seeds to –40 °C, resulted in lt 50 of –3 to –5 °C in December, so, it is less likely that these U. parvifoilia will become invasive in northern latitudes. Invasiveness of these U. parvifolia for higher zones, e.g., 6–8 could be greater and selection of these elms is suitable for zones 5 and lower. Planting these elms in zones 4, 3, and 2 will give us useful information regarding their winter performance.