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Patmore green ash (Fraxinus pennsylvanica `Patmore'), Bur oak (Quercus macrocarpa), and Austrian pine (Pinus nigra), were used to measure growth differences of trees produced using three different production methods: balled and burlapped, plastic container, and fabric container (grow bag). Two irrigation frequencies were also established. A pressure chamber was used to measure the xylem water potential and to determine tree water requirements and irrigation scheduling. The balled and burlapped trees showed the least new growth of the three production methods across all three tree types. The production method showing the most new growth varied by genera. Plastic container ash trees grew considerably more than the fabric container ash; fabric container oak grew significantly more than plastic container oak; and there was no measurable difference between the new growth of the plastic container and fabric container pines. The fabric container transplants required more frequent irrigation than did the balled and burlapped trees. Under high temperature and drought conditions, fabric container trees showed stress earlier than did the balled and burlapped or plastic container trees.
Abstract
Total N content in the shoots of Chrysanthemum morifolium Ramat ‘Bright Golden Anne’ grown in hardwood bark was significantly greater when utilizing (NH4)2SO4 source of N than with KNO3 source. The NH4 + concn in the shoots was greatest at the low pH range when (NH4)2SO4 was the source of N. The NH4 + concn in the media was greatest at the low pH range when utilizing the (NH4)2SO4 and NH4NO3 sources of N.
The greatest dry wt of shoots was obtained if test plants were treated with both NH4 + and NO3 − forms of N with NH4NO3 source of N at the higher pH range and without the nitrification inhibitor.
The objective of these experiments was to evaluate the reaction of ‘Snow Angel’ coral bells (Heuchera sanguinea) and Orange Carpet hummingbird trumpet (Epilobium canum ssp. garrettii ‘PWWG01S’) to repeated foliar applications of three plant growth regulators at two application rates. The plant growth regulators applied during a stock plant study and followed by a propagation study were 200 and 400 ppm ethephon, 250 and 500 ppm benzyladenine, and 50 and 100 ppm gibberellic acid 4 and 7 (GA4+7) + benzyladenine. The stock plant study was conducted to assess the efficacy of plant growth regulators, vegetative growth (height and width growth index), the number of vegetative cuttings, as well as the fresh weight (FW) and dry weight (DW) of the harvested vegetative cuttings. The propagation study was conducted to determine the effects of the plant growth regulator treatments on the rooting of the vegetative cuttings. The stock plant study showed that GA4+7 + benzyladenine (50 and 100 ppm) significantly increased production of ‘Snow Angel’ coral bells cuttings compared with all other treatments. However, no significant differences in FW or DW were observed with ‘Snow Angel’ coral bells between treatments. In the propagation study, no significant difference in rooting percentage was observed after 4 weeks. The Orange Carpet hummingbird trumpet stock plant study resulted in a greater number of vegetative cuttings with GA4+7 + benzyladenine (50 and 100 ppm) and benzyladenine (250 ppm) treatments. Fresh weight of vegetative cuttings harvested from plants treated with GA4+7 + benzyladenine (50 or 100 ppm) were the lowest. The only treatment that showed increased vegetative cutting production with no effect on FW was benzyladenine (250 ppm) on Orange Carpet hummingbird trumpet.
This study aimed to assess the effects of plant growth regulators (PGRs) on stock plant production of mojave sage (Salvia pachyphylla) and ‘Avalanche’ cape daisy (Osteospermum hybrid) that received foliar sprays of the following three PGRs: 200 and 400 ppm ethephon; 250 and 500 ppm benzyladenine; and 50 and 100 ppm gibberellic acid 4 and 7 (GA4+7) plus benzyladenine. Vegetative growth [height and width growth index (GI)], the number of vegetative cuttings, and fresh weight (FW) and dry weight (DW) of the harvested vegetative cuttings data were collected. A propagation study was conducted concurrently to determine the effects of the PGR treatments on rooting vegetative cuttings. GA4+7 plus benzyladenine (50 and 100 ppm) increased the production of both mojave sage and ‘Avalanche’ cape daisy cuttings by ≥18% more than the other treatments. The GI, FW, and DW results showed similar trends across experiments 1 and 2 for each perennial. In the propagation study, the rooting percentage did not differ after 4 weeks, indicating that the use of GA4+7 plus benzyladenine in production protocols could benefit producers of both perennials.
Abstract
Hardwood bark was used in combination with other materials as media for forsythia and juniper plants in containers with various growing procedures, bark sources, and fertility practices. Based on dry wt, the most rapid growth of forsythia was obtained in a bark and fine sand medium; whereas, the least growth was obtained in soil, peat, and perlite. However, pfitzer juniper plants under 2 different fertility regimes grew most rapidly in a bark, soil, and peat medium, slowest in a bark and torpedo #2 sand medium, and at an intermediate growth rate in soil, peat, and perlite. The standard mix (soil, peat, and perlite) was more acidic than the experimental mixes containing bark and sand. Chlorotic plants were more numerous in acidic mixes. Leaf tissue analyses from the plants grown in the peat amended bark and standard mix had higher Fe and Mn concn than plants grown in a bark-sand mix.
Stock plant productivity is an important concern for growers of mojave sage (Salvia pachyphylla) because this species produces more woody growth as the plant ages. The objective of the study was to determine the best growth substrate and container size combination to maximize stock plant productivity. A secondary objective was to determine whether the stock plant treatments influenced the rooting of vegetative cuttings. Three different container sizes (3, 12, and 15.5 qt) and four soilless substrates composed primarily of bark, peat, and perlite (substrate 1); bark, peat, and vermiculite (substrate 2); bark, peat, and coarse perlite (substrate 3); and peat (substrate 4) were used. The stock plant experiment was conducted using 12 treatment combinations, and a subset of those stock plants was selected randomly for the rooting study that immediately followed the stock plant experiment. Stock plants responded to substrate treatments differently. The most successful stock plants, which produced more cuttings per plant and per square foot, as well as larger cuttings, were those grown in substrate 3. Regardless of substrate, the highest number of cuttings per square foot was obtained from stock plants grown in 3-qt containers, indicating that the smaller containers allow for the most efficient use of space when growing mojave sage stock plants for 4 to 6 months. The rooting of vegetative cuttings was successful (88% to 100% of cuttings rooted after 4 weeks under mist) for all treatment combinations.
Landscape plant evaluations were conducted in eight states: Colorado, Minnesota, North Carolina, Ohio, Oregon, Pennsylvania, Texas, and Vermont for 17 switchgrass (Panicum virgatum) and five little bluestem (Schizachyrium scoparium) cultivars. Additional locations in Florida (Fort Lauderdale, Fort Pierce, Quincy, and Wimauma), Nebraska (Lincoln), and Lubbock and San Marcos completed 1 or 2 years of the trials. Plants were established in 2012 and data were collected for 3 years, 2013–15. Sites were asked to compile annual data on plant height, width, flowering time, fall color, pests, foliage color determined by the Royal Horticultural Society’s color chart, plant form, flowering date, floral impact, self-seeding, winter injury, landscape impact, and mortality. Texas A&M Agricultural Research and Extension Center (Overton), Florida (all four locations), and Vermont had the highest mortality rate. Southern Florida locations lost 50% of their plants by the end of 2014. Wide variation was reported for landscape impact, individual cultivar height, and width from different regions of the United States. Three of the 17 switchgrass cultivars, Cloud 9, Northwind, and Thundercloud, had a rating of 4.0 or higher averaged over six or more locations for plant form, floral, and landscape impact. ‘Shenandoah’ and ‘Warrior’ switchgrass had a rating of 4.0 or higher averaged over six or more locations for plant form and landscape impact, but not floral impact. Only one of the five little bluestem cultivars, Blue Heaven® rated 4.0 or higher, for plant form and landscape impact when averaged over six or more locations. This range of variability in landscape plant performance demonstrates the importance of local plant evaluations.