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- Author or Editor: Charles H. Gilliam x
The objective of this study was to evaluate the potential use of container substrates composed of whole pine trees. Three species [loblolly pine (Pinus taeda), slash pine (Pinus elliottii) and longleaf pine (Pinus palustris)] of 8–10 year old pine trees were harvested at ground level and the entire tree was chipped with a tree chipper. The chips from each tree species were then further processed with a hammer mill to pass a ½-inch screen. On 29 June 2005 these three substrates along with 100% pinebark were mixed with the addition per cubic yard of 9.49 kg·m–3 Polyon 18–6–12 (18N–2.6P–10K), 2.97 kg·m–3 dolomitic lime and 0.89 kg·m–3 Micromax. One gallon (3.8 L) containers were then filled and placed into full sun under overhead irrigation. Into these containers were planted 72 cell plugs of Catharanthus roseus`Little Blanche'. Data collected were pre-plant chemical and physical properties of substrates, as well as plant growth index (GI), plant top dry weight, root ratings, and plant tissue (leaves) nutrient analysis at 60 days after planting (DAP). The test was repeated on 27 Aug. 2005 with C. roseus Raspberry Red Cooler. Top dry weights were on average 15% greater for the 100% pinebark substrate over all others at 60 DAP. However there were non differences in plant GI for any substrate at 60 DAP. There were no differences in plant tissue macro nutrient content for any substrate. Tissue micronutrient content was similar and within ranges reported by Mills and Jones (1996, Plant Analysis Handbook II) with the exception of Manganese. Manganese was highest for slash and loblolly pine and well over reported ranges. There were no differences in root ratings. There were no differences in substrate physical properties between the three whole tree substrates. However the 100% pinebark substrate had on average 50% less air space and 25% greater water holding capacity than the other substrates. Physical properties of all substrates were within recommended ranges. Based on the results of this study substrates composed of whole pine trees have potential as an alternative sustainable source for a substrate used in producing short term nursery crops.
Abstract
Gardenia jasminoides Ellis and Ilex crenata Thunb. ‘Compacta’ were field-grown with 4 irrigation rates based on 0%, 25%, 50%, and 100% replacement of net evaporation from a class A pan. Irrigated gardenia were larger than nonirrigated gardenia, and those grown with 50% and 100% replacement of net evaporation had greater total root growth than nonirrigated plants. Root number, root dry weight, and fibrous root number in a 20-cm rootball were generally greater with irrigated plants than nonirrigated plants. Ilex crenata shoot growth was greater also with irrigation versus nonirrigation. Based on this data, 25% replacement of net evaporation resulted in plants of both species being similar to higher irrigation rates.
Abstract
Photinia Χ fraseri Dress (Fraser Photinia) plants were dug and burlapped in the morning and afternoon during midsummer with or without previous irrigation or antitranspirant treatment (di-1-p methene = Vapor Gard). Plants were shipped for one day, held for 2 weeks under lath, and then planted. Moisture stress, indicated by shoot water potential, was monitored throughout the study and survival was rated in September. Use of the antitranspirant and morning digging reduced moisture stress of plants. Morning-dug plants had 80% or greater survival even without irrigation. Afternoon digging gave low survival with or without irrigation but afternoon digging plus Vapor Gard gave 100% survival.
Abstract
Boston fern [Nephrolepsis exaltata (L.) Schott ‘Compacta’] was grown with 3 rates of 2 slow-release fertilizers and with one rate of liquid fertilization. Greatest fern dry weight occurred with ferns grown with liquid fertilization (20N–0.8P–16.6K) or Osmocote (19N–2.5P–8.3K) at the 1.8 kg N/m3 rate. After 16 weeks of simulated commercial production, one-third of the ferns were moved to a low-light interior environment, while one-third were held in the greenhouse. Six weeks later, ferns moved to the interior environment were greener in color, had greater nutrient content, and exhibited less growth than did ferns held in the greenhouse.
Abstract
Postemergence applications of 1.1 and 0.6 kg/ha of sethoxydim (2-[l-ethoxyimino) butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-l-one) and fluazifop-butyl (butyl 2-[4-(5-trifluoromethyl-2-pyridyloxy)-phenoxy]propionate), respectively, resulted in 90% control of common bermudagrass (Cynodon dactylon) when applied directly over field-grown ornamentals. Comparable control was achieved by either single application or 2, half-rate, split applications. Of the 12 species tested, only ‘Hexe’ azalea was damaged by applications of fluazifop-butyl to a degree that the plants were unsaleable. All other species exhibited tolerance to both sethoxydim and fluazifop-butyl at the rates required to achieve grass control.
Abstract
In field production of nursery stock, plant losses may occur after digging but before plants leave the nursery, thereby reducing profitability. Although little information is available, it appears this plant loss may result from moisture stress induced by root pruning at digging and subsequent handling procedures (2, 3). To ensure adequate roots in the rootball, most nurserymen dig root-balls in accordance with the American Standard for Nursery Stock (ASNS) (1), which allows for increasing rootball size with increased shoot growth.
Abstract
Postemergence and preemergence control of goosegrass [Eleusine indica (L.) Gaertn.] and large crabgrass [Digitaria sanguinalis (L.) Scop.] were evaluated with clopropoxydim, fenoxaprop-ethyl, xylofop-ethyl, and poppenate-methyl. None of these herbicides was injurious to Rhododendron obtusum ‘Coral Bells’, Ilex crenata ‘Compacta’, Euonymus alatus ‘Compacta’, Juniperus horizontalis ‘Plumosa’, or Thuja occidentalis ‘Pyramidal’ and, depending on rate, provided acceptable grass control. Only xylofop-ethyl at 0.12 kg ha−1 and poppenate-methyl at 1.12 kg·ha−1 consistently provided at least 90% control. Poppenate-methyl also provided preemergence activity for one to six weeks. Chemical names used: (E,E)-2-[l-[[(3-chloro-2-propeny)oxy]imino]butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-eyclohexen-l-one (clopropoxydim); (±)-ethyl 2-[4-[(6-ehloro-2-benzoxazolyl)oxy]phenoxy]propanoate (fenoxapropethyl); 2-[4-[(6-chloro-2-quinoxalinyl)oxy]-phenoxy]propionic acid (xylofop-ethyl); and methyl-3-hydroxy-4[4-[[5-(trifluoromethyl)-2-pyridinyl]oxy]phenoxy]-pentanoate (poppenate-methyl).
Adsorption of 14C-labeled oxadiazon was evaluated in three soilless media and a mineral soil at concentrations between 0.1 and 100 mg·kg-1. Adsorption, which was at least 96%, was not influenced by absorbent type (medium vs. soil) or by oxadiazon concentration. However, desorption was greater in the media than in the soil. After five water extractions, 5.4% of the applied oxadiazon was recovered from media, but only 0.4% was recovered from the soil. In the soil and in two of the media, leaching with water failed to displace oxadiazon 2 cm below the surface to which it had been applied. No oxadiazon was detected below 4 cm in the third medium. Oxadiazon is sufficiently adsorbed to resist leaching-based displacement. Oxadiazon is not likely to enter the environment by escaping from treated containers. Chemical name used: 3-[2,4-dichloro-5-(1-methylethoxy)phenyl]-5-(1,1-di-methylethyl)-1,3,4-oxadiazol-2-(3H)-one (oxadiazon).
Two inch caliper Acer rubrum, Quercus phellos, and Platanus occidentalis were planted March 26, 1990, into 8' × 8' planting holes that were lined with either Typar Biobarrier, Dewitt Pro-5 Weed Barrier or left unlined as a control. There has been little or no root penetration beyond the Biobarrier for the 3 tree species during the first 3 years of this study. At the end of 1990, the control and the Dewitt Pro-5 had similar root penetration numbers. By the end of 1991, the Dewitt Pro-5 had greater root penetration than did the control for A. rubrun. Root penetration of Dewitt Pro-5 and the control treatment was similar for Q. phellos and P. occidentalis. There were no differences in root penetration for Dewitt Pro-5 and the control in 1992 for any species. There were no differences in height for any tree species following the 1990 or 1991 growing seasons and no difference following the 1992 growing season for A. rubrum and Q. phellos. The control treatment had the grearest height for P. occidentalis in 1992. There were no differences in caliper due to root control treatment for the 3 species during the first 3 years of this study.