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Abstract

Manganese toxicity was expressed as leaf chlorosis, early leaf abscission, reduced flower bud number, reduced growth, and internal bark necrosis (IBN). Increasing Ca or decreasing Mn in the solution were effective in correcting IBN, while increasing B or pH were ineffective. High solution Mn was associated with a decrease in bark Ca, and high solution Ca was associated with decreased Mn accumulation. Severe IBN was observed on the ‘Delicious’ scion, but no bark symptoms were visible on the EM IX clonal stock. Manganese concn were similar in both stock and scion bark, but Ca levels in the stock bark were substantially higher than those in the scion.

Open Access

Abstract

An amended pine bark growing medium was extracted for varying lengths of time using modified Spurway, Louisiana State Univ. (LSU), and double acid analytical systems. Concentrations of P, K, Ca, and Mg were then determined in the filtrate. As the extraction time was lengthened, the quantity of P, K, Ca, and Mg removed from the medium increased for each system. The concentration and type of nutrients removed varied according to the composition and action of the extractant.

Open Access

Seasonal pattern of cold tolerance and proteins were studied in the leaves of sibling deciduous and evergreen peach (Prunus persica). In contrast to deciduous peach that undergoes endodormancy in fall, evergreen peach does not (leaves are retained and shoot tips elongate under favorable conditions) (Arora et al., Plant Physiol. 99:1562-1568). Cold tolerance (LT50) was assessed using electrolyte leakage method. Proteins were separated by SDS-PAGE. Electroblots were probed with anti-dehydrin (Dr. T. Close) and anti-19 kD, peach bark storage protein (BSP) antibodies. LT50 of leaves successively increased from about -7C (18 Aug.) to -15C and -11.5C (23 Oct.) in deciduous and evergreen genotypes, respectively. The most apparent change in the protein profiles was the accumulation of a 60-kD protein during cold acclimation in the leaves of deciduous trees; however, it did not change significantly in evergreen peach. Immunoblots indicate that 60-kD protein is a dehydrin protein. PAGE and immunoblots indicated that 19-kD BSP disappeared progressively during summer through fall in the leaves of deciduous peach, but accumulated to large amounts in bark tissues. Similar inverse relationship for its accumulation in leaf vs. bark tissue was not evident in evergreen peach. Results indicate that BSP expression may be regulated by altered source/sink relationship.

Free access

The objective of this study was to determine the influences of 8 commercial media, 4 peat-based and 4 pine bark-based, on the effects of paclobutrazol applied to the media of each plant at pinch in a spike formulation or as a drench (two weeks after pinch) to `Celebrate 2' poinsettias. The peat-based media were Baccto Grower's Mix, Baccto High Porosity Professional, Baccto High Porosity Professional with Bacctite, and Baccto Rockwool Mix. The pine bark-based media were Metro 360, 366, 700, and 702. Paclobutrazol was applied to the media at 10 treatment combinations (0, 2, 4, 6 and 8-0.05% spikes, 1 and 2-0.2% spikes, 1 0.08% spike, and 0.25 and 0.50 mg drenches in each 15 cm pot). Spike and drench formulations of paclobutrazol reduced plant size. Plants grown in the peat-based media were more sensitive to paclobutrazol than those grown in bark-based media. Stem length of those plants treated with paclobutrazol spikes was less than those treated with an equal amount of paclobutrazol as a drench in all media except the Rockwool Mix and Metro 702.

Free access

An experiment with a factorial treatment combination in a split plot design with five single plant replications was conducted to evaluate the effects of five rates of fertilizer addition and two irrigation volumes on plant growth in a composted turkey-litter-amended pine bark substrate. Main plots were daily applications of 600 or 900 ml/3.8-L container. Subplots were either 0, 1.0, 2.0, 3.0, or 4.0 g N additions (Osmocote High H 24N–1.7P–5.8K) per container topdressed on a substrate composed of pine bark amended with 8% (by volume) composted turkey litter. No additional amendments were made to the compost amended substrates. An additional “industry control” treatment consisted of an 8 pine bark: 1 sand (by volume) substrate amended with 3.0 kg/m3 dolomitic limestone and 0.9 kg/m3 Micromax and topdressed with 3.5 g N (Osmocote High N) per container. After 134 days, Cotoneaster dammeri `Skogholm' and Rudbeckia fulgida `Goldsturm' plants were harvested and shoot and root (cotoneaster only) dry weights were determined. Cotoneaster shoot and root dry weights and rudbeckia shoot dry weight increased linearly as N rate increased from 0 to 4.0 g N. Irrigation volume did not affect cotoneaster shoot or root dry weights. Rudbeckia shoot dry weight was 18% greater with 900 ml than with 600 ml of irrigation. Rudbeckia growth in compost amended substrate was greater than in the industry control when topdressed with ≥1.0 g N. Shoot growth of cotoneaster in the industry control substrate and compost amended substrate with ≥ 3.0 g N applied was similar.

Free access

Abstract

Rewetting of gasifier residue (GR) at 0% of container capacity was greater than milled pine bark (B) or Canadian sphagnum peat moss (P). The percentage of container capacity necessary to obtain 80% rewetting of GR was substantially lower than for either P or B (5%, 23%, and 25%, respectively). Neither the rewetting of B, P, or GR at 0% of container capacity, nor the percentage of container capacity necessary to produce 80% rewetting of these media were affected by Aqua-Gro wetting agent (WA). Addition of GR in excess of 75% substantially increased the percentage of rewetting of both B and P.

Open Access

Race 1 of Plasmodiophora brassica isolated from high altitude of vegetable production district induced clubroot on cabbage, and Chinese cabbage. Inoculation of race from northwestern coast of Taiwan resulted clubroot of Chinese cabbage neither in cabbage. The addition of bark slag or silica slag significantly decreased clubroot infection and increased the weight of Chinese cabbage in the infected field. The addition of 3 gram slaked lime +1 gram KC1 +1.78 gram ammonium sulfate + 1 gram calcium superphosphate at 500 gram soil 2 month after transplanting increased dry wight of cabbage and decreased infection root hair followed by inoculation of race 1.

Free access

Abstract

Carbon-nitrogen relationships and pH of 2 milled hardwood bark-amended media were influenced similarly by 3 N sources, (NH4)2SO4, NH4NO3, and Ca(NO3)2 incorporated at 0, 0.89 and 1.78 kg/m3 prior to composting. Nitrogen source did not affect overall growth; however dry weight and growth index of Cotoneaster dammeri Schneid cv. Royal Beauty increased with increasing N rate. Source and rate of N had little effect on the foliar analysis, and all values were within the acceptable range for woody ornamentals.

Open Access

Abstract

Hardwood bark, amended with either urea (CO(NH2)2) or ammonium nitrate (NH4NO3) was composted in 210 liter drums at 10 to 40°C or heated to 55°. In the supplemental heat composted (SHC) bark amended with CO(NH2)2, pH increased to 6.8 to 7.4 within the first week. Bark amended with CO(NH2)2 generated more heat than bark amended with NH4NO3. Phenolic content decreased (as indicated by the Folin-Ciocalteu (F-C) method), and germination percentage of Lactuca sativa L. cv. Grand Rapids seed in water extracts of bark samples increased with time. Additions of polyvinylpyrrolidone (PVP) to extracts decreased phenolic content and increased the percentage of seed germination. Plant growth assays using Chrysanthemum × morifolium Ramat ‘Bright Golden Anne’ revealed a possible N deficiency in SHC NH4NO3 treated bark. Plants grown in SHC CO(NH2)2 amended bark did not have as severe a N deficiency. As time of composting increased, naturally composted (NC) bark treated with either N source gave plant growth comparable to that of the control plants grown in a medium of peat:perlite:vermiculite:soil (3:2:2:1 v/v).

Open Access

The objective of this study was to determine the influences of 8 commercial media, 4 peat-based and 4 pine bark-based, on the effects of uniconazole applied as a media drench to `Gutbier V-14 Glory' poinsettias. The peat-based media were Baccto Grower's Mix, Baccto High Porosity Professional, Baccto High Porosity Professional with Bacctite, and Baccto Rockwool Mix. The pine bark-based media were Metro 300, 360, 500, and 700. Uniconazole was applied to plants grown in each media at 5 rates (0, 2, 4, 6, and 8 mg · 15 cm por1).

Uniconazole effectively reduced plant height and width, bract dry weight, and bract number in all media. Plants grown in the Metro products, however, tended to be larger than those grown in the Baccto products. Bract size and number, plant weight, width and height were greatest in Metro 360. The rockwool mix produced the smallest plants. Plants grown in the peat-based media were more sensitive to uniconazole drenches. Plants grown in Metro 360 were the least sensitive to uniconazole drenches.

Free access