(A50) had lower shoot dry weight, and plants grown in 30% to 50% ash in Expt. 1 (A30, A40, A50) and 40% and 50% ash in Expt. 2 (A40, A50) had lower root quality ratings than plants grown in commercial substrate (Fafard 3B). Table 3. Means of plant
root ash weight (RAW) were recorded. Bermudagrass SDW was obtained by drying the plant tissue in a convection oven at 71 °C for 72 h before weighing. Roots were washed to remove germination mix, scanned (Epson Expression 1680; Seiko Epson Corp., Nagano
Abstract
Control of green ash (Fraxinus pennsylvanica Marsh.) and red oak (Quercus rubra L.) root growth in containers treated with CuCO3 and its effects on root regeneration following transplant were studied. Root elongation was controlled by applying 100 g CuCO3/liter of flat-white exterior acrylic latex paint to the interior surfaces of plastic containers. Plants grown in CuCO3-treated containers did not require root-pruning, whereas root-pruning was required to correct root deformations of plants grown in untreated containers. Root pruning removed up to 37% of root dry weight. When plants grown in CuCO3-treated containers were transplanted to 45.6-liter containers, root dry weight beyond the original root ball was greater than that of root-pruned seedlings transplanted from untreated containers. Seedlings transplanted from CuCO3-treated containers to field plots in July, August, or September showed enhanced shoot growth for two growing seasons compared with root-pruned control seedlings. Seedlings transplanted from CuCO3-treated containers appeared to suffer less stress than root-pruned control seedlings transplanted on the same date. Green ash seedlings transplanted in July had greater shoot growth than those transplanted in August and September over two growing seasons.
Rooted cuttings of `Dark Red Hegg' poinsettia were potted in root media containing 0, 50, or 100 percent by volume of coal bottom ash in peat::vermiculite (50:50, v/v), one cutting per 1 liter pot. The plants were placed in a closed loop nutriculture system and irrigated with 200 mg N.liter-1 of (N-P-K) 20-8.8-17.8. 15-2.2-22.25. or 20-4.8-21.6 (commercial Hydrosol + Ca(NO3)2). each with soluble trace elements. Fertilizer solutions were maintained at pH=6.0-6.5 and E.C.=1.6-2.5 dS.m-1. Media pH and E.C. tended to increase with amount of ash in the media. The 20-8.8-17.8 fertilizer reduced pH values 0.6-0.8 in all media. Plants were of equal height in all media. Average bract cluster diameters of plants in 100 percent coal ash were reduced compared to those in 0 and 50 percent coal ash by the 15-2.2-22.25 fertilizer. but not by the other two fertilizers. Plant top dry weights in 100 percent ash were reduced below those in 0 and 50 percent ash by the 20-8.8-17.8 and the 15-2.2-22.25 fertilizers.
Plant development, leaf morphology, leaf cuticular wax content, and leaf water relations were determined for seven tree species exposed to consecutive cycles of drought. The objective of the experiment was to identify plant taxa suitable for landscapes prone to drought. On the day drought treatments began, plant development traits and leaf morphology varied among species. Leaf cuticular wax content was different among species and ranged from 0.053 mg·cm–2 in California white oak (Quercus lobata Née), to 0.200 mg·cm–2 in Texas red oak (Quercus buckleyi Buckl.). Was content in Bur oak (Quercus macrocarpa Michx.) and Shumard oak (Quercus shumardii Buckl.) averaged 0.105 and 0.11 mg·cm–2, respectively. At harvest, Texas red oak plants treated with drought had the highest root-to-shoot dry weight ratio which averaged 3.1. In contrast, plants of Arizona ash (Fraxinus velutina Torr.) and California white oak that were frequently irrigated had the lowest root-to-shoot dry weight ratio. Drought did not affect stem elongation, total lamina area, leaf dry weight, and specific leaf weight. Abaxial leaf surfaces of Arizona ash were the most pubescent and averaged1836 trichomes/cm2. Drought-stressed plants of golden rain tree (Koelreuteria paniculata Laxm.) had the most negative midday leaf water potential, which averaged –2.5 MPa. Plants of Chinkapin oak (Quercus muehlenbergii Engelm.) that were irrigated frequently had the least negative predawn leaf water potentials. Predawn leaf water potentials tended to be more negative for Arizona ash and golden rain tree than for the oak species. These results suggest that some species of oak might perform well in landscapes prone to drought.
The most widespread deformation observed in container production is root circling. Consequently, root circling often reduces growth, root regeneration, and tree anchorage at transplanting time. The objectives of this study were to test the effectiveness of Cu(OH)2 lined containers on restriction of root tips, tree growth, and potential root regeneration (PRR). Two species were used in this study: Fraxinus pennsylvanica and Acer saccharinum. Species were grown for one season in containers lined with one of six combinations of polymer (P) (0, 30, and 60 g·m–2) and copper (Cu) (0%,0.4%, and 0.8%) -coated fabric. Two other treatments were included as controls: a plastic container and a fabric container. Seedlings of each species were harvest twice: at the first season and after being transplanted from 10- to 75-liter containers. Treatments were randomized in complete blocks with six repetitions. Results of root circling length and dry weight indicate good restriction of root tips for two combinations (30 g of P/m2–0.8% Cu; 60 g of P/m2–0.8% Cu) for all species. However, treatments did not cause any reduction in stem height, trunk diameter, or stem and root dry weight. At the end of the transplanting season, PRR was greater for two combinations (30 g of P/m2–0.8% Cu; 60 g of P/m2–0.8% Cu), especially for green ash. No significant differences were observed between a plastic fabric and the two treatments cited for the other growth parameters. No phytotoxic symptoms were observed throughout the experiment.
Easter lilies (Lilium longiflorum Thunb. `Nellie White') were forced in root media composed of 1 peat: 1 vermiculite (v/v) mixed with coal bottom ash (CBA) at rates of 0%, 25%, 50%, 75%, or 100% CBA. Lilies in all levels of CBA were equal in mean per plant flower bud numbers, fresh and dry weights, and numbers of yellow or brown lower stem leaves. Lilies in 100% CBA were significantly lower in mean stem length than plants in 0% or 50% CBA. Plants in 100% CBA required more frequent irrigation than plants in all other media. Media pH and solution electrical conductivity increased with increase in percent CBA. Analysis of leaf tissue showed no difference in nutrient levels between plants in 0% or 100% CBA.
Soil probe samples were taken in the upper 1 m of the soil profile 0.5 and 1 m from the base of five blueberry cultivars (Vaccinium spp.) grown in a modified-pH soil. The samples were divided into 12 sections by depth: mulch, 0-5, 5-10, 10-20, 20-30, 30-40, 40-50, 50-60, 60-70, 70-80, 80-90, and 90-100 cm. Weights of the organic fraction of blueberry roots were determined by subtracting ashed weights from dry weights for each sample section. Duplicate soil probe samples were taken and soil pH determined at the 12 depths and two distances. Root weights were highest in the upper 20 cm of the soil profile at the 0.5 m distance for all cultivars. Soil pH was 5 and below in the upper 20 cm of the soil. Yield of 11 cultivars was obtained for five years (1988-1992). Total yield averaged over 5 years showed `Blueray' as the highest yielding cultivar with 4.43 kg/plant per year. `Patriot', `Elliott', and `Colville' were lower than `Blueray' but similar to each other, with yields of 3.42, 3.11, and 3.03 kg/plant per year, respectively.
Bare-root, 4-ft whips of green ash (Fraxinus pennsylvanica `Marshall's Seedless') were planted in June 2001 in a randomized complete-block design with three trees per plot. An incomplete factorial design was used to test whether annual fertilizer rate and/or application dates affected growth. Treatments were fertilized from 0 to 4 times per year in mid-April, mid-June, mid-August, and/or mid-October. A rate of 1 lb of nitrogen (N)/1000 sq ft was used whenever fertilizer was applied to a plot. Each treatment received 0, 2, 3, or 4 lbs N/1000 sq ft/year depending on the number of applications. Caliper, height, and terminal growth were measured annually for three growing seasons. At the end of seasons 2 and 3, one plant per plot was destructively harvested and processed to obtain dry weights of shoots and roots, and the shoot to root ratio was calculated. Data were analyzed by analysis of variance with least square means contrasts. Treatment effects on top weights, root weights, and shoot to root ratios were nonsignificant. There were significant treatment differences for caliper and terminal growth in years 1 and 2, but not 3. A set of orthogonal contrasts was used to determine that the effect was due primarily to growth differences in plants receiving 2 vs. 3 or 4 lbs N/1000 sq ft/year, but that 3 vs. 4 lbs made no difference. Another set of planned, but nonorthogonal contrasts was used to compare application date effects. Plants fertilized in June were greater in caliper and terminal growth in the first 2 years than plants not fertilized in June. There were nonsignificant effects of fertilizing vs. not fertilizing in late fall or early spring.
A recycling nutriculture system was redesigned to improve growth and flowering of Tagetes erecta L., cv., Inca Yellow in four media; loose rockwool (RW), coal bottom ash (CBA), pinewood peelings (PWP) and CBA:PWP (1:1, v/v). Three nutricycle frequencies of 12, 6 and 4 per 12 hour light period were set with a nutricycle duration of 5 minutes. Volume, height and fresh and dry weights of marigolds in CBA, PWP and CBA: PWP were comparable to that of marigolds in RW. Flower diameters of plants in CBA, PWP and CBA:PWP were increased and days to harvest decreased compared to plants in RW. Plants in CBA: PWP increased in fresh weight compared to CBA or PWP plants. No interaction occurred between media and nutricycle frequency at 12 or 4 cycles per 12 hours; however a malfunctioning timer caused prolonged flooding of plant root zones at the 6 cycle setting. This resulted in decreased plant volume and fresh and dry weights at this frequency. These results show that growth and flowering of marigolds in CBA and PWP comparable with that in RW can be achieved with more than 1 nutricycle frequency.