Ground Pine Bark Research Articles

Occurrence of Volutella Blight Caused by Pseudonectria foliicola on Boxwood in Tennessee.

Boxwood (Buxus sp. L.) is a very popular evergreen shrub in the United States which is widely used as landscape plant and fresh greenery. Boxwood 'Green velvet' (B. sinica var. insularis x B. sempervirens) plants grown in field condition exhibiting Volutella blight symptoms were found in a commercial nursery in Warren Co., Tennessee in May 2019. Leaves appeared red, brown or tan color on affected plants. Waxy, salmon pink colored fruiting bodies (sporodochia) were observed underneath the affected leaves using a hand lens (Figure 1). Leaf drop was also observed on plants. Black lesions under the bark were observed in some of the plants. The disease severity (percentage leaf area diseased) was nearly 40% and the disease incidence was nearly 30% of 1,000 plants. Infected leaf and stem tissues collected from four symptomatic plants were surface sterilized with 70% ethanol and washed with sterile distilled water. Culturing the infected leaf and stem pieces, 5-mm in size, on potato dextrose agar (PDA) consistently yielded white fluffy aerial mycelium growth with scattered salmon-color slimy masses of conidia forming from sporodochia after 10 days incubation at 25°C in a 12-h fluorescent light and dark cycle. A total of two isolates (FBG2020_396 and FBG2020_405) were hyphal tip purified on PDA. The conidia (n = 50) were hyaline, aseptate, fusiform to ellipsoidal measuring average of 7.8 × 3.3 μm (range: 4.84 to 13.2 μm × 2.2 to 4.64 μm). To confirm the pathogen identity, total DNA was extracted using UltraClean Microbial DNA Isolation Kit (MO BIO Laboratories, Inc., Carlsbad, CA) directly from a 5-day old culture of isolates (FBG2020_396 and FBG2020_405) on PDA. The ribosomal DNA internal transcribed spacer region (ITS), β-tubulin (tub2) and part of 28S large ribosomal subunit (LSU) regions were amplified by PCR using the primer pairs ITS 5/ITS 4, T1/BTb2 and LR0R/LR5, respectively (Glass and Donaldson 1995; O'Donnell and Cigelnik 1997; Rehner and Samuels 1994; Vilgalys and Hester 1990; White et al. 1990). Newly generated sequences - GenBank/NCBI acc. nos. MW459251, MW465902 (ITS), MW464656, MW464657 (tub2) and MW459255, MW465903 (LSU) were 100% identical to Pseudonectria foliicola L. Lombard & Crous ex-type (CBS 123190) sequences KM231776, KM232035 and NG_058095, respectively. To complete Koch's postulates, six boxwood 'Green velvet' plants grown in 10 cm square pots (containing 40% coarse sand and 60% ground pine bark) were inoculated by spraying conidial suspension of P. foliicola [FBG2020_396 (1 × 105 conidia/mL)] obtained from 2-wk-old PDA cultures. Plants were covered with clear plastic humidity domes for 3 days and then they were maintained in a growth chamber at 25°C and 60% RH in a 12-h fluorescent light and dark cycle. Six control boxwood plants were maintained in the same environment without pathogen introduction. Pathogenicity test was conducted twice. After 10 days, typical symptoms of Volutella blight developed on the inoculated plants and microscopic examination revealed the same pathogen morphology as the original isolate. Pseudonectria foliicola was consistently re-isolated from leaves and stems. All control boxwood plants remained symptom-free and P. foliicola was not isolated from the leaves or stems. Pseudonectria foliicola causing Volutella blight has been reported on B. sempervirens in Czech Republic (Spetik et al. 2020), New Zealand (Lombard et al. 2015); Buxus sp. in Illinois, Maryland, Massachusetts, North Carolina and Washington (Salgado-Salazar et al. 2019). To our knowledge, this is the first report of Volutella blight of boxwood caused by P. foliicola in Tennessee. Pseudonectria foliicola is an opportunistic pathogen and infects weak, stressed, and injured boxwood plants/cuttings (Rivera et al. 2018). This pathogen could cause a serious economic loss to boxwood nursery growers, as it can significantly affect the ornamental value of boxwood plants and fresh greenery. Integration of sanitation practices with other disease management strategies such as biorational products and reduced-risk fungicides will be necessary for limiting the spread of pathogen and successful management of P. foliicola on boxwood in both field and postharvest conditions.

First Report of Phytopythium vexans Causing Root and Crown Rot on Flowering Cherry in Tennessee.

Flowering cherry (Prunus serrulata Lindl. 'Kwanzan') rooted cuttings grown in propagation beds containing 40% coarse sand and 60% ground pine bark in a commercial propagation nursery in Warren County, Tennessee were exhibiting root and crown rot in December 2016. Dark brown to black soft lesions were observed in the roots as well as the crown region of flowering cherry rooted cuttings and those rooted cuttings were non-marketable due to lesions. Disease incidence was approximately 60% of 10,000 plants. Phytophthora ImmunoStrip test (Agdia Inc., Elkhart, IN, USA) was performed and the test result was positive. Diseased plant tissues were surface sterilized with 70% ethanol and washed twice with distilled water. Culturing the affected root and crown parts (1 cm pieces) on V8-PARPH, an oomycete-selective medium consistently yielded whitish radiate mycelial growth pattern with spherical zoospores, filamentous to globose oogoni, elongated, and cylindrical antheridia with constrictions (De Cock et al., 2015) after 7 days of incubation at 25°C in a 12-h fluorescent light and dark cycle, which is the typical morphology of Phytopythium vexans (de Bary) Abad, de Cock, Bala, Robideau, Lodhi & Lévesque. To confirm pathogen identity, total DNA was extracted using the UltraClean Microbial DNA Isolation Kit (MO BIO Laboratories, Inc., Carlsbad, CA, USA) directly from a 3-day old culture of isolate (FBG2017010) on V8 medium. The internal transcribed spacer (ITS) and 28S large subunit of ribosomal RNA, and cytochrome c oxidase subunit I (CoxI) of mitochondrial DNA (mtDNA) genes/ region were amplified by PCR using the primer pairs ITS1/ ITS4 (White et al., 1990), NL1/ NL4 (Baten et al., 2014), and Levup and Fm85mod (Robideau et al., 2011), respectively. The PCR products were sequenced and the sequences (GenBank accession nos. MT533275, MT533451, and MT547980) were compared to the voucher specimens. They were 99.23, 99.60, and 98.92% similar to those of P. vexans isolates in the NCBI database (HQ643400, KR092144, and HQ708996, respectively). To complete Koch's postulates, 'Kwanzan' flowering cherry rooted cuttings grown on propagation substrate (10 cm pot containing 1 kg sterilized 40% coarse sand and 60% ground pine bark) were inoculated with identified pathogen and observations were taken on root rot disease symptoms. Five plants were inoculated with 100 ml of pathogen agar-slurry (1 plate of a 7-day old culture of isolate FBG2017010/1 L of sterilized water), and five control plants were drenched with agar slurry. The plants were maintained in the greenhouse condition (day/night temperature of 26/24°C), and irrigated twice a day for 2 min by overhead irrigation system. After 2 weeks, dark brown to black necrotic root lesions developed on all inoculated cuttings and P. vexans was consistently re-isolated from the inoculated plants. The morphology of the pathogen isolated on the V8-PARPH medium was identical to the original isolate. All control plants remained symptom-free and P. vexans was not isolated from the root tissue. To our knowledge, this is the first report of P. vexans causing root and crown rot in 'Kwanzan' flowering cherry in Tennessee, which can be a potential threat for the nursery crop production. The identification of P. vexans, the causal agent of Phytopythium root and crown rot is important in determination and implementation of effective management strategies.

The effect of gradual dietary pine bark meal supplementation on milk production of dairy cows fed a grass silage-based diet

In a search for novel sustainable feed resources for ruminant livestock, interest towards wood-based feed materials such as bark has risen. To evaluate the feed potential of ground bark, a dairy cow feeding experiment was conducted using 24 high yielding (average milk yield in the beginning of the experiment 38.0 ± 4.53 kg/d) Nordic Red cows in a 3 × 3 Latin square design using 21-day periods. The cows were offered grass silage-based diets supplemented with 3 different concentrate feeds; a control concentrate containing no additional bark meal (C) or two different concentrate feeds containing low (LB, 87 g/kg of dry matter (DM)) or high (HB, 173 g/kg DM) level of dried ground pine bark meal supplement. Experimental concentrates were fed at a level of 12.4 kg per day resulting in feeding of ca. 1 and 2 kg of bark meal per day at low and high levels, respectively. The good quality grass silage used as the basal feed elicited high total daily feed DM intake which was on average 25.6 kg. The palatability of all experimental concentrates was good. Dietary bark meal increased the intakes of silage DM and total DM, but decreased yields of milk, energy-corrected milk, milk fat and protein, and concentrations of milk constituents although numerical differences between treatments were small. Bark meal supplements decreased linearly metabolizable energy intake, but had no significant effect on the estimated intake of amino acids absorbed from the small intestine as the concentrate feeds were balanced by rapeseed meal. Dietary bark meal decreased linearly the feed efficiency. Milk from all treatments had good sensory properties. This study demonstrated that the energy value of bark meal was very low compared to the traditional feeds as demonstrated by the decreased production results. The economic output of bark meal inclusion depends on the savings in replacing traditional feeds with bark meal, and the losses as reduced milk sales. In long term, other aspects may be considered such as potential shortage and elevated prices of traditional feeds and need to use non-human edible feed components in animal production, but under current conditions, it cannot be recommended as a feed component for high producing dairy cows.

Influence of tannin-rich pine bark supplementation in the grain mixes for meat goats: Growth performance, blood metabolites, and carcass characteristics.

The objective was to evaluate the use of condensed tannin (CT)-rich ground pine bark (PB) in grain mixed diets on meat goat growth performance, blood metabolites, and carcass characteristics. Twenty four Kiko crossbred (Capra aegagrus hircus) growing male kids (BW = 36.9 ± 2.5 kg) at approximately 8 months of age were assigned randomly to 2 treatments with 3 replicates per treatment and 4 goats per replicate. The goats were fed grain mixed diets composed of either 30% bermudagrass hay (BGH) plus concentrate (control) or 30% PB plus concentrate. Diets were fed at 1.2% of BW. In addition, all goats grazed a crabgrass/bermudagrass (CB)-based pasture. The feeding trial lasted for 55 d. Using ground PB as a supplement did not negatively affect BW, average daily gain (ADG), carcass characteristics, meat pH, and meat color compared to the control diet. Plasma gamma-glutamyl transferase (P = 0.03), glucose (P < 0.01) and Ca concentrations (P = 0.04) were higher for PB than for BGH, respectively. The 30% PB supplementation does not negatively affect animal performance, blood metabolites, and carcass parameters.

Growth and establishment of container-grown London planetrees in response to mulch, root-ball treatment and fertilization

We conducted two experiments to evaluate the impact of cultural treatments on growth and establishment of container-grown London planetrees (Platanus × acerifolia’ Bloodgood’). In both experiments, 48 trees grown in 100 l (#25) black plastic containers were assigned at random to one of three root-ball treatments prior to planting; no treatment (Control), outer 3 cm of roots removed around entire root-ball (Shave), or outer circling roots disentangled from the root-ball (Tease). In Experiment 1, half of the trees were fertilized with 400 g of controlled release fertilizer (15-9-12; N-P2O5-K2O) at planting and the remainder of the trees were not fertilized. In Experiment 2, half of the trees were mulched with an 8 cm deep × 2 m diameter ring of coarse ground pine bark at planting and the remainder of the trees were not mulched. In Experiment 1, fertilization at planting increased SPAD chlorophyll content on two of four measurement dates but did not affect cumulative height or caliper growth after two years. After two growing seasons, root-ball treatments (shaving or teasing) increased root growth outside the original root-ball compared to control trees. Both root-ball treatments also reduced circling roots. In Experiment 2, mulching at planting increased soil moisture and cumulative tree height and diameter growth. Shaving increased new root growth and both root-ball treatments improved root architecture and reduced circling roots. Overall, the study demonstrates that root-ball manipulations can stimulate new root growth and reduce circling roots. Mulch is a valuable aid to conserve soil moisture and increase tree growth. Fertilization at planting provided little benefit in this experiment, which may have been related to a high level of soil fertility at the site or nutrient loading of the trees from nursery culture prior to transplanting.

Influence of pre-planting application of dolomite at various rates in coir-dust containing root media on the growth of red-leaf lettuce

This research was conducted to evaluate various levels of dolomitic lime incorporated as pre-planting fertilizers on the growth of red-leaf lettuce. To achieve this, three root media were formulated by mixing coir dust with expanded rice hull (CD+ERH, 8:2, v/v), carbonized rice hull (CD+CRH, 6:4, v/v), and ground pine bark (CD+GRPB, 6:4, v/v). During formulation, equal amounts of essential nutrients, except dolomitic lime, were incorporated into all root media and the levels of dolomitic lime were varied from 0 to 7.5 g L -1 at 1.5 g increments. Seedlings of red-leaf lettuces at the 3rd leaf stage were transplanted into each medium treatment. Crop growths were measured 5 weeks after transplant and soil solutions were collected every week and analyzed for pH, EC, and nutrient concentrations. The treatments showing the heaviest fresh and dry weights in CD+ERH, CD+CRH, and CD+GRPB were 4.5 g, 4.5 g, and 7.5 g L -1 of dolomite, respectively. The pHs of three root media yielding the highest crop growths were in the ranges of 6.4 to 7.1. These ECs in CD+CRH medium were around 1.0 dS m -1 higher than those of CD+ERH and CD+GRPB when application rates of dolomitic lime were equal. K⁺ concentrations were higher than Ca +2 and Mg +2 concentrations until week 2 in three root media. But Ca +2 and Mg +2 concentrations were higher than K⁺ concentrations after week 3 in all root media. The concentrations of PO₄-3 in all root media got abruptly lower until week 2. These results indicate that appropriate levels of dolomitic lime, as pre-planting nutrient charge fertilizers in CD+ERH and CD+GRPB media, are 4.5 and 7.5 g L -1 , respectively.

Effect of plant tannin-containing diet on fatty acid profile in meat goats

Phytochemical plant tannins are phenolic compounds that interfere with biohydrogenation (BH) of monounsaturated-(MUFA) and poly-unsaturated fatty acids(PUFA). The objective of the present animal study was to investigate the effects of three different levels of phytochemical tannin-containing ground pine bark diet on fatty acid profiles of goat meat, with particular reference to MUFA and PUFA. The saturated fatty acids (SFA), PUFA, and PUFA/SFA ratios in subcutaneous adipose tissue as well as MUFA and PUFA composition of mesenteric kidney fat were increased with increasing phytochemical tannin-containing ground pine bark supplementation. The study showed that phytochemical plant tannins could be a means to moderate the accumulation of unsaturated fatty acids with the aim of improving percentage of these PUFA/SFA ratios in goat meat. The effects would be useful to improve carcass fatty acids composition and human health.

The effects of tannins-containing ground pine bark diet upon nutrient digestion, nitrogen balance, and mineral retention in meat goats.

BackgroundPine bark is a rich source of phytochemical compounds including tannins, phenolic acids, anthocyanins, and fatty acids. These phytochemicals have potential to significantly impact on animal health and animal production. The goal of this work is to measure the effects of tannins in ground pine bark as a partial feed replacement on feed intake, dietary apparent digestibility, nitrogen balance, and mineral retention in meat goats.ResultsEighteen Kiko cross goats (initial BW = 31.8 ± 1.49 kg) were randomly assigned to three treatment groups (n = 6). Dietary treatments were tested: control (0 % pine bark powder (PB) and 30 % wheat straw (WS)); 15 % PB and 15 % WS, and 30 % PB and 0 % WS. Although dry matter (DM) intake and digestibility were not affected (P > 0.10) by feeding PB, neutral detergent fiber (linear; P = 0.01), acid detergent fiber (linear; P = 0.001) and lignin digestibility (linear; P = 0.01) decreased, and crude protein (CP) digestibility tended to decrease (P = 0.09) as PB increased in the diet, apparent retention of Ca (P = 0.09), P (P = 0.03), Mg (P = 0.01), Mn (P = 0.01), Zn (P = 0.01) and Fe (P = 0.09) also increased linearly. Nitrogen intake and fecal N excretion were not affected (P > 0.05) by addition of PB in the diet, but N balance in the body was quadratically increased (P < 0.01) in the 15 % PB diet compared to other diets. This may be due to more rumen escape protein and less excreted N in the urine with the 15 % PB diet. The study showed that a moderate level of tannin-containing pine bark supplementation could improve gastrointestinal nitrogen balance with the aim of improving animal performance.ConclusionThese results suggest that tannin-containing PB has negative impact on fiber, lignin, and protein digestibility, but positively impacted on N-balance.

Effects of Condensed Tannin-Rich Pine Bark Diet on Experimentally Infected With Haemonchus Contortus in Meat Goats

This study evaluated the effects of dietary supplementation of a novel condensed tannin-rich pine bark (PB) mixture diet on an in vitro gas production, in vivo animal performance, internal parasites, carcass production, and plasma metabolites in meat goats. Fifteen Kiko-cross meat goats (Capra hircus; body weight (BW) = 28.0 ± 1.0 kg) were randomly assigned to two experimental diets (control vs. PB supplementation): 1) control diet (70% grain mixture and 30% wheat straw (WS) and 2) 70% grain mixture with 30% PB. Animals were dewormed on day 10 and animals were artificially inoculated (day 20) with 5,000 infective stage (L3) Haemonchus contortus larvae. Feed intake and performance were monitored for 87 days. Blood samples were taken twice, once at the beginning and once at the end of the experiment. Fecal egg (FEC) was determined approximately every 2 week. At the end of the experimental period, goats were slaughtered, and abomasum parasite load was determined. Abomasal worms were identified and counted. All analyses were conducted using a GLM or MIXED pro - cedure of SAS, but in vitro gas analysis was conducted using non-linear procedure of SAS. Overall, there were no differences (P >0.10) in dry matter intake, body weight, and carcass traits between diets. H.contortus adult worm numbers were lower (P <0.05) for goats that were fed PB diet than for control. On day 84, control goats on control WS diet had greater (P = 0.01) FEC than PB diet group. It was concluded that feeding ground PB as a feed ingredient has the potential to decrease internal parasite infection without detrimental effects.

Efeito da porosidade do substrato casca de pínus no desenvolvimento de mudas de grumixameira¹

Objetivando-se avaliar o efeito da porosidade de substratos de casca de pínus no desenvolvimento de mudas de grumixameira (Eugenia brasiliensis Lam.), foi conduzido um experimento em casa de vegetação da Escola Superior de Agricultura "Luiz de Queiroz" - USP, Piracicaba-SP. Os tratamentos foram assim definidos: 100% casca de pínus moído sem separação de partículas; 100% casca de pínus &lt; 0,1 mm; 75% casca de pínus &lt; 0,1 mm + 25% entre 0,1 - 4,0 mm; 50% casca de pínus &lt; 0,1 mm + 50% entre 0,1 - 4,0 mm; 25% casca de pínus &lt; 0,1 mm + 75% entre 0,1 - 4,0 mm, e 100% casca de pínus 0,1-0,4 mm. As avaliações (diâmetro do caule, comprimento total e média de massa seca das plântulas) ocorreram aos 90; 120 e 150 dias após a semeadura. A baixa absorção de água nos estágios iniciais e a baixa aeração das raízes, promovida pelo substrato afetam o desenvolvimento de mudas de grumixameira, que se desenvolve melhor quando o espaço poroso total do substrato é inferior a 90% (v/v).

The Landscape Performance of Annual Bedding Plants Grown in Pine Tree Substrate

The objective of this study was to evaluate the landscape performance of annual bedding plants grown in a ground pine tree substrate (PTS) produced from loblolly pine trees (Pinus taeda) or in ground pine bark (PB) when transplanted into the landscape and grown at three different fertilizer rates. Begonia (Begonia ×semperflorens-cultorum) ‘Cocktail Vodka’, coleus (Solenostemen scutellarioides) ‘Kingswood Torch’, impatiens (Impatiens walleriana) ‘Dazzler White’, marigold (Tagetes erecta) ‘Bonanza Yellow’, petunia (Petunia ×hybrid) ‘Wave Purple’, salvia (Salvia splendens) ‘Red Hot Sally’, and vinca (Catharanthus roseus) ‘Cooler Pink’ were evaluated in 2005, and begonia ‘Cocktail Whiskey’, marigold ‘Inca Gold’, salvia ‘Red Hot Sally’, and vinca ‘Cooler Pink’ were evaluated in 2006 and 2007. Landscape fertilizer rates were 1 lb/1000 ft2 nitrogen (N) in 2005 and 0, 1, and 2 lb/1000 ft2 N in 2006 and 2007. Visual observations throughout each year indicated that all species, whether grown in PTS or PB, had comparable foliage quality in the landscape trial beds during the growing period. With few exceptions, dry weight and plant size for all species increased with increasing fertilizer additions, regardless of the substrate in which the plants were grown. For the unfertilized treatment, when comparing plant dry weight between PB and PTS for each species and for each year (eight comparisons), PTS-grown plant dry weight was less than PB-grown plants in three out of the eight comparisons. However, there were fewer differences in plant dry weight between PTS- and PB-grown plants when fertilizer was applied (PTS-grown plants were smaller than PB-grown plants in only 2 of the 16 comparisons: four species, two fertilizer rates, and 2 years), indicating that N immobilization may be somewhat of an issue, but not to the extent expected. Therefore, the utilization of PTS as a substrate for the production of landscape annuals may be acceptable in the context of landscape performance.

Response of Four Container Grown Woody Ornamentals to Immature Composted Media Derived from Waxed Corrugated Cardboard

Four containerized deciduous ornamental shrubs [deutzia (Deutzia gracilis L.), silverleaf dogwood (Cornus alba ‘Elegantissima’), red-osier dogwood (Cornus sericea L.), and ninebark (Physocarpus opulifolius L.)] were grown during each of two separate growing seasons using 12 different immature (nonaged) composts as media (year one, 12 weeks from start of windrowing; year two, 16-weeks) and also two control nursery mixes (100 percent ground pine bark; and 80:15:5 by volume of pine bark:sphagnum peat:top soil). The compost formulations (volume basis) consisted of spent mushroom substrate (50 percent), waxed corrugated cardboard, 0 percent, 25 percent, or 50 percent), and/or pulverized wood wastes (50 percent, 25 percent, and 0 percent). Supplemental N was added to some composts as poultry manure (18 kg·m−3), soybean wastes (24·kg·m−3), or both at the same application rates. Despite the immaturity of the compost media and the presence of high initial contents of soluble salts primarily from the spent mushroom substrate (EC ≤6.4 dS·m−1, 1:1 v/v medium:water extracts), the top dry weight (averaged over two seasons) of each of the four species grown in compost media, regardless of waxed corrugated cardboard (WCC) level, exceeded that obtained in 100 percent pine bark. Compared with the 0 percent WCC compost, plants of all four species grew better in 25 percent and/or 50 percent WCC compost media and growth in these treatments was more (silverleaf dogwood), similar (deutzia and red-osier dogwood), or less than (ninebark) that in the 80:15:5 nursery mix. Rapid leaching of the potentially toxic soluble salts from the containerized compost media within days after planting minimized any adverse effects on the plants. There was no difference in foliar concentrations of N, P, K, Ca, Mg, Fe, Mn, and Zn due to WCC level, or to the N supplements which had little or no effect on growth. The foliar contents of heavy metals (Cu, Ni, Cr, Cd, Co, and Pb) were low and/or below detection limits.

Response of Shade Trees Grown in In-ground Containers to Three Container Substrates

Abstract Two-year-old branched seedling whips of green ash, Fraxinus pennsylvanica Marsh. and European birch, Betula pendula Roth, were grown for two seasons (1991 and 1992) in 38-liter (# 10) rigid, plastic, in-ground containers in three different substrate treatments: 10%, 50% and 100% soil, containing 10:30:60, 50:30:20, or 100:0:0 of field soil:sphagnum peat:ground pine bark, respectively. Trees were also planted directly into the soil (field-grown) to serve as a baseline control treatment. Top dry mass, trunk diameter and root dry mass in 1991 and 1992 and two size categories of root dry mass (&amp;lt;3 and 3&amp;lt;6 mm) in 1991 were consistently greatest for container-grown trees in the 10% soil treatment and least in the 100% soil treatments. Corresponding results for the 50% soil treatment were intermediate between the other treatments or similar to the 10% soil treatment. In 1991, the top dry mass and trunk diameter of both species grown in containers with 10% soil and in 1992, the top dry mass of ash, in the same treatment, were greater than those of field-grown trees.

Iron-phosphorus interactions in the nutrition of seedling macadamia in organic potting media

Macadamia integrifolia cv. Keauhou seedlings were grown in an organic potting medium based on ground pine bark and peat and of pH 5.9. Interactive effects of iron (Fe) and phosphorus (P) on shoot growth and quality were studied by amending the medium with single superphosphate to provide 0-240 mg P/L, and either FeSO4.7H2O at 0-3 g/L or FeEDDHA at 0.1-0.4 g/L. Shoots of all seedlings, except those at the highest levels of ferrous sulfate with low P addition, were chlorotic, with symptoms typical of Fe deficiency. Shoot quality, as judged by degree of chlorosis, was correlated with Fe concentrations in unbuffered DTPA (1:1.5 by volume) and double acid (DA) (1:5 by volume) extracts of the media (r2 = 0.683 and 0.688), poorly correlated with P concentrations in these extracts (r2 = 0.284 and 0.289), and highly correlated with concentrations of both Fe and P in the regression equation (r2 = 0.845 and 0.865). Shoot quality was not as well correlated with Fe and P in ammonium acetate (NH4OAc) extracts. Optimum shoot quality was achieved in media (pH 5.9) whose DTPA, DA and NH4OAc extracts contained 2-9, 1.54 and 2-4 mg P/L and at least 60, 15 and 0.43 mg Fe/L, respectively. Leaf chlorosis did not occur if the Fe : P ratios of the extracts were &gt;4.5, &gt;1.7 and &gt;0.02, respectively.

Critical concentrations of sulfur in liquid feeds for plants in containers

Brassica oleracea, Matthiola incana, Brachycome multifida and Tradescantia fulminensis were grown in a greenhouse in potting mixes composed of ground pine bark or composted hammer milled softwood, and sand, materials commonly used in Australia. Fertilization was via liquid feeds containing similar concentrations of N, but with S (as sulfate) in concentrations ranging from 0.01 to 70 mg l −1 S. When the liquid feed was the sole source of S, it had to contain at least 15 mg l −1 S for maximum growth of B. Multifida and T. fulminensis. The crucifers Brassica oleracea and M. incana needed 25–27 mg l −1 S in the liquid feed. Critical concentrations of S in 1:1.5-volume extracts for the 2 groups of species were about 3 and 6 mg l −1. Drainage waters containing less than 12 and 16 mg l −1 S were associated with deficiency. When commercial liquid feeds with S concentrations ranging from 0.5 to 79 mg l −1 S were applied to M. incana at a constant 175 mg l −1 N, growth was directly proportional to S concentration up to about 30 mg l −1, even though the concentrations of other elements varied widely. The results are discussed in relation to the ability of water supplies and liquid feeds to supply adequate amounts of S.

Comparison of Chrysanthemum Growth in Pine Bark or Commercial Soilless Mixes1

Abstract Growth of Chrysanthemum morifolium Ramat was evaluated in ground pine bark:sand mixes; a soil:peat:perlite mix; and commercially mixed media. Flowering stem:dry weight of plants grown in barkrsand (3:1 or 2:1, by volume) were comparable to commercial mixes but 100% pine bark or soil:peat:perlite significantly reduced plant height and flowering stem dry weight.

Effects of Soil Amendments and Fertilizer Levels on the Establishment of Silver Maple

In developing a landscape, establishment of woody ornamentals is a major concern. Most recommendations suggest the use of some form of soil amendment (4, 17). Others go so far as to recommend digging the planting hole a year in advance and filling it with leaves and organic matter to form a composted planting media (3). However, their recommendations are seldom referenced by research findings. The same is true for the addition of fertilizers. Some authors maintain fertilizer should not be applied to newly planted landscape material the first year. They state that it takes year for new feeder roots to develop (4, 5, 8). Other advocate the use of diluted solutions of soluble fertilizers, but fail to mention rate and frequency of application (6, 10, 17). Allison and Anderson (1), using sawdust for soil improvements, observed harmful effects on crop yields when sawdust was applied alone. It depleted nitrogen in the form of ammonia and nitrates. Rigby (8) used ground pine bark as a growing medium for container nursery stock. His results showed the newly planted material required additional nitrogen fertilizer for the first few months. Gartner, et. al., (11) worked with several species of plant material and various mixes of hardwood bark, soil and perlite. The decomposition of the bark in the mix caused a severe nitrogen deficiency that was not corrected by normal fertilization practices. Later studies by Gartner, Meyer and Saupe (12) demonstrated that a slow release fertilizer incorporated in bark-amended mixes prevented nitrogen deficiencies. Allison and Murphy (2) and Matkin (15) found that hardwoods decomposed at a faster rate than softwoods (40-50% in 60 days) and the hardwoods were attacked more readily by the microorganisms and consequently required more immediate nitrogen. In further studies with wood by-products, Viljoen and Fred (22) and Lunt (14) reported that there was no toxic effects on plants due to sawdust and woodchips. Joiner and Conover (13) found that shredded pine bark proved to be an accessible, inexpensive substitute for peat as the organic component of soil mixtures with sand for container-grown pittosporum. Salter and Williams (19) studied the moisture characteristics and crop yields from sandy loam soils amended with farmyard manure and peat. Yield differences between the peat and control plots were small and inconsistent. Feustal and Byers (9) studied the moisture absorbing and retaining capacities of peat-soil mixtures. They stated that moisture retention properties alone should not be the basis for incorporating peat with soil. They did not recommend it as a soil amendment. Pellet (16) found that the addition of peat, vermiculite or sawdust to the soils of central Minnesota resulted in no better growth of landscape plants than unamended soil. In agreement with Pellet, Townsend (21) used a 50% sandy loam soil and 50% peat mixture and tested the effects of soil amendments on the growth and productivity of highbush blueberries. The unamended control plot yielded larger plants and better fruit over a five year period than the peat amended soils. Smalley, Pritchett and Hammond (20) found similar results in experiments with bermudagrass putting greens. However, they found that the addition of vermiculite to a loamy fine sand putting-green soil increased yield significantly. It was not advantageous to

Ancymidol Performance as Altered by Potting Media Composition1

Abstract The response of Chrysanthemum morifolium Ram. to drench applications of ancymidol was reduced if the potting media contained high quantities of ground pine bark. Aqueous movement of ancymidol was restricted by pine bark and sand in leaching tests. Bioassays with Setaria italica (L.) Beauv. indicated that the immobile ancymidol fraction in upper segments of pine bark and sand columns retained excellent biological activity.