English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Commercial production of pecan [Carya illinoinensis (Wangenh.) K. Koch.] generates significant woody biomass from hedge prunings with little economic value. Value-added uses could aid pecan growers, and one possible use is wood chips for potting substrates to lessen dependence on peatmoss, thereby aiding greenhouse growers. We evaluated vegetative growth and leaf nutrient responses of ‘Carpino’ garden chrysanthemum (Dendranthema 3grandiflorum) over a 60-day period. Plants were grown in five pecan wood chip substrate levels that substituted 0%, 25%, 50%, 75%, and 100% of peatmossbyvolume.Threewater soluble fertilizer (WSF) rates—Nat 0, 200, or 400mg·L (0–N, 200–N, and 400–N, respectively)—were applied with each irrigation and to each of the wood substitution treatments. The WSF and wood substitution treatments interacted strongly. In the presence of wood, (25L100%substitution levels), increasingWSF to 400–N increased cumulative evapotranspiration (ET), crop height, total leaf number and area, total leaf and stem dry weight, and leaf N and P concentrations. However, with 0% wood substitution, 400LN provided little or no such enhancements. With 25% to 50% wood substitution, root dry weight increased by 61% to 91% from 0–N to 200–N, which may be an adaptive response to nutrient-limiting conditions at 200–N. Appearance of a white rot fungal species in and atop pecan wood-supplemented substrate supports the likelihood that microbial activity was, at least in part, responsible for the nutrient limitations. High WSF at 400–N in combinationwith 25%pecanwood substitutionmaintained adequate fertility and shoot growth thatwas comparable to the conventional peat-only substrate at 200–N.With low tomoderate amounts of pecan wood, further adjustments toWSF rate and irrigation volume would support sustainable fertigation practices, reduce dependence on peatmoss by greenhouse industry, and provide a value-added recycling option for pecan growers. Recent concerns over peatmoss availability, cost, and harvest restrictions have created the need for alternative substrates for potted production of ornamental greenhouse and nursery crops (Jackson et al., 2008; Kuack, 2014; Taylor et al., 2012;Wright and Browder, 2005). Chipped wood from softwood trees has shown excellent potential to supplement peatmoss supplies with few changes in production practices (Boyer et al., 2012a;Murphy et al., 2011). Pine wood substrate studies on ornamental crops have revealed limitations of the wood use, particularly reductions in substrate water and nutrient holding capacities with increased potential for nutrient leaching losses (Fain et al., 2008; Gaches et al., 2011; Jackson et al., 2009; Murphy et al., 2011; Witcher et al., 2014; Wright and Browder, 2005; Wright et al., 2008), and reductions in leaf N, P, and K concentrations (Jackson et al., 2008; Wright et al., 2006). Comparatively little data are available on the use of hardwood chips in greenhouse substrates. Pettersen (1984) reported ranges in wood lignin concentrations (% of dry weight) of 20% to 26% in 49 U.S. hardwood species and 26% to 31% in 35 U.S. softwood species. Lower lignin in hardwood presents a higher proportion of relatively rapidly degradable C at the expense of substrate fertility due to higher collateral nutrient demands of microorganisms. Hardwood chips may thus be less satisfactory for substrates than softwood chips because of their decomposition rate and nutrient immobilization (Nelson, 2012).Murphy et al. (2011) compared effects of hardwood and softwood chips in potting substrates on growth of several herbaceous ornamental species and their findings supported the unfavorable prognosis for use of hardwood chips. In Fall 2012, we completed a pilot study at two nearby commercial greenhouse and nursery production sites using various rates of pecan wood chips in the substrate, prepared as described below for the present investigation. A pecan wood chip incorporation rate as low as 25% (peatmoss or pine bark substitution by volume) reduced total plant dried biomass of ‘Step’ pot chrysanthemum by 49% after 2.5 months, and by 21% in a hybrid lantana (Lantana L. ‘New Gold’) and a hybrid trailing rose (Rosa L. ‘Red Cascade’) after 6 months. These plants were subjected to only one fertilization regime, opening the possibility for further study to address the effects of fertilizer rate on crop performance. Reports on pine wood substrate have shown that increasing fertilizer rate is necessary to overcome growth-related suppressions of the wood (Jackson et al., 2008;Wright andBrowder; 2005; Wright et al., 2006, 2008). Still et al. (1972) reported that the visual appearance of pot chrysanthemum shoots on a substrate amended with aged sawdust from white oak trees (Quercus alba L.) (33% to 50% by volume) compared favorably to that on a conventional peat-only substrate, provided that soluble fertilizer rates were increased accordingly. However, similar data are lacking to support or disqualify the use of hardwood chips in greenhouse potting substrates, particularly in view of what appear to be small differences in lignin concentrations between hardwoods and softwoods noted previously. New Mexico pecan acreage has increased rapidly (U.S. Department of Agriculture, 2015a) and the state recently ranked second in the United States in total pecan production and economic value (U.S. Department of Agriculture–NASS, 2015b). Do~na Ana County has the highest concentration of pecan farms in New Mexico and thus has an important impact on U.S. pecan production (Lillywhite et al., 2007). As pecan trees mature, pruning becomes essential to maintain crop productivity and quality (Picchioni et al., 2000a). Over the last decade, annual hedge pruning has become common in New Mexico pecan orchards with increased availability of equipment and positive effects on annual productivity (R.J. Heerema, personal communication). Kallestad et al. (2008) determined that as many as 38,000 t of dry prunings are generated annually in the Mesilla Valley of Do~na Ana County where there are also greenhouse and nursery producers. A similar scenario applies throughout the entire southern United States, where HORTSCIENCE VOL. 51(2) FEBRUARY 2016 177 | SOIL MANAGEMENT, FERTILIZATION, AND IRRIGATION

Vegetative Growth and Leaf Nutrient Status of ‘Carpino’ Chrysanthemum on a Pecan Wood-amended Commercial Substrate