Progress 10/01/03 to 09/30/08
Outputs
OUTPUTS: Objective 1: Project personnel have recently completed a study to quantify physicochemical properties of Chihuahuan Desert soil irrigated with treated saline industrial effluent using an experimental land application water treatment plant constructed by the City of Las Cruces. The results (in press) revealed that in the upper 15 cm of soil depth, saline and sodic irrigation water reduced the the saturated hydraulic conductivity by 64% to 82%, depending on presence or absence of vegetation cover, or type of cover. Losses in saturated hydraulic conductivity were attributed to deterioration of soil structure arising from the high sodicity of the saline effluent. Currently, personnel are completing the data processing phase in preparation for a 4-year environmental impact assessment of saline effluent irrigation on nutrient compositional changes in the site's soil, shrub vegetation, and herbaceous vegetation. Objective 2: Several 10-day vase-life studies on Lupinus havardii (big bend bluebonnet) have reached completion. In one study, we have shown that 'White Select' and 'Texas Sapphire' differ markedly in flower abscission. Without ethephon vase solution addition of 50 uM, 'white Select' expressed no flower abscission, whereas 'Texas Sapphire' dropped over 80% of its flowers by 10 days in the vase. With constant exposure to ethephon in the vase, however, significant floral abscission on 'White Select' stems was observed, suggesting that this cultivar may lack the ability to synthesize ethylene. Complete assessment of changes in fresh weight, flower numbers, nutrient recycling, and responses to ethephon is in progress. Objective 3: An important rationale to this study is to quantify the amount of nitrogen (N) needed by vigorous and non-vigorous (compact) poinsettia cultivars, and to evaluate growth and quality under 'resource efficient' and 'resource inefficient' management conditions (low N, low leaching versus high N, high leaching, respectively). Our study is applicable to 'open-loop' overhead irrigation. We have found that growth and postharvest quality of a compact cultivar, 'Silverstar Red', were highest with the 'resource efficient' management strategy of 50 ppm N and a leaching fraction (LF) of 0 to 5%. However, this management strategy was ineffective for the vigorous 'Festival Rose' even with growth regulator application; instead, the latter cultivar performed best under 'resource inefficient' management of 200 ppm N and an average LF of 15% to 25%. We measured the amount of N in roots, stems, green leaves, and red bracts at the close of study. In the cultivar-dependent optimal treatments noted above, mature 'Silverstar Red' plants (compact) contained a total of 0.59 +/- 0.05 grams N per plant, whereas mature 'Festival Rose' plants contained a total of 1.65 +/- 0.06 grams N per plant. Thus, a 4-fold difference in fertilizer N requirement was matched by an approximate 3-fold difference in N content per plant. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.
Impacts
Objective 1: Benefits of controlled releases of saline effluent on desert soil and xeric vegetation are obtainable, but must account for possible deleterious effects of high sodium on soils and vegetation. Financial reward for municipalities includes low-cost, environmentally sustainable wastewater treatment, and reduced salinization of the Rio Grande. Objective 2: American Society for Horticulture Sciences Outstanding Ornamental Publication award for the article entitled, 'Correlative Supply and Demand Functions in Lupinus havardii: A forgotten side of cut flower physiology' Authored by G.A. Picchioni, W.A. Mackay, and M. Valenzuela-Vazquez. Presented at the ASHS Annual Meeting, Orlando, Fla., July 21, 2008. Objective 3: Findings should contribute to 'fine-tuning' N management of poinsettia according to cultivar vigor, thereby conserving water and N in high-input greenhouse production systems, and reducing N losses from the greenhouse. While the findings also reveal that use of the 'resource efficient' strategy for compact poinsettia cultivars may be highly beneficial, this strategy may not be feasible for vigorous cultivars under 'open-loop' irrigation.
Publications
- No publications reported this period
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Progress 01/01/07 to 12/31/07
Outputs
A stand establishment study on 15 turf-type tall fescue cultivars was completed and a peer-reviewed article was published. A four-year environmental impact study of salt-affected industrial effluent application to a Chihuahuan Desert upland is nearing completion (2002-05). Effluent application has resulted in the accumulation of both stress-related minerals as well as essential minerals in the soil at depths sampled up to 2.1 m. On effluent-irrigated land, for example, soil salinity in the soil saturation extract has reached as high as 5 to 6 dS/m at average sampled depths of 0.75 to 1.05 m under co-dominant shrub members Larrea tridentata and Prosopis glandulosa. Control (nonirrigated) plot salinity has remained stable and generally at or below 1 dS/m throughout all sampled depths and years of study. Sodicity on the irrigate plot (assessed as sodium adsorption ratio) has reached as high as 35 by the end of the 4-year study but has remained at or below 10 for the
non-irrigated site. In addition, Cl concentration of the treated plot soil saturation extract has reached 50 meq/L, or ≈5 times that of the control site. Four years of effluent application increased the soil NO3 and soluble P concentrations in the top 30 cm depth by 2 to 4 times that of non-irrigated land. At termination of the field study (2006), herbaceous dry matter production and shrub reproductive growth were stimulated under effluent irrigation. In a supplemental study involving nursery plant irrigation in the Chihuahuan Desert, we reported a holistic model for learning, independent research, and outreach by undergraduate students. In specialty cut flower crops research geared toward New Mexico growers, one study is nearing completion, with two other studies completed. In a field study summarizing yield, harvest quality, and postharvest quality changes of two Gomphrena sp. and two Celosia sp., an initial publication draft is nearing completion and should be submitted by
2008. Two separate greenhouse studies have involved Lupinus havardii (big bend bluebonnet) and have reached completion. In one greenhouse and postharvest laboratory study, we found that 1-methylcyclopropene (MCP) has considerable potential for environmentally-safe vase life extension of fresh-cut bluebonnets. In the second greenhouse production combined with laboratory vase life study, we hypothesized that postharvest growth of the L. havardii apical meristem is supported by redistribution of resources from mature regions of the inflorescence. Our findings confirmed the hypothesis, since the contributions of water, N, P, and K exports from senescing tissues to apical metabolic sink demands were at or near 100%.
Impacts
1) We identified tall fescue turfgrass cultivars and mowing practices amenable to southern New Mexico. Findings will aid desert turf managers in selection of wear-tolerant cool-season turfgrasses. 2) Benefits of controlled releases of saline effluent on desert soil and vegetation are obtainable. Xeric vegetation growth stimulation may be related to soil N and P accumulation, water availability, or both. Financial reward for municipalities includes low-cost, environmentally sustainable wastewater treatment, and reduced salinization of the Rio Grande. 3) Four species of Gomphrena and Celosia have excellent potential for dried flower production in southern New Mexico, may contribute to high value crop selection options, and address small farm diversification needs in our area. L. havardii can be added to the growing list of horticultural products amenable to postharvest life extension with MCP. By using L. havardii as a model, we were the first to report an internal
resource supply and demand balance sheet of water, total dry matter, and minerals reflecting postharvest reallocation of invested resources from mature reproductive tissues to generative reproductive tissues during vase life of a cut inflorescence. These findings have aided in our understanding of internal physiological factors that regulate cut flower desiccation, flower developmental plasticity, flower sink:source interconversions, and flower senescence.
Publications
- Picchioni, G.A., J. Singh, J.G. Mexal, and R. Goss. 2007. Merging the roles of learning, research, and outreach in a nursery irrigation exercise. HortTechnology 17:379-385.
- Valenzuela-Vazquez, M., G.A. Picchioni, L.W. Murray, and W.A. Mackay. 2007. Beneficial role of 1-methylcyclopropene for cut Lupinus havardii racemes exposed to ethephon. HortScience 42:113-119.
- Picchioni, G.A., W.A. Mackay, and M. Valenzuela-Vazquez. 2007. Correlative supply and demand functions of Lupinus havardii: A forgotten side of cut flower physiology? Journal of the American Society for Horticultural Science 132:102-111. (Cover article).
- Ray, W.F., G.A. Picchioni, D.M. Vanleeuwen, and R.M. Goss. 2007. First year responses of turf type tall fescue to different fertilization rates and mowing heights in semiarid conditions. HortTechnology 17:353-357.
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Progress 01/01/06 to 12/31/06
Outputs
A stand establishment study on 15 turf-type tall fescue cultivars was completed and a peer-reviewed manuscript submitted for publication in 2006. An irrigation scheduling model for land application of treated industrial wastewater to Chihuahuan Desert soils and their mixed vegetation members, Larrea tridentata and Prosopis glandulosa, was implemented in 2004. By 2006, the model was disseminated through peer-reviewed literature. Because of high salinity of the industrial effluent, soil salinity has reached as high as 5 to 6 dS/m at average sampled depths of 0.75 to 1.05 m. Control (nonirrigated) plot salinity has remained stable and at or below 1 dS/m throughout all sampled depths and years of study. Research is in progress to determine the effect of salinization on both soil and vegetation. This research should be nearing completion by end of 2007. In specialty cut flower crops suitable for New Mexico, three studies have been completed and are at various stages of
dissemination. In a field study summarizing yield, harvest quality, and postharvest quality changes of two Gomphrena sp. and two Celosia sp., an initial publication draft is nearing completion and should be submitted by 2007. Two separate greenhouse studies have involved big bend bluebonnet and have reached completion. In one greenhouse and postharvest laboratory study, we found that 1-methylcyclopropene has considerable potential for envirionmentally-safe vase life extension of fresh-cut bluebonnets. In the second greenhouse:laboratory study, our findings report postharvest mineral and dry matter redistribution changes.
Impacts
For the turf-type tall fescue study, publishable data should prove useful as a preliminary report for the semiarid region of the U.S. In the wastewater land application model, the City of Las Cruces Utilities Division personnel have learned how to schedule irrigation independently, based on NMSU technology transfer workshops conducted in 2005. Dissemination of the model through the peer-reviewed literature will allow our model to be used as a prototype for other small communities seeking cost-effective industrial wastewater management. Findings from the field-grown specialty cut flower research should be of value to New Mexico small farmers considering high value water use options (e.g., specialty cut flowers) in their production diversification schemes. For the big bend bluebonnet research, with a 2-day extension of vase life resulting from 1-methylcyclpropene, cost-effectiveness of water and fertilizer inputs at the production stage will ultimately be improved. For
example, a retailer would need 33% fewer shipments due to delayed spoilage, which would in turn require 33% less production inputs, including water and fertilizer in the greenhouse production environment.
Publications
- Saucedo, D., T.W. Sammis, G.A. Picchioni, and J.G. Mexal. 2006. Wastewater application and water use of Larrea tridentata. Agricultural Water Management. 82:343-353.
- Ruiz, A., T.W. Sammis, G.A. Picchioni, J.G. Mexal, and W.A. Mackay. 2006. Irrigation scheduling protocol for treated industrial effluent in the Chihuahuan Desert. American Water Works Association Journal. 98:122-133.
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Progress 01/01/05 to 12/31/05
Outputs
An irrigation scheduling model for the Chihuahuan Desert mixed vegetation system of Larrea tridentata and Prosopis glandulosa was implemented in 2004. During the 2002-2003 seasons, a total of 50 cm of salt-affected treated industrial wastewater was applied to a 0.4-ha treated plot, and soil salinity (EC) was increased to a maximum of 2 to 3 dS/m at any sampled depth to 2.1 m. During the 2004 season, 56 cm of treated effluent were applied to the treated plot, raising the soil salinity to as high as 5 to 6 dS/m at average sampled depths of 0.75 to 1.05 m. Control (nonirrigated) plot salinity has remained stable and at or below 1 dS/m throughout all sampled depths and years of study. Despite the increase in soil salinity, no detrimental effects on the vegetation growth have been experienced through three wastewater irrigation seasons totaling about 1 m of irrigation (2002-2004). Vegetation growth assessment and chemical analyses of soils and vegetation through the 2005
season are in progress. In research on specialty cut flower crops suitable for New Mexico, a field study summarizing yield, harvest quality, and postharvest quality changes of two Gomphrena sp. and two Celosia sp. is in progress. Preliminary results show that C. argentea and C. spicata had cumulative annual dried flower yields of 5.6 and 6.7 T/ha, respectively, over 3 harvests and by 135-140 days after field transplanting. After 4 harvests and 160 days of transplanting, G. globosa had a cumulative annual dried flower yield of 17.2 T/ha, whereas after 4 harvests and 190 days after transplanting, G. haageana yielded only 13.5 T/ha. While the Celosia yields were relatively similar per unit time, land area, and across a given number of harvests, G. globosa may be able to yield more annual flower tonnage over 30 less days of production as compared to G. haageana. Postharvest research on fresh-cut Lupinus havardii has included two studies. In one study, postharvest application of the
ethylene action inhibitor 1-Methylcyclopropene (1-MCP) at 160 nl/L was shown to delay termination of vase life of 'Texas Sapphire' by approximately 2 d. The average vase life of control (non-treated) bluebonnets was about 4 days, whereas the average vase life of 1-MCP-treated bluebonnets was approximately 6 days. In a second study, comparative vase life evaluations of 'Texas Sapphire' and 'White Select' revealed that 'Texas Sapphire' expresses a higher level of exogenous ethylene sensitivity as compared to 'White Select', as inferred by earlier declination of inflorescence fresh weight and earlier onset of flower abscission in the presence of 50 uM ethephon. However, postharvest apical expansion of 'Texas Sapphire' is significantly higher than that of 'White Select', raising the possibility that relative sink strength may be a factor in cut L. havardii senescence, in addition to ethylene. This hypothesis is currently under investigation.
Impacts
On average (2002-2004), approximately 96,000 m3 per year of salt-affected industrial wastewater can be land-applied to a Chihuahuan Desert upland site of 40 ha without observable environmental impact to the native vegetation and soils. This wastewater contained over 2000 mg/L total dissolved salts, equating to approximately 215 T of salt that would otherwise be released into the Rio Grande following high-cost tertiary water treatment. The land application process has therefore contributed to abatement of salt loading along the Rio Grande. The City of Las Cruces Utilities Division personnel have learned how to schedule irrigation independently, based on NMSU technology transfer workshops. Findings from the specialty cut flower research should be of value to New Mexico small farmers considering specialty cut flowers in their production diversification schemes. Results have allowed us to focus on specific crop selections that appear to have good market potential for both
fresh and dried flower markets in New Mexico. For the L. havardii study, with a typical 2-day extension of vase life of white-flowering lines, a retailer would need 33% fewer shipments due to delayed spoilage, which would in turn require 33% less production inputs, including water and fertilizer.
Publications
- No publications reported this period
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Progress 01/01/04 to 12/31/04
Outputs
In turfgrass research, maintaining growing season N rate (urea and sulfur-coated urea for 120 days) < 300 kg ha-1 provided acceptable color and quality of the warm-season hybrid bermudagrass [Cynadon dactylon (L.) Pers. X transvaalensis Burtt-Davy 'Tifgreen'] when compared to N rates > 300 kg ha-1. For 15 cultivars of the cool-season tall fescue (Festuca arundinaceae Schreb.), N at 200 kg ha-1 offered no improvement over 100 kg ha-1 on stand color rating. In a 2-year field tree establishment study [Asimina triloba (L.) Dunal], high soil saturation extract (SSE) sodicity (SAR > 8) delayed root expansion as compared to low sodicity (SAR < 3) even under low total SSE salinity (EC < 0.6 dS m-1). Modification of the soil with gypsum (5 to 10 T ha-1) ameliorated negative sodicity effects by increasing total tree biomass and the net uptake of N per tree by over 100% above a non-gypsum control. In a study involving native perennial Chihuahuan Desert plant species, Larrea
tridentata (DC.) Cov. and Prosopis glandulosa Torr., one year of saline wastewater land application (64 cm) increased SSE salinity in the top 60 cm of the soil profile to 3.5 dS m-1, as compared to an EC of < 1.5 dS m-1 in a non-irrigated control plot. In early autumn 2002, there were higher leaf Na and Cl concentrations (% of dry wt) in the treated plot than in the control plot (0.3% vs 0.4% Na; 1.4% vs 2.1% Cl, control and treated, respectively). On the treated plot, leaves of L. tridentata contained as high or higher Na and Cl concentrations as those of P. glandulosa, yet removed 2 to 3 times more Na, Cl, and N per branch. In floriculture research on Lupinus havardii Wats. racemes, use of vase water solutions for 10 days showed that 'Texas Sapphire' expressed earlier onset of raceme desiccation below the harvest value compared to 'White Select' (4 to 5 days, respectively) along with 100% floret abscission, with no floret abscission on 'White Select'. Differential sensitivity to
exogenous ethylene between 'Texas Sapphire' and 'White Select' was also observed. Racemes receiving continuous exposure to 50 uM 2-chlorophosphonic acid (CEPA) in the vase deteriorated more rapidly than in a non-CEPA control treatment. However, 3 days following harvest, 'White Select' racemes in CEPA retained about 80% of their initial water content and floret number, while 'Texas Sapphire' racemes retained only about 60% of their initial water and 10% of their initial floret number. Desiccation and floret abscission was strongly suppressed by the ethylene action inhibitor, silver thiosulfate (40 mg L-1 STS). During the first 5 days of vaselife in water, cut 'Texas Sapphire' racemes had a relative apical expansion rate (RER) at or above 0.06 mm mm-1 d-1, an apical length of 60-65 mm, and 9 to 10 newly opened flowers. By contrast, 'White Select' racemes had an RER of 0.04 mm mm-1 d-1, an apical length of 50-55 mm, and 6-7 newly opened flowers. In cut L. havardii racemes, apical sink
strength appears to be negatively correlated with inflorescence retention of water and florets, and thus may be involved in the regulation of raceme senescence.
Impacts
In summary, the turfgrass research findings will aid in maximizing acceptable bermudagrass quality, while minimizing maintenance costs and environmental impact of N fertilization, and emphasize the importance of residual soil N assessments in limiting fertilizer N losses to the environment. The recently-established wastewater application study will allow us to develop and disseminate an input-based management plan favoring best irrigation management practices to exploit the land and vegetation for wastewater disposal, and to prevent undo harm to the site. The ultimate economic impact of this project is apparent when considering the low-inputs of land application (<$50,000 per year in operation and maintenance) versus the multi-million dollar option of an engineered wastewater treatment plant plus its associated annual maintenance, operational, and depreciation costs. These data will aid in determining total vegetation removal of effluent components, preventing adverse
environmental impact to the site, and developing a practical management plan suitable for small communities seeking cost-effective wastewater handling protocols. Our results on trees point to the importance of environmental monitoring and assessment of vegetation in response to saline water application. One L. havardii plant can produce as many as 30 blooms that sell for $1 each in the wholesale trade. 300 plants could return about $9,000 in supplemental gross annual income needing less than 1,000 square feet of greenhouse space.
Publications
- Picchioni, G.A., C.J. Graham, and A.L. Ulery. 2004. Gypsum effects on growth and macroelement uptake of field-grown Asimina triloba (pawpaw) irrigated with low-saline, sodic water. HortScience. 39:11-4-1109.
- Quiroga-Garza, H.M. and G.A. Picchioni. 2003. Bermudagrass fertilized with slow-release nitrogen sources. II. Photoperiod effects on shoot growth and color. HortScience. 38:1441-1445.
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Progress 01/01/03 to 12/31/03
Outputs
Research has been directed at mineral nutrition and mineral stress on diverse ornamental plant species in conjunction with southwestern USA growing conditions, while addressing turfgrass N management, salt-affected wastewater, and floral postharvest physiology and quality maintenance. In turfgrass research, we found that lowering the N rate of the relatively soluble slow-release N sources, sulfur-coated urea and urea (300 kg/ha per 120 days), provided acceptable color and quality of the warm-season hybrid bermudagrass [Cynadon dactylon (L.) Pers. X transvaalensis Burtt-Davy 'Tifgreen']. Higher N rates (> 300 kg/ha per 120 days) produced significantly more shoot growth and did not appear to intensify color and quality sufficient to warrant the attendant risk of N loss, particularly under autumnal growing conditions with declining photoperiod, temperature, and N demand of the grass (Quiroga-Garza and Picchioni, 2003. HortScience. In Press). These findings are important
for maximizing acceptable bermudagrass quality, while minimizing maintenance (mowing) costs and environmental impact of N fertilization. In a second study involving 15 cultivars of the cool-season tall fescue (Festuca arundinaceae Schreb.) (Ray and Picchioni, unpublished data), N at 200 kg/ha offered no improvement over 100 kg/ha on visual ratings for overall quality, density, color, texture, or uniformity of the stand. Results suggest that residual soil N played a factor in maintaining visual quality ratings at the lower N rate, and re-establishes the essentiality for frequent assessment of residual soil N in limiting fertilizer N losses to the environment. Mowing height was a critical factor in determining the stand growth and quality rating. In research on trees, a 2-year field study on Asimina triloba (L.) Dunal (Picchioni et al., 2004. HortScience. In Press) has shown that saline-sensitive ornamental trees experience establishment problems under moderate to high sodic proportion
conditions [high sodium adsorption ratio (SAR)], even at low total soil salinity (EC < 0.6 dS/m). Supplemental gypsum (5 to 10 T/ha) increased total tree biomass and the net accumulation of N and other macroelements by over 100% above a non-gypsum control. In a second study involving fast-growing tree clones and species, long-term (7-year) application of salt-affected wastewater (EC to 4 dS/m) in Chihuahua, Mexico leads to eventual decline of three clones of hybrid poplar (Populus spp.) and seedlings of Robinia pseudoacacia L. However, three clones of Eucalyptus camaldulensis Dehn. continue to thrive in the saline conditions and appear to be emerging as desirable tree selections for maximizing biomass (wood products) production and saline wastewater reutilization. In floriculture research, our continued study with W.A. Mackay at Texas A&M University on Lupinus havardii Wats. (Big Bend bluebonnet) has confirmed the ethylene insensitivity of a breeding line that has been tentatively
named (White Select), with a vaselife of 2 to 4 days longer than the earlier L. havardii lines and cultivars.
Impacts
The hybrid bermudagrass findings suggest that it may be possible to avoid a late season N application, provided that a slow-release N source is applied at an adequate rate, and preceding the autumnal decline in N demand of the grass. By avoiding a late-season N application, as much as $30 to $50 per acre per year in slow-release N fertilizer cost plus labor could be saved. For an average regulation-sized golf course, approximately $2000 to $4000 could be saved per year per operator, not counting fuel and depreciation-on-equipment costs. We have identified tree species and clones suitable for wastewater reutilization as well as for economic return to the subsistence land owner along the USA/Mexico border region. We anticipate that the results will demonstrate economic incentives for using trees as a low-input solution to help solve environmental and economic problems on the border. The recently-established wastewater application study will allow us to develop and
disseminate an input-based management plan favoring best irrigation management practices to exploit the land and vegetation for wastewater disposal, and to prevent undo harm to the site. The ultimate economic impact of this project is apparent when considering the low-inputs of land application (<$50,000 per year in operation and maintenance) versus the multi-million dollar option of an engineered wastewater treatment plant plus its associated annual maintenance, operational, and depreciation costs.
Publications
- No publications reported this period
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