Location: Application Technology Research2020 Annual Report
The overall objective of this project is to conduct research that is relevant to the containerized nursery and greenhouse production (protected horticulture) industry, which will produce outcomes that enhance efficiency, improve economic return, and reduce environmental impact. The following objectives, which have been identified during the past project cycle; have been carefully selected by the Greenhouse Production Research Group to meet priority researchable needs of the industry. Staff and resources have been assembled to address these researchable objectives, and initial research has yielded a base of knowledge, appropriate research skills, and procedures to address this project. Over the five-year planned duration of this project, it is anticipated that there will be significant enhancement of floricultural and nursery productivity with optimization of water, nutrient, fertilizer, and crop protection inputs while minimizing agrochemical, labor, and environmental impacts. Objective 1: Determine the role of silicon in management of abiotic stresses in protected horticulture production systems. Sub-objective 1.1: Elucidate the mode of action of supplemental silicon on the alleviation of abiotic stress symptoms. Subobjective 1.2: Identify a strategy for supplying supplemental silicon in protected horticulture systems. Objective 2: Determine the influence of environmental parameters on growth and development of protected horticulture crops and incorporate the information into user friendly decision support software such as Virtual Grower. Sub-objective 2.1: Quantify photosynthetic responses of protected horticulture crops to environmental parameters. Sub-objective 2.2: Evaluate energy-efficient lighting and heating strategies for bedding plant production. Sub-objective 2.3: Expand the decision support model Virtual Grower to include additional production parameters and crops. Objective 3: Develop management strategies for containerized crop production systems that improve crop growth, reduce costs, and reduce loss of nutrients and agrichemicals to the environment. Sub-objective 3.1: Quantify the chemical and physical properties of novel materials that provide producers with substrates that are economical, sustainable, and effective. Sub-objective 3.2: Determine the utility of biochar for supplying phosphate and potassium in peat and bark-based substrates. Sub-objective 3.3: Through improved understanding of weed biology,develop methods for weed control in crops and sites where herbicides are not labeled. Objective 4: Develop improved techniques for monitoring invasive ambrosia beetles in nurseries based on new knowledge of behavior, movement, and flight activity across different habitats. Objective 5: Characterize the role of tree health on the host-selection and host preference behavior of ambrosia beetles in ornamental nurseries. Objective 6: Develop improved technology for applying or improving the efficacy of chemicals to effectively manage ambrosia beetles and evaluate alternatives to conventional insecticides for managing ambrosia beetles in nurseries.
A multi-disciplinary team will address the goal of enhancing containerized crop production in the context of protected horticulture by utilizing a three-fold approach to address production efficiency, economic return, and environmental impact. Plant nutrition, including the role of silicon as mediated through soilless media composition, will be studied to determine how plant stress is impacted by nutrient supply in both floricultural and nursery crops. Environmental parameters, such as light, temperature, and carbon dioxide, will be evaluated for their influence on growth and development and results will be incorporated into our decision support software model, Virtual Grower. Management strategies will include chemical and physical quantification of substrate components, as well as determination of the utility of novel components as sources of macronutrients in nutrient deficient soilless media, and the improved understanding of weed biology to improve control approaches for crops and sites which lack current herbicide alternatives.
This report summarizes progress for this project which began 10/15/18 and ended 6/30/20. Research will be continued under the new project 5082-21000-001-00D, “Sustainable Production and Pest Management Practices for Nursery, Greenhouse, and Protected Culture Crops”. Objective 1: We sought to determine the role of silicon (Si) in management of abiotic stresses in protected horticulture production systems. Supplying supplemental Si as a water-soluble application or as a substrate amendment improved growth compared to non-Si-amended plants during cold stress and drought stress. Collaborative research with The University of Toledo identified that Si can alleviate copper toxicity in Nicotiana tabacum by reducing root copper (Cu) concentration, downregulating the expression of a copper transporter, and increasing the expression of ethylene biosynthetic genes; this suggests a regulatory function of Si in plants. We identified strategies to supply supplemental Si to plants in protected horticulture systems; these include water-soluble potassium silicate and substrate amendments of calcium silicate (e.g. wollastonite), steel slag, or rice hulls. Amendment rate, substrate pH, and crop duration impact plant Si uptake. While all sources evaluated were suitable for potted crop production, water-soluble potassium silicate had the highest uptake percent. Substrate Si amendments may be considered as slow-release sources of Si for crops with long production cycles. Particle size did not impact rice hull properties with respect to Si availability or substrate pH adjustment, but fine wollastonite particles increased pH and Si availability more than coarse particles when amended at the same rate. Objective 2: Research focused on determining the influence of environmental parameters on growth and development of protected horticulture crops and incorporating the information into user-friendly decision support tools. Optimizing environmental conditions in greenhouses and other controlled environments is important for enhancing yield while improving resource use efficiency, but they are often crop or cultivar specific. We developed photosynthetic response curves to light intensity and carbon dioxide (CO2) concentration for four herbs (basil, oregano, parsley, and sage) and eight tomato cultivars. Additionally, in collaboration with researchers at The University of Toledo, we discovered the combination of elevated temperature (37 °C) and carbon dioxide concentration (700 ppm) drastically hinders growth of tomato in controlled environments. This is due to the onset of leaf hyponasty (upward bending of a leaf), which reduced light interception and led to reduced photosynthesis and biomass accumulation. This phenomenon varied in severity across different tomato cultivars and appears to occur in compound-leaved plants in Solanaceae. Objective 3: Researchers sought to develop management strategies for containerized crop production systems that improve crop growth, reduce costs, and reduce loss of nutrients and agrichemicals to the environment. A system for sequestering phosphorus (P) in container substrates was developed by amending the bottom layer of a container substrate with iron (Fe)-enriched pine bark. Results suggested that a layer of Fe-modified substrate could dramatically reduce P leaching and subsequent runoff from containerized nursery plants. Research was conducted to determine the effect of composts on microbial communities within peat-based substrates used for greenhouse production. Microbial communities changed over time, regardless of the initial treatment conditions. Furthermore, microbial communities tended to become similar across substrate treatments, suggesting the environmental conditions have more influence on microbial communities than initial substrate components or amendments. Efficacy of the primary herbicide classes was determined as a function of time, light level, and irrigation frequency. While longevity of herbicides differed by chemical class, greater irrigation frequency reduced herbicide efficacy while light and substrate type had no measurable impact on herbicide longevity. Research was initiated and is underway in Oregon, Louisiana, Virginia, and Ohio to assess the ability of stratified substrates, organizing or layering substrates of varying particle size to optimize hydrology, to reduce mineral nutrient inputs, irrigation requirements, agrichemical leaching, and weed pressure of containerized horticultural crops. Preliminary results have demonstrated the ability to reduce water and mineral nutrient inputs by 15% or reduce weed pressure based on techniques employed. Objective 4: In collaboration with researchers from North Carolina State University and Cornell University, we characterized the species diversity and seasonal activity of exotic and native ambrosia beetles in high density apple orchards in New York, North Carolina, and Ohio. Ambrosia beetle attacks on apple trees were also monitored and recorded. The dominant species of exotic ambrosia beetles were documented. Research was conducted by ARS scientists at Wooster, Ohio, in collaboration with researchers from Virginia Polytechnic Institute and State University (Virginia Tech) and University of Padua , Italy, in 2019 and 2020 to test a range of ethanol release rates from lures to determine the optimal release rate for mass trapping ambrosia beetles as part of push-pull management strategy. Field experiments were conducted in Ohio, Virginia, and Italy. Interspecific variability was documented for the preference of different ethanol release rates of ethanol among different key species of exotic ambrosia beetles. These results are being used to improve mass trapping and interception tactics for ambrosia beetles. Volatile compounds emitted from the fungal symbiont of an exotic ambrosia beetle were identified by gas chromatography-mass spectrometry (GC-MS). The olfactory response of the exotic ambrosia beetle to the volatile compounds were characterized using an electroantennogram to measure firing of neuronal receptors. These results are being used to improve the monitoring of ambrosia beetles, and to further understand interactions between ambrosia beetles and their fungal symbionts. Monitoring and seasonal activity of flea beetles in nursery crops was initiated in 2019. Commercially available sticky cards (traps) of various colors were tested for monitoring red-headed flea beetle activity in nurseries. Plants in monitored plots were also visually inspected for beetles and feeding damage to help evaluate trap efficacy. We thought there might be a complex of flea beetles attacking plants, but only red-headed flea beetles were found. Beetles were found in nurseries in Erie and Lake Counties. Red-headed flea beetles emerged later than expected in 2019 (a month later based on previous reports), being first detected 2 July in Erie and 8 July in Lake County. Beetles were detected by visual inspection and on sticky cards on the same date. So far, visually inspecting plants was as effective as sticky cards and easier to use. Objective 5: Research on the relationship between duration of stress on trees and ambrosia beetle colonization was initiated in FY18, continued in FY19 and planned for May FY20. To date, the influence of flood duration on colonization success of ambrosia beetles was tested on ‘Golden Delicious’ apple trees (Ohio), flowering dogwoods (Ohio), and eastern redbuds (Virginia). So far, the data indicates colonization success increases as flood duration increases, and trees flooded for short time-periods can tolerate attacks. Ambrosia beetles attack then tend to abandon trees flooded for short time-periods, and the attack entrances heal over. In 2018, dogwood trees flooded for only three days were attacked and showed no adverse effects, then survived winter, bloomed in spring 2019, and again in 2020 and appear healthy. In collaboration with Virginia Polytechnic Institute and State University, a proprietary product was tested for alleviating tree stress to minimize tree vulnerability to ambrosia beetles. Field experiments were conducted in Ohio and Virginia using trees that were irrigated with ethanol to induce ambrosia beetle attacks. Irrigating the roots of the vulnerable trees with a proprietary product showed promise for disrupting the colonization success of ambrosia beetles, potentially by disrupting establishment of the fungal symbiont. These results could lead to the development of an alternative to conventional insecticides for managing ambrosia beetles. In collaboration with researchers from University of Padua, we assessed host colonization and preference patterns of ambrosia beetles in relation to ethanol concentrations within host tissues. Tree bolts were soaked in varying concentrations of ethanol and deployed in tree fruit orchards in Padua, Italy. The colonization success of different species of ambrosia beetles will be compared in relation to the different concentrations of ethanol in the host substrates.
1. Adding silicon to soilless substrates improves horticultural crop production. Management of abiotic and biotic stresses is costly for greenhouse-grown crops and limited chemical control options exist, especially for edible crops. Silicon is a plant beneficial element that can help mitigate many of these stresses, but limited research exists on suitable silicon sources, method of application, and application rates. ARS researchers at Toledo, Ohio, have quantified plant silicon uptake for commercially available silicon-containing soilless substrate amendments. This research has led to grower trials at research and commercial greenhouses and increased adoption of incorporating silicon amendments into substrates, providing benefits such as management of cold stress.
2. Long-lasting insecticide netting for protecting trees from ambrosia beetles. Ambrosia beetles are destructive wood-boring insects of ornamental and horticultural trees. Alternatives to trunk applications of conventional insecticides are warranted to reduce non-target drift and negative impacts on pollinators. Netting impregnated with insecticides has shown promise for protecting fresh cut logs from wood-boring bark and ambrosia beetles, but the tactic has not previously been evaluated using horticultural trees. ARS researchers in Wooster, Ohio, led a team of multi-state scientists to evaluate long-lasting insecticide netting for protecting stems against ambrosia beetles. Treated netting reduced attacks compared to untreated netting and/or unprotected trees in Mississippi, Ohio, Tennessee, and Virginia. Fewer ambrosia beetle specimens were also dissected from trees that were protected with treated netting compared to untreated netting. These results indicate long-lasting insecticide netting could be used to protect horticultural trees from ambrosia beetles and minimize non-target impacts of conventional insecticide sprays.
3. Attraction of invasive ambrosia beetles to ethanol-treated tree bolts. Ethanol-treated tree stem sections (bolts) from various species were tested as monitoring tools for invasive ambrosia beetles in ornamental tree nurseries. Bolts treated with ethanol may be more attractive to and selective for damaging invasive ambrosia beetles than standard ethanol baited traps. Bolts were treated by soaking in 10% ethanol or a cavity was drilled in the end of a bolt and filled with 95% ethanol. Both treatments were at least as attractive and often more attractive to damaging species than ethanol baited traps. Furthermore, bolts were much more selective having reduced bycatch compared to traps making them easier for growers to determine presence of damaging species. Bolts also have potential as part of an interception strategy to improve efficacy of insecticide treatments against ambrosia beetles.
4. Improved substrate models lead to higher precision irrigation. Specialty crops are increasingly being produced in containers for controlled environment agriculture. Growing media comprised primarily of pine bark or sphagnum peat are utilized in these container systems. The amount of water retained in the media for plant use and the daily wetting and drying that dictates irrigation remains a figurative ‘ black box’. A comprehensive model to understand the amount of water applied, retained, and lost from growing media was developed and validated by ARS researchers in Wooster, Ohio. The model not only provides a lower cost method to analyze the properties of newly developed growing media, but also provides guidance on how to deliver more precise irrigation and avoid excess runoff of water containing agrichemicals. Precision irrigation from these models will benefit specialty crop growers and consumers by reducing production costs and reducing the potential for irrigation runoff adversely affecting sensitive ecosystems.
Owen Jr., J.S., Lebude, A.V., Calabro, J., Boldt, J.K., Gray, J., Altland, J.E. 2019. Research priorities of the environmental horticultural industry founded through consensus. Journal of Environmental Horticulture. 37(4):120-126.
Meng, Q., Boldt, J.K., Runkle, E.S. 2020. Blue radiation interacts with green radiation to influence growth and predominantly controls quality attributes of lettuce. Journal of the American Society for Horticultural Science. 145(2):75-87. https://doi.org/10.21273/JASHS04759-19.
Shreckhise, J.H., Owen, J.S., Eick, M.J., Niemiera, A.X., Altland, J.E., White, S.A. 2019. Dolomite and micronutrient fertilizer affect phosphorus fate in pine bark substrate used for containerized nursery crop production. Soil Science Society of America Journal. 83(5):1410-1420. https://doi.org/10.2136/sssaj2018.12.0493.
Altland, J.E. 2019. Efficacy of preemergence herbicides over time. Journal of Environmental Horticulture. 37(2):55-62.
Ranger, C.M., Werle, C.T., Schultz, P.B., Addesso, K.M., Oliver, J.B., Reding, M.E. 2019. Long-lasting insecticide netting for protecting tree stems from attack by ambrosia beetles (Coleoptera: Curculionidae: Scolytinae). Insects. 11(1):8. https://doi.org/10.3390/insects11010008.
Rassati, D., Contarini, M., Ranger, C.M., Cavaletto, G., Rossini, L., Speranza, S., Faccoli, M., Marini, L. 2019. Fungal pathogen and ethanol affect host selection and colonization success in ambrosia beetles. Agricultural and Forest Entomology. 22(1):1-9. https://doi.org/10.1111/afe.12351.
Shreckhise, J.H., Owen Jr, J.S., Eick, M.J., Niemiera, A.X., Altland, J.E., Jackson, B.E. 2020. Dolomite and micronutrient fertilizer affect phosphorus fate when growing crape myrtle in pine bark. HortScience. 55(6)832-840. https://doi.org/10.21273/hortsci14558-20.
Reding, M.E., Ranger, C.M. 2019. Attraction of invasive ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) to ethanol-treated tree bolts. Journal of Economic Entomology. 113(1): 321-329. https://doi.org/10.1093/jee/toz282.
Fields, J.S., Owen Jr, J.S., Stewart, R.D., Heitman, J.L., Caron, J. 2020. Modeling water fluxes through containerized soilless substrates using HYDRUS. Vadose Zone Journal. 19(1):e20031. https://doi.org/10.1002/vzj2.20031.
Poudyal, S., Owen Jr, J.S., Fernandez, R.D., Cregg, B. 2020. Sensitivity of Hydrangea paniculata plants to residual herbicides in recycled irrigation varies with plant growth stage. Water. 12(5):1402. https://doi.org/10.3390/w12051402.
Majsztrik, J., Owen Jr, J.S. 2020. Improving nutrient management in the cultivation of ornamental plants in greenhouse, container and field production (Chapter 11). In: Marcelis, L. and E. Heuvelink. Achieving sustainable greenhouse cultivation. Burleigh Dodds Science Publishing, Cambridge, UK. 23 pp.
Esquivel, C., Martinez, E., Baxter, R., Trabanino, R., Ranger, C.M., Michel, A., Canas, L. 2020. Thiamethoxam differentially impacts the survival of the generalist predators, Orius insidiosus (Hemiptera: Anthocoridae) and Hippodamia convergens (Coleoptera: Coccinellidae), when exposed via the food chain. Journal of Insect Science. https://doi.org/10.1093/jisesa/ieaa070.
Samarakoon, U., Palmer, J., Ling, P., Altland, J.E. 2020. Effects of electrical conductivity, pH, and foliar application of calcium chloride on yeld and tipburn of Lactuca sativa grown using the nutrient–film technique. HortScience. https://doi.org/10.21273/HORTSCI15070-20.
Bell, N., Stoven, H., Owen, J.S., Altland, J.E. 2019. Cold hardiness of Grevillea in western Oregon. HortTechnology. 30(1):117-121. https://doi.org/10.21273/HORTTECH04377-19.
Liu, Q., Sun, Y., Altland, J.E., Niu, G. 2020. Morphological and physiological responses of Cornus alba to salt and drought stresses under greenhouse conditions. HortScience. 55(2):224–230. https://doi.org/10.21273/HORTSCI14460-19.
Yafuso, E., Fisher, P., Bohorquez, A., Altland, J.E. 2019. Water and air relations in propagation substrates. HortScience. 54(11):2024–2030. https://doi.org/10.21273/HORTSCI14145-19.
Jahromi, N., Fulcher, A., Walker, F., Altland, J.E., Wright, W., Eash, N. 2018. Evaluating on-demand irrigation systems for container-grown woody plants grown in biochar-amended pine bark. HortScience. 53(12):1891-1896. https://doi.org/10.21273/HORTSCI13541-18.