Checklist for Assessing and Mitigating Runoff in Greenhouses and Nurseries

Transcription

1 Checklist for Assessing and Mitigating Runoff in Greenhouses and Nurseries The following checklist provides a basis for self-assessing potential runoff in greenhouse and nursery sites, as well a checklist of management goals (MGs) and management practices (MPs) that can be used for mitigation. Please fill out this questionnaire as completely as possible. The first section concerns general information regarding your operation. The nature of your operation and the types of crops that you grow can dictate some of the problems you may face in controlling runoff and leaching from your property. The rest of the questionnaire is the checklist, which is divided into sections based on management goals and the related management practices. If you do not understand a management practice question or require further information to complete the questionnaire, review the explanatory narratives provided under the corresponding management goal. If a question is not applicable to your operation, check the NA box. However, please consider carefully before checking NA because some practices are always applicable to nursery operations. For example, unless there are nurseries with no pest problems, the management practice of monitoring crops for pests would always be applicable. Answering no to any question indicates a management practice that you may need to consider. Answering no does not necessarily suggest that nonpoint source pollution is occurring or imply a violation of water quality. However, you may be able to further reduce potential runoff and groundwater contamination by implementing this management practice in the future. This checklist was designed to be applicable for a wide variety of operations and crops including container nurseries, field soil nurseries, and greenhouse operations, and to cover runoff issues across locations and climates. When considering the implementation of additional management practices, always consider local and crop-specific recommendations. Your participation is appreciated and important for documenting the positive practices adopted by the industry. Contact your local cooperative extension office for more information on good management practices. Julie Newman, Floriculture and Nursery Crops Advisor University of California Cooperative Extension 669 County Square Drive Ste 100, Ventura, CA Phone: 805/ jpnewman@ucdavis.edu

2 GENERAL OPERATION Larger operations that use greater volumes of water may have a higher potential to create runoff. Operations that do not use all the property space for production may have more options for managing runoff such as reuse on landscaped areas or construction of collection ponds. Nonproduction areas must also be managed to avoid contributing contaminants to runoff or creating runoff. Plant type may affect runoff potential based on moisture and leaching requirements. The amount or type of required chemical inputs for specific plants, such as fertilizers and pesticides, can affect contaminants that may be found in runoff. Indoor greenhouse operations may have different runoff issues than do outdoor nursery or shadehouse operations. Greenhouses must assess roof runoff management and the use of shading compounds; outdoor nurseries may need to assess soil erosion. Container operations may have different runoff issues than do in-ground operations, depending on various factors such as irrigation frequency, irrigation efficiency, and soil/media properties. For example, a container nursery may have a higher surface water runoff potential, whereas a nursery with in-ground production may have a higher subsurface leaching potential. Sediment from erosion may be the main source of pesticide runoff in an in-ground operation, and spilled potting soil may be the main source in a container nursery. Permeable surfaces are less prone to runoff, though groundwater infiltration may be a problem. Many ditches and drainage structures are part of a storm water system and may drain to water bodies. A higher potential to contaminate water bodies exists when a growing operation is located adjacent to streams, lakes, naturally occurring or constructed wetlands, or other waterways. In addition, an operation s runoff may be subject to greater scrutiny by regulators if it flows directly into impaired waters. DATE: NURSERY LOCATION (State, County): Circle acres (ac) or square-feet (ft 2 ) below: 1. How large is the area in production? 1. ac/ft 2 total production 2. How large is the entire operation? 2. ac/ft 2 total property 3. What types of plants are produced and how large is the area in production for each type? 4. What types of indoor or outdoor operations are there and how large are they? 3. ac/ft 2 4. ac/ft 2 ac/ft 2 ac/ft 2 ac/ft 2 ac/ft 2 ac/ft 2 cut flowers potted plants for indoor use bedding plants and other annuals woody ornamentals herbaceous perennials, ornamental grasses propagation (e.g., flower seeds, cuttings, plugs, tissue cultured material for use by other growers) greenhouse ac/ft 2 shade house or hoop house most or all of the year ac/ft 2 uncovered but overwintered in house ac/ft 2 uncovered year-round 2

3 5. What types of container or in-ground operations are there and how large are they? 5. ac/ft 2 container ac/ft 2 pot-in-pot ac/ft 2 field-grown and dug ac/ft 2 field-grown and cut ac/ft 2 hydroponic Indoor floor surfaces: 6. What types of floor surfaces are used in indoor production? (Check all that apply.) 6. cement plastic weed cloth bare soil gravel, shells, mulch, pervious concrete or other permeable paving other N/A (no indoor production areas) Outdoor floor surfaces: 7. What types of floor surfaces are used in outdoor production? (Check all that apply.) 7. cement plastic weed cloth bare soil gravel, shells, mulch, pervious concrete or other permeable paving other N/A (no outdoor production areas) 3

4 8. What types of irrigation systems are used? Estimate the percentage of each type. 8. % low volume (drip stake, drip tape, other microirrigation) % hand water % capillary (ebb-and-flow, flooded floor, or capillary mat) % overhead (sprinkler, boom, water cannon, center pivot, traveling gun) 9. Estimate the percentage of total production acreage on a water recycling system or systems (if any). 9. % recycled 10. Does your operation drain into open surface water or any engineered or constructed drainage or flood control systems? 10. Yes No 11. If yes, indicate the types of water bodies and drainage systems your property drains into. 11. creek or river wetland pond drainage ditch or storm drain constructed wetland impoundment (basin) other 4

5 A. IRRIGATION MANAGEMENT GOALS AND MANAGEMENT PRACTICES Management Goal A.1: Design or retrofit your irrigation system for improved irrigation uniformity and efficiency to reduce runoff and leaching. Irrigation system performance can be measured by irrigation efficiency (how much of the applied water is used by plants) and uniformity (the capability of an irrigation system to evenly deliver water). Determining irrigation uniformity is an important step in limiting runoff and groundwater contamination. A system with low uniformity will typically overwater some plants to provide adequate water to other plants. Irrigation system audits can be done by the nursery operator, but it is often easier to have it done by professionals. Discharge from sprinkler heads or microirrigation devices should be collected to quantify irrigation uniformity and rate and diagnose problems of clogging. Pressure measurements should be taken at key locations in pipelines and tubings to characterize the system pressure distribution. Pressure typically controls the discharge rate so maintaining appropriate system pressure increases the overall irrigation uniformity. Operational conditions of the irrigation components such as valves, gauges, and filters should also be noted. Based on irrigation audits, irrigation systems can be retrofitted for improved performance. Some overhead systems (including impact sprinklers, traveling gun, and water cannons) are more prone to creating runoff due to high susceptibility to wind and evaporation losses. If necessary, other irrigation methods should be implemented to more efficiently deliver water such as booms, drip, or subsurface systems. To maintain uniform pressure in drip irrigation systems, use emitters that minimize pressure differences or use pressure compensating emitters; in overhead systems, flow control nozzles can be used when pressure is too high or variable. Runoff will be greater and occur more quickly on sloping ground. When growing on slopes, design your system to compensate for pressure differences at the top and bottom of the slope. Emitters with different flow rates should not be combined in the same watering zone to maintain good uniformity. Emitter flow rates must be correlated with plant types and container size as flow rates that are too high will apply water faster than plants can absorb and runoff will result. Use appropriate and uniform nozzle sizes; use sprinkler heads with a high uniformity rating and space them appropriately for optimal distribution uniformity. A.1.1. Do you conduct in-house irrigation audits or use professional services to determine the uniformity and efficiency of the system and make appropriate adjustments based on these audits? A.1.2. If irrigation uniformity remains low after all practical improvements have been made, have you considered converting to an irrigation system with the potential of high uniformity? A.1.3. Do you use pressure regulators where appropriate? A.1.4. Do you use emitters that minimize pressure differences or pressure compensating emitters? A.1.5. When using overhead or impact systems, do you use flow control nozzles when pressure is too high or variable? A.1.6. When growing on slopes, do you compensate for pressure differences at the top and bottom of the slope by running the main line vertical to the slope with pressure controllers at each horizontal line junction, and running each subline horizontal to the slope, including a pressure control valve? A.1.7. Do you ensure that each watering zone has spray stake or emitters with similar flow rates and avoid combining emitters with different flow rates in the same watering zone? A.1.8. Do you correlate emitter flow rates for spray stakes and drippers with plant types, media infiltration rates, and pot sizes in each watering zone? 5

6 A.1.9. Do you use appropriate and uniform nozzle sizes? A Do you use sprinkler heads with a high uniformity rating? A Do you use appropriate sprinkler spacing to assure proper overlap to attain optimal distribution uniformity? Management Goal A.2: Regularly maintain your irrigation system so that it continues to operate efficiently. Regular system maintenance includes inspecting and repairing all leaks and replacing worn, outdated, or inefficient irrigation system components and equipment. It also includes flushing and unclogging lines, emitters, and sprinkler heads and regularly cleaning filters. Even if you only hand water, you should regularly inspect for hose leaks and crimps and regularly clean nozzle filters. Keep maintenance records and maintain a regular audit schedule. A.2.1. Do you regularly inspect for leaks in mains and laterals, in irrigation connections, in hoses, or at the ends of drip tape and feeder lines and repair any found leaks? A.2.2. Do you regularly flush and unclog lines and emitters, keeping them free of mineral deposits and biological contaminants such as algae and bacterial slimes? A.2.3. Do you ensure that appropriate filtration is used and regularly clean filters? A.2.4. Do you maintain appropriate pressure throughout the system? A.2.5. Do you regularly replace worn, outdated, or inefficient irrigation system components and equipment? A.2.6. Do you keep maintenance records and update them regularly? A.2.7. Do you have a schedule for regular audits? Management Goal A.3: Regularly manage crops, crop areas, and irrigation systems to avoid applying water to noncropped areas or applying irrigation when not needed. Good irrigation requires applying the correct amount of water to just the locations desired. To reduce runoff when using overhead irrigation, containers should be placed as closely as possible without reducing plant quality due to reduced light. With drip systems, each emitter should be located in a pot to prevent runoff. When containers are moved, such as during harvesting operations or in retail areas, plants should be consolidated and the irrigation should be shut off in unused portions to avoid creating water zones from emitters located outside of the pots. Some emitters such as spray stakes can be "turned off" when not in use. Overhead emitters with check-valves can prevent line drainage and drip damage. The cumulative effect of many emitters creating small individual amounts of runoff can result in large overall runoff volumes. Spray patterns should be checked to ensure water is being applied only to plants, and not to walkways or roads. Hand watering should be performed carefully to avoid overwatering and creating runoff in between pots and on walkways; using an on/off mechanism will help keep water in the pots and prevent watering areas between pots. A.3.1. When spacing plants in areas irrigated with overhead or impact systems, do you regularly place plants as closely together as possible to avoid applying water to noncropped areas? 6

7 A.3.2. Do you manage spray stake and dripper systems to ensure that every emitter is located in a plant or pot? A.3.3. Do you manage harvest operations and retail areas to avoid emitters located outside of pots? A.3.4. Do you consolidate plants and shut off irrigation in unused portions, including spray stakes and other emitters that can be turned off when not in use? A.3.5. Do you use overhead emitters with check valves to prevent line drainage and drip damage? A.3.6. Do you use an on/off valve in hand-watering systems to prevent runoff? A.3.7. Do you check regularly to ensure that spray patterns of overhead irrigation systems uniformly deliver water only to plants, without creating overspray in walkways and edges? Management Goal A.4: Use appropriate irrigation rates and scheduling. Irrigation scheduling should ideally be based and adjusted on environmental conditions and plant moisture requirements. Methods include measuring plant water use by weighing plant containers; estimating evapotranspiration (amount of water loss in a given surface area) using evaporation pans, atmometers, or automated weather stations; and direct measurement of soil moisture in the root-zone of a crop using moisturesensing instruments such as tensiometers. By using multiple sensors to make decisions, irrigation can be set based on time, sunlight intensity or calculations that predict how quickly plants are drying based on changes in humidity and temperature. Plant types or container sizes with similar moisture requirements should be grouped into watering zones as much as possible to avoid overwatering some plants to provide adequate moisture to others. When using overhead irrigation systems, avoid irrigating outdoors in windy conditions that can lead to significant loss of distribution uniformity. Pulse irrigation is the practice of splitting irrigations into smaller increments (e.g., five-minute continuous irrigation changed to applying two, two-minute pulse applications). The goal is to reduce the amount of water applied by irrigating in smaller increments that can be more effectively used by the plants, rather than one larger increment that produces excessive leach rates and runoff. Automatic timers can assist in implementing more complicated irrigation schedules such as pulsing and avoid operator errors associated with manual systems. However, timers must be checked for accuracy and managed to correlate schedules with changing environmental conditions and plant growth stage; irrigation that operates during unsupervised off-hours should be routinely checked. A.4.1. Do you base irrigation scheduling and amount on environmental conditions and plant moisture needs? A.4.2. Do you regularly adjust irrigation schedules to reflect changes in weather, plant needs, or measured soil moisture values? A.4.3. Do you group pot sizes or plant types in watering zones according to moisture requirements? A.4.4. Do you avoid irrigating outdoors in windy conditions unless using drip? A.4.5. Do you use pulse irrigation to split irrigation into smaller increments that can more effectively be used by plants? A.4.6. When automatic timers are used, do you check regularly for accuracy and adjust to correlate scheduling with changing environmental conditions and plant growth stage? 7

8 Management Goal A.5: Provide appropriate training for personnel involved in irrigating in a language that personnel clearly understand, and maintain records documenting training. Provide appropriate employee training in irrigation management in a language that employees clearly understand. Training should include irrigation scheduling, application practices, system evaluation and maintenance, and runoff management. Assign irrigation duties only to trained employees who will carefully monitor plant moisture requirements. Establish and maintain records of personnel training provided. A.5.1. Do you provide training to ensure that irrigation duties are performed only by personnel who understand and practice appropriate irrigation scheduling, irrigation application practices, and crop management practices related to runoff management? A.5.2. Do you ensure that appropriate personnel are trained in proper irrigation system maintenance procedures and recordkeeping? A.5.3. If in-house irrigation audits are performed, do you ensure that personnel are trained to evaluate irrigation systems correctly and regularly? A.5.4. Do you keep records of employee training and maintain them for at least 5 years? B. NUTRIENT MANAGEMENT GOALS AND MANAGEMENT PRACTICES Management Goal B.1: Evaluate irrigation water, soils, growing media, and plant tissue to optimize plant growth and avoid overfertilization. Fertilizer application is essential to commercial floriculture and nursery production, but it also can be an environmental issue. Inefficient fertilizer use can be a significant source of nitrogen and phosphorus that can harm water quality. It is important for growers to understand and implement practices that minimize the loading of these nutrients into surface waters and groundwater. A water quality management program begins with knowing what is in your irrigation water before it is applied. In addition to monitoring the ph and salinity hazard of irrigation water, growers should have water tested for other constituents that become toxic to plants if they accumulate, such as boron. Regularly testing irrigation water quality maintains good plant health and avoids problems associated with poor water quality. Furthermore, if well water is used on-site for human consumption, well water should be regularly tested for contamination from fertilizers. Simple testing equipment can be used to test parameters such as EC, ph, and nitrate-nitrogen. Nutrients already present in the irrigation water should be considered in fertilizer management: irrigation water can be a significant source of calcium, magnesium, and sulfur. In addition, some water sources contain enough nitrogen to be a significant fertilizer source. Overfertilization and resulting high levels of nutrients in runoff and leachates can be minimized with sound nutrient management. Soil or growing media testing should be conducted regularly and used for making fertilizer management decisions; over-fertilization can result if nutrients already present are not taken into account. It is generally recommended that the chemical properties of media be tested whenever a new formulation of a mix is used, and at regular intervals during crop production. Plant tissue testing can also be a useful tool for diagnosing nutrient deficiencies and monitoring fertilizer practices. Although the nutritional requirements of most ornamental crops are not well defined, there are general guidelines for some crops that can be utilized. Fertilizer levels should be monitored in fertigation water to ensure that injectors are operating properly. Water quality and fertilizer use records can assist in the proper management of nutrients. B.1.1. Do you monitor the quality of your irrigation source water seasonally or annually, analyzing for levels of constituents such as bicarbonates (HCO 3 - ), sodium (Na), chloride (Cl - ), nitrate (NO 3 - ), boron (B), soluble salts, and ph? 8

9 B.1.2. If well water is used on-site for human consumption, have you tested the well water regularly for contamination from fertilizers? B.1.3. Do you maintain records of irrigation source water quality? B.1.4. Do you consider nutrients already present in your irrigation water, recovered runoff, composts, manures, and previous fertilizer applications in fertilizer management decision making? B.1.5. Do you regularly test soil or growing media for nutrients, soluble salts, and ph? B.1.6. Do you test plant tissue to determine concentrations of macro- and micronutrients? B.1.7. Do you use information and recommendations from soil, growing media, and plant tissue analyses in fertilization management? B.1.8. When available, do you use nutrient recommendations for your specific crop? B.1.9. Do you regularly test fertigation water to monitor fertilizer levels and ensure that injectors are operating properly? B Do you maintain records of fertilizer use? Management Goal B.2: Conduct efficient fertilizer and leaching practices. Nitrogen is often applied in excessive amounts to ornamental crops. Although some crops will take up some excess nitrogen, the unneeded nitrogen moves easily in water and soil particles. In mineral soils, phosphorus often chemically binds to soil particles, so that the dominant movement of phosphorus off-site will frequently be with eroded soil sediment moving with runoff water. However some soils have a lower phosphorus-fixing capacity, which can result in the phosphorus dissolved in water moving offsite in concentrations of environmental concern. In contrast, the solubility of phosphorus in soilless container media is relatively high, especially in acidic media, and phosphorus can be easily leached out of containers by rainfall or excessive irrigation. Incorporated fertilizers must be thoroughly mixed and evenly applied at correct rates to provide good nutrition and avoid leaching. Composts and manures that are not thoroughly composted may contribute bacteria and other contaminants to runoff. Top-dressed fertilizers must be carefully applied to keep granules in the pot or around the plants at the correct rate. Highly soluble liquid fertilizers are easily leached and must be carefully managed to minimize runoff. Controlled-release fertilizers can greatly reduce nitrogen losses if they are applied correctly. A limitation of controlled-release fertilizers is that application of nutrients cannot easily be varied according to crop needs. The likelihood of nitrogen leaching losses from controlled-release fertilizers is greatest in the first few weeks after planting, when plant root systems are limited, nutrient demand is low, and plants are consuming relatively small amounts of water. Fertilizer management that provides nutrients at appropriate growth stages will result in better plant nutrition and minimize nutrient losses to the environment. Salt accumulation in soil or container media can decrease yield and crop quality, although different plants have different tolerances to salts. Leaching is generally necessary to flush excess salts from the root zone. Excessive leaching or leaching performed too frequently will contribute to runoff and groundwater contamination. The electrical conductivity (EC) of leachate or root media can be monitored with simple equipment in order to determine the need for leaching. Use of high fertilizer concentrations may require more leaching to avoid build-up in containers. The optimum amount of leaching is 10 15%. This means 10 15% of the water applied runs through the container or root zone. Taking the time to measure the actual amount of leachate will demonstrate how easy it is to apply excess water that causes excessive leaching. Excessive leaching represents wasted water, fertilizer, and greater runoff volumes to manage, as well as potential groundwater contamination. B.2.1. Do you incorporate solid fertilizers in a manner that optimizes nutrient availability to growing roots? 9

10 B.2.2. When using composts or manures, do you ensure that they are thoroughly composted before application? B.2.3. Do you carefully apply top-dressed fertilizers to keep granules in the pot or around the plants at the correct rate? B.2.4. Do you ensure that injected fertilizers are carefully mixed and applied at the correct rate? B.2.5. Do you calibrate fertilizer injectors to accurately deliver liquid fertilizer through the irrigation system? B.2.6. Do you use slow-release or controlled-release fertilizers? B.2.7. Do you time fertilizer applications with environmental parameters and the growth stage of the plants? B.2.8. Do you flush excess salts from the root systems by using carefully managed leaching practices? B.2.9. Do you use the electrical conductivity (EC) of root media or leachate water to determine leaching practices? B Do you set irrigation schedules to perform appropriate leaching by turning the fertilizer injectors off (using clear water) at set irrigation events or by applying the appropriate leaching fraction with fertilizer water at each irrigation? B Do you measure the amount of leaching that occurs and ensure that only 10 to 15% of the water applied runs through the container? Management Goal B.3: Avoid fertilizer material spills during all phases of transport, storage, and application. All nurseries should have a plan for dealing with fertilizer spills ground water contamination can result even from a small fertilizer spill. Fertilizers should be stored in a manner that prevents their direct entry into groundwater or surface water, complying with local, state, and federal guidelines. They should be placed in covered and secure locations to prevent direct contact with water from rainfall or irrigation, and should be kept as far as possible from wells or surface water. The storage area should provide secondary containment to prevent movement of fertilizers in the event of a spill. The secondary containment should have an impermeable floor, as well as waterproof curbs around the storage area. Fertilizer storage tanks should also have secondary containment. Mixing and loading fertilizers should be conducted on an impermeable surface such as a concrete pad, where you can retain, collect and reuse most spilled fertilizer. Small quantities spilled in the mixing and loading area regularly in the same place can build up in the soil and eventually reach the ground water. All fertilizer operations should be performed at least 100 feet downslope of a well. Ensure that fertigation equipment is calibrated and tanks are free of leaks. Be careful not to spill fertilizers when transporting or transferring them, and display appropriate placards on vehicles. When applying fertilizers in the field from a tractor or rig, shut off fertilizer applicators during turns and use check valves when possible. In the event of a spill, promptly sweep up dry fertilizer and return it to the storage container, or place it in a properly labeled sealable container. Liquid spills can be recovered by pumping the solution into labeled tanks for reuse. Fertilizer bags should be disposed in trash bins with lids. Make sure injected fertilizer does not backflow into wells or other water sources. Backflow prevention devices should be tested annually, and the date and results of the tests should be recorded and saved. B.3.1. Do you have a plan for dealing with fertilizer spills? B.3.2. Do you store fertilizers in a storage structure that complies with local, state, and federal guidelines? 10

11 B.3.3. Do you locate fertilizer storage and mixing areas as far away as possible from water conveyances (streams, creeks, and storm drains)? B.3.4. In the fertilizer storage facility, do you include a concrete pad and curb to contain spills and leaks that is protected from rainfall and irrigation? B.3.5. Do you equip fertilizer tanks with secondary containment to contain spills and leaks? B.3.6. Do you conduct fertilizer mixing and loading operations on an impermeable surface such as a concrete floor in a covered area or where potential for runoff is low? B.3.7. Do you perform fertilizer operations at least 100 feet downslope of a well or other water supply? B.3.8. Do you regularly verify that fertigation equipment is properly calibrated and fertilizer solution tanks are free of leaks? B.3.9. When transporting fertilizer, are you careful not to overfill trailers or tanks, being sure to cover loads properly and display appropriate placards on vehicles? B When transferring fertilizer into on-farm storage or into a fertilizer applicator, do you ensure that you do not allow materials to spill? B Do you immediately clean up fertilizer spills according to a predetermined protocol? B Do you use check valves on application equipment? B When applying fertilizer from a tractor or rig in a field, do you shut off the fertilizer applicators during turns? B Have you installed backflow prevention devices, and do you check them at least once a year, recording the date and result of this check? B Whenever you are injecting fertilizer into irrigation water, do you make sure that you do not allow backflow into wells or other water sources? B Do you dispose of fertilizer bags in trash bins with lids? Management Goal B.4: Provide organized training sessions for personnel handling fertilizers in a language that personnel clearly understand and maintain records documenting training. Employees who handle fertilizers should receive training in the application and use of fertilizers, including proper calibration of equipment and safe leaching practices, in a language that they clearly understand. They should also receive training on safe fertilizer transport and storage practices. Assign fertilizer and leaching duties only to trained employees. All employees should receive training on what to do in case of a fertilizer spill. Establish and maintain records of personnel training provided. B.4.1. Do you provide training to ensure that appropriate personnel understand how and when to use fertilizers? B.4.2. Do you provide training to ensure that appropriate personnel understand how and when to leach? 11

12 B.4.3. Do you provide training to ensure that appropriate personnel understand safe fertilizer transport, storage, and disposal practices? B.4.4. Do you provide training for all personnel on what to do in case of a fertilizer spill? B.4.5. Do you keep records of personnel training provided and maintain them for at least 5 years? C. PEST AND AGRICULTURUAL CHEMICALS MANAGEMENT GOALS AND MANAGEMENT PRACTICES Management Goal C.1: Establish an integrated pest management (IPM) program to reduce pesticide use and the potential contamination of groundwater and surface water with pesticides. The best method for mitigating pesticide runoff is to reduce chemical inputs by establishing an IPM program. The backbone of an IPM program is an ongoing monitoring (scouting) program to detect pests (e.g., insects, mites, snails, slugs, pathogens, weeds, and vertebrates) before crop damage. Monitoring records include pest counts, degree of injury, and other data needed to determine pest pressure and pest population trends. Environmental parameters such as temperature and humidity can also be monitored to predict growth of pest populations, including the use of degree-days to predict insect development and computer modeling programs for disease forecasting. Relative estimates of pest population densities are determined from data collected by the scout, and these population densities are compared over time. Economic thresholds are established to determine when the benefit of controlling a pest is worth the pesticide application cost and the associated potential hazards some damage may be tolerated, for example damage on lower leaves of cut flowers, which are removed before flowers are sold to the final consumer. Pesticides are applied only when justified by pest population size and crop damage threshold levels, resulting in fewer pesticide applications and reduced pesticide runoff and drift, in addition to improved plant quality, lower pest management costs, and reduced exposure of workers to pesticides. All personnel who are involved in scouting should be trained to identify pests and damage symptoms and be familiar with pest life cycles. Furthermore, training other employees who handle or walk the crop can increase the inflow of data to the scout when employees communicate pest problems that they see. Accurately diagnosing a problem may require professional assistance before a control action is taken. Always have a diagnosis before treating because applying the wrong treatment can exacerbate the problem and results in unnecessary use of pesticides. When pests become pesticide-resistant, chemical use often escalates. This can be avoided by rotating pesticides with different modes of action. Using the lowest pesticide rate reduces pesticide loads in runoff and helps to avoid pesticide resistance. Spot spraying (spraying only identified areas in the nursery and plant parts where pests reside) and directing spray (spraying towards the part of the plant where the pest resides, e.g., terminals for thrips and lower plant portions for spider mites) can result in reduced pesticide use. The use of adjuvants such as spreader-stickers can also reduce the amount of pesticides applied. To ensure that your control tactics are effective, consult your cooperative extension office for the most recent IPM recommendations for your crops. C.1.1. Do you regularly monitor (scout) your crop for insects, mites, and other nursery pests such as snails and slugs, looking for pests and for pest damage, including disease symptoms? C.1.2. Do you regularly inspect the crop and noncrop areas for weeds? C.1.3. Do you regularly inspect crop and noncrop areas for vertebrate pests? C.1.4. Do you ensure that all personnel who scout are trained to identify disease symptoms and pests commonly found in your nursery and are familiar with pest and pathogen life cycles? 12

13 C.1.5. Do you update training as new pests and diseases are introduced? C.1.6. Do you train other employees who handle or walk the crop, such as irrigators and flower harvesters, to recognize common pests and diseases so they can communicate problems they see to the scout? C.1.7. Do you use diagnostic lab services or other professional assistance to identify unknown pathogens, pests, or growth problems before implementing a control measure? C.1.8. Do you monitor environmental parameters to help predict growth of pest and pathogen populations? C.1.9. When applicable, do you use degree-days to predict insect development and timing of pesticide applications, or computer modeling programs for disease forecasting? C Do you keep records of pest counts, degree of injury, and other data needed to determine pest pressure and pest population trends? C Do you summarize monitoring data collected over time by graphing to illustrate pest population trends, or compare current data with the previous collection period? C Do you base decisions on using pesticides and other control options on monitoring information? C Do you use economic thresholds in deciding when and if chemical pesticides should be used? C Do you use monitoring and threshold data to select the most appropriate control strategies? C Do you use techniques to reduce pesticide use such as spot spraying, direct spraying, applying pesticides at the lowest recommended rate on the label, and adjuvants? C Do you rotate pesticides with different modes of action? C Do you use the most recent IPM recommendations for your crops? 13

14 Management Goal C.2: Use good sanitation and other preventive control techniques to avoid pest problems and maintain a healthy production environment. Pesticide use in the nursery and pesticide loads in the environment can be reduced by practicing preventative control techniques, including good sanitary practices, use of resistant varieties, and proper plant culture. Prevention is the best control method and is critical to any IPM program. Sanitation practices remove pathogen sources before they spread. By heat steaming or chemically treating planting beds and recycled container media before establishing a new crop, pest problems can be eliminated from previous crops. Weeds must be removed because many plant disease vectors and other pests proliferate on weeds. Sterilizing tools between use on infected and highly susceptible crops will help prevent the spread of disease. Keeping hoses off the floor will prevent pathogens from being transferred to the plants. Standing water should also be eliminated to avoid spread of disease or a breeding area for pests. Hand dispensers and foot baths at production house entrances and in propagation facilities can be used to disinfest hands and shoes. All plant material brought into the nursery must be free of pests and diseases. Certified or culture-indexed stock is available for some plant species that are vegetatively propagated and tested to confirm that they are free of specific pathogens. Carefully inspect all new shipments, discarding or treating any that are infested, and quarantine plants prior to introduction to the nursery; also inspect and treat propagation areas. Infested plant material that is discarded should be disposed promptly, in a manner whereby other plants will not become infected by the discarded material. Pest problems can also be prevented by selecting plants that are tolerant or resistant to pests and diseases whenever possible; many pest problems can be prevented by providing good growing conditions to avoid environmental stresses. C.2.1. Do you inspect plant material brought into the nursery to ensure that it is free of pests and diseases? C.2.2. Do you treat or discard infected plant material promptly before introducing it into the growing area in a manner whereby other plants will not become infected by the discarded material? C.2.3. Do you inspect propagation areas and treat or discard infected plants before they are introduced into the growing area? C.2.4. Do you quarantine new plants before introducing them into growing areas? C.2.5. Do you eliminate weeds in the growing environment and noncropped areas? C.2.6. Do you fumigate, heat steam, or chemically treat planting areas and recycled media before establishing new crops to eliminate pests from previous crops? C.2.7. Whenever possible, do you select plants that are tolerant or resistant to pests and diseases? C.2.8. Do you use certified or culture-indexed stock where available and feasible? C.2.9. Do you keep irrigation hose nozzles off the ground to avoid contaminating plants? C Do you avoid standing water in the growing environment? C Do you remove diseased plants, destroying them or treating them in an isolated area? C Do you use hand dispensers and foot baths at production house entrances and in propagation facilities to disinfest hands and shoes, ensuring that appropriate employees use them regularly? 14

15 Management Goal C.3: Where feasible and appropriate, use nonchemical control tactics to reduce overall pesticide use. The use of non-chemical strategies slows the development of pesticide resistance and reduces pesticide pollutant loads that can contaminate the environment. Cultural controls are modifications of normal plant care activities that reduce or prevent pests (e.g., locating susceptible varieties together so you can intensify pest management strategies in this area, and separating new plantings from older plantings to avoid movement of pests to newer crops). Mechanical control tactics reduce pests using methods such as hand-picking, physical barriers, or machinery (e.g., hand-pulling weeds, applying mulch for weed control, and installing screens to exclude insects). Environmental control methods indirectly control pests by manipulating the physical environment (e.g., heat treatments used to control soil-borne pests, altering humidity and temperature to control foliar pathogens, improving drainage and aeration of planting media to prevent pathogenic problems). The use of natural or released predators or parasites to keep harmful pests in check can be highly effective when combined with good management practices and judicious selection and use of chemical agents. Learn to identify naturally-occurring beneficial organisms so that you can watch for them in your monitoring program. Spot spraying and direct spraying can be used to conserve beneficial organisms. Ant control is important when relying on insect parasitoids for pest control because ants often attack and kill beneficial parasitoid insects. C.3.1. Do you incorporate cultural controls (modifications of normal plant care activities) to reduce or prevent pests? C.3.2. Do you incorporate mechanical controls into your IPM program using methods such as hand-picking, physical barriers, or machinery to reduce or prevent pests? C.3.3. Do you use environmental control methods (manipulating the physical environment to reduce pests and prevent damage)? C.3.4. Are you familiar with the beneficial insects and mites that naturally occur in your growing area? C.3.5. Do you monitor populations of beneficial insects and mites (natural or introduced)? C.3.6. When beneficial insects are present, do you consider the effects of pesticides on them and use compatible pesticides whenever possible? C.3.7. Do you use control strategies that conserve beneficial insects and mites such as direct spraying, spot spraying, and reduced pesticide rates? C.3.8. Have you incorporated commercially available beneficial organisms into your IPM program on crops where their use has been demonstrated to be effective? C.3.9. Do you prevent ants from disrupting natural enemies? 15

16 Management Goal C.4: When chemical pest control is necessary, select reduced-risk pesticides to prevent contamination of groundwater or surface water with toxic chemicals. Pesticides should be selected for lower migration-risk based upon site conditions, pesticide label, and hazard warnings. Consider formulation, application timing, runoff potential, and leaching potential. Migration-risk associated with specific pesticides can be checked using online resources, e.g., WIN-PST, a pesticide environmental risk screening tool developed and supported by the USDA-NRCS National Water and Climate Center ( the University of California s PesticideWise website ( the Water Quality Compare Treatments within the University of California IPM Pest Management Guidelines ( or the Pesticide Action Network ( Whenever possible, avoid pesticides that will potentially contaminate surface water and disrupt aquatic life, including organophosphate insecticides (e.g., chlorpyrifos, diazinon); carbamate insecticides (e.g., carbaryl); and synthetic pyrethroids (e.g., cyfluthrin, permethrin, bifenthrin). After application, pyrethroids are strongly adsorbed on soil and organic materials. They will move offsite primarily when the soil or potting media particles have eroded away under the force of storm runoff or irrigation-induced runoff. Therefore, effective steps for mitigating runoff of pyrethroids involve reducing offsite movement of potting mix, associated organic materials, and eroded soil. Be especially careful if your property is adjacent to water bodies in runoff-sensitive areas, select pesticides with low aquatic toxicity and low mobility. In areas where there are shallow water tables, or where soils are permeable or have low organic matter content, avoid the use of groundwater-risk pesticides. Also be especially careful not to apply these types of pesticides in rainy weather. Additionally, choose pesticides that are the most selective for the target pest species, avoiding the use of broad-spectrum pesticides whenever possible. This will enhance natural population control mechanisms and reduce pesticide need as well as protect ecosystems. C.4.1. Do you consider site conditions, pesticide labels, and hazard warnings of migration risk when selecting pesticides? C.4.2. Whenever possible, do you select pesticides that do not potentially contaminate groundwater? C.4.3. Do you avoid the use of groundwater-risk pesticides in rainy weather, in areas of shallow water tables, and where soils are sandy or have low organic matter content? C.4.4. Whenever possible, do you select pesticides that will not potentially contaminate surface water? C.4.5. Whenever possible, do you choose pesticides that are the most selective for the target pest species, avoiding the use of broad-spectrum pesticides? Management Goal C.5: Apply pesticides in a safe manner to reduce pesticide loads and potential runoff. Apply pesticides according to the label and follow environmental hazard instructions. Know the exact location of the area to be treated and the site conditions, including the potential hazard of spray drift or subsequent pesticide movement to the surrounding areas. Schedule pesticide applications to avoid pesticide movement offtarget. Do not apply pesticides before scheduled irrigations, unless the product must be activated by moisture and is so indicated in the label instructions. Control the quantity of irrigation water to limit pesticide movement in irrigation water runoff and percolation. When applying pesticides outdoors, it is important to consider weather conditions (e.g., fog, rain, wind), scheduled irrigation, and pesticide characteristics for potential leaching and runoff. Calibrate pesticide spraying equipment and replace worn nozzles to ensure the best coverage, effective pesticide applications, and accurate application rates. Also check equipment for leaks and malfunction and replace cracked hoses and faulty gauges. Accurately measure pesticides to assure that you are within the label rate and to eliminate disposal problems associated with excess spray solutions. Maintain records of the amount and type of pesticides applied. Use these records to plan future pest control measures and limit pesticide accumulation. 16

17 C.5.1. Do you accurately measure pesticides to assure that you are within the label rate and to eliminate disposal problems associated with excess spray mix? C.5.2. Do you know the exact location of the area to be treated, as well as the potential hazard of spray drift or subsequent pesticide movement to the surrounding areas? C.5.3. Do you apply pesticides according to the label and follow environmental hazard instructions? C.5.4. Do you calibrate pesticide spray equipment to ensure the best coverage and efficacy of pesticide applications and accurate application rates? C.5.5. Do you check equipment for leaks and malfunctions and replace worn nozzles and screens, cracked hoses, and faulty gauges? C.5.6. Do you avoid spraying pesticides outdoors when wind could move them off-target as drift? C.5.7. Do you avoid applying pesticides when rain or scheduled irrigation could move pesticides in runoff and ground percolation? C.5.8. Do you maintain records of the amount and type or pesticides applied? Management Goal C.6: Avoid pesticide spills and leakage during all phases of transport, storage, and application. Leaks or spills can occur during transporting, storing, or while using pesticides. Pesticide storage structures should comply with legal requirements, be fireproof, be located as far away from waterways as possible or at least 100 feet from wells, include a concrete pad and curb to contain spills and leaks, and be protected from rainfall and irrigation to prevent pesticide residues from washing into surface water bodies. Check pesticide labels for special storage instructions. Keep an up-to-date inventory of the pesticides and a spill kit available at the storage facility. A spill kit should include: detergent, hand cleaner, and water; absorbent materials such as absorbent clay, sawdust, or paper to soak up spills; a shovel, broom, dustpan and chemical resistant bags to collect contaminated materials; and a fire extinguisher. Spill kits should also be available at other appropriate sites where pesticides are used. Pesticides should always be transported in the back of a covered truck, and all containers should be secured to prevent breaking or spilling. Pesticides should not be left unattended in a vehicle unless they are in a locked container. Care should be taken when transporting pesticides, transferring them into storage, and transferring them into pesticide application equipment to prevent materials from spilling. Pesticide mixing and loading operations must be conducted on an impermeable surface such as a concrete floor to avoid saturating the soil with pesticide. Perform operations involving pesticides in areas over 100 feet down-slope of a well or other water supply. Whenever pesticides are injected into irrigation water, make sure that you do not allow backflow into wells by use of a mechanical anti-siphoning device or an air gap. Check backflow devices at least once a year. Use check valves on pesticide application equipment and when applying pesticides from a tractor or rig in a field, shut off the nozzles during turns. Regularly verify that pesticide solution tanks are free of leaks. Immediately clean up pesticide spills, and do so according to a predetermined protocol. Always refer to the pesticide product MSDS for information on cleaning up and decontaminating small spill sites. Clean up any spilled potting media that contains pesticide residues. If pesticides are mixed into potting media before potting, concrete curbs or sand bags should be used to isolate these areas so that the potting mix does not get washed away in the runoff. Triple rinse or pressure rinse empty pesticide containers and add the rinse to the spray tank. Do not contaminate nearby bodies of water when disposing of equipment wash water. Apply excess spray mix and rinse water from pesticide application equipment to the crop; do not spray it on bare ground. This will reduce pesticide contamination in non-target areas during the clean up process following application. Dispose of pesticides and pesticide containers according to label instructions and in an environmentally safe manner. 17