(May 13, 2019 Fresno, CA) – Today, Randy Giumarra, the Chairman of the California Fresh Fruit Association (CFFA) Board of Directors announced that Ian LeMay will serve as the new president of CFFA. LeMay will succeed GeorgeRadanovich, who has held the position since 2016 and will be leaving CFFA to promote sound ag labor policy inWashington, DC.
Chairman Giumarra stated “Ian’s appointment is a reflection of our Board’s commitment to establishing long-term leadership for our industry.” Giumarra continued, “Our Board and I have worked closely with Ian over the past four years. We are confident in his abilities and look forward to his leadership. I’d also like to take thisopportunity to thank George for his time, leadership and impact that he has made over the last three years. George’sservice is greatly appreciated by our entire membership.”
LeMay has dedicated his career to supporting and advocating for the continued success of California agriculture. Since 2015, LeMay has served as CFFA’s Director of Member Relations and Communications. From 2011 to 2015, LeMay served as the District Director for Congressman Jim Costa who represents California’s 16th. Congressional District. As District Director, LeMay managed the Congressman’s district staff and advised theCongressman on a number of issues including agriculture, water and transportation. Prior to working for Congressman Costa, LeMay worked as a California Market Specialist for the Lindsay Corporation. LeMay is arecent graduate of the California Agricultural Leadership Program (Class 48).
“I am humbled and appreciate the opportunity to continue to serve the members of the California Fresh Fruit Association in a new capacity,” said LeMay. “I came to the Association four years ago because I believe in its mission, deeply respect its history and see infinite potential in advocating for the permanent fresh fruit growers and shippers of California. I consider myself fortunate to have had the opportunity to observe two great Association leaders in Barry Bedwell and George Radanovich, and thank them for their commitment to bettering our industry. The challenges that face us are many. These have not been easy years for our industry, but I remainconfident in the future of California agriculture and our opportunity to advocate for meaningful policy with aunified voice.”
LeMay will begin his tenure as CFFA President on June 1st. Ian and his wife Molly reside in Fresno with their two children, Emery Rose and Ellison James, and will welcome their third child this August.
ABOUT THE ASSOCIATION
For more than eighty (80) years the California Fresh Fruit Association has been the primary government relations organizationserving the fresh fruit industry. It is a voluntary public policy organization that works on behalf of our members – growers, shippers, marketers and associates – on issues that specifically affect member commodities: fresh grapes, kiwis, pomegranates, cherries, blueberries, peaches, pears, apricots, nectarines, interspecific varieties, plums, apples and persimmons. It is the Association’s responsibility to serve as a liaison between regulatory and legislative authorities by acting as the unified voice of our members. The challenges are. countless for growers, shippers and marketers as they strive to remain viable in an ever-changing market. Increasing regulatory requirements make it difficult to flourish, regardless of the size of the operation.
The Association’s dedicated staff advocates daily in the best interest of our members to ensure that regulators and legislators are using sound science and accurate information when considering laws or rules that will be imposedon industry members. However, aside from the variety of issues the Association works on, there is an important networking component. As each company has its own business interest, the membership as a whole shares acommon, vested interest in the long-term health of tree fruit, fresh grape and berry communities in California.
For the second year in a row, the U.S. Department of Agriculture (USDA) National Agricultural Statistics Service (NASS) is predicting a record California almond crop for the upcoming production year. According to the NASS 2019 California Almond Subjective Forecast issued today, California almond orchards are expected to produce 2.50 billion pounds of nuts this year, up 8.69% from last year’s 2.30 billion-pound crop.1
This forecast comes about two weeks after NASS released the2018 California Almond Acreage Report, which estimated total almond acres for 2018 were up 2% from 2017 at 1.39 million acres. Bearing acres – orchards mature enough to produce a crop – were reported at 1.09 million acres, up 6% from the previous year. Looking ahead, NASS reported preliminary bearing acreage for 2019 at 1.17 million acres, up 7.3% from 2018.2
“I am excited by the future of the California almond industry. As our crop grows, our improvements in technology and innovative practices are growing with us, from advances in pest management that look beyond traditional applications to significant progress in water use efficiency. The Almond Orchard 2025 Goals highlight these successes and drive our industry to press onward towards the California almond farm of the future,” said Almond Board President and CEO Richard Waycott.
The first of two reports for the upcoming crop, the Subjective Forecast is based on opinions obtained from randomly selected almond growers located throughout the state via a phone survey conducted in April and May. NASS asked growers to indicate their total almond yield per acre from last year and expected yield for the current year based on field observations. The sample of growers interviewed is grouped by size of operation, and different individuals are interviewed each year, allowing all growers to be represented. NASS then combines the yield estimates obtained from each grower and extrapolates the information to arrive at the numbers reported in the Subjective Forecast.
While the Subjective Forecast provides early estimates of the upcoming crop after it is set, NASS’s 2019 California Almond Objective Report will provide a more precise estimate as it uses a more statistically rigorous methodology to determine yield. The report’s data is based on actual almond counts and measurements gathered from over 850 orchards throughout the state and includes the weight, size and grade of the average almond sample broken down by both growing district and variety.
The California Almond Objective Report will be released on July 3, 2019, at 11:50 a.m. PDT. NASS conducts the Objective Report, the Subjective Forecast and the Acreage Report in order to provide the California almond industry with the data needed to make informed business decisions.1
USDA-NASS. 2019 California Almond Subjective Forecast. May 2019.2
USDA-NASS. 2018 California Almond Acreage Report. April 2019.
Statement by Mike Wade, California Farm Water Coalition Executive Director: California has always prided itself on cutting-edge ideas. It is the place others turn to for new solutions to old problems. We are currently faced with a choice to continue that tradition of innovation with a fresh approach to water and environmental management or chain ourselves to outdated practices of the past.
Last fall, in a historic first, competing water interests came together to produce a voluntary agreement (VA) that will govern water use, habitat projects, and implement new science-based management practices. The Public Policy Institute of California (PPIC) says the VA would, “increase flows in rivers and the Delta and make major investments in habitat. And perhaps most important, create sustainable funding for these efforts (including fees on water diversions), while improving scientific research on and governance of restoration efforts.”
This agreement is the result of years of collaboration between government agencies, water users and environmental interests, conducting scientific studies and projects that put the new science into practice. The VA takes us out of the slow grind of the existing regulatory process and allows us to use scientific structured decision-making to address problems as we go.
The California Legislature is considering a budget this week with funds specifically earmarked for the VA that could provide additional momentum to this progress. Funding from the voter-approved Proposition 68 will help jump start this science-based process. That would mean choosing science-based rules and voluntary, holistic approaches to problems rather than the outdated regulatory status quo. The PPIC says, “What’s clear is that negotiated solutions to water conflicts are fairer and longer-lasting than top-down regulatory solutions or, worse yet, litigated solutions where judges end up trying to manage water.”
And there’s no reason to cling to the past. It’s clear that the current outdated system isn’t working for anyone. Endangered fish populations continue to struggle; farmers face dwindling water supplies; urban users make continuous cutbacks; groundwater supplies are dangerously depleted; and current policy does not address new challenges we face from climate change.
One of the many things this process has revealed is that helping struggling fish populations takes more than water, which is important, but not the only habitat feature fish need. It takes a combination of water at the right time plus attention to habitat, food supply and predator control.
There are other ingredients essential to this agreement. Under the VA, change happens now. Additional water for environmental purposes and habitat restoration begins immediately. That means we reap the benefits today. The regulatory approach could take decades. Plus, in another important first, agricultural water users will pay fees to implement ongoing environmental projects. While there is a need for initial Prop 68 funding, user fees are critical to long-term success because they are an ongoing source of funding.
In a letter to legislators in support of the VA, a group of statewide organizations, including the California Chamber of Commerce and the Bay Area Council, summed it up this way: “The Voluntary Agreements provide a tremendous opportunity to provide more water for fish, wildlife and habitat restoration and a more reliable water supply for a growing state with climate and water supply challenges. The Voluntary Agreement will replace the policy and legal conflicts that have defined the last three decades. Instead, they rely on a collaborative and adaptive management process that will move the state substantially closer to the coequal goals of providing a more reliable water supply for California and protecting, restoring, and enhancing the Delta ecosystem.”
California must choose. The Voluntary Agreement represents the future and a new path away from a failed regulatory approach.
Statewide Survey by Farm Bureau & UC Davis Finds Farmers Turning to Labor-Saving Crops:
Despite raising wages and increasing benefits, California farmers are failing to find enough people to pick fruits and vegetables and harvest other crops, and they are offsetting this labor shortage by changing to less labor-intensive crops and adding automation. Moreover, farmers are calling on Congress to enact agricultural workforce reform that would allow immigrants to work as guest workers legally in order to help them grow food.
The findings come in a survey of more than 1,000 farmers statewide conducted by the California Farm Bureau Federation in collaboration with the University of California, Davis.The results are consistent with a similar voluntary survey by the bureau in 2017.“
The farm labor supply is declining, and farmers are responding by changing their production practices,” said the study’s co-author, Zachariah Rutledge, a doctoral student in the UC Davis Department of Agricultural and Resource Economics. “These results are important because they show how big of a problem this is for California farmers, and they suggest that the problem is not going to go away in the near future.”
The survey, “Still Searching for Solutions: Adapting to Farm Worker Scarcity Survey 2019,” was co-authored by J. Edward Taylor, professor and vice chair in the same department and affiliate faculty of the UC Davis Center for Poverty Research. This is part of a larger look at the dwindling farm-labor supply conducted by UC Davis researchers.
Taylor recently completed a long-term study showing that fewer young people from Mexico have the need or interest to come to the United States to pick crops.
In the recent survey, 56 percent of respondents reported that they were not able to hire the number of workers they desired at some point during the previous five years. Of those reporting recent labor shortages, 70 percent said they had more trouble hiring people in 2017 and 2018. Among the survey’s other findings:
86 percent of farmers responding to the survey said they had raised wages in efforts to hire enough people
61 percent reported they had hired a farm labor contractor to recruit employees
37 percent said they had adjusted cultivation practices by, for example, reducing or delaying weeding and pruning
31 percent of farmers reported changing the acreage of their main crop, and some of this group reported switching acreage to less labor-intensive crops
In California alone, farmers and ranchers hire nearly 473,000 employees during peak season. Experts calculate, according to the survey, that 50 to 70 percent of the hired workers are not authorized to work in the United States.
Changing worldwide food supply
The findings show the potential for changing the worldwide food supply as farmers move to crops that require fewer human hands to get the crops to market. One farmer commented in the survey, “We have had to abandon berry fields and row crop fields that were good harvest quality due to the unavailability of workers during critical harvest times.” Another farmer reported leaving acres of pole tomatoes and strawberries to rot because there was no one to pick them.
Meanwhile, 57 percent of those who changed crops were planting more crops such as squashes, tree nuts, corn or cotton, which require less labor. Almost three-quarters of farmers cited rising labor costs as the reason for switching to labor-saving technology. More than 50 percent said it was because they didn’t have enough employees. Farmers reported adding technology such as a mechanical harvesters and specialized tractor attachments.
Just under 6 percent of those surveyed said they had enrolled in the federal H-2A work visas program for temporary agricultural workers in the past five years in an effort to bring in more workers, with most saying the temporary visas aren’t practical for small growers.
Farmers also report in this survey, echoing a nationwide trend, that their children do not want to continue in the farming business with the growing challenges of finding workers and making a living.
The Almond Alliance of California has selected Bill Lyons, a third generation farmer from Modesto, as its Member of the Year. The award was announced at the Alliance’s annual convention held in Napa April 30-May 2.
“Bill played a leading role in helping transform the former Almond Hullers and Processors Association into the Almond Alliance with an increased emphasis on advocating for all sectors of the California almond industry,” explained Alliance President Elaine Trevino. “He has been a relentless advocate for the industry and was instrumental in forming the California Almond Industry Political Action Committee, helping to give the industry high visibility among state decision makers. He has also distinguished himself as chair of the Alliance’s Government Relations Committee which provides guidance to the board on critical legislative and regulatory issues impacting the California almond industry.”
Lyons was recently appointed by Gov. Gavin Newsom as Agriculture Liaison in the Office of the Governor, responsible for reporting to the Newsom Administration on a wide range of agricultural and water policy issues. Under Gov. Gray Davis, he served as Secretary of the California Department of Food and Agriculture from 1999 to 2004.
While Lyons has stepped down from his Alliance roles due to his appointment, he remains a strong voice for the California agriculture on issues ranging from water to foreign trade. “Bill understands the complexity of production, food safety, environmental, water and trade issues affecting California agriculture,” said Trevino. “He brings us a seat at the table and provides a much needed balanced perspective to critical policy discussions.” Bill understands the importance of including diversity of opinions in important policy discussions.
During the time he oversaw his family’s 95-year-old farming and cattle ranching operation in Stanislaus County, Lyons has received numerous national and state awards for his environmental stewardship and conservation efforts. The family farming operation produces a wide range of agricultural commodities, including almonds, walnuts, tomatoes, corn, wheat, oats, rye, alfalfa, beans and wine grapes, as well as beef cattle.
Lyons served from 1984-1993 as a director on the Modesto Irrigation District, which serves over 250,000 electrical urban and agricultural and water customers, providing him a unique perspective on the issues facing both agriculture and urban water and electrical customers.
As a conservationist, Lyons has been recognized by the United States Fish and Wildlife Service for his conservation and environmental efforts, and has received the United States Department of Agriculture National Environmentalist Award. He was selected as the western regional finalist for the National Fish and Wildlife Foundation 2010 Conservationist of the Year Award.
Bill’s alma mater, California State University at Chico, honored Bill in 2000 with the Distinguished Alumni Award. He and his wife, Suzy, live in Modesto and have four children and five grandchildren.
Read more about the proceedings of the Almond Alliance’s 2019 convention in the coming issue of Pacific Nut Producer Magazine. Subscribe for FREE today at:
About the Almond Alliance of California
The Almond Alliance of California (AAC) is a trusted non-profit organization dedicated to advocating on behalf of the California almond community. California almonds are an economic powerhouse, generating more than $21 billion in economic revenue and directly contributing more than $11 billion to the state’s total economy. California’s top agricultural export, almonds create approximately 104,000 jobs statewide, over 97,000 in the Central Valley, which suffers from chronic unemployment. The AAC is dedicated to educating state legislators, policy makers and regulatory officials about the California almond community. As a membership-based organization, our members include almond processors, hullers/shellers, growers and allied businesses. Through workshops, newsletters, conferences, social media and personal meetings, AAC works to raise awareness, knowledge and provide a better understanding about the scope, size, value and sustainability of the California almond community. For more information on the Almond Alliance, visit https://almondalliance.org/or check out the Almond Alliance on Facebook, Twitter and Instagram.
Rep. Mike Thompson (D-Napa Valley, CA), the founder and Co-Chair of the Congressional Wine Caucus, announced today that Rep. Dan Newhouse (R-Yakima Valley, WA) has been selected as the new Co-Chair of the Wine Caucus. Newhouse, a lifelong farmer and winegrape grower, represents the premier wine regions of Columbia Valley, Yakima Valley and the Walla Walla Valley. Newhouse will serve as only the fifth Co-Chair of the Wine Caucus in its 20-year history and the first Co-Chair from outside of California.
“Over the years, Mike has built the Wine Caucus into a bipartisan institution on Capitol Hill and an invaluable resource for the 10,000 wineries all across the country,” said Robert P. “Bobby” Koch, President & CEO of Wine Institute. “We are thrilled with the selection of Rep. Newhouse as the new caucus Co-Chair and know that he and Mike will continue to do everything they can to support and grow value-added agriculture like wine. Rep. Newhouse’s vast experience in agriculture in the Pacific Northwest will only strengthen the caucus as it pursues key industry priorities including renewal of the Craft Beverage Modernization Act and opening up critical export markets.”
“When the Congressional Wine Caucus was founded, we had a mission to educate our fellow Members about the strong economic contributions made by grapegrowers and winemakers to our communities and to ensure they have a voice in Congress. I am proud that my new Co-Chair, Rep. Dan Newhouse, is a fellow grapegrower and knows these issues firsthand,” said Thompson. “Together we will continue our mission of advocacy and education in order to support our nation’s incredible wine community from the vineyard to the glass.”
“I am proud to represent the flourishing, high-quality wine region of Central Washington, and I am honored to join my friend and colleague Rep. Mike Thompson to serve as the first Co-Chair of the Congressional Wine Caucus from Washington State,” said Rep. Newhouse. “Mike truly understands the priorities and concerns of the wine community, and I look forward to working with him to ensure that our nation’s wine industry – from winegrape growers to winemakers and sellers – can continue to thrive and grow.”The Congressional Wine Caucus was founded in 1999 to educate Members of Congress on the many benefits and challenges of growing winegrapes and making wine. The Caucus hosts numerous events and policy briefings throughout the year designed to foster collaboration between policy makers and grapegrowers and winemakers with the goal of promoting a vibrant and sustainable American wine industry.
Wine Institute is the public policy advocacy association of nearly 1,000 California wineries and affiliated businesses working at the state, national and international levels to enhance the environment to responsibly produce, promote and enjoy wine. California wineries are responsible for 81% of U.S wine production and more than 90% of U.S. wine exports. They also contribute $114 billion annually to the U.S. economy and create 786,000 jobs across the country of which 325,000 are in California, bolstering economies through hospitality, taxes and tourism and enhancing communities through environmental and social sustainability. See: www.wineinstitute.org.
USDA extended the deadline to May 17 from May 1 for agricultural producers to certify 2018 crop production for payments through the Market Facilitation Program (MFP), which helps producers who have been significantly affected by foreign tariffs, resulting in the loss of traditional exports. USDA’s Farm Service Agency (FSA) extended the deadline because heavy rainfall and snowfall have delayed harvests in many parts of the country, preventing producers from certifying harvested production.
Payments will be issued only if eligible producers certify before the updated May 17 deadline.
The MFP provides payments to producers of corn, cotton, sorghum, soybeans, wheat, dairy, hogs, fresh sweet cherries and shelled almonds. FSA will issue payments based on the producer’s certified total production of the MFP commodity multiplied by the MFP rate for that specific commodity.
“Trade issues, coupled with low commodity prices and recovery from natural disasters, have definitely impacted the bottom line for many agricultural producers,” said FSA Administrator Richard Fordyce. “The MFP payments provide short-term relief from retaliatory tariffs to supplement the traditional farm safety net, helping agricultural producers through these difficult times. Weather conditions this fall, winter and early spring have blocked many producers from completing harvest of their crops, and we want to make sure producers who want to finalize their MFP application have an opportunity.”
U.S. Secretary of Agriculture Sonny Perdue launched the trade mitigation program to assist farmers suffering from damage because of unjustified trade retaliation by foreign nations. FSA implemented MFP in September 2018 as a relief strategy to protect agricultural producers while the Administration works on free, fair and reciprocal trade deals to open more markets to help American farmers compete globally. To date, more than $8.3 billion has been paid to nearly 600,000 applicants.
The MFP is established under the statutory authority of the Commodity Credit Corporation Charter Act and is administered by FSA.
Masked Chafer (AKA white grubs) have been problematic for blueberry growers, particularly in the Central Valley of California. The good news is that researchers and entomologists have come up with both organic and conventional methods treatments for these soil pests. Watch this brief interview UC Cooperative Extension Farm Advisor David Haviland to learn about these options and read more about it in California Fresh Fruit Magazine.
Emission devices or emitters are vital component of drip/microirrigation systems as they control the dripping (emission) of water and fertilizer solution to the plant.Drip emitters basically slow down the flow rate to a “trickle” by dissipating the energy of the flow through frictional resistance.This makes it possible to deliver water and fertilizer solution to the plant in a frequent localized manner and at, essentially, constant rate; and that is the principal advantage of this method of irrigation.
Efficiency of a drip irrigation system refers to the ratio of the water delivered to the plant to satisfy its water requirements to the total applied water.High efficiency of a drip system is usually desired. Emission uniformity (EU) is a prerequisite for the high efficiency of the system as will be explained later.
Though drip systems are designed around EU, emission uniformity of the system is also influenced by the emitter selection.Therefore, the emitter should be selected prior to the initiation of the system design.Changing the emitter choice after completion of the design could degrade the system.Proper selection of emitter enables using smaller diameter laterals, longer laterals or less sub-main lines which means less costly system while maintaining the desired system uniformity and efficiency.
To help you select the appropriate emitter, a discussion of emitters flow characteristics are presented followed by a description of some of the commonly used types of emitters.A guideline for emitter selection is then provided.
Emitter Flow Characteristics
Drip emitters regulate water flow by dissipating the flow energy through frictional resistance.Laminar flow emitters regulate water flow by dissipating energy via friction against the walls of long and narrow path.Microtubes and spiral path emitters are examples of laminar flow emission devices.
On the other hand, turbulent flow emitters regulate water flow by dissipating energy by friction against the walls of the water passage and also between the particles themselves during their turbulent movements.Orifices, nozzle emitters, tortuous path emitters and jets or sprayers are typically turbulent emitters.The drip tapes that utilize orifices are also turbulent flow devices.
Laminar Flow Emitters
In a laminar flow the fluid particles move along parallel paths in layers or laminas.The magnitude of the velocities of adjacent laminas is not the same and liquid viscosity (i.e., resistance to poring) is dominant in controlling liquid movement and suppresses any conditions that may cause turbulence.
Hydraulic investigations showed that in a laminar flow, the flow rate “Q” of the emitter is directly proportional to the operating pressure and a change in operating pressure will produce an equal percentage of change in flow rate, i.e., if (H1/H2) = 1.1, then (Q1/Q2) = 1.1, and a change of 10 percent in operating pressure would result in a change of 10 percent in flow rate.
Therefore, the flow rate through laminar flow emitters is pressure sensitive (i.e., less pressure compensating, see turbulent flow emitters below).It is also temperature sensitive since it is influenced by the changes in viscosity of water which changes with temperature, i.e., the higher the water temperature the lower the water viscosity and the larger the discharge rate Q.Laminar flow emitters are also more susceptible to clogging because of their low flow velocity and their relatively long and narrow flow path.However, laminar flow emitters are inexpensive and with proper system maintenance will have satisfactory performance.These emitters are more suitable for short run laterals, where head loss is not very large and flow rate would not suffer large change between emitters.
Turbulent Flow Emitters
In turbulent flow the particles of the fluid moves in a haphazard fashion in all directions.While the viscosity is dominant with laminar flow, both inertia (that property of matter because of which a force must be exerted on a body in order to accelerate it) and viscosity affect the turbulent flow pattern.
Therefore, for turbulent emitters hydraulic investigations showed that the flow rate Q will vary with the square root of the operating pressure H, i.e., Q1/Q2 = [H1/H2]1/2 , and a change in operating pressure H of 10 percent would produce a corresponding change in flow rate Q of only 5 percent, i.e., if[H1/H2] = 1.10, then Q1/Q2 = [H1/H2]x = [H1/H2]1/2 =1.05.Thus, turbulent flow devices are less sensitive to pressure variations (more pressure compensating) than laminar devices, i.e., the same pressure change will produce much smaller change in discharge rate with turbulent flow emitters than with laminar flow ones.
The practical application of this conclusion is that if all other factors being equal, the length of laterals for turbulent drip tape for a given design uniformity could be longer than those of laminar drip tape while maintaining the same desired value of EU.Where the length of the lateral line is fixed (e.g., by field dimensions) the use of turbulent drip tape, for instance, will result in higher uniformity than laminar one due to less flow rate variation with turbulent flow.Hydraulic investigations also showed that the flow rate, Q, with turbulent flow emitters is independent of viscosity and therefore it is much less affected by water temperature than laminar flow emitters.Moreover, the flow path of the turbulent emitters is wider than that of the laminar flow ones which make them less susceptible to clogging than the laminar flow emitters.
Discharge Exponent, x
The exponent “x” mentioned above is usually referred to as the “discharge exponent”.The value of this exponent is usually close to unity (≈ 0.7 – 0.8) for laminar flow emitters and about 0.5 – 0.6 for turbulent flow emitters.
Coefficient of Variation, Cv
Manufacturing variability is a common industrial phenomenon where no two items are made exactly the same particularly for items of very narrow internal passages such as drip emitters.A minute change in the dimension of these passages could make a significant difference in the emitter discharge rate especially the pressure compensating ones.The coefficient of manufacturing variability for the emitter (Cv) is used as a measure of expected variations in discharge of new emitters from the average discharge, qa, of a particular sample of the given emitters when operated at a constant pressure head.Usually, emitter manufacturers provide the values of Cv for their products.
The discharge rate of representative sample of emitters operating at a given pressure essentially follows a bell-shaped normal distribution curve. Where qais the average emitter discharge, approximately 68 percent of the discharge rates fall within (qa ± Cv) , 95 percent of the discharge rates fall within (qa ± 2 Cv), and 99.7 percent of the discharge rates fall within (qa ± 3 Cv).
This means that for Cv values of 10% (0.10)samples of emitters with qaof 1gph, 68 percent of emitter discharge rate would fall within the discharge range of (qa ± Cv) or0.9 to 1.1 gph, 95% percent of emitter discharge rate would fall within the range of (qa ± 2 Cv) or 0.8 to 1.2, and 99.7 percent of emitter discharge rate would fall in the range of (qa ± 3 Cv) or 0.7 and 1.3 gph respectively.
Also for Cv values of 5% (0.05) samples of same emitters. 68 percent of discharge rate would fall within the discharge range of (qa ± Cv) or 0.95 to 1.05 gph, 95% of discharge rate would fall within the range of (qa ± 2 Cv) or 0.9 to 1.1, and 99.7 percent of discharge rate would fall in the range of (qa ± 3 Cv) or 0.75 and 1.25 gph respectively.
Therefore, the smaller the Cv value of a given sample of emitters the less different, or the more uniform, is the sample and the better the emission uniformity (EU) of water in the field.Table 1 provides the ranges and the common evaluations (classification) of Cv values.
Table 1. Coefficient of manufacturer variability, Cv
A higher Cv values, is used for line-source tubing because it is difficult to keep Cv and price both low.However, because line-source outlets are usually closely spaced the effect of higher Cv value on discharge uniformity is minimized.
Emission Uniformity, EU
Emission uniformity (EU) is a critical characteristic around which drip irrigation system is designed.EU indicates how uniform the system applies water in the field.High EU is a prerequisite for high efficiency.Irrigation efficiency could be expressed as how much of the applied water is added to the plant root zone.
It is not possible to acquire high efficiency with low uniformity, EU, because with low uniformity higher percentage of the field area will receive either less water or more water than the average application needed to satisfy the crop water requirements.To remedy this deficiency more water will need to be applied to the field to satisfy the requirements of the under-irrigated parts of the field.This will result in over-irrigating the rest of the field and that means more water is lost away from the root zone resulting in lower irrigation efficiency.
With high EU, only small percentage of the field will be under-irrigated and the volume of water needed to provide for the under-irrigated parts of the field will be much smaller, the losses will be smaller as well, therefore, the efficiency will be higher.However, it is possible to have a low efficiency with high EU.This is not contradictory to what was previously stated that high EU is a prerequisite for high efficiency. For example, if high EU is achieved in a field but excessive amount of water is applied to that field by applying irrigation water for much longer period of time than scheduled for delivering the estimated water requirements of the crop (i,e., over-irrigation) then, large amount of water will be lost away from the root zone and the irrigation efficiency will be low despite the achieved high EU.
Fig. 1. Typical layout of a microirrigated system
B:Types of Emitters
Emitters are usually grouped according to their flow patterns (e.g., laminar and turbulent flow), wetting patterns (e.g., point-source, line-source, multi-exit emitters), and special functions (e.g., pressure compensating and flushing emitters).Some emitters may combine more than one attribute, e.g., pressure compensating line-source emitter (drip tape).
Flow Pattern
* Laminar & Turbulent Flow Emitters
Turbulent flow emitters have the advantage of being less sensitive to pressure variation (i.e., more pressure compensating), less sensitive to water temperature variations, less susceptible to clogging and allow for longer lateral runs or less pressure variation for the same length of lateral run than laminar flow emitters.Laminar flow emitters are less expensive and more suitable for short-run laterals.On-line, in-line and drip tape come in either laminar or turbulent flow type.Both laminar and turbulent flow emitters may come in standard or pressure compensating type.
Wetting Pattern
*Point-Source and Line-source emitter
Drip irrigation with water discharged from emission points that are rather widely spaced, usually 3 ft or more, is commonly referred to as point-source application.When water is discharged from more closely spaced outlets it is called line-source application.Examples of point-source is on-line and in-line emitters (see Fig’s. 2 & 3).The most common discharge rate of point-source emitters is 1 gph.Other available sizes are 0.5, 1.5, 2.0 gph.Point-source emitters come in standard and pressure compensating models.
On-line emitters are commonly used for irrigating orchards and vineyards.The PE (polyethylene) laterals are usually laid on the ground surface (see Fig. 2).This type of emitters offers the user the advantage of installing an emission device exactly where wanted and the emitters are serviceable.Their disadvantage is that the end user must manually insert each emitter.
In-line emitters or drip lines are similar to on-line emitters but in this configuration they are pre-inserted into the PE tubing at specified intervals during the tubing extrusion process (see Fig. 3).The emitters may be cylindrical or flat “boat shaped”, and are attached to the inner tube wall via a controlled heating/adhesion process.Labor savings for the end user may be substantial since emitters are factory pre-installed.The drawback is that emission devices may exist where not needed, and they are not serviceable. Drip-line may be installed below the surface such that the soil surface may be kept dry.Both on-line and in-line emitters come in regular and pressure compensating types.
Examples of line source are single chamber and double chamber drip of relatively thin tubing, commonly known as “drip tapes” (see Fig. 4).Single chamber tubing has orifices punched or more complex emitters fabricated or inserted at intervals of 2 ft or less along the tubing.Double chamber tubing is a hose that has both a main and auxiliary bore separated by a single wall.Widely spaced inner orifices are punched in the separator wall between the main and the auxiliary bore; for each inner orifice, three to six exit orifices are punched at intervals of 0.5 to 2 ft in the outer wall of the auxiliary bore.
Drip tape may be classified according to their flow pattern as either turbulent or laminar.Turbulent drip tape controls flow rate by means of orifices or tortuous flow paths, while laminar tape utilizes small tubes or capillaries to control flow rate.These two types of drip tape exhibit different flow rate response to pressure variation (as explained earlier) and they are not mutually exchangeable for the purpose of system design.
Water is distributed evenly along the length of the drip tape through emission devices that may be spaced anywhere from 4” to 24” apart.Tube wall thicknesses vary from .004” to .015” (4 mil to 15 mil), emitter flow rates from 0.07 to 0.34 gph, and tube diameters from 5/8” to 1-3/8”.Drip tape is used extensively for irrigating vegetable and field row crops e.g., strawberries and tomatoes.It may be installed above or below the ground, and may be retrieved for multi-season reuse or disposed of at the end of each season.Drip tape is relatively inexpensive and is ready to install without any additional emission device installation labor.
*Sprayer, Jets or microsprinklers(see Fig. 7 & 8)
These are small applicators designed to spray water to cover an area of 10 to 100 ft2.Jets are mounted on risers or stakes (see Fig. 8) and spray water through the air as separate streams that create various foot printpatterns of water in the soil.A variety of patterns are available including full circle, half circle, hi/low trajectory, butterfly, etc.The versatility of patterns provides a great deal of flexibility for the end user to accurately apply water only where wanted, such as enveloping each tree in an orchard without wetting the trunk.Wetted diameter ranges from 10 to 35 ft and discharge rate from 5 to 30 gph.Flow through jets is turbulent with discharge exponent x = 0.5.Jets are commonly used on orchard crops like almond and citrus and on light textured soils.
Special Function
*Pressure-Compensating Emitters
This type of emitters provides varying degree of flow regulation with discharge exponent “x” value ranging from 0.0 to 0.4.For complete flow regulation x = 0.0.Pressure compensating devices may be either laminar or turbulent.In either case, these devices utilize the inlet pressure to modify the flow path size, shape or length.In this way, pressure-compensating devices are able to deliver the correct flow rate over a fairly wide range of inlet pressures, and within that range their flow rates are relatively constant.Pressure-compensating emitters are useful for use in undulating fields.
Pressure compensating emitters suffer from the drawback that the elastomeric material used in their construction has a tendency to change their properties as they age. The following graphs (Fig’s. 9 & 10) show the difference in performance between pressure-compensating and non pressure-compensating emitters.
*Flushing Emitters
This type of emitters is designed to have a flushing flow of water to clear the discharge opening every time the system is turned on.Continuous flushing emitters permit continuous passage of large solid particles whileoperating.Some on-line emitters and drip tape are manufactured with flushing capabilities.
*Multi-Exit Emitters(see Fig. 6)
Some on-line emitters supply water to two or more points through small diameter auxiliary tubing; they are used in orchards where large trees may require several emission points for each tree.They are usually more expensive than single exit emitters.
E.A Guideline for Emitter Selection
The pressure variation within the system and the flow characteristics of the selected emission devices influence the uniformity of water distribution (EU) of a drip/microirrigation system.While the control of pressure variation by proper system design is certainly required, the selection of the emitter device itself is also vital for achieving the desired high EU and high system efficiency (e.g., x & Cv).Moreover, emitter selection is critical for specifying the water treatment and the filtration equipment for the drip system.Filtration requirement for a given emitter is specified by the emitter manufacturer.User preference might also be a factor and personal and local experience may influence the choice of emitter.
However, two very important items to be considered in emitter selection are the percentage area wetted, which is related to delivering the required amount of water to the plant at the design pressure, and the reliability of the emitter against clogging and malfunctioning.
It is recommended to provide a sufficient number of emission points to wet between one-third and one-half of the horizontal cross sectional area of the potential root-zone.Field observations have shown that the density of emission points required to obtain such percentage of wetting can be based on an assumed discharge of 1 gph emitters.For perennial crops, the number of emitters can be increased with the age of the plant and stage of growth.However, the initial pipe network must be designed to meet the needs of the mature plants.It is usually recommended that the filtration process should remove all particles larger than one-tenth the diameter of the emitter passage way.Also, regular flushing of laterals can significantly reduce emitter clogging (see Fig. 11).
Conclusion
Generally, the selection of an emitter depends on the soil to be wetted, plants to be grown and their water requirements, quality of irrigation water and emitter discharge. The cost ofemitter should be also be considered as the average total cost of emitters may amount to about 20-25 percent of the total cost of the system.The following points together with above provided explanations may provide a guideline for emitter selection.
First determine the general type of emitter that best fits the needs of the crop to be irrigated and the area to be wetted, i.e., continuous wetting pattern for vegetable crops where a drip tape could be suitable, on-line emitters for irrigating orchard crops,jets where relatively coarse textured soil prevails or where light water applications with large foot print could be more suitable for the crop requirements.The use of pressure compensating emitters may be advantageous for undulating terrain.
Second, according to the required discharge, spacing, and other field conditions, choose the specific emitter needed, i.e., which drip tape, jet pattern, or on-line emitter could be more fitting for supplying the water requirements of the crop, e.g.,for drip tape, is it going to be for one season, 4 mil, or for several seasons, 25 mil.Third, determine the required discharge (q) and operating pressure head (H) for the average emitter that fits the system design and prevailing conditions (e.g., water quality, soil properties, weather conditions).
It is also important to examine the emitter characteristics described above i.e., x, Cv, filtration requirements.Emitters with discharge exponent (x) closer to 0.5 is more pressure compensating, less sensitive to temperature changes and less susceptible to clogging than the ones with the value of x closer to one. The smaller the Cv value for the emitter the more uniform is water application in the field.Emitters with Cv between 0.03 to 0.05 are expected to provide higher EU and consequently higher system efficiency than the ones with Cv between 0.07- 0.09.
Filtration requirement as stated by the emitter manufacturer should also be considered, the smaller the required mesh number (number of opening per inch) the less susceptible the emitter to clogging.Emitters that require mesh number 160 is less susceptible to clogging than the ones that requires 260 mesh number for filtration.However, the filtration requirements as stated by the emitter manufacturer should be fulfilled.Also, enquire with emitter manufacturers regarding the tolerance of emitter components to chemicals such as acid and chlorine usually used for system cleaning and disinfection.Finally, local and personal experience should be taken into consideration.
For more information, visit www.agridrip.com or contact F.A.Hassan, an irrigation & Soils Consultant at Agro Industrial Management at “fahassan@aol.com“
With the largest pistachio crop ever in the west last year coupled with international trade issues, some might be concerned about prices and how to move such a large inventory; however, American Pistachio Growers (APG) reported that the demand is out there at their annual conference, and APG unveiled some exciting new marketing plans for the coming year, including a new market in India. Watch this brief interview with Judy Hirigoyen from APG, and read more about it in Pacific Nut Producer Magazine.
announced that Ian LeMay will serve as the new president of CFFA. LeMay will succeed GeorgeRadanovich, who has held the position since 2016 and will be leaving CFFA to promote sound ag labor policy inWashington, DC.
