Agriculture in California

The table below shows the top 21 commodities, by dollar value, produced in California in 2017. 's home and apricots ==Specific crops==

Alfalfa Orloff et al., 2009 find Glyphosate use in this crop is driving resistance here. Almonds Almonds contribute a mean of 0.77 pounds N2O-N emissions per acre per year in Mediterranean agriculture systems. Apple The Fuji variety is a recent import from Fujisaki, Aomori, Japan. it quickly became the most produced apple here. Apricot For a common pest see . In 2021 the state harvest was on for a yield of , and at that brought $327,369,000. Drought and heat can significantly reduce the harvest in some years. The Polyphagous Shothole Borer and the associated disease it carries have been a great concern here since their discovery on home avocado trees in LA County in 2012. Hungerford 1923 and Hungerford & Owens 1923 found the pathogen on cultivated barley in the central part of the state and also on H. murinum here. UC IPM provides integrated pest management plans for blueberry (Vaccinium spp.). Broccoli , Salinas Almost all of the country's broccoli is grown here. For an invasive pest of this crop see the painted bug ''''. This is not necessarily a waste product, as it can be useful as fumigant. is a state marketing order representing growers and intermediaries here. The USDA FAS's Market Access Program funds international advertising especially in Canada, South Korea, Japan, China, and Australia. Lasting until early or mid-June every year, this is the second heaviest harvest after Washington. are harvested by hand with the stem (pedicel). and San Joaquin County, near Lodi is the highest producing county. , which became the major industrial crop by the 1920s--but despite the illustration this particular variety was unknown in the mission era.|left The 1870s saw the introduction of improved fruit varieties. In 1873, navel orange plants from Brazil were distributed by the U.S. Department of Agriculture. Luther C. Tibbets and Eliza Tibbets successfully cultivated these in Riverside, leading to widespread planting of the sweet, seedless navel orange, which became the backbone of the California citrus industry. The Valencia orange, introduced in 1876, matured in summer and fall, complementing the winter-ripening navel and providing oranges year-round. The Eureka lemon (from Sicily) and Lisbon lemon (from Spain) were introduced in the same period, offering improved varieties and year-round crops. Grapefruit was introduced from Florida in the 1880s. The completion of major railroads (Southern Pacific in 1877, and the Santa Fe in 1885) and the introduction of ventilated boxcars revolutionized distribution, opening national markets and triggering a planting frenzy in southern California. By 1885, the number of citrus trees in California had grown from 90,000 (in 1875) to 2 million, and to 4.5 million by 1901. The 1890s brought pest control advances (spraying, fumigation) and frost protection (heaters, later wind machines). The University of California established its Citrus Experiment Station in 1907, supporting research and innovation. Cooperative marketing emerged with the formation of the California Fruit Growers Exchange in 1905, later known as Sunkist Growers Inc., which helped standardize and market California citrus worldwide. In the early 20th century California dominated the nation's citrus supply, especially from Los Angeles and Orange counties. Since then the geography has shifted. Florida is now dominant in oranges. By the 1980s, California supplied about 75% of the nation's lemons. It was the second largest orange producer in the U.S., ranked third in grapefruit, and was a major source of limes and tangerines. Today about 90% of the state's citrus production is located in five counties, namely Fresno, Kern, Tulare, Ventura and Riverside. Apart from home gardens, citrus is no longer a factor in Orange and Los Angeles counties. The Mediterranean climate affords a lower rate of post-harvest disease than in some of the world's growing regions, similar to the Mediterranean itself, Australia, and most of South Africa. Postharvest problems that do occur tend to be mostly blue and green Penicillium spp. (See below.) Cotton Gossypium spp. are extensively grown in the Imperial Valley. Despite wide establishment elsewhere in the southwest the San Joaquin Valley did not suffer permanent establishment. UC IPM provides management information. California was an early adopter of Bt cotton, but at a low proportion of acreage. The SJV does not use it at all. However Bt resistance has been slow to develop here and in Arizona and in Texas. In the California/Arizona population Tabashnik et al., 2022 find Cry1Ac resistance and Cry2Ab resistance are common but the causative mutations do not cause Vip3Aa resistance. '''' is common in the Imperial Valley. The southwest water shortage is reducing yield and acreage in the 2020s. Interferometric synthetic aperture radar (InSAR) surveys show this crop is a significant cause of groundwater-related subsidence. and are effective against the complex of '''' and . Ortiz et al., 2017 provides a polymerase chain reaction (PCR) method which differentiates the California race 4 strain from all others based on the gene. University of California Integrated Pest Management (UC IPM) provides practices for its control including Glenn County. Some Pythium spp. are seedborne diseases in cotton. UC IPM provide management information. Several Tetranychus spider mite species are common on cotton here including the Pacific Spider Mite (Tetranychus pacificus), the Two-Spotted Spider Mite (T. urticae) Eradication of the in this and neighbouring states was greatly aided by the deployment of Bt cotton. The eradication program began elsewhere and was extended to the California Cotton Belt in 2007. Dennehy et al., 2011 find bollworm remained 100% susceptible to Cry1Ac and Cry2Ab2 through 2005 here and in Arizona. Pyrethrins are commonly used in this crop. Deynze et al., 2005 performs the first gene flow analysis in California cotton. Lacewings and whiteflies ('''') are common pests of this crop. G. barbadense is grown in a small part of the country including the southern part of this state. Delia platura is a common seed predator of this crop. Limonius spp. are pests of germination and seedling stage. '''' is often confused for other species including some beneficial insects. Spodoptera praefica is a late season pest and rarely an early season pest. '''' spp. affect seedlings. Empoasca fabae is the most common leafhopper in the San Joaquin Valley. Euschistus servus damages bolls. '''' is a pest of seedlings, young plants, squares and early bolls. Caliothrips fasciatus is a pest of the mature plant. The larvae of '''' are pests of bolls and squares. Gryllus spp. are pests of the early stages. Autographa californica is found mostly in May and early June here. '''' is the most common aphid in this crop. '''' is a pest of the young plants. Cucumbers farmer's market From 19972000, the state's acreage varied between bringing in $57,969,000$67,744,000. By 2021 The distant second is Arizona. The detection of the Red Palm Weevil (Rhynchophorus ferrugineus) in 2010 was very concerning to this valuable industry. Oysters, abalone, mussels, channel catfish, rainbow trout, and salmon are farmed commercially. Grapes Lettuce UCCE's Vegetable Research & Information Center provides comprehensive production advice for this crop. Lettuce (Lactuca sativa) is commercially grown in the Central Valley, Central Coast, and deserts (the Imperial and Coachella valleys). It is one of the most labor-intensive crops in the state. Aphids are a major problem for lettuce on the Central Coast. See ' for an important aphid, and ' and '''' for biocontrols. The Beet Armyworm (BAW, Spodoptera exigua) is a polyphagous insect pest in this crop. For a devastating disease see . Okra Okra is not produced in any significant amount here. Imperial County grows the largest number of acres in the state. , 2008 Olives Newton Pierce surveyed olive culture in the state and throughout the country for the United States Department of Agriculture (USDA) in 1897. Olives throughout the state suffer from the introduced Olive Fruit Fly. Neofusicoccum mediterraneum, Diplodia mutila, and D. seriata cause significant disease here. More specific controls than currently available are needed for N. mediterraneum in highly susceptible cultivars, namely Sevillano and Gordal, and early harvest may be needed for D. seriata. The primary goal is to improve the sales of olive oil grown in California. The acreage of table olives declined by 55 percent between 2005 and 2025. Parsley Soil solarization is an alternative to soil treatment with methyl bromide. Stapleton et al., 2005 eliminate almost 100% of annual weeds in this crop with solarization alone. The (CFPA) represent the industry. (Although the CFPA is a separate incorporation, it has always been operated by the CCPA's staff.) The overwhelming majority of the country's peaches are grown here, for sales of $308.3 million. cling deliveries for processing purposes have been on a downward trend for years. From in 2010, delivered tonnage declined to in 2021. Most of the private breeding programs for peach in the country are found in California, with a significant amount of the public breeding also being performed here. In the 1970s that put growers on the "pesticide treadmill" increasing control costs, resistance, and resurgence of previously controlled adversaries. Pear Psylla is one of the most serious of these pests, both due to its speed of insecticide resistance evolution and because it vectors the pear decline phytoplasma. The (Pristiphora abbreviata, not to be confused with the Pear Slug Caliroa cerasi) is a minor pest here and usually easily controlled. Integrated pest management (IPM) has a long history of successful use in this crop. Persimmon California produces of Fuyu persimmons a year. Most persimmons produced in California are seedless. Pistachios Total pistachio acreage increased from between 2002 and 2022 as the hardy trees can thrive with moderately salty water and soil, which is widespread in parts of the Central Valley. Ferrisia gilli is an economically significant pest of pistachio here. F. gilli was formerly known as a California population of F. virgata, only being studied sufficiently to recognize that it is distinguishable from F. virgata due to its severe impact on pistachio and almond in this state. See ' and '. Plums |alt=Picking prunes in Kings County, 1905 96% of the country's prunes and >70% of plums are grown here. Of that, >80% has come from the Sacramento Valley since the 1960s. Pome Pomes grown here include and . For a common disease see . Pomegranates In pomegranate (Punica granatum), Black Heart (or "Heart Rot") is one of the most common diseases, as it is around the world. Rice By 2006, California produced the second-largest rice crop in the United States, after Arkansas, with production concentrated in six counties north of Sacramento. California's production is dominated by short- and medium-grain japonica varieties, including cultivars developed for the local climate such as Calrose, which makes up as much as 85% of the state's crop. Small grains UC ANR (University of California Division of Agriculture and Natural Resources) has a program specifically for small grains. see and . UC-IPM also produces publications specifically for pest management in these crops. Although small grains are not a large part of the overall agricultural productivity of the state, they are important enough in particular locations for ANR to have Extension workers especially for San Diego County, and Sonoma. is an industry initiative which also cooperates extensively with the University of California breeding programs. See for a weed of these crops. Stonefruit Stonefruits are crops of the genus Prunus. Largest harvests by weight are almond, apricot, cherry, peach and plum. So much of North America's stonefruit is grown here that almost all available propagation material is adapted to California specifically. Strawberries Strawberries (Fragaria × ananassa) in the United States are almost entirely grown in California 86% of fresh and 98% of frozen in 2017 with Florida a distant second. The 2017 harvest was worth $3,100,215,000. and consumers. Some towns have annual strawberry festivals, see . The Driscoll's company began with strawberries here and still grows and sells here, and they have since expanded to other states, countries, and types of berries. Cal Poly runs the for both research, and producer education. Labor costs have increased drastically since 2018 especially in this crop, see . Timber Almost 40% of the state is forest, . Tomatoes The Federal Risk Management Agency provides crop insurance for fresh market tomato here, through the regional office in Davis. 90% of FMT here comes from nine counties, San Joaquin County, Merced, Fresno, San Diego, Kern, Stanislaus, Kings, Tulare, and Sacramento. Tomatoes contribute a mean of per year in Mediterranean agriculture systems. Walnuts California walnuts account for nearly all the walnuts grown in the United States. In 2017, walnut production was the seventh most valuable agricultural commodity in California, valued at $1.59 billion in cash receipts. Walnuts contribute a mean of emissions per year in Mediterranean agriculture systems. in some years inoculum from the Sierra Nevadas initiates the state's epidemics. Wheat sown in the fall (autumn) in the valleys suffers from stripe rust carried from wild grasses in the mountains. This is not the only source however, as stripe will also overwinter in Sacramento Valley wheat cover. See . Wine ==Livestock==

Red meat In 2022, California meat production exceeded 181 million pounds of beef, 49 million pounds of pork, and 3 million pounds of mutton. Harris Ranch a ranch and feedlot operation is California's largest beef producer, producing of beef per year in 2010. Fowl In 2024, California's 8,864,000 egg-laying chickens produced 201 million eggs, 2.2% of the US total, while leading states Ohio and Iowa each produced over 1 billion eggs. The domestic fowl industry suffers from avian malaria. (Gallus gallus/G. domesticus) and (Anas platyrhynchos domesticus) are commonly infected, as well as various wild birds. Testing has been done since the Herman group made the first reports of P. relictum infection, in Herman 1951, Herman et al., 1954, and Reeves et al., 1954. (See and '''' for the parasite and vectors, and for testing.) ==Regions==

Central Valley The Central Valley of California is one of the world's most productive agricultural regions. More than 230 crops are grown there. The top four counties in agricultural sales (2007 data) in the U.S. are in California's Central Valley: Fresno ($3.731 billion), Tulare ($3.335 billion), Kern ($3.204 billion), and Merced ($2.330 billion). Its agricultural productivity relies on irrigation both from surface water diversions and from groundwater pumping (wells). About one-sixth of the irrigated land in the U.S. is in the Central Valley. Central Valley groundwater pollution is an ongoing environmental issue in the area. There are 6,000 almond growers who produced more than 1.8 million tonnes in 2013, about 60 percent of the world's supply. Parts of the Valley are quarantine due to an ongoing pest eradication. The area is also a significant producer of organic produce, with 68,868 acres in cultivation and annual sales of $412,347,000. ==Organic farming==

California has more certified organic farms than any other state. In 2016, more than a million acres in the state were certified organic. CA grows 90% or more of the U.S. production of Organic almonds, artichokes, avocados, broccoli, cauliflower, celery, dates, figs, grapes, strawberries, lemons, lettuce, plums, and walnuts. There are two primary laws that regulate organic production: at a federal level, the Organic Foods Production Act of 1990 and at a state level, the California Organic Food and Farming Act of 2016. Both laws lay out standards for production, processing, handling and retailing that must be followed in order to label a product as "organic". The USDA, California Organic Products Advisory Committee, and the California County Agricultural Commissioners monitor and ensure these standards are followed by administering enforcement actions for any violations. Any agricultural operation selling more than $5,000 in products per year is required to acquire organic certification, if they seek to sell their products under the organic label. Multiple organizations are accredited to certify operations organic. ==Environmental and natural resources==

Water use The largest overall water users in California are the environment, agriculture and urban/ municipal uses. In an average year, about 40% of California's water consumption, or approximately , is used for agricultural purposes. However, the exact proportion of total water usage for agriculture varies widely between 'wet' and 'dry' years. In wet years, agriculture is responsible for closer to 30% of total water consumption and in dry years closer to 60%. Water for agriculture comes from two primary sources: surface water and groundwater. Surface waters include natural bodies of water along with a network of human-built reservoirs with aqueducts and canals that carry water from the source to the agricultural users. California is one of the top five states in water use for livestock. Water withdrawals for livestock use in California were /day in 2010. Saudi Arabian companies and individuals have bought land here and in Arizona to benefit from subsidized water. Around 15% of overall alfalfa production goes to exports. Water quality Agricultural impacts on water quality concentrate around concerns of the following contaminants: nutrients, pesticides, salts, pollutants, sediment, pathogens, and heavy metals. These contaminants enter water bodies through above-ground surface runoff of rainwater or excess irrigation water, or percolating through the soil and leaching into groundwater. Water quality concerns affect most regions of the state and tend to be exacerbated during periods of drought. At present, all irrigated agricultural operations in the State are required to participate in the Irrigated Lands Regulatory Program. The regulatory program began after the California Legislature passed Senate Bill 390 (SB390) in 1990, that eliminated a blanket waiver for agricultural operations to discharge wastewater without any specific environmental standards. Water supply A major source for Southern California's water supply, both agricultural and urban, is the Colorado River from which an aqueduct has been built to transport the water from the river to Riverside. Colorado River irrigation is essential for agriculture to the Salton Sea Basin, which supports key agriculturally productive areas such as the Imperial Valley. Another aspect of the agricultural water supply in California is the transfer of water that takes place from northern to southern California. In northern California, the Shasta Dam contains the flow of the Sacramento River, preserving water for California's use, and pumping stations in the California Delta extract water transferring that water across the San Joaquin Valley and southward. A key component to the distribution of the water supply are the irrigation districts and water agencies who are responsible for delegating water as to meet the demand of those within the area as well as clarify and legal arbitration as to water rights. The agency tasked with overseeing the state's water supply and any projects associated with the upkeep of the supply is the California Department of Water Resources (CDWR). As part of the 2019-2020 California Spending Plan, the CDWR received $2.336 billion with $833 million going towards projects overseen by the California Natural Resources Agency and $1.503 billion going towards the control board supervised by the California Environmental Protection Agency. One of the CDWR's major projects is the State Water Project (SWP) which distributes 34% of the water that flows through its various channels. The SWP also is one of the largest suppliers of hydroelectric power in the state. The mussels have continued to spread and present an ever-expanding threat to pipelines. Air pollution In 2014, California agriculture soils contributed to 51% of statewide greenhouse gas emissions. California's Mediterranean climate supports irrigation events such as nitrification which encourage nitrous oxide production. Mean nitrous oxide emissions (the biggest contributor to ozone depletion of all the major agricultural greenhouse gases) have been reported to be "four times higher in irrigated compared to rain-fed systems". Another factor which frequently contributes to increased N2O emissions are warm soil temperatures (a common occurrence in California). ==History==

Pre-1850 Some California hunter-gatherer tribes, including the Owens Valley Paiute, developed irrigation. Native Californians were skilled at gathering materials from plants at all times of the year, allowing the consistent gathering of materials from any and all local plants. Depending on when various plants—including succulents, flowers, and trees—bloomed or became ripe, different aspects of the plant could be accessed or harvested by Native California peoples. . Black oak acorn harvests were increased by cultural burning, which stimulated acorn growth and increased biodiversity in the area. Cultural burning was commonly practiced by throughout California to maintain a healthy landscape that produced quality resources, as the Karuk, Yurok, Hupa peoples all regularly burned areas of bear grass and California hazelnut and to encourage the growth of stronger stems that could be used for basketry. In the late 1700s, Franciscan missionaries established Spanish missions in California. Like earlier Spanish missions established in Baja California, these missions were surrounded by agricultural land, growing crops from Europe and the Americas, and raising animals originating from Europe. Indigenous workers from Baja California made up a large part of the initial labor force on California missions. In the early 1800s, this flow of laborers from Baja California had largely stopped, and the missions relied on converts from local tribes. By 1806, over 20,000 Mission Indians were "attached" to the California missions. As missions were expected to become largely self-sufficient, farming was a critically important Mission industry. George Vancouver visited Mission San Buenaventura in 1793 and noted the wide variety of crops grown: apples, pears, plums, figs, oranges, grapes, peaches, pomegranates, plantain, banana, coconut, sugar cane, indigo, various herbs, and prickly pear. Livestock was raised for meat, wool, leather, and tallow, and for cultivating the land. In 1832, at the height of their prosperity, the missions collectively owned over 150,000 cattle and over 120,000 sheep. They also raised horses, goats, and pigs. The Spanish (1784–1810) and Mexican (1819–1846) governments made a large number of land grants to private individuals from 1785 to 1846. These ranchos included land taken from the missions following government-imposed secularization in 1833, after which the missions' productivity declined significantly. The ranchos were focused on cattle, and hides and tallow were their main products. There was no market for large quantities of beef (before refrigeration and railroads) until the California Gold Rush. 1850–1900 Rapid population growth drove an increase in importation of agricultural products, and, within a few years, a massive growth in in-state agriculture. In the first years of the gold rush, the state relied on agricultural imports arriving by ship, from Australia, Chile, and Hawaii. During these years, there was rapid growth in vegetable farming for local markets. This was followed by an expansion of grain farming. A shift in the economic dominance of grain farming over cattle raising was marked by the passage of the California "No-Fence Law" of 1874. This repealed the Trespass Act of 1850, which had required farmers to protect their planted fields from free-ranging cattle. The repeal of the Trespass Act required that ranchers fence stock in, rather than farmers fencing cattle out. The ranchers were faced with either the high expense of fencing large grazing tracts or selling their cattle at ruinous prices. Irrigation was almost nonexistent in California in 1850, but by 1899, 12 percent of the state's improved farmland was irrigated. Luther Burbank moved to Santa Rosa, California in 1875, and developed numerous commercially successful varieties of plants over the next 50 years. 1900–1950 The 1902 Newlands Reclamation Act funded irrigation projects on arid lands in 20 states including California. In 1905, the California legislature passed the University Farm Bill, which called for the establishment of a farm school for the University of California (at the time, Berkeley was the sole campus of the university). The commission took a year to select a site for the campus, a tiny town then known as Davisville. establishing the right to collective bargaining for farmworkers in California, a first in U.S. history. Individuals with prominent roles in farm worker organizing in this period include Cesar Chavez, Dolores Huerta, Larry Itliong, and Philip Vera Cruz. Through 1995 there were 50,000 Mixtecs every year in California agriculture. They were usually not the only indigenous Mexican ethnic groups Zapotecs and Mayans were also usually working the same jobs. ==Agricultural crime==

California nut crimes have involved the theft of millions of dollars of nuts (almonds, pistachios, cashews and pecans) in multiple incidents since 2013. Water theft for agriculture has been an issue in times of drought, with the State assessing fines up to $1.5 million. ==Pests==

Despite its expansive geography, some pests are so severe, so polyphagous, and/or so wide-ranging as to be economically significant to the entire state. In 2022, 181 million pounds of pesticide were applied in California, treating 92 million cumulative acres. The most used pesticides include sulfur, mineral oils, glyphosate, 1,3-dichloropropene, Lambda-cyhalothrin, Chloropicrin, and Abamectin. The (Amyelois transitella) first entered from Arizona in 1942 and quickly began attacking walnut, date palm, and fig – despite its common name it is only a minor pest of citrus. In the decades since it has become a notorious pest of almond, pistachio, and pomegranate and remains problematic for walnut as well. The moth was confirmed to be present in California in 2007, and spraying programs in 2007–2008 lead to the Light brown apple moth controversy. Tavener et al., 2011 finds novaluron works well but only when carried by horticultural mineral oil. Hosts include strawberry. (Diaphorina citri) are a major invasive threat to citrus. On the other hand, jackrabbits, cottontails, and brush rabbits are a problem for pistachios. The lagomorph biocontrol myxoma virus is epidemiologically endemic in native lagomorphs. olive Olives throughout the state suffer from the introduced (Bactrocera oleae) here. OFF is native to the Mediterranean basin and appears in some of the earliest written documents of human history, and is now found throughout much of the world. '' are common crop pests here. '' is one of the most common, especially for lettuce. In cherry orchards the most common are crows (Corvus brachyrhynchos), crowned sparrows: (Zonotrichia spp.), European starlings (Sturnus vulgaris), house finches (Carpodacus mexicanus), house sparrows (Passer domesticus), scrub-jays (Aphelocoma californica), and (Pica nuttalli''), but also in apple, blueberry, and grape, and the American Robin is a problem for some of these. Probably present since the late 1980s, the GWSS was only confirmed here in 1994. The staff of the does inspections of all material entering the county to prevent that from happening. In 1997 the (BGSS, Graphocephala atropunctata, the primary PD vector) arrived here and the two have combined badly ever since. Besides vectoring PD they are also themselves a sucking pest and Hewitt et al., 1949 found they will often additionally go through reproduction on the vines. A block in Napa suffered a 100% crop loss in 2009 due to a burrowing worm. (Blapstinus fuliginosus), Monitoring and eradication continue especially because of the wide host range of the grubs but also due to the grubs' and adults' destructiveness. but may have been found in northern Marin in early 2014. Himler et al., 2011 find the Rickettsia sp. nr. bellii symbiont rapidly invaded the population of California, Arizona and New Mexico. Aleyrodes spiraeoides is a native whitefly. , central Los Angeles A , Bagrada hilaris was first detected here in 2008 in San Diego, Orange, Los Angeles, 2009 in Ventura, Riverside, and Imperial counties; 2010 in Kern, San Bernardino; no new discoveries here in 2011; 2012 in Santa Barbara & San Luis Obispo; 2013 in Monterey, Santa Cruz, San Benito, Fresno, Tulare, San Francisco; 2014 in Inyo, Kings, Merced, Stanislaus, Santa Clara, Alameda, San Mateo, and Yolo. s are common pests here including the (WTPB, Lygus hesperus). A vacuum collector is often used for WTPB in strawberry, called the BugVac. The (Drosophila suzukii) is a major insect pest of soft body fruits here, peach and nectarine, and blueberry. is a parasitoid which has been successful as a biocontrol here. Other ' species include ' and '''' which vector sour rot and bunch rot pathogens between grape bunches. and strawberry. Turelli et al., 1991 uses a genetically modified Wolbachia to suppress D. simulans to suppress its vectored diseases here. The (Estigmene acrea) is very common here, but usually causes no damage because they are a native pest with many natural enemies acting as biocontrols. SMC can be significant in strawberry. and in 2006. The (Figeater Beetle, Cotinis mutabilis) is occasionally a pest of ripened fruit, including apricot, caneberry, fig, grape, peach, and plum. For s (BAW, Spodoptera exigua) in strawberry and lettuce S. exigua populations here have long standing carbamate resistance. First identified here in 1992 in La Mesa, San Diego County by Haagsma et al., the (Coptotermes formosanus) has been here since at least 10 years prior. In the time since there have been new infestations mostly suspected to be independent introductions in Canyon Lake, Riverside County in 2020, Rancho Santa Fe, San Diego County in 2021, Highland Park, Los Angeles County in 2021. The Formosan Termite is a pest of sugarcane, and citrus, but it is most often a structural pest. s (Diabrotica balteata, Acalymma vittatum, D. undecimpunctata) are common pests here. s (Daktulosphaira vitifoliae) is a perennial aphid problem here. Islam et al., 2013 explains some of the genetic diversity of the population here by sexual reproduction, but their sampling leaves open other possibilities for the remainder. The detection of the (Rhynchophorus ferrugineus) in 2010 was very concerning to this valuable industry. The last sighting was on January 18, 2012. Several ' mosquitoes are common here including ', ', and '. The southern part of the state suffers from the (Spotted Alfalfa Aphid, Therioaphis trifolii). The most common permethrin kdr allele here is kdr-his, although kdr and super-kdr are also present. The (Mexican fruit fly, Anastrepha ludens) has repeatedly invaded the southern part of the state. Sterile insect technique (SIT) has been used to great success to eradicate them every time, both here and in Texas. Studies of the Medfly invasion here show that there have been many almost-invasions at the state's airports and other ports, most of which have failed to establish '''' is a genus of . Two-Spotted Spider Mite is also a major pest of strawberry, s (Aphis gossypii, Melon Aphid) afflict cotton and melon crops here. The (Scirtothrips perseae) and (Oligonychus perseae) are two invasive pests here. The (Chloridea virescens, Heliothis virescens) is common on cotton in the Imperial Valley. (Frankliniella occidentalis) is a major pest of horticulturals around the world. The (Plutella xylostella) is a common insect pest here. Several ' are present. ' is found as an exotic pest here. '''' is an invasive crayfish across the Western US. Lymantria dispar (spongy moth, gypsy moth) is an established pest here. (Aonidiella aurantii) is an invasive pest here. The (Otiorhynchus sulcatus) is mostly found in the Central Coast AVA but does rarely occur elsewhere. '''' (Cribrate weevil) is common in the San Joaquin Valley. Helicoverpa zea (syn. Heliothis zea) is common in several parts of the state including all strawberry growing areas. s occur natively here. Scutigerella immaculata is an introduced pest restricted to high moisture soil. Some slugs (Gastropoda spp.) are vegetable and fruit pests here. European Earwigs are most destructive from April to July here. Eotetranychus lewisi is found in coastal areas including Oxnard and Salinas. is the most common cutworm here. Pandemis pyrusana is present and eats the leaves of several crops. Aedes albopictus is a pest of livestock concern. , eradication ceremony The (Pectinophora gossypiella) was devastating to cotton growers here and throughout the southwest. Chu et al., 1996 reports a management program in the Imperial Valley in which government imposed practices successfully reduced populations. ==Weeds==

Rejmanek & Pitcairn 2002 overview 53 weed eradication campaigns in the state, and find that any infestation smaller than was usually successfully eradicated, while anything which had already reached was essentially impossible to do. (Melilotus officinalis L. Lam.), (Stellaria spp.), (Poa annua Linnaeus), (Capsella bursa-pastoris Linnaeus Medikus), (various Digitaria spp.), (Euphorbia maculata Linnaeus Small), and (Cyperus esculentus) are common weeds here, including in strawberry and parsley. Glyphosate-resistant marestail first appeared in the state in the Central Valley in 2005 and this resistance spread unusually rapidly through the southern Valley thereafter. (Conyza bonariensis, Erigeron bonariensis) is one of the major here. In the Central Valley the most common weeds are cool-season grass weeds (), thistles (Asteraceae), mustards (Brassicaceae), fiddleneck (Boraginaceae), warm-season grass weeds, warm-season Cyperaceae, amaranths (Amaranthaceae), morning glory (Convolvulaceae), and (Tribulus terrestris, Zygophyllaceae). Achmon et al., 2018 dramatically lowered seed bank viability, biomass, and density of all these weeds, and improved tomato yield using biosolarization using tomato and grape crop waste. It was first observed here in 1892 and has since spread to every coast of the state, and into one coastal county of Oregon. Wild beet is only significant in small grains in Imperial, where dicamba and 2,4-D are necessary. See also . (Amaranthus palmeri) was first discovered in San Diego County by Sereno Watson in 1876. In California it is found in all but the northernmost counties. (radish (Raphanus sativus) × Jointed charlock (R. raphanistrum)) has replaced all of its ancestral populations in the state. Di Tomaso and Healy 2007 find Chenopodium album requires years of continuous management for any significant seedbank reduction. ==Pathogens==

Xylella fastidiosa X.fastidiosa was first discovered here by (1856–1916) in 1892. It has ever since remained a constant pathogen of many crops here, Alston et al., 2013 estimates that PD cost the state $92m in 2013 GWSS remains a common vector of PD and as such is a severe drag on the entire continent's wine grape and table grape pricing and supply. These areas are defined by small streams and ornamental irrigation. There are two major divisions here, a lineage from Bakersfield and Santa Barbara and another from Temecula and the north. Zhang et al., 2011 compares a PD strain to EB92-1 and finds that they are surprisingly similar. Vanhove et al., 2020 elucidates the current genetic situation of PD strains here, including population structure and their evolution. Xf in stonefruit Xf is also significant in stonefruit here, causing Almond leaf scorch disease and other diseases. and grape. Fungicides are used multiple times per seasons and as a result resistance to almost every mode of action is common. was first discovered in 2018 in Santa Maria and reported by Mansouripour & Holmes 2020. Bc was not previously known to produce a leaf spot phenotype in strawberry. B. cinerea is a common cause of postharvest losses in this industry. Most B. cinerea inoculum is introduced via aeroplankton. Though gray mold elsewhere may be caused by both B. cinerea and B. pseudocinerea in California B. pseudocinerea is unknown on strawberry. Other pathogens of grape (caused by grapevine red blotch virus, GLRaV-3) costs the state $90 million annually. The seriousness of (Uncinula necator) has been recognized since at least 1859 in the northern grape district. Newton B. Pierce was working in the area a few decades before his discovery of Pierce's Disease, and over the 1860s he watched U.necator spread to the south. The first case of U. necator demethylation inhibitor resistance (DMI resistance) was found in this state in 1980. (caused by Phomopsis viticola) is also a major trunk disease here. Fusarium spp. Fusarium is a genus of many species which are ubiquitous around the world, including here. (Fusarium oxysporum f. sp. fragariae) had only been seen once before, in Queensland, in one sample of Winks & Williams in 1966, until appearing again here in 2006 and identified by Koike et al. 2009. it has spread throughout the state. Henry et al., 2017 apply a Japanese PCR-based test of nuclear ribosomal intergenic spacer and elongation factor 1-α. In early 2012 a previously unknown plant disease (an unidentified Fusarium) and vector (a Euwallacea, preliminarily termed the , PSHB) were detected in Los Angeles and Orange Counties. This is especially a disease affecting avocado growers, but also other crops in this state and in its other invasive range, in Israel. is a disease of . Race 4 is so common here that varieties are screened for resistance before development or deployment. Unlike other strains it does not require a vector, a root-knot nematode. Race 4 isolates here are more pathogenic on Gossypium barbadense than on G. hirsutum. Alternaria spp. Various Alternaria spp. are significant fungal diseases here and often receive strobilurin, iprodione, azoxystrobin, and tebuconazole treatments. is a common pomegranate disease worldwide. Out of the group of causative species, here Luo et al., 2017 find it is caused by A. alternata and ''. Michailides et al.'', 2008 finds the can suffer at a rate of 10% or more here. is common here. It is caused by various species of this genus and relatives including: Ulocladium atrum, A. alternata, rarely other Alternaria spp., Dendryphiella vinosa, and Curvularia spp. Epicoccum purpurascens causes Alternaria of breba only. Candidatus Phytoplasma The phytoplasma (Candidatus Phytoplasma pyri) was first found here in the Sacramento Valley in 1948. Other pathogens causes , a common disease here. The (Aphelenchoides fragariae) and (Meloidogyne hapla) are the two most common here, although RKN is rarely seen by CalPoly Strawberry Center's diagnostic lab. Even rarer are the (Pratylenchus penetrans), (Ditylenchus dipsaci), (Xiphinema americanum), (Longidorus elongatus), (Aphelenchoides ritzemabosi and A. besseyi), and other (Meloidogyne incognita and M. javanica) nematodes. – a soilborne pathogen – is a common cause. Stromatinia cepivora (garlic white rot) was identified in the San Francisco area in the 1930s and Gilroy in the 1940s. It continues to be a problem for garlic growers in the state. (Mycosphaerella rubi, anamorph Septoria rubi) is common here. s (biovars of Verticillium dahliae) are found here as in any other ecozone. This includes . In strawberry, methyl bromide has historically been vital to prevention, and with phase out, this disease is of increasing concern. In all cases some fumigation is necessary, and if fumigation is not possible then solarization and/or rotation are the only remaining options. Note that MB+chloropicrin also provides an uncharacterized growth promoter effect in this crop. Frequent use has produced streptomycin resistance in (Erwinia amylovora) here, first found in the state's pear isolates by Miller & Schroth 1972. This disease is a problem of pomes, including pear. of peach is primarily caused by Armillaria mellea and A. solidipes here. '''' afflicts tomato here. is a phytoplasma of apricot here. (Bremia lactucae) is common on lettuce here. Kim et al., 2015 finds '''' isolates from citrus here have developed fludioxonil resistance, Thiabendazole (TBZ) is also commonly used in citrus here. (Tilletia indica, syn. Neovossia indica) has spread from Asia to this continent, and since 1996 has been found in this country. (Spiroplasma kunkelii) affects corn (maize, Zea mays) here. (Phytophthora ramorum) is a widespread disease of oaks here and in Oregon, and is also found in Europe. and was quickly found in Oregon as well. P. ramorum is of economic concern due to its infestation of Rubus and Vaccinium spp. No tests are available for Phytophthora fragariae var. fragariae. Raspberry ringspot virus is a common pathogen in California. Diagnosis is performed by cross infection of one of the alternate hosts which are herbaceous. Hosts of Strawberry latent C virus include strawberry. Diagnosis of Strawberry vein banding virus is performed by cross infection of an herbaceous alternate host or by PCR. Hosts of Tobacco streak virus include strawberry. Hosts of Xanthomonas fragariae include strawberry. Tomato necrotic dwarf virus is originally known from Imperial County. More than 1 virus is usually present in any strawberry plant which has progressed to symptomatic infection. Lettuce Mosaic Virus has caused severe losses at times up to 100%. ==Insurance==

As with the entire country there is USDA subsidized crop insurance for the state. ==Research, testing, and propagation material==

researcher and Hmong farmer (FPS) is a part of UCD's College of Agriculture which serves the horticultural industries. FPS performs several services including testing for diseases (especially viral diseases), identifying varieties of unknown plant samples, and supplying cuttings (vegetative propagation material) from in situ individuals they maintain. See and . The University of California is one of the two institutions claiming ownership of the CRISPR/Cas9 patent. farmworker learning additional skills in Salinas, 2018 ==Labor==

California farms employed at least 850,000 hired farmworkers in 2024. Many of these were seasonal or part time, with the total paid work equivalent to 420,000 full time jobs. The majority were Mexican-born. Some of these farmworkers are not employed here all year but instead travel to other agricultural employment while California is in the off season. Academic study, Data, and Training The UC Davis Farm Labor program studies the state's farmworkers and provides information about them. In addition to advising producers, the Statewide Integrated Pest Management program (UC IPM) began training farmworkers in 1988. Regulatory Oversight The state Department of Industrial Relations (DIR) regulates and provides information for workers and employers. DIR's Labor Enforcement Task Force (LETF) enforces such requirements as overtime. UCANR and UCCE also provide information for employers' business planning. Enforcement of state laws and regulations regarding farm labor and pesticides is the responsibility of the s. Labor History The union organizing campaign of César Chávez and its impact on the industry has become a well known chapter in American history. His movement was also joined by artists such as famed theater and film director Luis Valdéz. Ecofeminists have supported the United Farm Workers' strikes including Chávez's Grape boycott, especially for their positions on pesticides. Despite the Immigration Reform and Control Act of 1986, Taylor & Thilmany 1992 found that the state's farmers did not reduce their hiring of illegal immigrants as farmworkers. Indeed, illegal immigration inflows increased in the 1990s. By the late 1990s the large immigrant population had expanded the workforce, reduced wages and working time per worker. The reanalysis of Khan et al., 2004 finds that increased production of labor demanding crops increases agricultural labor demand, but does not necessarily have to because the same workers could have been hired to perform more hours. For many decades the Immigration and Naturalization Service (INS) and Customs and Border Protection (CBP) left farmworkers alone. Especially in the Northern Sacramento Valley and Southern San Joaquin Valley, farmworkers had risen to a high proportion of the population by 2013. The broader implications of intensified immigration enforcement are significant. The U.S. agricultural industry relies heavily on immigrant labor, with undocumented workers comprising a substantial portion of the workforce. In California, estimates suggest that undocumented immigrants make up about 70% of the state's agricultural workers. Despite the passage of the California Agricultural Labor Relations Act of 1975, by 2012 unions were less popular with farmworkers than they had been before it was passed. Farmers here were solid supporters of candidate and then President Trump, but were quickly surprised by the rhetoric of the administration due to the labor situation in the industry. As late as 2017 the illegal workforce was still projected to grow. During and after the escalated deportation raids the lack of normal labor opened opportunities for others. The 2022–2023 California floods devastated berry and greens cultivation areas, and impacted worker housing. Unions In 2021, the Supreme Court of the United States under Cedar Point Nursery v. Hassid struck down the right of organizers to enter California farms outside of working hours to unionize workers. Protests • In April 2024, over 100 farm workers protested for better wages and working conditions, asking for a minimum of US$26/hr. In 2024, farmworkers in Santa Barbara County earned an average hourly wage of ~$17/hr. Immigrant Labor California's agricultural sector is heavily dependent on immigrant labor, with a significant portion of its workforce lacking legal status. According to the U.S. Department of Labor's National Agricultural Workers Survey (NAWS), conducted between 2015 and 2019, approximately 49% of hired crop farmworkers in California were unauthorized immigrants. As of 2019, 9% of all unauthorized immigrants in California are employed in this industry. A 2010 study estimated a total of 165,000 indigenous farmworkers from Mexico and Guatemala and family members in California Enforcement of labor laws has had little success in improving working conditions. Harrison & Getz 2015 study organic fruit and vegetable workers here and find that working conditions generally improve with increasing farm size. Stockton et al., 2017's meta analysis shows workers were earning two-thirds of the average Californian due to a combination of low wages and underemployment. Recent immigration enforcement actions have had notable impacts on California's agricultural communities. For instance, a workplace raid in Kern County in February 2025 led to the detention of numerous farmworkers, disrupting local farming operations and instilling fear among immigrant laborers. ==See also==