Drone Spraying in Merced County, CA for Almonds, Forage and Row Crops

Merced County drone spraying rates

Drone spraying in Merced County is quoted per acre for application only. Growers supply materials under their PCA's recommendation, or the operator sources them and bills at cost. California drone work is published at roughly $14–22 per acre for row crops and alfalfa and $18–35 for orchards.

Service	Typical rate	Notes
Almond and pistachio fungicide	from $17/acre	Bloom, petal fall, spring disease passes
Hull-split insecticide	from $17/acre	Navel orangeworm timing
Alfalfa and corn silage	from $14/acre	Weevil, aphid, early mite passes
Tomatoes and sweet potatoes	from $16/acre	Insecticide, fungicide, foliar nutrients
Herbicide (row crops, fallow, field edges)	from $15/acre	Broadcast or spot

Quotes depend on block size, tree height and row spacing, gallons per acre on the label, the number of blocks per trip and whether a school or sensitive site limits the hours. Each visit carries a $350 minimum, so small ranches often combine blocks into one trip.

Merced County crops by value

The Merced County 2023 Annual Report on Agriculture puts gross production at $4.22 billion. The county describes itself as the fifth-largest agricultural county in the nation, and agriculture supports about 38,800 jobs.

Commodity	2023 value	Harvested acres
Milk	$1,289M	—
Almonds	$445.6M	161,506
Sweet potatoes	$335.3M	17,254
Cattle and calves	$334.1M	—
Chickens	$271.1M	—
Tomatoes	$245.1M	27,700 processing, 4,232 fresh
Corn silage	$139.3M	91,167

Pistachios add 20,919 acres and alfalfa hay 37,422. Spray work therefore runs along two lines: orchards on the east side and around Atwater, Livingston and Le Grand, and row crops and dairy forage from Hilmar to Los Banos and Dos Palos.

Almond and pistachio spray timings

UC IPM sets the almond disease calendar, and every pass is time-sensitive:

Timing	Target
Full bloom	Brown rot
Petal fall + 2 weeks	Shot hole
2 and 5 weeks after petal fall	Scab
May	Rust, Alternaria
June–July, 1–5% hull split	Hull rot

Navel orangeworm control starts in winter: sample mummy nuts by January 15 and remove them by March 1. In-season, the key spray goes on at the start of hull split and no later than 1% split, with a second spray 2–3 weeks later where pressure is moderate to high. Spring rain often closes orchard floors to ground rigs right when bloom fungicides are due, and a drone keeps those passes on schedule without rutting the berms.

Processing tomatoes and curly top

Beet leafhopper carries curly top virus into west-side tomato fields. CDFA's Curly Top Virus Control Program surveys Merced County, focusing on fallow fields and roadsides within 5 miles of the foothills. In May 2026 leafhopper counts averaged 0.1, against 0.5 in 2025 and 0.2 in 2024. The weed hosts include mustards, Russian thistle, kochia, bassia and mallow. CDFA treats rangeland and roadsides when counts justify it, so on the grower side the work is weed control on field edges and fallow ground. Drones are a practical way to reach ditch banks and corners a boom cannot.

Sweet potato fields

Merced County grows most of California's sweet potatoes. UC's 2026 sweet potato guidance runs from fumigation in April and planting around May 1, through nematicide timing in May and June, to harvest in September. Aphids that spread russet crack virus, plus Fusarium root rot, scurf and southern blight, are the main in-season concerns. Most nematode and fumigant work stays on the ground, but foliar insecticide and fungicide passes over dense vines suit a drone, especially once furrow irrigation has started.

Corn silage and alfalfa for Merced dairies

With milk worth $1.29 billion, forage spraying is a big share of the county's acres.

• Spider mites in corn: UC IPM advises treating before corn reaches 2–4 feet, because later sprays cover poorly. Check silage pre-harvest intervals: 30 days for propargite, 5 days for spiromesifen.
• Alfalfa weevil: larvae cause most damage from February to April, before first cutting. The treatment threshold is 20 larvae per sweep; cutting early is an alternative.
• Weed control: passes between cuttings, without wheel traffic on regrowth.

Drift planning near the Grasslands and refuges

The Grassland Ecological Area covers about 240,000 acres, all in Merced County. It is a Ramsar wetland of international importance and the largest remaining contiguous block of freshwater wetlands in California. About 250 bird species and roughly 160 duck clubs use it. Fields along the Grasslands, the San Luis and Merced national wildlife refuges and the irrigation canals near Los Banos and Gustine need deliberate drift planning: coarse droplets, downwind buffers, wind direction checks and products chosen with wetlands in mind. Groundwater plans add pressure on input efficiency: DWR approved the revised Merced Subbasin plan in August 2023, and the State Water Board decided in April 2026 that probation was not necessary for the Delta-Mendota Subbasin.

School hours and restricted materials

California requires a Notice of Intent, filed through CalAgPermits with the Merced County Agricultural Commissioner, before any restricted material is applied. Since February 24, 2025, DPR's SprayDays system has posted those applications publicly 24 hours ahead (48 hours for soil fumigants), on a one-square-mile grid, with a four-day window to begin. From January 1, 2026, manned and unmanned aerial applications within a quarter mile of a school are restricted Monday through Friday, 6 a.m. to 6 p.m., and the NOI must list allowed days and times. Fields near schools in Merced, Atwater, Livingston and Los Banos are flown early, late or on weekends.

Pilot certification and airspace in Merced County

Every drone pesticide pilot in California holds a DPR Unmanned Pest Control Aircraft Pilot Certificate: Apprentices fly under a Journeyman's direct supervision, and a Journeyman needs one year as an Apprentice and 50 or more spray hours. Pilots must register with the Agricultural Commissioner in each county before working. Operators also hold FAA Part 107 and Part 137 certification and a Section 44807 exemption for aircraft of 55 pounds or more. Castle Airport in Atwater has Class D airspace with a 4.6-mile radius when activated by NOTAM, and Merced Yosemite Regional (MCE) sits just southwest of downtown Merced, so pilots check LAANC and NOTAMs before flying near either field.