The initial 2024-25 California Navel orange forecast is 78.0 million cartons, up 2% from the previous year. These forecasts are based on the results of the 2024-25 Navel Orange Objective Measurement (O.M.) Survey, which was conducted from June 8 to August 25, 2024. Estimated fruit set per tree, fruit diameter, trees per acre, bearing acreage, and oranges per box were used in the statistical models estimating production.
This forecast includes production of conventional, organic, and specialty Navel oranges (including Cara Cara and Blood orange varieties).
Survey data indicated a fruit set per tree of 414, up 24% from the previous year. The average September 1 diameter was 2.063 inches, down 5% from last year. Bearing acreage is estimated at 110,000, which results in a forecasted yield of 709 cartons per acre.
CARA CARA PRODUCTION FORECAST
Cara Cara variety production is forecast at 9.0 million cartons. Survey data indicated a fruit set per tree of 301, up 10% from the previous year and 15% above the five-year average of 262. The average diameter on September 1 was 2.142 inches, 2% below the previous year and 2% below the five-year average of 2.180 inches.
SURVEY SAMPLE
A sample of 804 Navel orange groves was randomly selected proportional to county and variety bearing acreage, and 749 of the groves were utilized in this survey. Once a grove was randomly chosen and grower permission was granted, two trees were randomly selected.
For each randomly selected tree, the trunk was measured along with all connected branches. A random number table was then used to select a branch, and then all connected branches from the randomly selected branch were measured.
This process was repeated until a branch was reached with no significant limbs beyond this point. This randomly selected branch, called the terminal branch, was then closely inspected to count all fruit connected to this branch, as well as all of the fruit along the path from the trunk to the terminal branch. Since each selected path has a probability of selection associated with the path, a probability-based method was then applied to estimate a fruit count for the entire tree.
In the last week of the survey period, fruit diameter measurements were made on the right quadrant of four trees surrounding the two trees of every third grove. These measurements were used to estimate an average fruit diameter per tree. Of the 749 utilized groves, 126 were in Fresno County, 425 were in Tulare County, 171 were in Kern County, and 27 were in the remaining counties.
SURVEY HISTORY
A Navel Orange Objective Measurement Survey has been conducted in the Central Valley every year since the 1984-85 crop year, except for the 1991-92 season due to a lack of funding. The data from the first two years were used for research purposes in developing crop-estimating models. The Cara Cara forecast was undertaken at the request of the California Citrus Advisory Committee starting with the 2018-19 crop year.
Beginning in the 2023-24 crop year, only state level forecasts will be published, and the Central Valley forecasts will be discontinued.
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