Fig in California

The fig, Ficus carica L., is indigenous to western Asia and has been cultivated since antiquity. Figs are easy to grow in most warm climates, but produce their best fruit in Mediterranean climates with hot, dry summers and cool, wet winters. Mature trees are cold hardy to 15-20⁰F and require full sunlight for maximum fruit production. Fig trees will tolerate average to poor soil (pH from 5.5 to 8.0) and are somewhat drought and salt tolerant once established due to an extensive root system (Sadhu 1992). Figs grown in high lime soils produce higher quality fruits to be used for drying (Bapat and Mhatre 2005). Fig production in California is primarily located in Fresno, Madera, and Kern counties in the San Joaquin Valley, Riverside and Imperial counties in Southern California. In 2013, 28,900 tons of fruit were harvested from the 7,300 commercial acres in the state. This crop had a market value of $15,522,000 (USDA 2014).

The Calimyrna cultivar was originally imported from Turkey into the San Joaquin Valley in the late 1800s. It is gynodioecious, with separate male and female trees, and produces large golden fruit with true seeds. The female Calimyrna fig requires a male caprifig with small non-edible fruits and the Blastophaga wasp for pollination and normal fruit development. The flowers inside the caprifig produce pollen which is transported to the female Calimyrna fig by a Blastophaga wasp. An opening on the end of the fruit allows the Blastophaga wasp entry to collect pollen from male capri figs that  pollinates female Calimyrna flowers. The pollination is an artifact of the female wasp’s unsuccessful attempt to lay eggs for the next generation of wasps. As she searches for short styled gall flowers suitable for her ovipositor the pollen she picked up departing the caprifig is deposited on the receptive flowers of the Smyrna type figs.

Female Calimyrna fruit contains an aggregate of small flowers which bloom within the fruit. The Caprifig and Blastophaga wasp were introduced into orchards in California in 1899, resulting in the beginning of successful fig production. Commercial growers of Calimyrna figs hang paper bags of Blastophaga-infested Caprifigs in the orchards to ensure effective fertilization of fruit. To ensure sufficient fertilization of the calimyrna figs, and prolong the growing season, growers typically deposit 2-3 caprifigs per bag every three days over the course of three to four weeks.