If actions needed to contain infestation

The early navel harvest usually begins in the Southern San Joaquin Valley in mid-October and judging by the level of maturity of the navels now, harvest is probably going to occur right on schedule.

Last season, many citrus packinghouses in northern Kern and Tulare counties were surprised to find large numbers of an insect called the glassy-winged sharpshooter in shipments of navel oranges arriving from southern Kern County.

Glassy-winged sharpshooters are a concern because they are efficient vectors of the Xylella bacteria responsible for Pierce's disease of grapes. In response to this concern, the California Department of Food and Agriculture, the United States Department of Agriculture, County Agricultural Commissioners and grower organizations took aggressive action to eliminate movement of this pest to areas of production within the state that are free from infestation.

The major form of action taken was a requirement by most packinghouses that fruit be treated with an appropriate pesticide before shipment and that shipments of fruit out of the infested area be inspected upon arrival at packinghouses. If glassy-winged sharpshooters were found to be present in the shipment, the fruit shipment was sent back to Kern County. However, it was difficult to inspect fruit that was contained in the large bins used for moving fruit to the packinghouse and some areas adjacent to the packinghouse became infested with glassy-winged sharpshooters.

As long as most of northern Kern County and Tulare County are deemed to be free of glassy-winged sharpshooters, prevention of the movement of this pest to these areas is the duty of the ag commissioners in Kern and Tulare counties.

Prevention change

Since methods of preventing movement of this pest used last year did not appear to be adequate to prevent the spread of this pest, citrus growers be aware that what was permissible last year in terms of shipping fruit north from southern Kern County may not be so this fall. The problem with more stringent methods of detecting and preventing glassy-winged sharpshooter movement, however, is that they may not be economically feasible.

Grower meetings are being scheduled involving packinghouse personnel, growers, and government officials in the hope that solutions to the problem of transporting fruit into noninfested areas without moving glassy-winged sharpshooters might be found.

The major other option currently open to citrus growers in the infested areas is to transport their fruit to packinghouses in Riverside County, which has been infested with this insect for some time. Moving fruit from one infested area to another infested area is permitted. While the distance to Riverside County is somewhat longer, the economics of not having to risk fruit being rejected at the packinghouse and then having to move it south to Riverside County anyway, of not having to treat the fruit with pesticide before picking, or of not having to develop a time-consuming or potentially fruit-damaging screening protocol in the orchard may outweigh the extra transportation costs of shipping all the fruit south initially.

Packinghouses in Riverside County are preparing to increase their capacity to handle the large volumes of fruit expected. Whatever the outcome, it is clear that growers in southern Kern County that are planning to ship their fruit north this season, are again going to be concerned with more than just the color and the sweetness. of the fruit before picking commences.

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