Asparagus Research

The Washington Asparagus Commission Research & Development Farm has eleven acres devoted to research on pest management, production, and irrigation. Projects for the 2012 harvest season include pest management trials on insects and weeds. The production and irrigation research will include projects on irrigation, plant densities, varieties and fertility.

This year’s funding from the Washington State Commission on Pesticide Registration is $5,000 to perform weed control trials using newly registered pesticides on organic asparagus.

The total research budget for the year 2012 is $57,000.

Crop Description

Asparagus is a perennial crop. The underground portion of the plant consists of crowns that produce edible stems each spring. Young crowns are grown from seed planted in beds and transplanted the following year in to a field. Asparagus beds with good care will produce for over 20 years; however 12 to 14 years is typical. The stems, or spears, are harvested at 7 to 9 inches in length. Harvest begins in April and lasts 60 to 80 days.

Asparagus is harvested daily by hand. After harvest is over, the spears are allowed to grow in to fern. The fern stage produces the nourishment for the crown that will result in the next year’s crop. Most insect and disease problems occur during the fern stage. Approximately 90% of Washington’s asparagus is produced for the fresh market with the remaining amounts going into frozen or pickled products. Asparagus is one of the most labor intensive crops in the state with between 50% and 70% of all costs going to labor.

 

Key Pest Issues

The primary insect pest is European asparagus aphid. Control of this insect is required for successful production of asparagus. Other arthropod pests are the 12-spotted asparagus beetle, common asparagus beetle, green peach aphid, spotted cutworm, redbacked cutworm, the asparagus miner and garden symphylan. Cutworms attack the spears during harvest. The spotted asparagus beetle causes damage by laying eggs and feeding on the spear. Both beetle species, asparagus miner and the European asparagus aphids are pests of the fern stage. Control against aphids and or spotted asparagus beetle are required in most fields every year.

During harvest, in the first and last few years of production, asparagus is a poor competitor with weeds. The most challenging weed species in asparagus are Canada thistle, field bindweed, puncturevine and common groundsel. Other important weeds are Russian thistle, kochia, lambsquarter, redroot pigweed, yellow nutsedge, quackgrass and barnyardgrass. Numerous other weed species are pests in asparagus.

The primary disease of asparagus is fusarium crown and root rot. This disease plays a role in the decline of virtually every asparagus field. Other important fungal diseases are asparagus rust and purple spot or stemphyllium. Viral diseases include asparagus virus 1, asparagus virus 2 and tobacco mosaic virus.

There is interested in expanding the organic portion of the asparagus in Washington is currently very small. Inability to control EAA and the expense of controlling weeds severely limits the production of organic asparagus.

Pesticides in Asparagus

Aphids are primarily controlled by disulfoton and occasionally with dimethoate. Beetles and cutworms are controlled by carbaryl, Lorsban and Pounce. No effective means are known for asparagus miner and garden symphylan. The most commonly used herbicides are Sencor, diuron, glyphosate, trifluralin, Sandea and Poast. The primary fungicide used on Washington asparagus is mancozeb.

Critical Pest Issues

Di-Syston is being removed from the market, finding a replacement for the product is a critical goal for the asparagus industry. Growers are in need of controls for puncturevine and field bindweed.

Asparagus Data

Washington State Pesticide Usage Data

Washington Asparagus Production by County