Integrated Pest Management in Asparagus

Integrated Pest Management in Asparagus 

Asparagus officinal - is a spring vegetable, a flowering perennial plant species in the genus Asparagus. It was once classified in the lily family, like its Alliums cousins, onions and garlic, but the Liliaceous have been split and the onion-like plants are now in the family Amaryllidaceous and asparagus in the Asparagaceae. Asparagusofficinalis is native to most of Europe, northern Africa and western Asia, and is widely cultivated as a vegetable crop

  Army Worms - These are the larvae of several species of night flying moth. Most significant for the vegetable grower is the Beet Armyworm which feeds on a very wide variety of vegetable crops (beans, beets, celery, corn, lettuce, onion, peas, pepper, potato, tomato and more).

Asparagus Beetle -   The common asparagus beetle (Crioceris asparagi) is an important pest of asparagus crops both in Europe and in North America. Asparagus is its only food plant. The beetle is about half a centimeter long, metallic blue-black in color with cream or yellow spots on its red-bordered elytra. The larvae are fat gray grubs with dark heads.

Asparagus Miner -   The asparagus miner is a bivoltine stem-mining fly and a major pest of asparagus. It is small (~2–5 mm) with a shiny black body and black legs. Under a dissecting microscope or with a hand lens, one can confirm the identity of the fly by checking that the costa (the thicker marginal vein) ends at vein R4+5. In addition, the fly has five conspicuous orbital bristles emerging from the middle of its head.

Cut Worms -    Black and variegated cutworm moths have wingspans of 38 to 51 mm. The forewings of black cutworm moths are dark with three black dashes and a white splotch near the tip of each wing. Forewings of variegated cutworm moths are basically yellowish or light brown with pale mottled designs.
European Asparagus Aphid -   The European asparagus aphid is a small blue-green to gray-green aphid about 0.06 inch (1.5 mm) in length. The aphid is often covered with a powdery wax. Unlike most aphids, the cornicles of European asparagus aphid are reduced to practically invisible openings on the abdomen. 
Garden Symphylan -    The garden symphylan is an occasional but very destructive pest of most field crops. Symphylans are not insects. They are more closely related to centipedes and millipedes. Garden centipede is another name commonly used for the garden symphylan.
Thrips -    Thrips species feed on a large variety of plants and animals by puncturing them and sucking up the contents. A large number of  thrips species are considered pests, because they feed on plants with commercial value. Some species of thrips feed on other insects or mites and are considered beneficial, while some feed on fungal spores or pollen.
Asparagus Virus I and II

§SYMPTOMS AND SIGNS

§Asparagus viruses I and II produce no distinct symptoms unless both viruses infect the plant. Either virus by itself may only slightly reduce vigor. When both are present in the same plant, survival and vigor are severely reduced, especially in young plants. The combination of both viruses may be partly responsible for the reduction in the profitable life of asparagus plantings. Also, when plants are infected with both viruses, they become more susceptible to Fusarium wilt.

Crown and Spear Rot 

§SYMPTOMS AND SIGNS

§Phytophthora spear rot is characterized by soft, water-soaked lesions on shoots at, slightly above, or below the soil level. The lesions elongate rapidly and become light brown. As the lesion collapses and shrivels, the affected side of the spear becomes flattened, and the shoot becomes extremely curved and may even collapse. This symptom is not diagnostic, however, as insect and mechanical injury can result in crooked spears. Infected young storage roots appear water soaked but firm.

Fusarium Wilt - §SYMPTOMS AND SIGNS

§Mature plants infected with Fusarium gradually decline in productivity and growth. During the summer, infected plants are characterized by one to several stunted, bright yellow ferns. A reddish brown vascular discoloration, which may extend into the crown, is present at the base of stalks infected by Fusarium oxysporum f. sp. asparagi. Crowns and belowground portions of stems exhibit reddish flecks or sunken brown lesions, which can be seen by cutting them open. Reddish brown, elliptical lesions occur on storage roots of infected plants. Feeder roots, most of which may be rotted off completely, show reddish brown discoloration.

Purple Spot - §SYMPTOMS AND SIGNS

§Purple spot is of major concern when new spears are emerging and being harvested. The pathogen produces elliptical, slightly sunken lesions 0.03 to 0.06 inch across and up to 0.125 inch long. Initially lesions are reddish-purple and later develop a tan-brown center, especially if the lesion is large. Lesions usually appear on the lower half of new spears and are very superficial. The internal tissue of the spear is not affected.

Rust - §SYMPTOMS AND SIGNS

§

§Rust is most common on fern growth after the harvest season is over. Infections begin in spring from spores that overwintered on crop debris. These infections produce the orange stage (pycnia and aecia) of the disease. Occasionally, this stage can be found in spring on emerging spears from new or established plantings. The orange stage is characterized by light green patches on new spears that mature into yellow or pale orange pustules in concentric ring patterns. Spores produced by these spring stages are airborne to new fern growth. 

  Infection occurs and brick red pustules develop on stalks, branches, and leaves of the fern. These red pustules produce airborne, rust-colored spores (urediospores) in a powdery mass, which can reinfect the fern and increase disease incidence. Fern yellowing and browning, defoliation, and dieback may occur. As ferns mature and senesce, or autumn weather begins, the black spore stage may develop. The same pustules that produced the red spores begin producing black spores (teliospores). The pustule will slowly convert in appearance to a powdery mass of jet-black spores. These black spores are the overwintering stage of the fungus. The overall effect of rust on asparagus is reduced plant vigor the following year and reduced yields.