Which are the most important pests of artichokes and how to control them
The Artichoke aphid (Capitophorus elaeagni) is an insect that causes significant damage to artichokes when the weather conditions and cultivation practices favor its growth. The insect feeds on the foliage causing curling and discolorations (turning yellow). The farmer can also observe deformations of the infested buds and a reduction in plant growth rate. The damage is more extended in younger plants. Aphids are known to deposit honeydew on the infected foliage, causing further infections by fungal pathogens. Usually, sooty mold covers the buds, reducing the final yields and product quality. Other important aphid species are the green peach aphid (Myzus persicae) and the bean aphid (Aphis fabae).
Once the cultivation has been attacked, management is quite tricky. Artichoke farmers usually use products with malathion, pyrethrins, neem oil, and insecticidal soaps (always ask your local licensed agronomist). However, since the pests develop resistance to pesticides, the best method to control them is through biological management. Pheromone traps are a commonly used technique. They attract male insects preventing them from mating with females, leading to gradual population reduction. Using natural enemies of the insect (predator insects) is another commonly used and effective pest control method. There are several commercial products containing living predators able to attack pests in various development stages, usually the eggs, and put them under control.
Artichoke plume moth
The artichoke plume moth (Platyptilia carduidactyla) is considered to be the most devastating pest of artichokes. It can cause extensive yield losses (25-50% loss of buds), especially in perennial artichokes. The pest (larvae) feeds (open tunnels) on foliage, stems, and floral buds, damaging the bracts and leaving the buds underdeveloped and deformed. Stems turn black and wilt. The farmer may also observe excrement (frass) on the infected areas of the plant.
The farmer can monitor the population of the insect by using pheromone traps. It is advised to check the plants weekly, and when more than 3% of shoots are infested by plume moth larvae, then control measures are needed. The control of the insect depends on integrated management measures and has two main action periods: one during the summer (from stalk cutback until early fall) and the other in winter (ditch period). During the summer, the farmer can irrigate and cultivate his/her fields, adding by ground rig a suitable and certified insecticide if needed. In organic cultivation, Bacillus thuringiensis can be used as an alternative. During the winter, the insecticides are sprayed. In addition, natural enemies of the moth, like parasitic wasps, have successfully been used in artichoke. In areas where the pest causes significant problems, the farmer can soak the transplants in a solution of the entomopathogenic nematode, S. carpocapsae. Finally, the grower can cut back the stalks (2-3 inches below soil level) and remove all infested artichoke buds.
Which are the most important disease of artichokes and how to control them
Bacterial crown rot
The pathogen Erwinia chrysanthemi causes the disease, and some common symptoms of crop infection include wilted older and younger leaves, especially during days with high temperatures. Moreover, the farmer may observe dark discoloration on the stems. Crown tissue is also affected, starts to soften, and periodically rots and collapses. The entire plant has a reduced growth rate, and at the final stages of the infection, it entirely collapses.
The main control measure is the use of healthy propagation material and to disinfect your tools when moving from one plant or field to another, during harvesting and propagation to reduce the spread of the pathogen.
Gray Mold (Botrytis Disease)
This fungal disease caused by Botrytis cinerea is the cause of crop failure (unsuccessful production) in some areas. The pathogen is favored by increased humidity and warm weather (moderate temperature) and can successfully infect plants with damaged tissue from frost, pests, or poor handling (mechanical damage). Farmers may observe wilts on the entire plant; most infected parts are covered by a whitish to gray mold. Crowns become watery, soft, and have a characteristic smell of rot.
Disease management begins with obtaining proper precautionary measures. These include weed control, safe distances between plants, good soil drainage, and avoiding foliar wetting. The general condition of the plants (nutrients and water level, sun exposure) can also boost their tolerance against the pathogen. Moreover, all infected heads should be removed and disposed of, while the rest of the harvested buds should be stored in appropriate conditions (cooling). Chemical treatment (fungicides) is used only if the problem is severe and always under supervision from a local licensed agronomist. As mentioned previously, during harvesting and propagation, it is crucial to use proper sanitation and to disinfect your tools when moving from one plant or field to another.
Other economically important diseases that can periodically cause yield losses in artichokes are the Powdery mildew and Ramularia leaf spot, the Verticillium wilt, and the Curly dwarf (virus). All the diseases mentioned above could become a severe threat to the crop in dense and poorly aerated plantations, in monoculture, and when the environmental conditions are favorable for the growth and transmission of the pathogens (e.g., rainy weather).
Weed management in Artichoke Farming
Weed management in artichoke farming is critical and should be performed in annual cultivations and perennials during the first 1-2 years of plants’ growth. After that moment, the plants cover-shade the soil with their extensive canopy reducing weed emergence. Some of the most important weeds causing problems in artichokes are the: buttercup oxalis (Oxalis pes-caprae), mustards (Brassica spp.), swinecress (Coronopus spp.), chickweed (Stellaria media), and sowthistle (Sonchus spp.). Farmers generally use a combination of control measures like hand weeding, herbicides, mulching (2-3 in), and cultivation (e.g., shallow tillage).
Artichoke Pests, Diseases, and Weed management