Diseases and pests of perennial vegetables
Horseradish root rot occurs on heavy and little airy soils. Inside the roots, there are lots of brown tissues, usually forming a fairly regular ring. The cause of this disease is unknown and if it occurs, try to get new seedlings.
Horseradish is also attacked by the fungus Vericillium albostrum, which causes reddening of the vascular ethmoid bundles. Vessels infected by this fungus lose their ability to conduct water. Plants wilt initially, and then they gradually die off. In the case of horseradish verticillosis, a few years' break in the cultivation of this plant is required, remove diseased plants and plant healthy seedlings.
Asparagus can be attacked by asparagus rust and rot at the base of the asparagus stem. In the first case, the pathogen (Puccinia asparagus), starting in April, produces five more spore forms on asparagus stalks and branches, accompanied by various discoloration of infected tissues. The above-ground parts of infected plants turn yellow prematurely and die. This disease is prevented by cutting in the fall (below ground level) stalks and their burning. Young plantations from mid-May, and yielding from the beginning of July, co 10-14 days are sprayed with concentration of Cynkotox 0,3%. With root rot, asparagus is a pathogen (different species of Fusarium) attacks the roots and the base of the stem, causing them to rot and turn brown. Sick plants have lower yields, they wilt and eventually die. Such plants must be dug up and burned, and the stumps must be treated with disinfectants before planting into the ground, e.g. Sadoplonem 75 by 10 minutes.
Pests that attack asparagus – asparagus shank (the larvae feed inside the shoots), asparagus violinist and twelve-dot po-violinist (colorful beetles and brown-green larvae feed on the shoots) – fights off, by spraying plants before flowering with liquid insect 50 (0,15%) or Basudin 25 EC (0,1 5%).
Rhubarb suffers from leaf spot and root rot and petiole rot. In the first case, there are more or less extensive brown spots on the leaves, usually with a red border, which causes premature leaf blade dieback. As soon as the first spots appear, the plants must be sprayed with Kaptan or Cynkotox. In the second case, the pathogens attack the petiole base, root necks, and some roots as well. As a result, the leaves on the plant wilt, and sometimes whole plants die and have to be removed.