Catalpa bignonioides, also known as catalpa (Catalpa bignonioides), is a very decorative tree with an interestingly shaped crown, decorative large leaves and beautiful flowers. Unfortunately, it is not uncommon forcatalpa to turn yellow, dryor to have white or brown spots on the leaves. See what are the most commoncatalpa diseasesand how to combat pests that threaten bignonium catalpa.
Catalpa withers and dries up as a result of being infected with verticillosis
Fig. witeks1968, forum.PoradnikOgrodniczy.pl
Catalpa fungal diseases
Werticiliosis- this is the most common catalpa disease, in which it is clearly visible thatcatalpa turns yellow and dries upThere are disturbances in the attacked catalpa uptake of water from the soil, the symptom of which is shoot wilting. Alsoleaves on shoots turn yellow, brown and die offDead leaves usually do not fall off. Not all shoots of a diseased tree appear infected, often only some of them are devoid of leaves, and the rest appear he althy.
The fungi that cause this catalpa diseasedevelop in soil and penetrate deep into plants through wounds on the roots or through the contact of he althy roots with sick ones. The pathogen is very resistant and can survive in the substrate for many years. When we notice that the trees are infected, we have to remove them and water the plants growing in the neighborhood with Topsin M 500 SC as a precaution.
Catalpa withers and dries up as a result of being infected with verticillosis
Fig. witeks1968, forum.PoradnikOgrodniczy.pl
Powdery mildew- this is a catalpa disease as a result of which we observe numerous,mealy, white spots on the leavesDisease symptoms in the form of white, mealy spots usually appear on the youngest catalpa leaves, on their upper side. Under the mycelium, the tissues turn brown and die. The tarnish may also appear on shoots and flowers. Plants grow more slowly and affected organs deform. Strongly controlled plants dry up.
Powdery mildew on rose leaves. The symptoms on catalpa are identical
Fig. © PoradnikOgrodniczy.pl
Powdery mildew is a disease that attacks many different garden plants, including bignonium catalpa. The fungus hibernates on fallen, infected leaves and shoots. In order to limit the spread of the pathogen, in autumn we rake the fallen leaves that may be a source of infection in the next year. After finding disease symptoms, spray the plants3 or 4 times every 7-10 days with Topsin M 500 SC. This agent can be used alternately with the biopreparation Biosept Active.
Catalpa leaf blotch- as a result of infection with this disease, brown spots are observed on catalpa leaves. On both sides of the infected leaves, there are various sizes ofdark brown spots with a reddish-brown or yellow borderBlack spots or a delicate dark coating are visible on the upper side of the leaf blade. The dead tissues burst, and then the center of the stains may crumble. In the advanced stage of the disease,yellowing of the leaves and their falling
The spores are transferred to the neighboring plants which they infect through the drops of splashing water. The fungus hibernates on fallen leaves. To prevent the spread of this catalpa disease , rake and remove fallen leaves in autumn, and spray the infected plants with fungicides, e.g.Topsin M 500 SC. To limit the use of chemical plant protection products, the selected fungicide can be used alternately with the natural preparation Biosept Active.
Vermillion lump- this catalpa disease initially manifests as light brown spots on the bark. Over time, the tissue dies and collapses. Then the spots merge with each other and cover the entire shoot, which turns brown and dies above the infection site, andcircular, orange or black small lumps appear on the affected tissueOn the border between he althy and diseased tissue a narrowing occurs, caused by an increase in thickness of he althy shoot fragments.
Especially susceptible to infection by vermilion nodules arecatalpa damaged by low temperature or dryInfection of the tissues occurs through mechanical damage on the shoots. Occasionally, a pathogen can enter a plant through the roots when the root of a tree comes into contact with soil-borne and infected roots or branch fragments of another plant.The fungus hibernates on diseased shoots and plant debris in the substrate.
Vermillion lumps. The fungus also attacks catalpa
Fig. © PoradnikOgrodniczy.pl
Fighting this catalpa diseaseshould begin with cutting out sick shoots below the visible symptoms, about 0.5 cm above the side branch. Plants should also be sprayed with a fungicide, e.g. Topsin M 500 SC mentioned above.
Armillary root rot- the bark of a sick tree starts to peel off it and can be easily torn off the trunk. On the infected bark, white patches of spores are visible and a specific mushroom smell is noticeable. In the autumn, Hymenoptera may appear around diseased plants - small, edible honey-colored mushrooms. Plants with a root system weakened by other pathogens and by unfavorable weather conditions (root flooding, drought) or mechanical damage are also more susceptible to infection by root rot.
Diseased catalpa trees should be removed , and since the mycelium of Hymenoptera can survive in the ground for many years, new trees should not be planted in the same place. There are currently no measures to combat this disease on the market. All that remains is to strengthen he althy plants by proper care, fertilization, the use of mycorrhizal vaccines and spraying with the natural preparation Biosept Active.
Pests of catalpa, bignonium catalpa
Peach aphid(Nectarosiphon persicae) is the most common catalpa pest. Aphids weaken plants, often transmitting viral diseases and favoring fungal infections.Distorted and twisted leaves are a symptom of the presence of aphids on catalpaThe underside of the affected leaves usually shows clusters of numerous larvae and maiden aphids. The wingless girls of the peach aphid mage have a length of 1.2-2.6 mm, and their bodies are yellowish green. Winged girls have a dark brown head and torso, and a yellowish-green abdomen with a dark brown spot.
Aphids attack many different species of plants
Fig. pixabay.com
The primary host of the peach aphid are plants of the genus Prunus, i.e. plums, peaches, cherries, apricots, bay leaves and bird cherry. Aphids winter on these trees, while in Catalpa they appear only in summer and autumn.
After noticingsymptoms of aphid feeding on catalpa , spraying is performed with the natural oil preparation Emulpar 940 EC, which causes immobilization and suffocation of the aphids under the oily coating created by this preparation. If this is not enough, you can use chemical insecticidal spraying, such as: Karate Gold, Mospilan 20 SP, Polysect 005 SL.
Spider mitesare tiny mites that suck the sap from the plant and feed on the underside of the leaf - they suck the juices out of it. The spider mite most often appears on the catalpa.The first symptom is tiny, point-like, mosaic-like yellowish discoloration on the top side of the leaf. Over timediscoloration covers the entire leaf, which curls and fallsA symptom of spider mites feeding on catalpa may also be a delicate cobweb. Spider mites can be combated naturally with the above-mentioned Emulpar 940 EC preparation. Spraying is performed after noticing the pest's feeding symptoms and in the early spring in order to eliminate forms overwintering on the plant. Among chemical insecticides, Karate Gold and Ortus 05 SC will be helpful.
MSc Eng. Anna Błaszczak
