Identification and Control Methods of Jujube Rust Disease Explained in Detail
(1) Symptoms: Jujube rust disease only damages the leaves. In the early stage, pale green small spots are scattered on the underside of the leaves, later gradually becoming raised and dark yellow, which are the uredinia of the pathogen. The uredinia are irregular in shape and mostly occur on both sides of the midrib, at the leaf tip and base. After the surface of the lesion ruptures, yellow urediniospores are scattered. On the upper side of the leaf, corresponding to the uredinia, green...
(1) Symptoms: Jujube rust disease only damages the leaves. In the early stage, pale green small spots are scattered on the underside of the leaves, later gradually becoming raised and dark yellow, which are the uredinia of the pathogen. The uredinia are irregular in shape and mostly occur on both sides of the midrib, at the leaf tip and base. After the surface of the lesion ruptures, yellow urediniospores are scattered. On the upper side of the leaf, corresponding to the uredinia, green small spots appear with irregular edges, and the leaf surface becomes mosaic-like. Finally the leaves dry up and fall early, thereby weakening the tree vigor and reducing yield and quality.
(2) Disease occurrence pattern: Jujube rust disease is a disease caused by fungal infection. It generally begins to occur in mid to late July, and from late August to September a large number of uredinia appear, continuously causing reinfection, entering the peak period of disease occurrence, and leaf drop begins. Abundant rainfall in August-September is favorable for the occurrence of the disease, while in dry years the disease is mild.
(3) Control measures:
① Strengthen cultivation management. Reasonable close planting, pruning overly dense branches, improving ventilation and light conditions; strengthening fertilizer and water management, draining accumulated water, preventing the orchard from becoming too humid, can reduce the occurrence of the disease.
② Spraying for protection. In early July, spray once with 1:2-3:300 Bordeaux mixture or 0.3 degree Baume lime sulfur mixture, and spray once more after 1 month, which can effectively control the occurrence of jujube rust disease.