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The bands start yellow but turn brown/red and can become purple with spots on the upper or lower surface of the needle. [3] Signs of Rhabdocline pseudotsugae include apothecia that mature below epidermis where swelling is visible. These fruiting bodies are present on the underside of needles.
Symptoms include needles developing yellow spots, horizontal brown bands around the needles, swelling of needles, and off-white fruiting bodies formed on infected needles. [ 2 ] [ 3 ] Because Cyclaneusma is an ascomycete it produces two spore types, an asexual ( conidiomata ) and sexual ( ascomycota ) spore.
Small water-soaked lesions, maturing into sunken and brown spots with or without a yellow halo. May show concentric rings with purple margins. Necrotic tissue may fall out to appear shot-holed. Leaf spot on many plants and crops. Septoria: Small brown spots, that turns light tan to white in the centre. Leaf spot on many crops Bipolaris
Black spot (Diplocarpon rosae) Black spot (class Leotiomycetes: family Helotiales) Diplocarpon rosae syn. Marssonina rosae – Marssonina rosae causes black spots on leaves. [4] The spots, which may be as much as 12 mm across, are generally circular and have an irregular edge often with a yellow halo. Leaves frequently turn yellow and fall early.
Young twigs never hang downwards and are yellow-brown in color. [6] The narrow, needle-like, evergreen leaves are quite sharply pointed and may be dull green, blue, or pale white. [9] Each of the needles is four sided with stomata on every side, stiff, and 1.6–3 centimeters (3 ⁄ 4 – 1 + 1 ⁄ 4 in) long. [6]
Rhytisma acerinum is a plant pathogen that commonly affects sycamores and maples in late summer and autumn, causing tar spot. Tar spot does not usually have an adverse effect on the trees' long-term health. [1] R. acerinum is an Ascomycete fungus that locally infects the leaves of trees and is a biotrophic parasite. [2]
The disease is found on pine trees (Pinus spp.) with two or three needles, such as ponderosa pine, jack pine and scots pine. [2] It is very similar to pine-oak gall rust, but its second host is another Pinus species. The fungal infection results in gall formation on branches or trunks of infected hosts.
Alternaria symptoms are small brown lesions on the surface of the collard leaf. Downy mildew produces small yellow fungal spots on the leaf that cause the plant to wither and die. Finally, black rot gets its name because its primary symptom is the bacteria will infect the veins of the plant and turn them black.