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Mycosphaerella musicola was first reported from Java in 1902 and by 1962 was found in most banana growing regions of the world. Although it is spread over short distances by conidia and ascospores, over long distances it is the movement of infected germplasm such as diseased leaves and suckers that is likely to be responsible.
Laminated root rot also known as yellow ring rot is caused by the fungal pathogen Phellinus weirii. Laminated root rot is one of the most damaging root disease amongst conifers in northwestern America and true firs , Douglas fir , Mountain hemlock , and Western hemlock are highly susceptible to infection with P. weirii .
Symptoms can overlap across causal agents, however differing signs and symptoms of certain pathogens can lead to the diagnosis of the type of leaf spot disease. Prolonged wet and humid conditions promote leaf spot disease and most pathogens are spread by wind, splashing rain or irrigation that carry the disease to other leaves.
It has been shown that the fungus usually requires wounds to infect the plant and necessary for the fungus to develop. The first symptoms of Pestalotiopsis palmarum begin as very small yellow, brown or black discoloration of the leaves. The disease can be restricted to the leaf blade or may only appear on the petiole and rachis right away.
The heartwood is a pale golden yellow, distinct from the very pale color of the sapwood and features narrow streaks of dark brown to black. Zebrawood can also be a pale brown with regular or irregular marks of dark brown in varying widths. It is almost always quartersawn to get the exciting alternating color pattern.
The leaves are compound pinnate, 20–30 cm long, with 5-11 (mostly 7-9) alternately arranged leaflets; each leaflet broad ovate with an acute apex; 6–13 cm long and 3–7 cm broad, with an entire margin and a thinly to densely hairy underside. In the fall, the leaves turn a mix of yellow, gold, and orange. [citation needed]
Pyrenophora tritici-repentis and Drechslera tritici-repentis is a necrotrophic plant pathogen of fungal origin, phylum Ascomycota. [1] The pathogen causes a disease originally named yellow spot but now commonly called tan spot, yellow leaf spot, yellow leaf blotch or helminthosporiosis.
Leaf scorch (also called leaf burn, leaf wilt, and sun scorch) is a browning of plant tissues, including leaf margins and tips, and yellowing or darkening of veins which may lead to eventual wilting and abscission of the leaf.