Search results
Results from the WOW.Com Content Network
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.
The presence of hairs on leaves, which may be coloured differently from the leaf itself, can also produce variable coloration. This is found in various Begonia species and their hybrids. Sometimes venal variegation occurs – the veins of the leaf are picked out in white or yellow. This is due to lack of green tissue above the veins.
Leaf spots can vary in size, shape, and color depending on the age and type of the cause or pathogen. Plants, shrubs and trees are weakened by the spots on the leaves as they reduce available foliar space for photosynthesis. Other forms of leaf spot diseases include leaf rust, downy mildew and blights. [4]
White rust is a disease in plants caused by the oomycete Albugo candida or one of its close relatives. Plants susceptible to this disease generally include members of the Brassica family. [1] White rust has been known to cause agricultural losses in fields cultivating members of this family including broccoli, cauliflower, and Indian mustard. [1]
Cucumber leaves afflicted with various stages of Cucumber mosaic virus. A mosaic virus is any virus that causes infected plant foliage to have a mottled appearance. Such viruses come from a variety of unrelated lineages and consequently there is no taxon that unites all mosaic viruses.
Edema causes the appearance of growths, mainly on the underside of leaves, and can also cause indentations on the top side of leaves. [4] The growths can take a different appearance depending on the plant species, but can often take the form of needle like hairs, blisters, [3] corky growths and white crusty eruptions. [4]
Wheat leaf rust (Puccinia triticina) is a fungal disease that affects wheat, barley, rye stems, leaves and grains. In temperate zones it is destructive on winter wheat because the pathogen overwinters. Infections can lead up to 20% yield loss. The pathogen is a Puccinia rust fungus.
White mold affects a wide range of hosts and causes sclerotinia stem rot. It is known to infect 408 plant species. As a nonspecific plant pathogen, [3] diverse host range and ability to infect plants at any stage of growth makes white mold a very serious disease. The fungus can survive on infected tissues, in the soil, and on living plants.