Search results
Results from the WOW.Com Content Network
A large tree, with finely fissured bark. White latex turning black upon contact with air. Leaves are simple, alternate, arranged spirally, clustered at twig ends. Flowers are borne in panicles, 12-24 cm long, golden yellow pubescent, in leaf axils or at branch ends. Flowers are polygamous, greenish white. Fruit is obliquely ovoid, 1-seeded. [4]
Black spot leaf disease is a physiological plant disorder that affects some grape varieties such as Concord.It is essentially a potassium deficiency that causes the leaves on a vine to turn purple and eventually black as chlorophyll is lost.
Solanum nigrum, the European black nightshade or simply black nightshade or blackberry nightshade, [1] is a species of flowering plant in the family Solanaceae, native to Eurasia and introduced in the Americas, Australasia, and South Africa.
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]
It can cause complete crop loss in warm, humid climates, but is virtually unknown in regions with arid summers.” [1] The name comes from the black fringe that borders growing brown patches on the leaves. The disease also attacks other parts of the plant, “all green parts of the vine: the shoots, leaf and fruit stems, tendrils, and fruit.
Black sigatoka is a leaf-spot disease of banana plants caused by the ascomycete fungus Mycosphaerella fijiensis (Morelet), also known as black leaf streak. It was discovered in 1963 and named for its similarities with yellow Sigatoka, which is caused by Mycosphaerella musicola (Mulder), which was itself named after the Sigatoka Valley in Fiji .
As the leaves develop, they become increasingly distorted, and ultimately thick and rubbery compared to normal leaves. The color of the leaves changes from the normal green to red and purple, until a whitish bloom covers each leaf. Finally, the dead leaf may dry and turn black before it is cast off. Changes in the bark are less noticeable, if ...
Important leaf sucking insects include species of aphids and plant lice including (Monellia spp. and Monelliopsis spp.), which suck the juices from leaves and often deposit a sticky substance called "honey-dew" on the leaf surface that may turn black and prevent photosynthesis; and the walnut lace bug (Corythucha juglandis), which causes damage ...