After reading this article you will learn about the toxicity symptoms of various nutrients in plants:- 1. Iron 2. Aluminum 3. Manganese 4. Copper 5. Zinc 6. Boron 7. Molybdenum 8. Chlorine.
Plant growth is reduced, Roots become thick and brown. Tiny brown spots appear on lower leaves of paddy plant. These spots begin to develop from the apex and then spread towards their base. Entire leaf become purplish if the toxicity is severe.
Usually roots are affected first and more severely than the shoot. Roots become thick and brown and their tips are enlarged.
The paddy crop display orange yellow chlorosis of leaves which may become necrotic if aluminum toxicity is very severe.
Young leaves become chlorotic; Minutex brown spots often appear on chlorotic leaves, leaf sheaths and lower parts of stems of cereal crops. The paddy plant is stunted. Tillering is reduced. Leaves especially the lower ones, develop brown spots on their veins and sheaths.
Young leaves develop interveinal chlorosis. Margins of older leaves are rolled. Older leaves are coloured reddish orange or pink .Ultimately they dry up. Roots become reddish brown and necrotic.
First young leaves develop interveinal chlorosis. Later these interveinal chlorotic areas turn reddish brown and dry up.
Reddish brown colorations often appear first near the base of the leaf and later spread towards the apex. The margin of the affected leaf is rolled. Roots become brown and necrotic.
Interveinal chlorosis of young leaves begins from their base and then spreads towards their apex. Then diffuse brown or reddish brown colour appears in the leaf margins and chlorotic areas.
Such colour is often very prominent in the interveinal areas and along veins which is often bluish green. The colouration intensifies and spreads to cover the entire interveinal areas which become dry and papery.
Yellowish white dis-colouration of the tip of older leaves of paddy plant is observed six weeks after the paddy crop has been transplanted.
Then their tips and margin become yellow. Then eliptical large dark brown spots appear in the dis-coloured area. Ultimately the entire leaf become light brown and dry up.
Molybdenum toxicity symptoms are brilliant golden yellow or blue tints, Reddish or golden yellow tints appear on shoots of potato and tomato while blue tints appear on shoots of barley and maize.
Chlorine toxicity symptoms are reduction in the number and size of leaves, bronzing and yellowing of the foliage and browning and scorching of leaf margins.