physiological disorder.pptx

physiological disorder in plants

1. Physiological disorders in crop plants

2. Introduction

3. Nutrient Deficiency physiological disorders

4. Nitrogen deficiency Younger leaves become pale green and the older leaves turns yellow eventually. leaves that will eventually turn brown and die. Plant growth is slow, plants will be stunted, and will mature early.

5. Phosphorous deficiency Plant growth will be slow and stunted, and the older leaves will have a purple coloration, particularly on the underside.

6. Potassium deficiency On the older leaves, the edges will look burned, a symptom known as “ scorch ” . Plants will easily lodge and be sensitive to disease infestation. Fruit and seed production will be impaired and of poor quality.

7. Blosson end rot Physiological disorder in tomatoes and pepper due to deficiency of calcium . Tissue typically at the blossom end turns brown and then black and becomes sunken and leathery

8. Bitter pit in apple Bitter pit is a disorder in apple induced by calcium deficiency. It occurs commonly in pears. The affected fruit have dark spots about 0.5 cm diameter which occur on the skin and/or in the flesh. The cells in the spots are necrotic and turn brown black

9. Magnesium deficiency Older leaves will be yellow in color with interveinal chlorosis (yellowing between the veins) symptoms. Plant growth will be slow and some plants may be easily infested by disease.

10. Sulfur deficiency A general overall light green color of the entire plant with the older leaves being light green to yellow in color as the deficiency intensifies.

11. Hen and chicken disorder This disorder is cause by the deficiency of boron resulting in more number of undeveloped round or oblate short berries with few berries attaining the normal shape characteristic of the variety.

12. Internal black rot Lesions are typically tan, roughly circular, and approximately 1/8 of an inch in diameter Deficiency of boron Underlying cause is cell death

13. Chlorine deficiency Younger leaves will be chlorotic and plants will easily wilt.

14. Copper deficiency Plant growth will be slow and plants stunted with distortion of the young leaves and death of the growing point.

15. Iron deficiency Interveinal chlorosis will occur on the emerging and young leaves with eventual bleaching of the new growth. When severe, the entire plant may be light green in color .

16. Whiptail Caused due to the deficiency of molybdenum In young plants the deficiency symptoms are chlorosis of leaf margins and the whole leaves turn while The leaf blades do not develop properly. When the deficiency is severe, only the midribs develop

17. Excess Fertilizer/ Nutrients

18. Manganese toxicity It causes new leaves to become pale and rapidly develop light necrotic areas on leaf margins near the apex that move towards the midrib between the veins This necrosis can appear as fine pinpoint spots on tendril leaves As the toxicity increases some leaves develop severely necrotic tips and margins that shrivel leaving the leaf cupped

19. Chloride toxicity Symptoms are similar to typical salt damage Leaf margins are scorched and leaf size is reduced and appear to be thickened Overall plant growth is reduced Chloride accumulation is higher in older tissues than in newly matured leaves

20. Ammonium toxicity Plants fertilized with ammonium-nitrogen (NH4- N) may exhibit ammonium-toxicity symptoms. Lesions may occur on plant stems, there may be a downward cupping of the leaves, and a decay of the conductive tissue at the base of the stem with wilting of the plants under moisture stress. Blossom-end rot of fruit will occur and Mg deficiency symptoms may also occur. Poor emergence followed by wilting and death of seedlings; browning of central root tissue etc

21. Vegetable splitting Roots get splitted making it unfit for market. Root splitting increases with soils having high content of nitrogen and also with higher concentration of ammonium compounds

22. 3.Low temperature and frost Plants differ in their tolerance to low temperature. Low temperature slow down plant’s growth Frost often causes the above-ground parts of sensitive plants to collapse into a mess of green tissue after ice has formed inside the plant and fractured all the cells

23. Leaf chlorosis and frost banding Chlorosis was caused by a disruption of chloroplasts caused by winter cold. Green chlorophyll pigments are often converted in to yellow pigment namely chlorophyllins . Leaf may appear with distinct bleached bands across the blade of young plants called frost banding eg : sugarcane, wheat and barley.

24. Leaf necrosis and malformations Spring frost causes various types and degree of injury including cupping, crinkling finishing and curling of leaves of apple trees and stone fruits. The distortion is caused by death of the developed tissues before the expansion of leaves.

25. Stem disorders Frost cracks develop when tree trunk or limps lost their heat too rapidly. The outer layer of bark and wood cool most rapidly and subjected to appreciable tension causing marked shrinkage and cracking following a sudden temperature drop. Affected timber of poor quality.

26. 4. High temperature 1. Leaf scorch High temperature causes leaf scorch directly or indirectly by stimulating excessive evaporation and transpiration.  Tip burn of potato is a widespread example for this disorder. Maize: Marginal scorching

27. 2. Sunscald In leaf vegetable crops like lettuce and cabbage, when leaves on the top of the head are exposed to intense heat, water soaked lesions or blistered appearance occur These irregular shaped areas become bleached and parched later

28. 3. Water core In fruit crop like Tomato, exposure to high temperature causes death of the outer cells of fruit skin. Subsequently corky tissue occurs beneath the skin, with watery appearance of the flesh near the core of the fruits faster. Often light stress is coupled with heat stress eg. sun scald of bean, sun burning of soybean and cowpea. In flower crop like chrysanthemum, increase in light intensity affects flower bud formation. Reproduction phase does not commence and modified into leaf like bracts. Pear: Water core

29. 5.Lack of light Adverse light intensity causes impaired growth and reduced vigour. Subsequently leaves gradually lose green colour, turning pale green to yellow, stems may dieback little every year. Insufficient light limits photosynthesis, causing food reserves to be depleted.

30. 6.Overwatering

31. 7.Underwatering The plant needs sufficient water to carry nutrients around to transpire from the leaf in order to keep a desirable leaf temperature and to maintain turgidity in some plant tissues In some plants leaves changes from shiny to dull as a first signal of water stress and also may change from bright green to grey green Flowers may fade quickly and fall prematurely Water should be applied as per requirements of the plants

32. 8.High concentration of co2 High concentration of CO2 is generally beneficial for growth and provide maximum benefit between 0.1 and 0.2 Kpa Photosynthetic activity actually reduces when CO2 concentration exceeds optimal level so plant may turn yellow Plants which are sensitive to higher levels of CO2 should not be grown in closed environments