Physiological Disorders of Fruit Crops / Sandhu Savreet and Bikramjit Singh Gill

1. Introduction 2. Aonla 3. Apple 4. Apricot 5. Avocado 6. Bael 7. Banana 8. Ber 9. Breadfruit 10. Carambola 11. Cashew nut 12. Cherry 13. Citrus 14. Coconut 15. Custard apple 16. Date palm 17. Durian 18. Fig 19. Grape 20. Guava 21. Hazelnut 22. Jackfruit 23. Jamun 24. Kiwi fruit 25. Litchi 26. Loquat 27. Mango 28. Mangosteen 29. Olive 30. Papaya 31. Passion fruit 32. Peach 33. Pear 34. Pecan nut 35. Persimmon 36. Pineapple 37. Plum 38. Pomegranate 39. Raspberry 40. Sapota 41. Strawberry 42. Walnut

Physiological or abiotic disorders are mainly caused by changing environmental conditions such as temperature, moisture, unbalanced soil nutrients, inadequate or excess of certain soil minerals, extremes of soil pH and poor drainage. The distinction between physiological or abiotic disorders from other disorders is that they are not caused by living organisms (viruses, bacteria, fungi, insects, etc.), but they are the result of abiotic situations (inanimate) i.e. their agents are non-living in nature which causes deviation from normal growth. They results in physical or chemical changes in a plant which is far away from what is normal and is generally caused by an external factor. Non-infectious disorders in some cases are easy to identify, but others are difficult or even impossible to recognize. Most of them are non reversible once they have occurred. For the identification of physiological disorders it is important that one must know that: a) Physiological disorders are often caused by the deficiency or excess of something that supports life or by the presence of something that interferes with life. b) Physiological disorders can affect plants in all stages of their development. c) They are non-transmissible because they occur without or in absence of infectious agents. d) Plant reacts differently to the same agent and sometimes response is seen as a little reaction to death. e) Dealing with physiological disorders often means dealing with the consequences from a past event. f) Generally damaged and undamaged tissue is clearly demarcated. g) Physiological disorders not only causes damage themselves but also serve as the ‘open door’ (entry) for pathogens.