The document discusses nutrient deficiencies and physiological disorders in horticultural crops, detailing common deficiencies in elements like zinc, manganese, and boron, and their symptoms across various crops. It also outlines corrective measures for these deficiencies, including soil applications and foliar sprays of essential nutrients. Additionally, the text highlights physiological disorders affecting crops such as bananas and mangoes, their causes, and suggested remedies to mitigate these issues.