Mineral Deficiencies in Plants

Description

Nutrient deficiency symptoms appear only after the nutrient supply is so low that the plants can no longer function properly. In such cases, it would have been profitable to have applied fertilizer long before the symptoms appeared. If the symptoms are observed early, it might be corrected during the growing season. Since the objective is to get the limiting nutrient into the plant as quickly as possible, with some nutrients and under some conditions this may be accomplished with foliar applications or side dressings. This leads to the abnormal conditions recognized as symptoms. Visual evaluation of nutrient stress should be used only as a supplement to other diagnostic techniques (i.e., soil and plant analysis). Deficiencies can occur even when the nutrient is in optimal supply if there are other factors like water logging, which can affect the soil’s ability to transfer the nutrient or the plant’s ability to access it. For example, high pH levels in soil restrict availability of zinc, copper, manganese and iron, and dry top soil can limit the uptake of calcium and boron early in the season. The present book describes a method of recognising by sight deficiency symptoms of the various mineral plant nutrients in commonly grown agricultural and horticultural crops.