Germination of seeds from carrot, lettuce, and pepper plants grown under severe nutrient deficiencies

Plants of carrot, lettuce, and pepper were grown in sand cultures receiving either a complete nutrient solution or one deficient in N, P, K, or Ca. An effort was made to produce severe deficiency, but not to a point at which no seeds would be produced. Plants showed various deficiency symptoms, including necrosis of the growing tips, with calcium deficiency, and necrotic spots along the leaf margins in the case of potassium deficiency. Seed yields were always depressed by low N, P, K, or Ca treatments. Percentage of normal seeds was depressed by low N, K, or Ca, but not by low P. At harvest, seeds from low Nand P treatments usually showed the same germination as that of seeds receiving complete solution. However, K deficiency resulted in lower germination in some experiments, as did Ca deficiency in carrots and peppers. In storage, seeds from low K and Ca treatments declined in germination faster than did seeds from the complete-solution treatments.