Relationship in Winter Wheat Between Lodging, Physical Properties of Stems, and Fertilizer Treatments 1

F. L. Miller and Kling L. Anderson CAUSES of lodging in cereal crops have attracted attention for over 100 years. Some of the early investigators (4, 19) thought that silica was the most important factor affecting the strength of culms, but others (7, 12, 17) considered lignin to be more important than silica in the conferment of stem strength. More recently, Phillips et al. (14) found a higher lignin content in the straw of lodged wheat plants dressed with sodium nitrate than in nonlodged control plants, from which it was concluded that a high lignin content made stems less resistant to lodging. Since lodging often causes considerable economic loss, attempts (1, 2, 5, 11, 13, 15, 18, 20) have been made to relate susceptibilities of crops to lodging to a wide range of physical characteristics and environmental regimes, but no over-all agreement on causes or effects exists. Similarly, in nutritional studies (8, 9, 10, 13, 19), apart from general agreement on the adverse effects of nitrogen on resistance to lodging, there is no widely held agreement on the effects of other major elements, more particularly phosphorus and potassium. Attempts have been made to relate varietal characteristics to lodging. Ability to recognize such characteristics early in a plant breeding program would be valuable, especially where lodging is not a regular occurrence. There is, however, no general agreement on the relative importance of varietal factors as indices of resistance to lodging though greatest consistency of results is found in length of lower internodes and thickness of schlerenchyma, resistance to