Some Manganese-iron Relationships in Tomato Fruits Grown on Marl, Peat and Sand Soils

take as well as to the supply and uptake of calcium. Evans and Troxler (4) working with blossom-end rot, a physiological disorder of the tomato fruit, have indicated that or ganic acids may have an influence on calcium assimilation. Blossom-end rot seems to be similar to blackheart of celery in that calcium appears to be a limiting factor as associated with conditions similar to those associated with blackheart of celery. In considering the nature of the suggested cause and the success of the foliar calcium treatment as well as the pertinent material in the literature, it appears that calcium must be supplied at the proper time and to the proper place for successful control of blackheart.