As indicated by tissue analysis, throughout the growing cycle. Manganese is not mobile within the plant, so must be continuously available, although in small amounts. Too much manganese is harmful, so tissue analysis testing is necessary. Amounts needed may vary by crop.
Manganese is essential to strong, healthy growth, and supplementing manganese is particularly beneficial in small grains, soybeans, sweet corn, and vegetable crops. It supports root growth, photosynthesis, pollination, respiration, and disease and stress resistance.