Table C. Phosphorus, potassium and sulphur recommendations for sunflower based on soil test levels and placement. Following are plant tissue analysis interpretive criteria used by the former Manitoba Agriculture Provincial Testing laboratory. These levels should be used for the top 1-3 most mature leaves collected at the bud stage. Consult with your soil and plant tissue laboratory for guidelines when sampling at other stages of growth. These reserves of water and nutrients are unavailable to most other annual crops, making sunflower a good rotational crop.
Sunflowers are very susceptible to seed-placed fertilizer injury.
To avoid seedling injury from fertilizer, best results are obtained by placing starter fertilizer in a band two inches below and beside the seed. Broadcast incorporated prior to seeding 2. Fall or Spring banding Table D. Sunflower tissue analysis interpretation. No provincial guidelines developed. Consult analytical companies.