chemicals and chemical agents used in agricultural and horticultural applications, particularly for application to crops, namely, fertilizers, fertilizer additives and supplements, mineral supplements for plants, plant growth regulators, plant hormones, hormone co-factors, micronutrients and flowable sulfur for use as a fertilizer, all for use in a treatment program for improving the ability of plants to withstand stresses, improve resistance to and inhibit attack by diseases and pests, increase genetic expression and achieve optimum growth, enhanced yield and improved quality by application to plants according to a systematic plan and provided as flowable solids, liquids or liquid solutions ready to apply or as concentrates