floriNEWS Magazine.pdf Jul. 2014 | Page 8

6 COLUMNIST metabolism including auxin-like responses and increased cytokinin levels. In addition organic acids in humic substances, including humic acid, inhibit the precipitation of calcium phosphate minerals, enhance phosphorus bioavailability and increase the availability of especially iron and zinc. Seaweed extract-based biostimulants on the other hand influence root development by endogenous auxins as well as other compounds in the extracts resulting in improved nutrient and water uptake hence enhanced plant growth and vigour. Cut flower growers may choose a plant biostimulant from the groups described above based on the benefits and composition of the product, mode of action, desired plant responses, crop conditions among others. Biostimulants cannot substitute fertilisers but improve plant mineral uptake efficiency, enhance plant metabolic processes and stress tolerance, promote growth and increase crop yields and quality. Biostimulant products are therefore not growth miracles but scientific growth enhancers. Besides, seaweed contains polysaccharides especially laminaran which stimulates natural defence responses in plants. CROP PROTECTION Fungicides Herbicedes Insecticides PGR CROP BIOSTIMULATION Amino Acids Sea Weeds Humic Acids CROP NUTRITION Fertilizers Soil Amendments Substrates Biostimulants are complementary to nutrition and crop protection “Amino acid-based biostimulant products directly play a vital role in nitrogen and carbon metabolism, and the resistance of plants to abiotic and biotic stress.” 8