Growth-promotion of plants with depolymerized alginates by irradiation

Alginate has been degraded by gamma-ray irradiation from a Co-60 source in liquid state (aqueous solution) and in solid state (powder form). The irrad iated alginate with a molecular weight less than 10(4) shows a strong effec t on the growth-promotion of rice and peanut. Low concentration of degraded alginate from 4% solution irradiated at 100 kGy is effective for the growt h-promotion of plants and the suitable concentrations are cn 50 ppm for ric e and ca 100 ppm for peanut. (C) 2000 Elsevier Science Ltd. All rights, res erved.