Ispitivanje utjecaja primjene bioalgeena i megagreena u uzgoju koprive provedeno je 2012. godine na porečkom Poljoprivredom odjelu Veleučilišta u Rijeci. Sjeme bugarskog podrijetla je zasijano polovinom ožujka, pikiranje obavljeno polovinom travnja, a sadnja u prvoj polovici svibnja. Prvo tretiranje preparatima obavljeno je u stadiju presadnica, drugo i treće nakon sadnje, zalijevanjem otopinom 1 % bioalgeena i folijarnom primjenom 0, 3 % megagreena. Praćen je porast i prinos koprive, udio lista, sadržaj suhe tvari i vitamina C. 0, 3 % megagreen je signifikantno djelovao na porast presadnica, % udio lista i sadržaj vitamina C. Najveći sadržaj suhe tvari u listu je utvrđen u netretiranoj koprivi. Cultivation of common nettle with testing of preparates bioalgeen and megagreen has been conducted in 2012 at the Agricultural department in Poreč, Polytehnic of Rijeka. Nettle of Bulgaran origin were sown in the middle of March, seedlings pricled out four weeks later and planted in the first half of May. First treatment with bioalgeen and megagreen was done in seedlings stadium, second and third after planting ; 1 % bioalgeen through watering and 0, 3 % megagreen foliar. Monitored were growth and yield of nettle, proportion of leaves, dry mass and vitamine C content in the fresh leaves. Megagreen 0, 3 % had significant effects on seedlings growth, percentage of leaves and vitamine C content. Highest dry mass content in fresh leaves was determined in the control variant.