Response of Growth, Productivity and Quality of Some Egyptian Clover Cultivars to Bio and Organic Growth Stimulators

A field experiment was conducted at the Experimental Farm, ElGemmeiza Agricultural Research Station, Egypt, during the2022/2023 and 2023/2024 seasons to evaluate the response of three Egyptian clover cultivars (Gemmeiza 1, Helaly, and Serw 1) to eight bio and organic fertilization treatments. The treatments included a control (T1), seed inoculation of NPK biofertilizer (T2), foliar applications of effective microorganisms “EM1” (T3), fulvic acid (T4), and dry yeast (T5), seed inoculation of NPK biofertilizer plus foliar application with each of EM1 (T6), fulvic acid (T7) or dry yeast (T8). Helaly cultivar mostly exhibited the best growth, forage productivity, and quality traits, while Gemmeiza 1 had the highestnumber of heads per square meter. Among fertilization treatments, T7 (NPK biofertilizer inoculation + fulvic acid) produced the highest growth, forage yield, and seed yield, while T8 (NPK biofertilizer inoculation + yeast) resulted in the highest protein and digestible protein percentages. The interaction effects showed that T7 significantly enhanced plant height, total dry weight, and seed yield in Gemmeiza 1, while it increased fresh forage yield in Helaly. Positive and significant phenotypic correlations were observed between fresh forage yield and growth traits, as well as between seedyield and its components. These results highlight the potential of bio and organic fertilizers to enhance the productivity and quality of the three tested Egyptian clover cultivars, especially Helaly cultivar when it was sprayed with growth stimulator (fulvic acid) at a rate of 2 g/ liter under the investigation conditions.