EFFECTS OF VARIOUS PLANT GROWTH REGULATORS ON THE NUTRITIVE VALUE AND YIELD OF ALFALFA

Abstract

Plant growth regulators (PGRs) were evaluated with regard to alfalfa quality parameters: acid detergent fiber (ADF), neutral detergent fiber (NDF), lignin, crude protein (CP), calcium, phosphorus and dry matter (DM) yield. PGRs mefluidide and chlormequat were applied 28 and 49 d after initiation of alfalfa spring growth in 112 and 225 L ha−1 of water, whereas maleic hydrazide, ancymidol, paclobutrazol, daminozide, dicamba, 2,4-DB, MCPB, flamprop methyl, carbofuran, accel and ethephon were applied 28 d after initiation of alfalfa spring growth in 112 L ha−1 water. Alfalfa ADF, NDF and lignin were significantly (P < 0.05) reduced in some trials by mefluidide, chlormequat, maleic hydrazide, dicamba, carbofuran and accel. Ancymidol and daminozide significantly (P < 0.05) increased fiber content and ancymidol significantly (P < 0.05) reduced the CP level. Carbofuran significantly increased CP (P < 0.05), calcium (P < 0.05) and phosphorus (P < 0.01). Mefluidide had significant (P < 0.05) effects on calcium and DM yield, but the nature of these responses was not consistent. Rate of mefluidide applied and time of application had significant (P < 0.05) effects on CP values. A large environment-PGR interaction was indicated.Key words: Mefluidide, chlormequat, maleic hydrazide, ancymidol, dicamba, carbofuran