Regulation Of The Yield And Quality Of Alfalfa

Alfalfa(Medicago saliva) is an excellent forage with good quality and ecological benefit. Alfalfa forage production is getting more and more attention with the animal husbandry development and agricultural industry adjustment. Yield and quality are the two most aspects in alfalfa. Presently, variety improvement, increment in P,K and microelement and selection on suitable cutting period are main methods to improve yield and quality. Little relevant researches on yield increment and quality improvement by plant growth regulators were reported.From 2001 to 2002,function mechanism and adjustment of various regulators on Aohan alfalfa was studied from the cooperation of yield and quality. DTA-6 growth promoter and DPC retardant which are little toxin and environmental friend, and their compound were selected.Alfalfa were treated by DTA-6 50, DPC50 and DTA-6 50+DPC50mg .L-1 on two levels after every cutting with 10cm height. The researches on effect of regulators on forage yield, quality, protein metabolism , hormone system were studied. The results were as follows,1 The retardant,DPC and their compound increased forage yield. The growth promoter,DTA-6 decreased forage yield. DPC inhibited plant height increment, increased branches and raised plant weight.DTA-6 made an increment on plant height, a decline on branches and plant weight. Plant height increment, which was not obvious compared with DTA-6 treatment ,were found in the compound treatments where branches and plant weight were raised.2 The regulator treatment improved agriculture characters and nutrition.The three regulators treatment raised crude protein content and increased crude protein yield in unit leaf area. Among various regulators treatment, DPC and the compound treatment increased crude protein content in leaves and stems and DPC 50 mg . L-1 made the most clear effect that crude protein in leaves and stems rose respectively by 4.87% and 2.26% compared with the control exclude that DTA-6 decreased crude protein content in the stems.3 DTA50+DPC50mg . L-1 made the best comprehensive treatment results which had the biggest increment on unit area yield and crude protein output, made an 1262.6kg . hm-2 yield and 363kg . hm-2 crude protein output increase compared with the controls.4 DTA-6 50, DPC40 50mg.L-1 increased amino acid content in leaves. DPC 50 mg .L-1 made an clear leave amino acid increment compared with the controls. Various regulators had large adjustment difference on essential amino acid, hemi-necessary amino acid and sulfur-amino acid and the overall DPC effect was better than other treatments.5 DTA-6 decreased the contents of NDF,ADF and hemicellulose in stems and leaves and DPC and the compound increased the contents of NDF.ADF and hemicellulose in stems and leaves.6 DPC and the compound changed material metabolism and distribution by adjustment on endogenous hormones in alfalfa .The levels of CTKS,ratio of IAA/ABA and GA/ABA were raised in plant after regulator treatment which was good for plant caducity redartance.7 The research showed suitable regulators could realize synchronous improvement of yield and quality in alfalfa.