Physiological characterization of cut-to-cut yield variations of alfalfa genotypes under controlled greenhouse conditions

摘要

In a temperate region, alfalfa (Medicago sativa) crops are usually harvested 3-6 times per annum. The biomass yields of first and second cuts in the spring are generally the highest. However, in subsequent cuts the biomass yields decline, with the final 1 or 2 cuts producing the lowest yields (Wang et al. 2009). This seasonal reduction in alfalfa biomass yields could be associated with prevailing changes in environmental factors such as rainfall and heat stress or due to biological characteristics of alfalfa crop itself. In this study, alfalfa was grown under controlled greenhouse conditions with suitable temperature, light, water and nutrient supply to determine the driving force in cut-to-cut biomass yield variations among alfalfa genotypes.