Estimation of total nitrogen content in sugar beet leaves based on chlorophyll fluorescence parameters

Abstract

Two sugar beet cultivars, Beta 356 and KWS9147, were grown in field trials at four different nitrogen contents (0, 75, 150, and 225 kg ha-1), and each fertilizer treatment was divided into four applications (100% prior to seeding; 70% prior to seeding and 30% at canopy development; 50% prior to seeding and 50% at canopy development; 30% prior to seeding and 70% at canopy development) in two consecutive growing seasons. Leaf chlorophyll fluorescence (ChlF) parameters and leaf nitrogen content were measured simultaneously at different growth stages, establishing an evaluation model of leaf nitrogen nutrition. The results showed that the correlation between ChlF parameters and leaf nitrogen content reached 0.7099** (canopy development), 0.8266** (storage root development) and 0.8607** (sugar accumulation stage). We conclude that the ChlF parameters can provide a decision-making method for N diagnosis and regulation in field production.

Keywords

• electron transport rate
• maximum electron transfer efficiency
• monitoring
• nitrogen nutrition index