Clementine mandarin: biomass formation, distribution and nitrogen uptake trends

Abstract

The aim of this study was to investigate the biomass formation and nitrogen (N) uptake trends during vegetative period in Clementine mandarin (Citrus reticulata Blanco). In this study, the organs (branch, leaf, flower, bud and fruit) of shoots <12 and >12 month-old were analyzed for biomass formation and distribution, N concentration and uptake amounts for 2 years. Results showed that biomass accumulation was 9.7 kg/tree at the beginning of production season, 62.8 kg/tree before harvest and 46.9 kg/tree at the end of production season. Nitrogen concentration showed a decreasing trend in leaves and fruits of shoots <12 month-old while a decreasing trend was observed in fruits and an increasing tendency for leaves in shoots >12 month-old. It is concluded that 1377 g N/tree accumulated in the shoots (<12 and >12 month) of the Clementine mandarin trees through one production season (262 days). This amount was provided by both soil and fertilizer N in addition to remobilization. In consideration of total N and organic matter values of the soils in the research groves and the amounts of N-containing fertilizer that were applied, it may be seen that remobilization may have a significant part of the supply of N for different organs in total throughout the production season or based on different periods. These results show that improvement in biomass and N allocation can be achieved in Clementine mandarins through proper tracking of N uptake during different growth stages and in different plant organs.