[Effects of nitrogen application level on photosynthate distribution of Korla fragrant pear trees].

Using C pulsed labeling technique, we examined the biomass and carbon accumulation of different organs as well as the distribution characteristics of C assimilate of 6-year-old Korla fragrant pear trees under three nitrogen application levels, ., 150, 300, and 450 kg N·hm (marked as N, N, and N, respectively). Results showed that the biomass, carbon accumulation, C fixation and leaf assimilation capacity of the whole pear tree increased while root to shoot ratio decreased with increasing nitrogen application.

[Characteristics of absorption, utilization, and distribution of N-urea for Korla fragrant pear in spring].

Six-year-old Korla fragrant pear trees were fertilized with N-labelled urea before early bud stage to examine the absorption, distribution, and utilization of urea. Results showed that there was a significant difference of N distribution rate in organs at different growth stages. N was pre-ferentially distributed in the roots , with Ndff (N amount absorbed from the fertilizer contribution rate of the total nitrogen organ) being the highest in roots following by new shoots at full-bloom stage.