Compared to the control (no calcium added), in treatment with 10 mmol/L calcium the height growth of the seedlings increased by 35.3%, basal diameter increased by 39.8%, biomass and root-shoot ratio increased by 28.1% and 29.8%, respectivel y.
To Platycladus orientalis seedlings, it is 0.1mg/L> 0.2mg/L>0mg/L>0.3mg/L>0.4mg/L, suggesting that the drought resistance of three arbor seedlings were more raised by lower concentration NBR treatment than higher concentration NBR treatment.
Adopting 6 transplanting densities(20cm×20cm,20cm×10cm,20cm×7.5cm,20cm×5.0cm,20cm×4.0cm,20cm×3.3cm) of seedling of Pinus sylvestris var.mongolica,the experimental results showed that the height growth of seedlings was not significantly different. The variation of ground diameter reached 1%.
Among 25 combinations,N3P3K5 was the best for the height growth and biomass accumulation of ginkgo seedlings,N3P1K3 and N5P1K5 were the best for the increase of chlorophyll content in leave,and N3P2K4,N2P3K4 and N3P3K5 were best for the increase of photosynthetic rate.
Effects of Cutting Density on Growth, Yield and Quality of Poplar Clone Seedlings
In order to identify the optimum cutting density for producing the highest number of plantable seedlings of poplar clones, a split-plot randomized block design was used to establish four cutting densities in plots.
Results indicated that the leaf area, stem and leaf biomass, and caliper of seedlings of all four poplar clones increased with the decrease in cutting density.
The quantity of first-grade seedlings (grade I) for clones Nanlin-95 and Nanlin-895 was achieved at the spacing of 40 cm×50 cm; for NL-1388 and NL-80351, it was 50 cm×50 cm.
According to the seedling quality and the number of plantable seedlings produced, the suggested cutting density for these four poplar clones was 50,000 stems/hm2.