Effect of nitrogen Nutrition on the growth and Development of Cymbidium

1. The effect of NO3-N and NH4 +-N on the growth rate of leaf buds and leaves: there was no significant difference between the two forms of nitrogen of lmM on the growth rate. With the increase of concentration (10.50mM), the growth rate was lower than that of 1mM, especially NH4+-N. For leaves, the NO3-N of 1 and 10mM is suitable, and 50mm 4 +-N is disadvantageous to the growth of leaves.

2. External morphology and morbidity: 1There was no significant difference in the appearance of 10mm NH4 +-N plants, but the plants treated with 50mMNH4+-N were dwarf and toxic, and the leaf morbidity was significantly increased at high concentration of NO3--N (50mM).

3. Effect on flower bud formation: no flower bud formation of plants treated with NH4+-N during flower bud formation, 1 and

Flower buds were formed in 10mm MNO _ 3-N treatment.

4. Effect on photosynthetic rate: the photosynthetic rate of NO3--N treatment was higher than that of NH4+-N treatment.

The photosynthetic rate of 10mMNO3--N treatment was the highest. High concentration of N (50mM) decreased the photosynthetic rate.

5. Effect on chlorophyll content and protein content: with the increase of nitrogen level, chlorophyll content increased, but the chlorophyll content of leaves treated with NH4+-N was higher than that of NO3--N. The protein content of plants treated with NH4+-N was higher than that of NO3--N and increased with the increase of concentration. (Ye Qingsheng, Pan Ruichi)