Effects of Bacterial Fertilizer on Growth and Photosynthesis of Bambusa tuldoides in Late Bamboo Shoot-forming Stage

Three-year-old Bambusa tuldoides plants were used in the study. A biofertilizer was applied at the rates of 0, 0.3, 0.6, 0.9, 1.2 or 1.5 kg per unit to patches of the plants. The photosynthetic properties, including net photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs), intercellular carbon dioxide concentration (Ci)and chlorophyll content of the leaves, as well asthe water usage efficiency (WUE) andbamboo shoot-forming rateof the plants were determined and fitted to a hyperbolic model for correlating the responses under varied lighting conditions. The correlation coefficients were better than 0.99 on the model fitting. For individual indicators, Pn increased sharply initially, then leveled off, and decreased after reaching the light saturation; and, Tr, Gs, and WUE hada similar response to the treatments, but Ci wasthe opposite. In varying degrees, the fertilizations increased the leaf utilization of high and low light. Thephotosynthetic parameters closely related to the chlorophyll content of the leaves and the shoot-formation of the plant. It was concluded that application of the biofertilizer at a rate of 0.6 kg·patch^-1 was optimal for the growth and developmentof B. tuldoides.