Using the self-reporting photo-quantity analysis, the light response curves of leaves under different RPARs are quite different (here, PAR is the PAR value at the top of the canopy). Under low light conditions, the overall photosynthetic value of the leaves grown is not small and there is no obvious light saturation point. It is because these leaves are located in the lower or inner layer of the canopy, and it is difficult to reach the point of light saturation due to shading. When the RPAR was greater than 40%, the photosynthetic light saturation point of the leaves decreased as the radiation conditions improved. The COZ concentration response curves of leaves under different RPARs also differ greatly. Under low light conditions, Pn reaches saturation when the COZ concentration is low, and the COZ saturation point of photosynthesis of the leaves is improved with the improvement of radiation conditions. It also increased, which was mainly due to the thickened leaves and increased chlorophyll after the radiation was improved, so its ability to assimilate COz was also enhanced.
Under different radiation conditions, the temperature response of the leaves showed a "convex" shape curve, but the leaves were dead. The optimum temperature is increased with the improvement of radiation conditions, and most of the blades are 20-300C. The radiation intensity obtained from the upper canopy and peripheral leaves is often subjected to more high-temperature stress, and this difference in the leaves contributes to the improvement of the overall photosynthesis ability of the canopy and to the full use of light energy. The response of leaf Pn to RH under different RPAR conditions was similar and increased slightly with RH. Under different RPAR conditions, the response of the blade to the Gong is also similar, and it increases with the elevation of the Gong, but the change is more significant when the Gong is lower than -1.SMPa. According to the height of the leaves in the crown can be divided into 3 categories, the lower leaves (Q.5m), middle leaves (1.5-2.5m) and the upper leaves (> 2.5m).
The self-reporting photo-quantity meter has a very important guiding significance for the orchard management pruning. Fruit trees are generally planted in rows and have a specific tree structure. The leaves in the canopy have great heterogeneity, and the radiation and photosynthetic capacity of the leaves in different parts vary greatly. Simply studying leaf photosynthetic characteristics Czi7, or using the layered model to study the photosynthetic characteristics of the tree crown can hardly reflect the overall photosynthetic laws of the crown, especially the photosynthetic difference circle of different parts of the crown. This difference is of great significance for the study of fruit tree characteristics, reasonable load, and precision pruning.
Determination of Net Photosynthetic Rate of Different Irradiated Apple Leaves by Self-Recording PhotoQuantum
One of the important factors affecting the growth and development of plants is photosynthesis. For orchards, photosynthesis directly determines the yield and quality. This is because light determines the distribution of leaf photosynthesis in the fruit tree canopy. The fruit tree canopy has a very complicated heterogeneity, and the photosynthetic capacity of the leaves in different parts of the tree canopy differs greatly. This difference is mainly caused by the radiation received by the leaves. When the leaves of fruit trees receive different radiation during their development, their photosynthetic organs will also change and change their photosynthetic capacity. Because the photosynthetic capacity of the different parts of the canopy and the absorbed radiation are in a certain proportion, the leaf P can be constructed. Simulations were performed with a mathematical model of photosynthetically active radiation (PAR). The recording of photosynthetically active radiation can be performed using a self-reporting photoquantometer.