Why must knocking be done in the early hours of the morning?

Rubber tapping, cutting the bark and bast of rubber tree to let the milk flow out. The method is as follows: First, apply force to the left wrist, hold the rubber knife with the index finger of the right hand, tilt the knife inward, insert the bark and gently pick it out. Knife: after holding the knife, you must accurately cut the square skins on the tree one by one; Knife collection: put down your hand, follow your right foot for half a step, turn slightly, face the rubber tree, scrape out the knife, and finish the knife collection neatly. Why do you have to cut the glue in the early morning? Rubber workers wear lampshades and practice tapping in the rubber forest before dawn. It turns out that there are a lot of latex tube in the bark of rubber trees. When the bark is cut, it will overflow. The speed and quantity of milk flow are closely related to temperature and air humidity. The temperature is the lowest and the humidity is the highest in the morning. At the same time, rubber trees rest all night, with sufficient water and minimal transpiration, and tapping is the best at this time. According to the analysis, the optimum tapping temperature is 36℃, when the latex output and dry rubber content are the highest. When the temperature is over, the water evaporates quickly, the latex solidifies quickly, the glue discharging time is short, and the yield is low. But the lower the temperature, the better. Below this temperature, the latex flows slowly, takes a long time to discharge, and the latex concentration is low, which is easy to cause bark disease or dead skin.