Peeled Onions,Fresh Peeled Onions,Peeled Fresh Red Onion,Fresh Yellow Onion Peeled Yirun Agricultural Cooperative , http://www.yiruncn.com
2. Branches freeze damage: normal development of the branches, although the cold resistance is stronger than the twigs, but the freezing temperature will occur when the cold is low. From the appearance point of view, there is no major change, but the interior becomes brown, causing serious black hearts. The frostbite's branches will not die for a time, but the xylem vessels will be blocked, the water will not be able to flow, the nutrients will be lacking, the germination will be late, the leaves will be thin or deformed, the growth will be abnormal, and the cold will soon die.
3.æ¡ æˆ Freezing injury: Branching at the intersection is due to the late stopping of life activities, poor cold tempering, and low cold resistance; if the angle at the raft is small, it affects the development of the tissues inside the angle, and the cold resistance is also low. When the jellyfish were frozen, the cortex was submerged or cracked in the frozen part, and the interior became black and the tissue died. In severe cases, the branches also died.
4. Frost damage of roots and stems: roots and stems refer to the base. In the root neck, the cortex darkens, lightly occurs in parts, and when it is heavy, it forms a black ring and surrounds the stem. The whole tree dies. The main cause of freezing and chilling of the root and neck is to enter the body to sleep later, and to release dormancy is earlier. In addition, near the surface, the temperature change is fierce, and it is also the cause of frost damage to roots and stems.
5. Root freezing damage: The external appearance of frost damage on the roots is the browning of the cortex, the separation of the cortex and the mass, and even complete shedding. Statistics show that the critical temperature for frost damage in different tree roots is also different. When the root soil temperature reaches the following temperature, the root system will be frozen: peach -10 °C; jellyfish -12 °C ~ -16 °C; apple -10 °C ~ -12 °C; Yamanashi -16 °C ~ -19 °C and so on.
6. Cold damage to flower buds: When the flower buds are severely frozen, all flower buds die and die, or the inner marrow becomes brown and the base of the scales turns brown. Sometimes the flower primordium is frozen or part of the flower primordium is frozen, and the stigma is black and dry. This is due to the retardation of flower development or malformation, and the frost damage at the late stage of flower buds shows that the pistil is frozen. As the flower buds are released from dormancy early, the early spring is most susceptible to freezing. In addition, the temperature in the deep winter season is unstable. The short-term high temperature causes the cold resistance of the flower buds to decline, and flower buds are often frozen.
Discussion on Several Performances of Frost Damage in Fruit Trees
1. Tender cold injury: Late growth, the development of immature twigs, because the organization is not full, the underdeveloped protective organization, easy to suffer freezing injury and death. For example, branches that are high in apples and pears are often overwhelmed by overgrowth and are not fully developed. After a severe winter cold, the entire branches become brown and dry.