Prevention and control measures of diseases and insect pests caused by heavy snow pressing and cutting branches of red bayberry

Red bayberry is an evergreen fruit tree, because of its dense branches and leaves, closed canopy, easy to snow, crisp branches, easy to be broken by snow, especially the bayberry trees in the shallow soil layer are often uprooted or lodged. There are three main aspects:

Red bayberry snow damage

(1) Frost injury: the lowest tolerance temperature of bayberry is-9 ℃. During the snow thawing period, alternate thawing and uneven cold and heat cause frost damage to branches, leaves and flower buds of bayberry, resulting in poor flower bud differentiation and reduced yield.

(2) injury: if the root system of the bayberry tree growing in the shallow place is lodged or uprooted, the root system is injured, the transport of nutrients is blocked, the injury is serious and the pruning is sawed off, the fruit needs to be hung again after 2 years; if the injury is minor, only part of the roots and branches are cut off, on the contrary, the flower bud differentiation is promoted, and the bayberry tree blossoms more, the fruit setting rate is high, the fruit quality is small, and the quantity of spring shoots is affected and the size of the year is formed.

(3) Diseases and insect pests: although heavy snow can kill some overwintering pests and germs in the bayberry orchard and reduce spring diseases, the wound heals slowly after bayberry branches and leaves are bruised, and after the beginning of spring, germs invade from the wound to encourage the spread of red bayberry cancer, brown spot and red clothing disease, leading to the outbreak of moths and other pests.

Second, manage the "trilogy":

(1) before heavy snow: red bayberry trees should be propped up or tied with ropes, especially around the canopy with a large number of branches and leaves, the "thinning of branches" method should be used in advance; there is often snow harm, and the natural happy shape of big branches should be trimmed (commonly known as "open skylight"). In this way, the branches are sparsely distributed, so as to facilitate snow fall and reduce snow damage.

Remove the snow from red bayberry

(2) when it snows heavily: shake down the bayberry trees in time. No matter whether the snow stops or not, once you find snow in the canopy, shake the snow or hit it with a bamboo pole to reduce the amount of snow in the canopy.

(3) after the heavy snow: it is necessary to strengthen the nursing of bayberry trees in time. After the snow injury, the red bayberry tree has many wounds and the tree potential is weak, so it is necessary to clear the garden, fertilize, cultivate the soil and spray in time to restore the tree potential as soon as possible.

3. Management measures:

(1) clear the garden in time: if there is still snow on the bayberry tree after the snow has stopped, shake it down as soon as possible to avoid breaking the branches; release the pillars or bindings in time and deal with the broken branches. For those that are completely broken, they should be sawed off as soon as possible, flattened, and coated with protective agents such as wax to prevent decay; for those that are not broken, they should not be sawed off easily, but should first be lifted or propped up by rope, restored to their original state, coated with wax at the injured site, etc., and tied up to promote their healing and restore growth. To the partial lodging, should retract the big branch, cut the root again, the height is less than 2.5 meters, and dig loose root place soil, part of the broken root is excavated, the tree body is held straight, and then fixed with big branch or rope, the root is re-buried in the soil, filled with new soil and firm; serious, it can be built into a circle with stones around, fill the soil, straighten up the tree, and the wound is coated with wax and other protective agents to prevent the sun from cracking or water mildew.

(2) cultivate soil and fertilize in time: some bayberry trees with exposed roots should add guest soil in time and apply a small amount of quick-acting fertilizer. Guest soil, it is best to use fresh yellow soil under awn dustpan or surrounding topsoil. The amount of basic fertilizer, determined according to the crown and growth potential, is generally applied with compound fertilizer 0.2~0.3kg or urea 0.l~0.2kg containing potassium sulfate per plant. If possible, spray as much as possible 1000-1200 times liquid efficient rare earth, or 0.2% potassium dihydrogen phosphate, or 0.2% urea and other foliar liquid fertilizer to quickly supplement tree nutrients.

(3) timely spraying: after snow damage, we should pay close attention to the prevention and control of bayberry brown spot, moths and other diseases and pests, and adopt the method of "mass prevention and control" for bayberry producing areas with relatively serious diseases and insect pests; for those red bayberry trees with weak growth or old trees, we should pay close attention to prevention and control on the basis of pruning, so as to reduce pests and maintain good growth as far as possible. The agent can use 15% carbendazim 800 × 1000 times, or 70% methyl topiramate 1000 times, or 65% mancozeb 800 times.