How to enhance lighting in greenhouse fruit trees

Sheltered fruit trees need good lighting, but the light intensity in the greenhouse is generally only 60% to 70% under natural conditions. At the same time, the natural lighting time in winter is short and the intensity is poor, which can not meet the demand for fruit tree growth. Mainly for the growth of fruit trees slender, thin pale leaves, after flowering, the fruit set rate is low, the fruit quality is poor. Therefore, in order to achieve high yields and high efficiencies, fruit trees must be first dealt with in the shed.

First, shady room construction should be less shading

Shed shelters should be selected, sunny spots, facing south and extending east and west. If there are adjacent sheds, the distance between the sheds should be maintained from 7 to 8 meters. It should be maintained at 9:00 a.m. on the winter solstice so as not to shade each other properly. In the premise of ensuring the structure of the shed is firm and easy to control temperature and humidity, the height of the shed must be properly reduced. The lower the height of a typical shed, the better the lighting effect. According to different tree species to determine the appropriate height of the shed, the shed height of 2.5 meters as the bottom. The structural pillars of the sheds should be less, and the pillars should not be too thick or too wide. The shade of the arches of the sheds should be so narrow that they would be less shady. Appropriate greenhouse lighting angle can increase lighting in the shed, the lighting angle is generally 24 to 28, and the angle of the rear roof is about 45 degrees.

Second, choose a good film and keep it clean

It is advisable to choose a transparent shed film such as polyvinylidene chloride-free long-life film and polyvinyl chloride fog film. Dropless film can improve the transmittance of 20% to 30%. The dust and snow on the cover film can be covered with a broom or wood poles or cleaned with a motorized sprayer. The inside and outside of the film can be kept clean, increasing the amount of light injected, which can enhance the effect of light. .

III. Selection and planting of tree species

Should choose tree dwarf tree species (variety) planting. In order to increase the utilization of light energy, it is necessary to plant trees in the north and south, and plant ridges in high ridges. The height of the trees in the northern part of the tree group is the highest in the north, and the lowest in the south is to form a slope with a north high and a low south.

Fourth, trimming and ventilation

For the fixed height of the seedlings, the front part of the tree is lower and the rear part is higher. The tree shape preferably grows one main branch along the east-west direction to form two main branches of the “丫” shape.

Through pruning, the air-transmitting and light-transmitting tree structure is constructed to evenly distribute all kinds of branches in the crown. During the growing season of the tree, pay attention to the topping of the tree, remove the standing branches, dense branches, and the buds at the slashing mouth, so that the light distribution within the canopy is reasonable and sufficient to prevent the overlapping, crowded and disorderly branches, resulting in canopy closure.

Fifth, increase lighting

An hour after sunrise, the grass is covered and grass is covered after sunset. The roller shutter can be used to uncover the grasshopper, which not only improves the work efficiency but also saves labor.

Even cloudy days, snow days, not only short illumination time and weak light intensity, lack of light should be installed to supplement the light source, increase lighting fixtures (such as high pressure sodium, red light, incandescent, fluorescent, etc.). For incandescent lamps, at least 2 to 500 watt incandescent lamps in a shed. After the leaves have been opened from the fruit tree, after the curtains are uncovered in the morning or in the evening, the light is turned on and the light is supplemented for no more than 3 hours per day.

Six, shop reflective film, hanging reflective screen

A zirconium-coated zirconium film is applied on the floor to reflect upwards from the ground, and the ground light can be reflected to the lower part of the crown. The laying of the retroreflective film can increase the light absorption at the top and back pudendal parts of the drooping fruit, increase the light intensity of the middle and lower layers of the crown, and promote the results and overall coloring. Reflective film, the average coloring index can be increased by 25% to 30%.

The retroreflective film is generally applied 20 to 25 days before fruit coloring. Laying reflective film should be walked along the tree and tiled on both sides of the tree. The outer edge of the reflective film is in line with the outer edge of the canopy, and can fully exert the effect of the reflective film. Reflective film can be used as a light curtain, attached to the back wall of the greenhouse, can increase light 20% to 30%.

In addition, timely ventilation can reduce the humidity inside the shelter, eliminate fog in the shelter and increase the light transmittance of the greenhouse.