What are the supplemental lighting methods for greenhouse strawberries in winter
Light is an important factor limiting the yield and profitability of greenhouse strawberries. When light is insufficient, it not only affects the normal growth and development of strawberries, but also directly affects the temperature, humidity and carbon dioxide concentration inside the greenhouse. Especially in winter, adverse weather all affects light, so how should the greenhouse supplement light? Follow the editor and take a look.
1. Light characteristics of the greenhouse
Because the greenhouse frame and covering materials block sunlight, the light intensity inside the greenhouse is only about 70% of that in the open field, and the old or new condition of the agricultural film also affects light intensity. If it is old film polluted by dust and mud, its light transmittance is only 40%. Moreover, the light distribution inside the greenhouse is extremely uneven, generally strong at the top and weak at the bottom. The higher the frame, the weaker the light intensity near the ground. Due to factors such as weather and operations inside the greenhouse, the light duration in the greenhouse is significantly shortened, which seriously affects flower bud differentiation and the opening of male and female flowers. For example, on rainy and hazy days, not only is the light intensity weak, but the light duration is also short.
2. Conventional supplemental lighting methods
When choosing agricultural film, high-quality drip-free film can be used, which can increase the light transmittance of the greenhouse. At the same time, the greenhouse film should be wiped and washed frequently to keep it clean, so as to maintain good light transmittance and increase light intensity. Some cultivation techniques can also improve the light conditions inside the greenhouse. For example, planting strawberries in a north-south row direction with a cultivation method in which large row spacing and small row spacing are the same can also allow each row to obtain better light conditions. Mulching with plastic film or hanging reflective curtains can also be done. They can reflect light energy, which can strengthen the reflected light and scattered light near the ground by 50%-70%, and plastic film also has a good heat preservation effect.
3. Artificial supplemental lighting
In winter and spring, there are many rainy days, and coupled with the influence of the facility's covering materials and dust and dew on the greenhouse film, the problems of insufficient light and imbalanced light quality composition inside the greenhouse are very serious. At this time, artificial supplemental lighting is needed to help crops have sufficient light for various physiological activities. Artificial supplemental lighting uses artificial light sources to simulate the effective wavelengths of sunlight for plants and promote plant photosynthesis and other physiological functions. At present, there are mainly four types of light sources used for supplemental lighting of strawberries: first, LED light-emitting diodes; second, high-pressure sodium lamps; third, fluorescent lamps; fourth, daylight lamps. Among them, high-pressure sodium lamps can significantly improve strawberry fruit quality and promote early ripening and marketing of the fruit, but the yield-increasing effect is average. LED light-emitting diodes can inhibit excessive growth, advance marketing, and have an obvious yield-increasing effect.
The above is an introduction to how to supplement light for greenhouse strawberries in winter. I hope it can help you. If you want to learn more related knowledge, please follow us.