Plant growth process, seed germination, seedling, growth and development, flowering and fruiting four stages, different stages of crop light requirements are different. Today, we will talk about the timing of crop time replenishment, we will explain from the following aspects.
1 Types of Crops
The growth lamp is mainly aimed at herbaceous plants.
Growth lamp is mainly aimed at herbaceous plants. Red light is the most effective growth lamp in inducing flowering, germination of some seeds, growth of stems and leaves, leaf abscission, formation of rhizomes and bulbs, dormancy of buds, and yellowing.
Fruit lamps are mainly aimed at woody plants.
Blue light is the most effective light source in opening stomata, delaying senescence, increasing protein content, phototropic reaction, chlorophyll synthesis, chloroplast differentiation and movement, inhibition of stem elongation and anthocyanin synthesis.
2. Requirements of crops for light
The greenhouse temperature of plant growth lamp is more than 10 C and less than 35 C, mainly considering the suitable temperature for the effective growth of crops. We explain the need for light at different crop stages.
Tomato is light-loving and shade-tolerant. Its light compensation point is 2000 lux, and its saturation point is 70 000 lux. The illumination is insufficient and the flower falls seriously. Tomato is a short-day plant, but the requirement is not very strict. Short-day is the basic requirement during flower bud differentiation. Most varieties blossom earlier under 11-13 hours of sunshine, and the plant grows vigorously, and the best under 16 hours of sunshine.
Hot pepper is a photophilic plant, but the light requirement is not strict. The light saturation point of hot pepper is about 30,000 lux, which is lower than tomato and eggplant. It belongs to short-day sunshine. As long as the sunshine duration reaches 1000 hours, it can meet the growth and development needs of hot pepper. Therefore, hot pepper is a neutral photophilic plant. The light requirement of Capsicum varies with different growth stages. If the light intensity is weak at seedling stage, it can lead to long internode, light leaf color and poor resistance of seedlings. On the contrary, if the light is good at seedling stage, the seedlings have short internodes, thick stems, dark leaves and strong resistance. During flowering and fruiting period, 10-12 hours of sunshine per day can meet the growth requirements, but excessive sunshine will affect the growth and development of hot pepper, so reducing the intensity of sunshine during this period will promote the growth of stem and leaf, increase the number of fruits, and enlarge the fruit. Therefore, field management should be strengthened after planting, so that the plants can be ridged as soon as possible. But if the light is too weak and the shade is too much, it will also affect the assimilation of pepper, make the plant growth and development poor, leading to yield reduction. During the flowering and fruit setting period of pepper, if there are many days of continuous rains and clouds, the number of flowering will be reduced, the fruit setting rate will be reduced, the fruit growth rate will be slow, and pepper diseases will be easily prevalent. Full-fruited period, such as too strong light, coupled with high temperature and drought, fruit without leaves and other shade, often have a burning birthday. The pepper fruit turns from green to red. If the light is sufficient during this period, the fruit will be bright in color.
Eggplant is insensitive to photoperiod, and the length of sunshine has little effect on the development of eggplant. Eggplant requires higher light intensity. Light quantity has a great influence on the growth and development of eggplant. Under weak light, photosynthesis decreases, yield decreases, pigmentation of purple varieties is not good, color difference is poor, and commodity value is affected. Especially in seedling stage, light intensity does not affect the growth and development of eggplant. Foot, delayed flower bud differentiation and flowering, reduced long style, increased middle style and short style. Therefore, artificial light supplementation and effective use of light should be used in cultivation of Eggplant in winter and spring.
Light is the main natural energy for photosynthesis of grapes, which has a great influence on their growth and development. Grape is a light-loving tree species. When the light is insufficient, the new shoots become thin, the internodes become longer, the leaves become thinner, and the color of the leaves becomes pale. It is difficult to form flower buds. Under dark conditions, grape flowers and fruits fall seriously or even fruitless.
The sum of solar irradiation time is usually in hours. The illumination time above a certain temperature is usually calculated on grapes, such as 1837.2 hours when the temperature is higher than 0, and 13330.9 hours when the temperature is higher than 10. The sunshine hours are the most in June-August, followed by February and September, and rainy in September.
Illumination is very important for pitaya cultivation. The light requirement of Pitaya seedlings may not be high in seedling stage, but it is very high in growing stage and fruiting stage. In order to harvest high quality pitaya fruit, efforts should be made in light and temperature. Fire dragon fruit belongs to cactus family. It is drought-tolerant and light-loving, so it is necessary to strengthen the light as much as possible. Increasing illumination for 1-3 cm long in the buds of Pitaya seedlings is beneficial to the growth of buds and the accumulation of flowering substances, and the illumination should be strengthened as much as possible in cloudy days or when the sun is not strong.
The requirement of illumination condition is different at different stages of strawberry growth, for example, short sunshine of 10-12 hours and lower temperature are required at flower bud formation stage, while longer sunshine time of 12-15 hours is required at flowering and fruiting stage and vigorous growth stage.
Strawberry likes warm and cool climate. Root growth temperature of strawberry is 5-30 C, suitable temperature is 15-22 C, stem and leaf growth temperature is 20-30 C, bud freeze injury occurs at-15-10 C, bud differentiation temperature must be maintained at 5-15 C, flowering and fruiting period is 4-40 C. Shading measures should be taken when strawberry oversummer temperature is higher than 30 C and sunshine is strong.
Disease prevention and control is mainly prevention, supplemented by drug treatment.