(1) The effect of light intensity on vegetable growth.
The light saturation point of most vegetables (when the light intensity increases to the light intensity when photosynthesis no longer increases) is about 50,000 Lux (Lux), but watermelon can reach 70,000-80,000.
Lux, cabbage, cabbage and peas are 40,000 Lux. Over the light saturation point, photosynthesis is no longer increased and accompanied by high temperature, which often results in poor vegetable growth. Therefore,
According to the different requirements of vegetable for light intensity, different shading net covering measures were selected in summer and early autumn to reduce light intensity and environmental temperature.
Grow in vegetables. The light compensation point of most vegetables (light intensity when the product of photosynthesis is offset by respiratory consumption) is 1500-2000 Lux.
Vegetables can be divided into three categories according to their different requirements for light intensity.
1. Vegetables requiring stronger light: watermelon, melon, cucumber, pumpkin, tomato, eggplant and pepper, taro and potato. This kind of vegetable is produced in rainy and rainy weather.
Low quantity and poor quality.
2. Vegetables suitable for moderate light intensity: cabbage, cabbage, radish, carrot, onion and garlic. They do not require very strong light, but grow poorly when the light is too weak. because
Therefore, this kind of vegetable should be covered with sunshade net in summer and early autumn, and should be removed sooner or later.
3. Vegetables with low light tolerance: lettuce, celery, spinach, ginger, etc.
(2) The effect of photoperiod on vegetable growth and development.
Photoperiod is the response of vegetable growth and development (flower bud differentiation, bolting and flowering) to the relative length of day and night. Daily Light Hours and Plant Development
It is related to yield formation. Vegetable crops can be divided into long-day, short-day and neutral-light vegetables according to the requirement of sunshine length for growth and development and flowering.
1. Long-day vegetable: Long sunshine (usually 12-14 hours or more) promotes flowering, while short sunshine prolongs flowering or does not. It belongs to long-day vegetable
Vegetables include cabbage, cabbage, mustard, radish, carrot, celery, spinach, lettuce, broad bean, pea, onion, etc.
2. Short-day vegetable: Shorter sunshine (usually less than 12-14 hours) promotes flowering, but does not blossom or prolongs flowering under long sunshine. It belongs to short-day nature.
Vegetables include cowpea, lentil, amaranth, towel gourd, hollow cabbage, agaric and late-maturing soybeans.
3. Medium-light vegetable: It can blossom under longer or shorter sunshine conditions. Medium-light vegetables include cucumbers, tomatoes, kidney beans, early-maturing soybeans, etc. Such kind
Vegetables do not require strict lighting time. As long as the temperature is suitable, they can blossom and bear fruit in spring or autumn.