There are many misconceptions in greenhouse vegetable management; growers should avoid these pitfalls
There are many misconceptions in greenhouse vegetable management
(Agricultural Wealth Network) Misconception 1: More fertilizer, more output. Many vegetable growers apply large amounts of fertilizer to greenhouse vegetable plots in pursuit of higher output. In fact, excessive fertilization causes reverse osmosis in the root system, leading to root death, and yield will decline or growth will be poor. Solutions: First, for greenhouses that have been planted for more than 3 years, control chicken manure and cow manure to within 2500 kg each, and reduce the amount of chemical fertilizer by about 50%; second, focus on applying cow manure, humic acid fertilizer and biological bacterial fertilizer to increase the soil carbon-to-nitrogen ratio, loosen the soil and improve aeration, and reduce salt and fertilizer damage; third, supplement boron, zinc and magnesium fertilizers to balance soil nutrients.
Misconception 2: More seedlings left, higher yield. Many vegetable growers tend to leave too many seedlings when planting, believing that more seedlings can produce a high yield. In fact, because winter temperatures are low, light is weak, photosynthesis is poor, and carbohydrate synthesis is low, only sparse planting can achieve high yield. Solutions: First, overwintering vegetables are better planted at a reasonable sparse density; second, in order to make full use of space, a management approach of dense planting in the early stage, thinning plants in the middle stage, and thinning branches in the late stage can be adopted, with the criterion that leaves and branches are not crowded, to increase total yield and total benefit.
Misconception 3: Higher temperature, faster growth. Many vegetable growers believe that the purpose of building a greenhouse is to keep warm, and that vegetables will grow faster at higher temperatures. In fact, vegetables have an upper limit requirement for temperature, generally 25°C to 32°C. If the temperature is too high, respiration increases, the organism's operation and physiological activities become disordered, plants grow excessively, and vegetative and reproductive growth become unbalanced, so yield actually declines. Solutions: First, set two ventilation openings in the greenhouse to cool it down in time. Second, strictly manage according to the temperature required by various vegetables during their growth periods and the suitable temperature requirements for each organ's growth period, to prevent high temperature from producing long vines but no fruit.
Misconception 4: Vigorous vines and branches mean good growth. Many people think that vigorous vines and branches mean a good crop. In fact, with more water and vigorous leaves, roots are necessarily shallow, nutrition is incomplete and yield is low, and excessive vegetative growth inevitably affects reproductive growth, so yield actually decreases. Solutions: First, in the seedling stage, master the technique of weak plants with deep roots, control water and control plants to promote roots, so that the underground part absorbs about 60% of photosynthetic products, while in the middle and late stages the underground and aboveground absorption each account for 50%; second, in the early stage, plant nutrient consumption accounts for 60%, and reproductive growth accounts for 40%; in the middle stage, each accounts for 50%; in the late stage, reproductive growth accounts for 60% to 70%, and vegetative growth only accounts for 30% to 40%, that is, ensure a certain assimilating leaf area in the early stage, and in the late stage control vines and promote fruit to increase yield.
Misconception 5: Frequent spraying, fewer diseases. Many vegetable growers spray once every 2 to 3 days in the middle and late stages of vegetable growth, believing that frequent spraying can prevent the spread of diseases. Solutions: First, accurately identify the disease and spray the right pesticide; preferably choose copper-containing and zinc-containing agents, which can not only sterilize but also enhance the plant's ability to resist pathogen invasion and promote crop growth; third, improve the ecological environment. With luxuriant branches and leaves and poor ventilation, spraying every day will not necessarily have a good effect, so leaves should be thinned to reduce humidity; third, for dead seedlings caused by soil-borne bacteria, emphasis should be placed on pesticide prevention in the seedling stage.
Misconception 6: More cropping cycles, more income. Many people believe that after investing in building a greenhouse, the land should not be left idle, so secondary crops follow the main crop, and the main crop is interplanted with secondary crops. With many planting cycles, the result is often poor and benefits are low. Solutions: First, for the overwintering main crop, it is better to plant one crop a year; for spring and autumn crops, two crops a year is suitable. Old eggplant, pepper and cucumber plants can be regenerated for one more harvest, and when prices are low, pull up the plants and let the land dry; second, each year in summer, leave a period of time for deep plowing and rain leaching to press down salt, exposure to sunlight for sterilization, and sealed greenhouse treatment to kill insects and mature the soil.
Misconception 2: More seedlings left, higher yield. Many vegetable growers tend to leave too many seedlings when planting, believing that more seedlings can produce a high yield. In fact, because winter temperatures are low, light is weak, photosynthesis is poor, and carbohydrate synthesis is low, only sparse planting can achieve high yield. Solutions: First, overwintering vegetables are better planted at a reasonable sparse density; second, in order to make full use of space, a management approach of dense planting in the early stage, thinning plants in the middle stage, and thinning branches in the late stage can be adopted, with the criterion that leaves and branches are not crowded, to increase total yield and total benefit.
Misconception 3: Higher temperature, faster growth. Many vegetable growers believe that the purpose of building a greenhouse is to keep warm, and that vegetables will grow faster at higher temperatures. In fact, vegetables have an upper limit requirement for temperature, generally 25°C to 32°C. If the temperature is too high, respiration increases, the organism's operation and physiological activities become disordered, plants grow excessively, and vegetative and reproductive growth become unbalanced, so yield actually declines. Solutions: First, set two ventilation openings in the greenhouse to cool it down in time. Second, strictly manage according to the temperature required by various vegetables during their growth periods and the suitable temperature requirements for each organ's growth period, to prevent high temperature from producing long vines but no fruit.
Misconception 4: Vigorous vines and branches mean good growth. Many people think that vigorous vines and branches mean a good crop. In fact, with more water and vigorous leaves, roots are necessarily shallow, nutrition is incomplete and yield is low, and excessive vegetative growth inevitably affects reproductive growth, so yield actually decreases. Solutions: First, in the seedling stage, master the technique of weak plants with deep roots, control water and control plants to promote roots, so that the underground part absorbs about 60% of photosynthetic products, while in the middle and late stages the underground and aboveground absorption each account for 50%; second, in the early stage, plant nutrient consumption accounts for 60%, and reproductive growth accounts for 40%; in the middle stage, each accounts for 50%; in the late stage, reproductive growth accounts for 60% to 70%, and vegetative growth only accounts for 30% to 40%, that is, ensure a certain assimilating leaf area in the early stage, and in the late stage control vines and promote fruit to increase yield.
Misconception 5: Frequent spraying, fewer diseases. Many vegetable growers spray once every 2 to 3 days in the middle and late stages of vegetable growth, believing that frequent spraying can prevent the spread of diseases. Solutions: First, accurately identify the disease and spray the right pesticide; preferably choose copper-containing and zinc-containing agents, which can not only sterilize but also enhance the plant's ability to resist pathogen invasion and promote crop growth; third, improve the ecological environment. With luxuriant branches and leaves and poor ventilation, spraying every day will not necessarily have a good effect, so leaves should be thinned to reduce humidity; third, for dead seedlings caused by soil-borne bacteria, emphasis should be placed on pesticide prevention in the seedling stage.
Misconception 6: More cropping cycles, more income. Many people believe that after investing in building a greenhouse, the land should not be left idle, so secondary crops follow the main crop, and the main crop is interplanted with secondary crops. With many planting cycles, the result is often poor and benefits are low. Solutions: First, for the overwintering main crop, it is better to plant one crop a year; for spring and autumn crops, two crops a year is suitable. Old eggplant, pepper and cucumber plants can be regenerated for one more harvest, and when prices are low, pull up the plants and let the land dry; second, each year in summer, leave a period of time for deep plowing and rain leaching to press down salt, exposure to sunlight for sterilization, and sealed greenhouse treatment to kill insects and mature the soil.