Cultivating strong seedlings is the basis for the high yield of rapeseed. The prevention of abnormal seedlings is a technical means to cultivate strong seedlings. Strong seedlings accumulated more dry matter, after transplanting, the hair roots became early, the survival was fast, the growth was vigorous, the stress resistance was strong, and the yield was high. Generally stronger than the weak seedlings increase production by 20% to 40%. In the late autumn of transplanting season, under the unfavorable conditions of autumn and winter climate, the growth of strong seedlings is even greater. To nurture strong seedlings, we must master the techniques of identifying inferior seedlings and nurturing strong seedlings in order to seize the high yield of rape.
One, seedling type According to the different seedling stage plant morphology, seedlings can be divided into strong seedlings, seedlings, seedlings, Quxie seedlings, shade foot seedlings, tall feet and other six types.
1. The seedlings of Miao Miao are short and strong, with short internodes, dense stem segments, densely arranged leaves, thick, short petiole, normal leaf color, thick and short neck, no tall feet, no bent stems, thick main roots, and many lateral roots. No pests and diseases.
2. Wang Miaowang Long seedlings are growers who grow too busy. It is mainly formed under conditions of long seedling age, excessive fertilization, and high temperature and humidity. The morphological characteristics of Wangchangiao seedlings are as follows: tall seedlings, numerous leaves, long petiole, tender tissue, and weak resilience. After Mong Miao transplanted, the hair roots were slow and the seedlings were late. The leaves often lost a lot of yellow, and the survival rate was low and they were susceptible to freezing injury.
3. Lean seedlings refer to poor plant vegetative growth, small number of leaves, small and short leaves, lack of chlorophyll and yellowing, short and thin plants, and it is also known as frozen seedlings.
The main reasons for the formation of skinny seedlings: First, a serious shortage of fertilizer and water; Second, the long time plot water, seedlings blocked development; Third, sowing too late, or affected by cold low temperature. After transplanting the thin seedlings, it is difficult to return to green seedlings, and some winters are not strong, spring and evening occur, and twitching resembles “onionâ€, which is of poor quality and low yield.
4. Quzhou seedlings are seedlings with severely bent roots and necks during the seedling period. Bed soil is too thin and compacted. Dew seeds are produced during sowing. The embryonic stems are completely exposed on the surface of the soil. It is also easy to cause the neck of the embryo to bend and form a curved neck seedling.
Quxuan seedlings are easily broken into waste seedlings when they are raised. It is difficult to maintain quality when they are transplanted. After transplanting, the live seedlings grow slowly and it is difficult to obtain high yields.
5. Shade leg seedlings are seedlings that emerge late due to excessive seeding and in the event of uneven seedlings. Such seedlings are shielded by early seedlings and large seedlings, lack of light, poor growth potential, thin and thin seedlings, fine roots and necks, small leaves, and low chlorophyll, petiole slender, less accumulated dry matter, and less vitality. After transplanting seedlings of shaded feet, a large number of leaves shed off and the live seedlings grow slowly. In the event of drought or cold current, they often die more.
6. The tall seedlings are the main stems that have been elongated in the seedbed, with obvious internodes, small leaves, and long petiole. After such seedlings are transplanted, the survival rate is slow, and the leaves are easy to dry off and fall off, causing the stems to be exposed on the ground. In case of cold wave, they are subject to freezing and cracking, and serious ones cause dead seedlings. The stem of the tall seedlings is hollow, and the absorption capacity of the roots is only about 40% of that of strong seedlings. It is prone to premature aging and lodging, and the disease is heavy, resulting in a large reduction in yield.
Second, nurturing strong seedlings must seize a few key measures:
1. Choose a seedbed seedbed is good or bad, has a great impact on the cultivation of strong seedlings, we must choose the terrain flat, leeward sunny, fertile soil, near water, irrigation and drainage convenience, in 1 to 2 years have not planted rape or cruciferous plants Plots make seedbeds.
Keeping the area of ​​seedbeds is an important condition for nurturing strong seedlings. The area of ​​the seedbed is small, the seeding density is increased, the seedlings grow high and the tall seedlings or weak seedlings are formed. Generally, the ratio of the seedbed area to the field area is 1:5-6.
2. Fine soil preparation, adequate base seed rape seed is small, top soil ability is weak, therefore, seedbed preparation must be fine. It is required that the soil is finely crushed, the topsoil be loose and flat, and the dryness and the wetness be appropriate to create conditions for seed germination, root extension, and seedling growth. Base fertilizer should be applied to the seedbed. Basal fertilizer is mainly farmyard manure with sufficient maturity, and nitrogen, phosphorus, potassium, and boron are used together. Per acre seedbed fertilizer application of 2000 to 3000 kilograms of fertilizer, urea 1 to 2 kilograms, potassium sulfate 0.5 to 1.0 kilograms, borax 0.5 kilograms, superphosphate 20 to 25 kilograms, mix well and apply to the surface soil layer, so that the topsoil layer loose Fertile, conducive to nurturing strong seedlings.
3. Select seeds, before appropriate sowing seeding, after removing pods and debris, drying 2 to 3 days, sun 3 to 4 hours a day, in order to improve the emergence rate. When planting, it needs to quantify the individual compartments, sow 5 to 7 days before transplanting and sowing, so as to treat them with marvellous fertilizer. In case of drought and dry soil, apply about 5000 kg of thin and decomposed human and animal excreta per acre seedbed, such as bed soil moist, Urea can also be traced 2 to 3 kg. Pour water once a day before transplanting to facilitate seedling growth.
During the seedbed, we must pay close attention to the occurrence of pests and diseases, and timely control of spraying to ensure that seedlings are robust and disease-free. Evenly broadcast. After sowing, cover with fine dry soil or sieved earth fertilizer to avoid dew.
The seeding rate should be based on seed size and emergence rate. In general, seeds weighing 2.5 to 3.0 g are seeded at a rate of 0.4 kg per acre seedbed, and seeds with a grain weight of 3.5 g or more are suitable for 0.5 kg to 0.6 kg. If the seeding rate is too large, a phenomenon of squeezing seedlings will occur. This will not only increase the workload of the seedlings, but also affect the quality of the seedlings, which will be detrimental to the cultivation of strong seedlings.
4. To strengthen management, and time to seedlings and seedlings after time. The time for the first seedlings should be carried out in 1 true leaf after the seedlings, and the requirement is to reach the seedlings without squeezing; the second seedlings should be carried out in 2 true leaves, and it is required that the seedlings and the seedlings do not overlap. When the seedlings enter the 3-leaf stage, the young seedlings will be planted with 90-100 seedlings per square meter.
When the seedlings are required to do "five to five to stay", that is, to weak seedlings to retain strong seedlings; to leave small seedlings to retain large seedlings; to inferior hybrid seedlings, leaving pure seedlings; to close seedlings, leaving uniform seedlings; to pests and seedlings, stay strong seedling. Ensure that the seedlings are "pure, uniform, full, and strong."
5. Top-dressing watering, prevention and control of pests and rapeseeds should be kept moist seedbed bed soil to whiteness is not degree. After Qimiao, it is necessary to control the water and promote the roots to lower. 1 to 2 leaf stages, combined with thin-sludge fertilization followed by seedlings; after 5 leaves, less watering, less fertilizer. During the seedbed period, it is necessary to grasp the principle of “early, diligent, and littleâ€. In the early stage, the promotion is mainly based on the promotion and control of the mid-term and the control of fertilizer and water in the later stage. Even if the seedlings are robust, they must also prevent madness.
One, seedling type According to the different seedling stage plant morphology, seedlings can be divided into strong seedlings, seedlings, seedlings, Quxie seedlings, shade foot seedlings, tall feet and other six types.
1. The seedlings of Miao Miao are short and strong, with short internodes, dense stem segments, densely arranged leaves, thick, short petiole, normal leaf color, thick and short neck, no tall feet, no bent stems, thick main roots, and many lateral roots. No pests and diseases.
2. Wang Miaowang Long seedlings are growers who grow too busy. It is mainly formed under conditions of long seedling age, excessive fertilization, and high temperature and humidity. The morphological characteristics of Wangchangiao seedlings are as follows: tall seedlings, numerous leaves, long petiole, tender tissue, and weak resilience. After Mong Miao transplanted, the hair roots were slow and the seedlings were late. The leaves often lost a lot of yellow, and the survival rate was low and they were susceptible to freezing injury.
3. Lean seedlings refer to poor plant vegetative growth, small number of leaves, small and short leaves, lack of chlorophyll and yellowing, short and thin plants, and it is also known as frozen seedlings.
The main reasons for the formation of skinny seedlings: First, a serious shortage of fertilizer and water; Second, the long time plot water, seedlings blocked development; Third, sowing too late, or affected by cold low temperature. After transplanting the thin seedlings, it is difficult to return to green seedlings, and some winters are not strong, spring and evening occur, and twitching resembles “onionâ€, which is of poor quality and low yield.
4. Quzhou seedlings are seedlings with severely bent roots and necks during the seedling period. Bed soil is too thin and compacted. Dew seeds are produced during sowing. The embryonic stems are completely exposed on the surface of the soil. It is also easy to cause the neck of the embryo to bend and form a curved neck seedling.
Quxuan seedlings are easily broken into waste seedlings when they are raised. It is difficult to maintain quality when they are transplanted. After transplanting, the live seedlings grow slowly and it is difficult to obtain high yields.
5. Shade leg seedlings are seedlings that emerge late due to excessive seeding and in the event of uneven seedlings. Such seedlings are shielded by early seedlings and large seedlings, lack of light, poor growth potential, thin and thin seedlings, fine roots and necks, small leaves, and low chlorophyll, petiole slender, less accumulated dry matter, and less vitality. After transplanting seedlings of shaded feet, a large number of leaves shed off and the live seedlings grow slowly. In the event of drought or cold current, they often die more.
6. The tall seedlings are the main stems that have been elongated in the seedbed, with obvious internodes, small leaves, and long petiole. After such seedlings are transplanted, the survival rate is slow, and the leaves are easy to dry off and fall off, causing the stems to be exposed on the ground. In case of cold wave, they are subject to freezing and cracking, and serious ones cause dead seedlings. The stem of the tall seedlings is hollow, and the absorption capacity of the roots is only about 40% of that of strong seedlings. It is prone to premature aging and lodging, and the disease is heavy, resulting in a large reduction in yield.
Second, nurturing strong seedlings must seize a few key measures:
1. Choose a seedbed seedbed is good or bad, has a great impact on the cultivation of strong seedlings, we must choose the terrain flat, leeward sunny, fertile soil, near water, irrigation and drainage convenience, in 1 to 2 years have not planted rape or cruciferous plants Plots make seedbeds.
Keeping the area of ​​seedbeds is an important condition for nurturing strong seedlings. The area of ​​the seedbed is small, the seeding density is increased, the seedlings grow high and the tall seedlings or weak seedlings are formed. Generally, the ratio of the seedbed area to the field area is 1:5-6.
2. Fine soil preparation, adequate base seed rape seed is small, top soil ability is weak, therefore, seedbed preparation must be fine. It is required that the soil is finely crushed, the topsoil be loose and flat, and the dryness and the wetness be appropriate to create conditions for seed germination, root extension, and seedling growth. Base fertilizer should be applied to the seedbed. Basal fertilizer is mainly farmyard manure with sufficient maturity, and nitrogen, phosphorus, potassium, and boron are used together. Per acre seedbed fertilizer application of 2000 to 3000 kilograms of fertilizer, urea 1 to 2 kilograms, potassium sulfate 0.5 to 1.0 kilograms, borax 0.5 kilograms, superphosphate 20 to 25 kilograms, mix well and apply to the surface soil layer, so that the topsoil layer loose Fertile, conducive to nurturing strong seedlings.
3. Select seeds, before appropriate sowing seeding, after removing pods and debris, drying 2 to 3 days, sun 3 to 4 hours a day, in order to improve the emergence rate. When planting, it needs to quantify the individual compartments, sow 5 to 7 days before transplanting and sowing, so as to treat them with marvellous fertilizer. In case of drought and dry soil, apply about 5000 kg of thin and decomposed human and animal excreta per acre seedbed, such as bed soil moist, Urea can also be traced 2 to 3 kg. Pour water once a day before transplanting to facilitate seedling growth.
During the seedbed, we must pay close attention to the occurrence of pests and diseases, and timely control of spraying to ensure that seedlings are robust and disease-free. Evenly broadcast. After sowing, cover with fine dry soil or sieved earth fertilizer to avoid dew.
The seeding rate should be based on seed size and emergence rate. In general, seeds weighing 2.5 to 3.0 g are seeded at a rate of 0.4 kg per acre seedbed, and seeds with a grain weight of 3.5 g or more are suitable for 0.5 kg to 0.6 kg. If the seeding rate is too large, a phenomenon of squeezing seedlings will occur. This will not only increase the workload of the seedlings, but also affect the quality of the seedlings, which will be detrimental to the cultivation of strong seedlings.
4. To strengthen management, and time to seedlings and seedlings after time. The time for the first seedlings should be carried out in 1 true leaf after the seedlings, and the requirement is to reach the seedlings without squeezing; the second seedlings should be carried out in 2 true leaves, and it is required that the seedlings and the seedlings do not overlap. When the seedlings enter the 3-leaf stage, the young seedlings will be planted with 90-100 seedlings per square meter.
When the seedlings are required to do "five to five to stay", that is, to weak seedlings to retain strong seedlings; to leave small seedlings to retain large seedlings; to inferior hybrid seedlings, leaving pure seedlings; to close seedlings, leaving uniform seedlings; to pests and seedlings, stay strong seedling. Ensure that the seedlings are "pure, uniform, full, and strong."
5. Top-dressing watering, prevention and control of pests and rapeseeds should be kept moist seedbed bed soil to whiteness is not degree. After Qimiao, it is necessary to control the water and promote the roots to lower. 1 to 2 leaf stages, combined with thin-sludge fertilization followed by seedlings; after 5 leaves, less watering, less fertilizer. During the seedbed period, it is necessary to grasp the principle of “early, diligent, and littleâ€. In the early stage, the promotion is mainly based on the promotion and control of the mid-term and the control of fertilizer and water in the later stage. Even if the seedlings are robust, they must also prevent madness.