Rape has a high yield and harvest, and these four key management points need to be mastered!
Yellow sepals, green clothes, thick leaves, and thousands of villages are squeezing new oil. Love him for his livelihood, not just idle flowers and wild grass. "At present, it is the season when rapeseed flowers bloom, and it is also a critical period for growth. It is necessary to absorb a large amount of nutrients to achieve stable growth, strong moss, and abundant pods. Therefore, scientific field management is crucial. In this issue of "Early Knowledge of Agriculture", we specially invite agricultural chemistry experts to talk about the field management of rapeseed flowers.
One is to clear ditches, regulate soil moisture, and prevent waterlogging. Some dryland oilseed rape systems are not compatible, while some rice stubble oilseed rape areas are low-lying. If there is more rain in the later stage, it will cause waterlogging during the flowering period, leading to the shedding of oilseed rape flower horns, an increase in shade horns, a decrease in seed setting rate, and premature plant senescence. It is necessary to carry out ditch cleaning and soil moisture management work as soon as possible, especially in low-lying fields, to ensure smooth drainage, prevent waterlogging in the fields, and lay the foundation for preventing premature aging in the later stage.
The second is to prevent and control pests and diseases and reduce losses. Within one week of the initial flowering stage of rapeseed (25% of the plants in the entire field begin to bloom), appropriate amounts of available boron fertilizer, molybdenum fertilizer, and other trace mineral elements should be added to promote growth, prevent sclerotinia disease, prevent flowering but not fruiting, prevent early senescence in the later stage, and prevent high temperature forced ripening. In areas where sclerotinia disease is prone to recurrence, another control should be carried out every 5-7 days. If aphid infestation occurs again in the later stage, appropriate pesticides should be selected in a timely manner for spraying control, and attention should be paid to using them with caution during flowering to avoid harm to bees.
To prevent and treat sclerotinia sclerotiorum, it is necessary to apply medication once during the initial and peak flowering periods, and to use medication on sunny days. 50 grams of 50% isocarbazone wettable powder or 50-70 grams of 50% chlorpyrifos wettable powder can be used as the agent per mu. To prevent and control Downy mildew, it can be done after the first occurrence of the diseased plant. 72% downy urea and 80~100g manganese zinc can be selected as the medicament, and it can be prevented and controlled again every 5~7 days. To prevent and control sclerotinia disease, Downy mildew and white rust should be treated at the same time, and 50 grams of 50% chlorothalonil or 80 grams of 70% thiophanate methyl can be used per mu. For the prevention and control of aphids and leafminer flies, an additional 5% efficient cypermethrin 30ml or 70% imidacloprid 5g per acre should be added. To prevent and control weeds in the rapeseed and gramineae family, 100 milliliters of 5% fenvalerate or 30 milliliters of 10.8% efficient fenvalerate can be used per acre. To prevent and control annual broad-leaved weeds such as bromegrass, rice croaker, Chinese wolfberry, and wild stork, 30-40 milliliters of 50% fenvalerate suspension agent can be used per acre. To prevent and treat flowers without actual symptoms, 30 grams of 21% boron fertilizer (or 150 grams of borax) and 150 grams of potassium dihydrogen phosphate can be added when controlling pests and diseases.
The third is to skillfully apply fertilizers to promote balance. In response to the situation of soil drought and increased planting area in most of the main winter rapeseed production areas last year, which resulted in longer sowing periods and complex seedling conditions for autumn and winter rapeseed, higher temperatures after winter, and multiple rounds of cold wave cooling processes leading to frost damage to thriving early flowering seedlings and late sowing weak seedlings, scientific application of bolt fertilizer and drone spraying of flower fertilizer and pod fertilizer are carried out according to the principles of local adaptation and classified management to promote balanced growth of rapeseed and prevent early senescence in the later stage, Ensure high yields and increased income. Give full play to the promoting effect of nitrogen nutrition on weak to strong growth, and appropriately increase the amount of nitrogen fertilizer used. Pay attention to the application of phosphorus, potassium, boron, magnesium and other nutrients during the flowering period, and cooperate with plant growth regulators to fully exert the anti stress and yield promoting effects of nutrients.
1. In areas with insufficient use of base fertilizer and winter wax fertilizer, a large proportion of weak seedlings, and severe frost damage, nitrogen fertilizer of 3-5 kg/mu should be applied in northern winter rapeseed areas such as Gansu, Henan, and Shaanxi; Apply 2-4 kg/mu of nitrogen fertilizer and 1-2 kg/mu of potassium fertilizer to winter rapeseed areas in the upper reaches of the Yangtze River, such as Sichuan, Chongqing, Guizhou, Yunnan, and the middle reaches of the Yangtze River, such as Hunan, Hubei, and Jiangxi; Apply 4-5 kg/mu of nitrogen fertilizer and 1-1.5 kg/mu of potassium fertilizer to winter rapeseed areas in the lower reaches of the Yangtze River, such as Jiangsu, Zhejiang, and Anhui. When applying bolt fertilizer, urea and potassium chloride can be evenly mixed before application, and corresponding nutrient rich compound fertilizers with high nitrogen, low phosphorus, and medium potassium can also be applied. For rapeseed fields with late sowing dates and severe frost damage, the amount of topdressing should be appropriately increased by 20% to 30% based on the seedling situation.
2. For plots with insufficient amounts of phosphorus and potassium fertilizer, spraying 0.3-0.5 kg/mu of potassium dihydrogen phosphate on the leaves from flowering to podding can effectively prevent premature senescence of rapeseed.
3. According to the available boron status in the soil, boron fertilizer can be supplemented by applying 0.3-0.5 kilograms of borax per acre during bolting. It can also be combined with the prevention and control of bacterial wilt disease for fertilizer spraying. Generally, 0.2 kilograms of borax per acre can be sprayed on the leaf surface with a concentration of 0.2%.
4. Magnesium deficiency has occurred frequently in acidic soil areas and high-yield areas in recent years. Fertilizer spraying can be combined with the prevention and control of sclerotinia sclerotiorum disease during flowering. Generally, magnesium sulfate is sprayed at a concentration of 0.4~0.5 kg/mu, with a concentration of 0.2%~0.5%. It can also be sprayed during the pod setting period.
The fourth is to harvest in a timely manner to ensure a bountiful harvest. When about 80% of the rape plants in the whole field are loquat yellow, they can be cut down with a rape windrower or manually, picked up and threshed with a rape self-propelled picking threshing machine after 5-7 days of drying in the field, or threshed with a full feed ordinary rice and wheat harvester after manual picking. Varieties with resistance to pod cracking, strong lodging resistance, and early maturity can also be harvested in one go using a rapeseed combine harvester when all rapeseed plants in the field are in a withered and yellow state.