2018 Technical Guidance on Spring Wheat Management for the Whole City of Zibo, Shandong
To ensure the smooth progress of spring wheat field management and a bumper wheat harvest, the Zibo Municipal Government of Shandong issued a notice on the 2018 technical guidance on spring wheat management for the whole city. Among these, the flag-leaf stage has high temperatures and strong transpiration, and is most sensitive to water, making it the critical period for wheat water demand. All types of wheat fields should ensure an adequate water supply at the flag-leaf stage of wheat, and when soil moisture is insufficient, flag-leaf water should be applied at the appropriate time.
Notice on Issuing the 2018 Technical Guidance on Spring Wheat Management for the Whole City
To the Agriculture Bureaus of all districts and counties, and the Local Affairs Bureaus of the High-tech Zone, Economic Development Zone, and Wenchang Lake Area:
The “2018 Technical Guidance on Spring Wheat Management for the Whole City” is hereby issued to you, please implement it accordingly.
Spring is an important stage for the transformation of wheat seedling conditions and growth and development, and it is also a key period for field management. All districts and counties should attach great importance to spring wheat field management, organize agricultural technical personnel early to conduct careful investigation and research, and formulate specific technical guidance for spring wheat field management according to local characteristics of wheat seedling conditions, soil moisture, and pest, disease, and weed conditions. It is necessary to base efforts on drought resistance, highlight classified guidance, strengthen the implementation of key technical measures, ensure the smooth progress of spring wheat field management, and lay a solid foundation for a bumper wheat harvest.
Zibo Municipal Agriculture Bureau
February 2, 2018
2018 Technical Guidance on Spring Wheat Management for the Whole City
In the autumn planting of 2017, a total of 1.542 million mu of wheat was sown in the whole city, a decrease of 0.02 million mu from the previous year. The pre-winter seedling conditions of wheat in the whole city were inferior to the previous year, with fewer population stems and tillers, weaker individual development, a decrease in the area of first-class seedlings, and an increase in the area of second- and third-class seedlings. According to the pre-winter seedling condition survey, the average number of stems per mu of wheat in the whole city was 685,000, a decrease of 28,000 from the previous year; the average number of tillers per plant was 3.9, a decrease of 0.4 from the previous year; the average number of leaves per plant was 5.4, a decrease of 0.2 from the previous year; the average number of large tillers with three or more leaves per plant was 2.4, a decrease of 0.6 from the previous year; the average number of secondary roots per plant was 5.1, a decrease of 0.4 from the previous year. The area of first-class seedlings was 908,000 mu, accounting for 58.8% of the total area, a decrease of 10.3% from the previous year. The area of second-class seedlings was 379,000 mu, accounting for 24.6%, an increase of 11.6% from the previous year. The area of third-class seedlings was 83,000 mu, accounting for 5.4%, an increase of 0.5% from the previous year. The area of excessively vigorous seedlings was 172,000 mu, accounting for 11.2%, a decrease of 1.8% from the previous year.
The main problem currently facing wheat production is drought, which is more severe in mountain dry fields and wheat fields that have not been watered in winter. According to data from the meteorological department, from September 1 of last year to January 31 of this year, the average precipitation in the whole city was 54.2 mm, 57.3% less than the same period in normal years (126.9 mm), and 55.2% less than the same period last year (120.9 mm). If there is no effective precipitation later, the drought will further expand and pose a threat to wheat production in our city. In view of the current wheat seedling conditions and climate characteristics, the guiding ideology for spring wheat field management this spring is “prevent root diseases and spring frost, provide classified guidance, regulate fertilizer and water, and scientifically combat drought to ensure a bumper harvest.” The following technical measures should be focused on:
I. Early efforts in drought resistance and seedling protection
(1) Do a good job in mobilization and deployment, and combat drought scientifically
All districts and counties should, as needed, establish special working groups, do a good job in dynamic drought monitoring and technical surveys, unite with water conservancy, agricultural machinery, and other relevant departments, make good preparations for materials and personnel, and fully prepare early-spring compaction equipment. To combat drought scientifically, watering should be done at the appropriate time according to soil moisture and seedling conditions in wheat fields, and blindly watering early should be avoided.
At the same time, attention should also be paid to the fact that wheat consumes the most water from jointing to before heading. Among these, the flag-leaf stage has high temperatures and strong transpiration, and is most sensitive to water, making it the critical period for wheat water demand. All types of wheat fields should ensure an adequate water supply at the flag-leaf stage of wheat, and when soil moisture is insufficient, flag-leaf water should be applied at the appropriate time.
(2) Compaction and shallow hoeing during the soil slurry-returning period to raise temperature and preserve moisture
Early-spring compaction of wheat fields is an important agronomic measure for controlling excessive vigor and promoting strength, and for raising and conserving soil moisture. For dry wheat fields, compaction after the soil thaws in early spring can promote the upward movement of lower-layer soil moisture, thereby raising moisture, preserving moisture, and resisting drought. Vigorously growing wheat fields and wheat fields with rough land preparation and many clods should also be compacted in time after the soil thaws in early spring. Compaction can be carried out after the soil thaws in early spring, on mornings without frost and without dew drops on leaves, after 10 a.m. Note that wheat fields with frost should not be compacted, so as not to damage wheat seedlings; saline-alkali and waterlogged low-lying wheat fields should not be compacted, to prevent salt return; wheat fields with excessively wet soil should not be compacted, to prevent soil hardening; and wheat fields that have already jointed should not be compacted, to avoid breaking internodes and causing insufficient spike number. Compaction should be combined with shallow hoeing, generally compacting first and then hoeing, so as to achieve a loose top and firm bottom, and the effects of raising moisture, preserving moisture, and increasing temperature.
Shallow hoeing is an effective measure for preserving moisture, increasing temperature, and promoting early growth. When the surface soil thaws 2 cm in early spring (the slurry-returning period), shallow hoeing should be carried out on all types of wheat fields to maintain soil moisture, raise surface temperature, eliminate overwintering weeds, and gain initiative for later wheat field management. Especially for wheat fields with dry soil and small populations and weak individual plants, shallow hoeing should be taken as the primary measure of early-spring wheat field management. In addition, after watering or rain and snow, when surface moisture is suitable, shallow hoeing should be carried out in time to break soil hardening, loosen the soil, preserve moisture, increase temperature, and promote root and tiller growth. When hoeing, it is necessary to truly achieve fine, even, level, and thorough hoeing, leaving no clods, not pressing wheat seedlings, and not missing weeds, so as to improve the hoeing effect.
(3) Water well for “seedling protection” early
For plots where drought has seriously affected the normal growth of wheat, when the daily average temperature is stably above 3°C and water can infiltrate relatively quickly after daytime watering, watering should be done promptly to protect seedlings, and the earlier the better. When watering, the following three points should be noted: first, irrigate with small amounts of water, avoid flooding irrigation and surface ponding, and prevent nighttime freezing; second, grasp the watering time, preferably at noon on a sunny day, that is, from 10 a.m. to 3 p.m., and finish by 4 p.m. at the latest; third, according to the principle of first severe and then light drought, apply “seedling protection water” according to local conditions, that is, first water wheat fields with severe drought, and then water wheat fields with lighter drought.
(4) Apply an appropriate amount of nitrogen fertilizer
For yellow seedlings, dead seedlings, or fertilizer-deficient wheat fields caused by drought and freezing, about 10 kg of urea per mu should be applied in combination with watering. Also apply an appropriate amount of diammonium phosphate to promote the growth of secondary roots and the formation of spring tillers, and improve the spike-forming rate of tillers.
(5) Drought resistance and seedling protection measures for dryland wheat fields
For dryland wheat fields without irrigation conditions, spring management should focus on compaction to raise moisture and shallow hoeing to preserve moisture, and early topdressing after rain while moisture is available should be done well, with 5-10 kg of urea per mu, which has a prominent effect on increasing the number of spikes per mu and grains per spike, improving grain weight, and increasing yield. At the same time, applying 5-8 kg of potassium fertilizer per mu can effectively enhance the drought resistance of wheat. In addition, spraying 1-1.5 kg of urea plus 100-150 g of potassium dihydrogen phosphate or water-soluble fertilizer per mu, diluted with 50 kg of water, on the leaves can promote strength and drought resistance.
In early spring, dead leaves in wheat fields should be promptly cleaned up, with key promotion of contiguous operations in dryland wheat fields based mainly on compaction. For weak-seedling wheat fields, after the soil returns to slurry, about 10 kg of urea per mu should be applied to help increase the number of spikes per mu and grains per spike, improve grain weight, and increase yield; for those without basal fertilizer, 10-15 kg of wheat formula fertilizer per mu should be added. Other dryland wheat fields should, from the standing-up to jointing stage, receive 10-15 kg of urea per mu using available moisture. For vigorously growing dryland wheat fields, compaction and shallow hoeing should be carried out in time after the soil thaws in early spring, so as to raise and preserve moisture. During the period from standing-up to jointing of wheat, topdressing should be done using available moisture, generally 10-15 kg of urea per mu.
II. Highlight classified guidance and do a good job in fertilizer and water management for all types of wheat fields
Spring fertilizer and water management should be adapted to local conditions and guided by classification. Where the pre-winter population is insufficient, fertilizer and water management from green-up to standing-up should be used to promote increased tillering before jointing; where the population is too large, measures such as shallow hoeing, compaction, and spraying chemical control agents should be used to control excessive vigor and promote strength.
(1) Vigorously growing wheat fields
Vigorously growing wheat fields generally have more than 800,000 stems per mu before the New Year. Because of their large population and slender leaves, after the jointing stage they are prone to causing field shading, poor light, and lodging. Therefore, spring management should adopt measures focused on control, combining control and promotion.
1. Rake the wheat early. For excessively vigorous wheat fields with many dead leaves, after the soil thaws in early spring, combine with shallow hoeing and use a rake along the wheat rows to rake out dead leaves.
2. Compact at the appropriate time. Compact from the green-up stage to the standing-up stage of wheat to control excessive vigor and promote strength.
3. Spray chemical control agents. For excessively vigorous wheat fields, spraying chemical control agents such as “Zhuangfeng'an” and “Maijujin” around the standing-up stage of wheat can inhibit elongation of basal internodes, control excessive plant growth, promote downward root growth, and prevent lodging in the late growth period. The general dosage is 30-40 ml per mu, diluted with 30 kg of water, sprayed on the leaves.
4. Determine the timing of spring topdressing and watering according to seedling conditions.
(1) For wheat fields where the vegetative growth of plants before the New Year was excessively vigorous, soil fertility was greatly consumed, and there is a phenomenon of “fertilizer deficiency,” if the population is not large and the number of stems per mu in early spring is below 800,000, topdressing and watering can be carried out at the standing-up stage according to seedling conditions. If the population is relatively large, topdressing and watering can be carried out after standing-up, generally 7-10 kg of urea per mu, to prevent vigorous seedlings from turning into weak seedlings.
(2) For excessively vigorous wheat fields without fertilizer deficiency, do not rush to fertilize and water in early spring. Attention should be paid to measures such as compaction, shallow hoeing, and spraying chemical control agents to properly control seedling growth and avoid excessive spring tillering. Generally, fertilization and watering should be carried out at the late jointing stage, with about 15 kg of urea per mu.
(3) For vigorously growing wheat fields that have suffered freezing damage, on the basis of early spring shallow hoeing and raking of wheat, about 7 kg of urea per mu should be applied at the standing-up stage of wheat, and then about 10 kg of urea per mu should be applied at the jointing stage in combination with watering.
(2) First-class wheat fields
The population of first-class wheat fields is generally 600,000-800,000 per mu, mostly strong seedlings. In terms of management measures, attention should be paid to rationally managing fertilizer and water to improve the spike-forming rate of tillers and promote large spikes with many grains.
For the fertilizer and water management of such wheat fields, nitrogen fertilizer postponement should be highlighted. For first-class wheat fields with relatively high soil fertility, sowing at the appropriate time, and a population of 700,000-800,000, 10-15 kg of urea per mu should be applied in combination with watering at the middle and late jointing stage of wheat to obtain higher yield. For first-class wheat fields with average soil fertility and a population of 600,000-700,000, about 15 kg of urea per mu should be applied in combination with watering at the early jointing stage of wheat.
(3) Second-class wheat fields
The population of second-class wheat fields is generally 450,000-600,000 per mu, a transitional type between weak seedlings and strong seedlings. The focus of spring field management is to promote the occurrence of spring tillers and improve the spike-forming rate of tillers.
For second-class wheat fields with relatively high soil fertility and a population of 550,000-600,000, 15-20 kg of urea per mu should be applied in combination with watering after the standing-up stage of wheat and before jointing; for second-class wheat fields with average soil fertility and a population of 450,000-550,000, 15-20 kg of urea per mu should be applied in combination with watering at the standing-up stage of wheat.
(4) Third-class wheat fields
The population of third-class wheat fields is generally less than 450,000 per mu, mostly late-sown weak seedlings. Spring field management should focus on promotion.
For late-sown wheat, as long as soil moisture is still acceptable, early-spring watering should be avoided as much as possible, so as not to lower soil temperature and affect soil aeration, delaying wheat seedling growth and development. Multiple shallow hoeings should be used to promote an increase in soil temperature, promote spring tillering, consolidate pre-winter tillering, and increase the number of spikes per mu. Under conditions of relatively good soil moisture, spring topdressing should be divided into two applications: the first, at the standing-up stage, starting when the 5 cm soil temperature is about 5°C, applying 7-10 kg of urea per mu and an appropriate amount of diammonium phosphate (5-10 kg) in combination with watering, to promote tiller and root growth and improve the spike-forming rate of tillers; the second, after jointing, applying 7-10 kg of urea per mu to promote wheat development and increase grains per spike.
III. Do a good job in forecasting and comprehensive control of pests, diseases, and weeds
Spring is a season with frequent outbreaks of various pests, diseases, and weeds. All districts and counties must do a good job in forecasting, prepare pesticides and equipment early, and implement comprehensive control.
(1) Chemical weed control
For wheat fields where chemical weed control was not carried out before winter or where the effect was poor, the best control period from green-up to before standing-up of wheat should be seized in spring, and chemical weed control should be implemented in time. For wheat fields dominated by broadleaf weeds, 1 g of 75% tribenuron-methyl wettable powder per mu or 10 g of 15% thifensulfuron-methyl wettable powder per mu can be mixed with water and sprayed for control; for resistant dicotyledonous weeds, 50-60 ml of 20% fluroxypyr emulsifiable concentrate per mu can be used; for heavy grass weeds, 3-5 g of 70% flucarbazone-sodium water-dispersible granules per mu or 25-30 ml of 3% mesosulfuron-methyl oil suspension concentrate per mu can be sprayed for control. Where mixed occurrence occurs, the above agents can be mixed for use.
When using herbicides, the use concentration and technical operating procedures must be strictly followed to avoid phytotoxicity. Choose sunny and warm weather for spraying, with the daytime maximum temperature above 10°C and the minimum not lower than 3°C; pesticide application is prohibited on windy days. For weeds that are large or where chemical control has poor effect, combine with shallow hoeing and hand pulling. After wheat jointing, it is very sensitive to chemicals, and the use of chemical herbicides is absolutely prohibited to prevent phytotoxicity.
(2) Strengthen comprehensive control of pests and diseases, with root disease control as the focus
The control of spring pests and diseases should follow the plant protection policy of giving priority to prevention and implementing comprehensive control, and vigorously promote the technology of staged treatment and mixed pesticide application to control multiple pests and diseases at the same time. The period from green-up to jointing is the peak period for infection and expansion of root diseases such as sheath blight, take-all, and root rot, and is also the peak period of damage by wheat spider mites and underground pests, making it one of the key links in comprehensive wheat control. For wheat spider mites, 0.9% abamectin at 3000 times dilution can be sprayed for control. For underground pests, 250-300 ml of 50% phoxim emulsifiable concentrate per mu can be applied into the soil with irrigation at the green-up stage. Where the above pests and diseases occur together, the above appropriate agents can be mixed and sprayed once for combined control.
The control of root diseases in spring is a key link to ensure smooth grain filling later, increase grain weight, and guarantee quality. Investigation of root diseases should be done well, and control should be carried out in time. To control sheath blight, 150-200 ml of 5% validamycin per mu can be diluted with 75-100 kg of water and sprayed at the base of wheat stems, with a second spray after an interval of 10-15 days; or carbendazim suspension concentrate or thiophanate-methyl can be used. To control root rot, fungicides such as triadimefon, diniconazole, and triadimefon can be used. High-yield creation demonstration plots can refer to the comprehensive root disease control method of Huantai County and do a good job in experimental demonstrations of root disease control: in early March, 500 g of 30% difenoconazole · propiconazole emulsifiable concentrate per mu mixed into poisoned soil and broadcast; from mid-March to mid-April, spray a mixed solution containing 25% tebuconazole and 30% difenoconazole · propiconazole 2-3 times per mu. During the control process, attention should be paid to the timing of control and the dosage of chemicals.
IV. Pay close attention to weather changes and prevent spring freezing damage
Spring freezing damage (late spring cold) is a frequent disaster in wheat production in our city. Close attention should be paid to weather changes, and measures should be taken scientifically according to seedling conditions and soil moisture to prevent it. Where conditions permit, watering before the arrival of a cold wave can increase water vapor in the near-surface air and release latent heat when condensation occurs, thereby reducing the range of ground temperature variation, with a very good effect on preventing spring freezing damage.
Wheat is a crop with tillering characteristics and strong self-regulation ability. Wheat fields that suffer spring freezing damage can still obtain a certain harvest as long as management is strengthened. Therefore, if freezing damage occurs, management should be strengthened in time for remediation. The main remedial measures are: first, timely topdressing and watering. Topdressing and watering can increase the spike-forming rate of high-position tillers. Generally, about 10 kg of urea per mu should be applied in combination with watering. Second, intertill to preserve moisture and increase soil temperature. Timely intertillage can store water and raise temperature, effectively promote tillering, and compensate for the loss of the main stem. Third, spray plant growth regulators on the leaves. After wheat is frozen, timely foliar spraying of plant growth regulators can promote the rapid growth of medium and small tillers and the rapid sprouting of dormant buds, significantly increasing the number of spikes and 1000-grain weight of wheat, and increasing wheat yield. Fourth, do a good job in pest, disease, and weed control. Frozen wheat fields are more vulnerable to pests, diseases, and weeds, and timely control should be noted.
V. Actively carry out experimental demonstrations of green yield-increasing models
In view of prominent problems in wheat production in our city, such as excessive sowing rate by some farmers, large inputs of water and fertilizer, and poor land preparation quality, all districts and counties should take transforming the agricultural development mode as the main line, firmly establish the concept of “green, yield-increasing, and efficient,” and focus on developing green yield-increasing models. The following technical measures can be highlighted in demonstrations and promotion:
(1) Water-saving technology of irrigation based on soil moisture measurement
The water-saving cultivation technology of supplemental irrigation based on soil moisture measurement for wheat is based on the water demand characteristics of key growth stages of wheat, setting target relative soil water content for key growth stages, and calculating the amount of supplemental irrigation needed according to the target relative soil water content and the measured relative soil water content. It ensures grain yield while saving water resources. According to relevant research by the Wheat Cultivation Research Laboratory of Shandong Agricultural University, compared with conventional irrigation technology, the water-saving cultivation technology of supplemental irrigation based on soil moisture measurement for wheat can reach a yield of 600 kg per mu, reduce irrigation amount by 15%-20%, and increase water use efficiency by more than 10%. Irrigation equipment can use drip irrigation, micro-sprinkler irrigation, self-propelled sprinkler irrigation, etc.
(2) Mechanical compaction technology
All districts and counties (especially the southern mountainous areas) should strengthen publicity and guidance on early-spring compaction technology for wheat. Early-spring compaction can press off dead leaves, crush soil clods, compact the bed surface, close soil cracks, help preserve water, and delay the time and frequency of watering after the New Year. It can control the top and promote the bottom, make wheat roots firm, promote early and rapid growth of tillers at lower leaf positions and root development, and make wheat seedlings grow robustly. For the compaction method, it is now recommended to use special wheat compaction machinery, which can improve operational efficiency and compaction effect compared with traditional compaction methods, and better meet the needs of modern agricultural development.
(3) Water-fertilizer integration technology
All districts and counties should, in light of local realities, formulate work plans for vigorously promoting water-fertilizer integration technology in grain production, carry out experiments, demonstrations, training, guidance, and effect monitoring for water-fertilizer integration technology, and strive to improve the effect, efficiency, and benefits of promoting water-fertilizer integration technology.
(4) Green control technology
Vigorously promote the application of biological pesticides and high-efficiency, low-toxicity, low-residue pesticides to replace highly toxic and high-residue pesticides. Select pesticide-saving and efficiency-enhancing adjuvants, promote measures such as insect-killing lamps to kill pests, achieve reduced pesticide use, and improve the quality of agricultural products. Promote technologies such as self-propelled spray machinery for normal-volume pesticide application and drones for low-dose pesticide application to improve control efficiency and effect. Comprehensively apply agricultural control, biological control, physical control, ecological pest control, and other technologies, expand pilot integration of green wheat control and specialized unified prevention and control, and continuously improve the level of green control of wheat pests and diseases.