Effect Analysis of "One Prevention Double Reduction" of Aerial Control in Corn Fields in Daiyue District, Tai’an City

Juqing GE

Daiyue District Administrative Examination and Approval Service Bureau, Tai’an 271000, China

Abstract The main technical content of full mechanized corn production in Daiyue District is explained, and the problems of disease and insect pest control in the middle and late growth stage of corn in full mechanized production are analyzed. "One prevention double reduction" of corn performed by unmanned aerial vehicle (UAV) and self-propelled sprayer is compared and analyzed, and some suggestions are put forward for further popularization and application of full mechanized corn production.

Key words Corn; Full mechanized production; Aerial control; One prevention double reduction

1 Introduction

Daiyue District, Tai’an City, Shandong Province, has undertaken the demonstration project of full mechanized high-yield corn cultivation technology since 2015. The popularization and application of full mechanized corn production technology plays an active role in promoting the level of modern agricultural equipment, optimizing the structure of agricultural machinery equipment, liberating labor force, improving agricultural labor productivity and promoting the moderate scale of land management in Daiyue District. Leaf spot disease, corn borer, cotton bollworm and aphid often occur severely in the middle and late growth stage of corn. The field is closed with high temperature and is slippery during the rainy period. It is difficult for farmers to apply pesticides to prevent and control the diseases and insect pests. In order to solve this problem, "one control and double reduction" is performed through popularization and application of aerial control by unmanned aerial vehicle (UAV), that is, chemical agents are sprayed once in the great trumpet period of corn, to reduce the initial occurrence quantity of ear worms in the middle and late stage and alleviate the prevalence of diseases. In order to expand the popularization and application of UAV aerial control technology, UAV aerial control application demonstration sites have been established in Dawenkou Town and Mazhuang Town. For the difficult part of disease and insect pest control in the middle and late stage of full mechanized corn production, the popularization and application of UAV control technology of one prevention double reduction has achieved good results.

2 Overview of demonstration site and demenstration content

2.1 Overview of demenstration siteThe demonstration site is located in Dongwu Village, Dawenkou Town, Daiyue District. This area is the central area of "Wenyang field", with flat terrain, good irrigation and drainage conditions, deep soil layer, good soil structure, long distance away from buildings and convenient transportation. It belongs to the temperate continental monsoon climate zone, with the average annual precipitation of 696.4 mm, the sunshine duration of 2 630 h, the annual accumulated temperature of 4 215 ℃, and the frost-free period of 193 d on average. The previous crop was wheat, and the soil is loam, pH 6.9.

2.2 Demonstration content

2.2.1Regional setting. (i) One prevention double reduction region of UVA. Through full mechanized corn production technology, disease and insect pest control in the middle and late growth stage of corn was carried out by UVA, and a total of 13.33 hm2corn fields were sprayed. (ii) One prevention double reduction region of conventional sprayer manual operation. In conventional planting mode, disease and insect pest control in the middle and late growth stage of corn was carried out by self-propelled sprayer manual operation. (iii) Blank control area. The area of the three regions respectively was 13.33 hm2, and all fields were under consistent field management.

2.2.2Corn varieties, agents, apparatus and parameters. The corn variety Zhengdan 958 (Henan Qiule Seed Technology Co., Ltd.) was chosen as the material tested. The chemical agents used were 5.7% emamectin benzoate WDG (Zhejiang Welldone Chemical Co., Ltd.), 50% benzole propiconazole EW (Jiangsu Kesheng Group Co., Ltd.). The P30 plant protection UAV (2019) of Xaircraft (Guangzhou Xaircraft Co., Ltd.) and ZF-PWQ self-propelled air supply sprayer (Qufu Zhongfa Machinery Equipment Co., Ltd.) were used. According to the recommended requirements of dosage and water consumption, the dosage of plant protection UAV was 240 g/hm2, and the water consumption was 15 kg/hm2; the dosage of self-propelled sprayer was 300 g/hm2, and the water consumption was 450 kg/hm2.

2.2.3Application time and data survey. (i) Application time. Agents were sprayed on August 5 in one prevention double reduction region of UAV. Agents were sprayed from August 5 to 6 by ZF-PWQ self-propelled air supply sprayer in one prevention double reduction region of conventional sprayer manual operation.

(ii) Disease survey. On August 20, the damage status of corn leaf spot was investigated. Samples were collected from 10 points of each plot, 10 plants each point, to investigate the incidence of functional three leaves (ear leaf, upper and lower ear leaves).

(iii) Investigation on insect pests and control effect. The control effect against insect pests was investigated on August 25. Samples were collected from 5 points of each plot, 10 plants each point, to record the number of live insects and calculate the control effect. The effect of leaf protection was investigated on September 15. Samples were collected from 5 points of each plot, 10 plants each point. The standard of green leaves was that the effective photosynthetic area accounted for more than 60% of the total leaf area. The total number of leaves and green leaves in each corn plant was investigated, and the rate and effect of leaf protection were calculated.

(iv) Yield monitoring. The corn was harvested mechanically and the yield of each treatment was measured.

3 Results and Analysis

3.1 Comparison of dosage, water consumption and operation efficiency of each treatmentAs shown in Table 1, the dosage and water consumption of UAV for disease and insect pest control were lower than those of self-propelled sprayer, and the operation efficiency was much higher than that of conventional medical equipments. The average dosage of UAV was 20% less than that of self-propelled sprayer. The average water consumption of UAV was 1/30 of that of self-propelled sprayer. The operational efficiency of UAV was 25 times of that of self-propelled sprayer.

Table 1 Comparison of dosage, water consumption and time of each treatment

3.2 Control effect on corn diseases and insect pestsThe corn leaf spot of each treatment was investigated at 15 d post application, and the occurrence of corn borer, cotton bollworm and aphid was investigated at 20 d post application. As shown in Table 2, the control effect of using UAV for prevention and control of corn diseases and insect pests was better than that of using self-propelled sprayer. The control effect of UAV was 16.4% higher than that of self-propelled sprayer for corn leaf spot, 13.2% higher for corn borer, 16.1% higher for cotton bollworm, and 27.7% higher for aphid.

Table 2 Effects of different treatments on prevention and control of corn diseases and insect pests

3.3 Effects of leaf protection on cornThe effects of each treatment on leaf protection were investigated at 40 d post application. As shown in Table 3, the leaf protection effect of using UAV for prevention and control of corn diseases and insect pests was better than that of using self-propelled sprayer. The rate of green leaf was 11.4% higher, and the effect of leaf protection was 31.2% higher.

Table 3 Effects of different treatments on leaf protection of corn

3.4 Effects on corn yieldIn the harvest period, the yields of corn in each treatment area were measured in the field. The yields of aerial control, conventional medical equipment control and blank control area were 9 180, 8 745 and 8 160 kg/hm2, respectively, and the yield of using UAV for prevention and control of diseases and insect pests was better than that using self-propelled sprayer. The yield in aerial control area was 29 kg/667 m2more than that in conventional medical equipment control area, with a yield increase of nearly 5%.

4 Conclusions and discussion

The above test results showed that the use of UAV aerial control technology for "one prevention double reduction" had obviously better effect than self-propelled sprayer in the full mechanized corn production. UAV aerial control technology could solve the problem of difficulties in pesticide application due to tall plants and high temperature crown closure in the middle and late stage of corn, which also saved water, reduced diseases and insect pests in the middle and late stage, and had obvious effect on protecting leaves. Particularly, it played an important role in protecting leaves, improving photosynthesis and increasing yields by avoiding contact between spraying equipment and plants. (i) The dosage and water consumption per unit area of UAV were much less than conventional medical equipments, and the dosage was reduced by 20%. The water consumption of UAV was only 1/30 of that of self-propelled sprayer, which greatly reduced the cost, pesticide consumption and agricultural non-point source pollution caused by pesticides. (ii) UAV aerial control technology had good prevention and control effect of corn diseases and insect pests, and the relative control effect of UAV on corn diseases and insect pests was 13.2%-27.7% higher compared with self-propelled sprayer. (iii) UAV aerial control technology had good effect on corn leaf protection, and the effect was 31.2% higher than that of self-propelled sprayer. (iv) The yield of corn plots by UAV aerial control was high, and the per unit area was 5% higher than that by self-propelled sprayer.

In addition, UAV aerial control has much higher control efficacy than self-propelled sprayer, which saves the labor and time, and avoids or greatly reduces the risk of damage caused by sudden diseases and migratory pests that can not be timely controlled by conventional mechanical equipments. Meantime, operators do not directly contact with pesticides in the process of agricultural UAV aerial control, which avoids the occurrence of accidents caused by improper spraying of pesticides. It is the rainy season in the middle and late growth stage of corn. UAV not only solves the problem of poor management of farmers under high temperature and high humidity weather, but also solves the problem that the field is muddy and slippery in rainy season and machinery can not work in the field.

5 Suggestions

5.1 Cultivating large grain production householdDue to the small area of cultivated land and low economic benefits in agricultural production, the farmer households with family as the unit mainly participate in grain production by the elderly and women, and young and middle-aged labor force mainly work in cities. In grain production, new technologies and new varieties are less applied, and the field is poorly managed, with low degree of mechanization. The main source of economic income of large grain production households is the scale benefit of grain production. In order to reduce labor costs, increase output, improve quality and grain production benefits, they will pay more attention to mechanized application and new varieties and new technologies, such as standardized cultivation, soil testing, formula fertilization, disease and insect pest control. Accordingly, large grain production households and grain farmers’ cooperatives should be cultivated and guided to apply machinery, to improve their application enthusiasm of mechanization. Moreover, the mechanization production technology can be promoted by large grain production households and grain farmers’ cooperatives, so as to raise quality and increase efficiency of grain production.

5.2 Increasing subsidies for purchasing machineryWith the continuous promotion of full mechanized corn production, mechanization is more and more recognized by the majority of farmers. However, agricultural machinery and equipments, especially high-end machinery such as UAV plant protection equipment, require relatively high economic investment, and it is difficult for growers to bear such economic cost investment. It is suggested that the government should properly increase the agricultural machinery purchase subsidy, reduce the cost of farmers’ machinery purchase, and improve the enthusiasm of farmers’ application of full mechanized corn production.

5.3 Doing well in experiments and demonstrationsThrough the construction of demonstration fields, the promotion and application effects of full mechanized technology of crop production are displayed, with each period of full mechanized production, such as land preparation, sowing, plant protection and prevention, and harvesting, as specific examples. Especially in the middle and late growth stage of corn, the aerial control technology of insect pests and diseases free farmers from high temperature, hot and humid weather environment and heavy work. In the experimental and demonstration areas, a comprehensive mechanized technology integration model, equipment scheme and technical route for full mechanized corn production that is suitable for local production and can be replicated and extended shall be formed. And through holding training courses, on-site meetings, technical lectures, media publicity and other forms, the full mechanized production of agricultural crops is popularized, so as to improve the scientific farming level of agricultural technicians and farmers in the project area.