Better Droplet Deposition and Internode Shortening Effects of Plant Growth Regulator EDAH on Maize Applied by Small Unmanned Aerial Vehicle Than Electric Knapsack Sprayer

Abstract

Maize (Zea mays L.) lodging is an important factor limiting its yield increase worldwide. EDAH (containing 27% ethephon and 3% DA-6) is commonly used to decrease lodging. There is an urgent need to select efficient application methods of agrochemical for better spray deposition. In our research, an unmanned aerial vehicle (UAV) (15 L ha−1 and 30 L ha−1) with EDAH dosages of 72 and 90 g a.i. ha−1, and electric knapsack sprayers (EKS) (450 L ha−1) with dosages of 90 g a.i. ha−1 were used to compare the droplet deposition distribution, uniformity and maize growth. According to our research, EDAH applied by UAV had a higher droplet deposition rate than EKS; EKS had a higher droplet coverage rate, deposition density, droplet distribution uniformity. At the same dosage of EDAH, the UAV had a better effect on controlling maize growth than EKS, and almost equal effects were detected when the dosage applied by the UAVs was decreased by 20%. Considering the lodging occurrence and yield, we recommend that the dosage of EDAH applied by UAVs should be 72 g a.i. ha−1 when there is weak lodging and 90 g a.i. ha−1 when there is heavy lodging, with a spray volume of 15 L ha−1.

Enhancement of Waterlogging Tolerance and Improvement of Grain Quality in Waxy Maize With Exogenous EDAH: A Mixture of Ethephon and Diethyl Aminoethyl Hexanoate

“…The research found that exogenous plant growth regulators can delay the degradation of chlorophyll in plants . In our study, we discovered that EDAH effectively mitigates the detrimental impact of waterlogging on leaf photosynthesis by enhancing stomatal conductance, as previously reported by Wang et al (2016) and Wang, Hussain, et al (2022). Waterlogging experienced during the V6 and VT stages resulted in reduced leaf G s , consequently leading to a decline in C i , P n and T r .…”

“…(2016) and Wang, Hussain, et al. (2022). Waterlogging experienced during the V6 and VT stages resulted in reduced leaf G s , consequently leading to a decline in C i , P n and T r .…”

“…Research has shown that by formulating ethylene and DA-6 in a ratio of 27%: 3% as a mixture of ethephon and diethyl aminoethyl hexanoate (EDAH), it can serve as a novel plant growth regulator with promising prospects (Xu et al 2017). The plant growth regulator EDAH, comprising the actions of ethylene and DA-6, not only effectively inhibits maize internode elongation, reducing plant height and ear height (Xu et al 2017;Zhang et al 2019Zhang et al , 2014, but also enhances leaf chlorophyll content and photosynthetic rate, delays leaf senescence and improves grain-filling rate and grain weight, thereby increasing crop yield (Gao et al 2017;Gong et al 2021;Ren et al 2022;Wang, Hussain, et al 2022).…”

Evaluation of the deposition and distribution of spray droplets in citrus orchards by plant protection drones

“…found that the use of additives significantly increased the particle size of droplets and reduced the proportion of small droplets in the experiment of evaluating additives in the South Fruit Pear Garden, which can effectively reduce the risk of droplet drift and help to improve the pesticide utilization rate. In addition, studies have shown that flight mode, flight altitude, and side wind speed all affect plant protection UAV spray droplets ( Qin et al., 2016 ; Wang et al., 2016 ), because the downward rotating airflow wind field affects the droplet motion during plant protection UAV operations, and changes in altitude alter the uniformity of droplet distribution ( Wang et al., 2022 ). Therefore, it is necessary to fully study the effects of the body structure and flight parameters of plant protection UAVs on droplet deposition, explore reasonable use techniques in the field, and provide data support for future use, to minimize the adverse effects of plant protection UAV operations and better utilize the advantages of plant protection UAVs in orchard control.…”

Characteristics of unmanned aerial spraying systems and related spray drift: A review

“…On one hand, the operating efficiency of a single UASS has increased from 2 to 3 hectares per hour to the current 15–20 hectares per hour within the past 5 years ( Chen H. et al, 2021 ). The result of single-machine efficiency implies that more chemicals can be sprayed in a short time ( Wang Z. et al, 2022 ), however more pesticide droplets may also be scattered in the air ( Liu et al, 2021 ). The overall environmental risks due to efficiency improvements need to be assessed.…”