Broadcasting of tiny granules by drone to mimic liquid spraying for the control of fall armyworm (Spodoptera frugiperda)

Abstract

BACKGROUND The fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), is an invasive pest. Maize is one of its preferred host plants. The traditional application of granules has been effective for the control of FAW. Nevertheless, the challenge is to develop an application method that is less labor‐intensive and also efficient. RESULTS Tiny granules in the size range of 0.38–0.55 mm were prepared by the centrifugal granulation method for drone application. The in‐swath distribution patterns of granules deposited on sticky tapes were similar to the distribution of aqueous droplets through drone spraying. In the range of 1.5–3.5 m, a relatively higher aircraft height of flight can provide a more uniform distribution pattern of deposited granules, but resulted in less deposit of tiny granules in the whorl of maize plants. Similarly, the deposit of granules in the whorl of maize plants significantly decreased when the flight speed increased from 4 to 6 m s−1. Granules gathered in the whorl accounted for 50.8–58.7% of total granules deposited in the maize canopy. The field experiment demonstrates granular formulations (containing 0.25% chlorantraniliprole + 0.15% emamectin benzoate, or higher concentrations) can provide better and longer duration of FAW control than the aqueous spray formulation at the whorl stage of maize plants. CONCLUSION Broadcasting of tiny granules by drone can provide better FAW control than liquid spray. The architecture of the maize plant and the downward airstream of the drone create favorable conditions for the deposition of granules in whorls. © 2021 Society of Chemical Industry.

Control Efficacy and Deposition Characteristics of an Unmanned Aerial Spray System Low-Volume Application on Corn Fall Armyworm Spodoptera frugiperda

“…The corn growth periods were small, with flaring open stages. FAW kills the growing point of corn plants, causing numerous holes in the whorls and upper leaves (Yan et al, 2021 ). The field observation and survey rate of the harmed corn plants reached above 10%, and most of the corn plants reached the damage level of 3 (Davis scale) (Davis et al, 1992 ).…”

“…There were two main considerations in using this sampling method. On the one hand, the droplet was mainly deposited on the first leaf from the top of the corn; on the other hand, the FAW mainly lays eggs and hatches on the first leaf from the top of the corn (Yan et al, 2021 ). For analyzing the droplet deposition, 11 sampling points were uniformly arranged in the experiment plot.…”

“…Phani et al ( 2021 ) studied the effects of different pesticides on the control effect of FAW using high-volume spraying, and screened out the pesticides with better control effect. Yan et al ( 2021 ) studied the control effect of FAW by using a plant protection UASS to spray solid particles of pesticides. Lu et al ( 2021 ) used a plant protection UASS to study the effect of spraying time on the control effect of FAW and recommend the best spraying time.…”

Application of insecticides by soil drenching before seedling transplanting combined with anti-insect nets to control tobacco whitefly in tomato greenhouses

“…The challenge for a pesticide product is to develop a new application method that is efficient and less labor intensive 27 . Seedling box application of systemic pesticides before transplanting was previously adopted in rice in Japan as a labor-saving method with less impact on the environment 28 , 29 .…”

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

“…Currently, UASS has been widely used over flat fields or terraces with low-lying crops, including grain crops such as wheat, corn, rice, and cash crops such as cotton, citrus, and grapes ( Pan et al, 2016 ; Sarri et al, 2019 ; Wang L. et al, 2019 ; Chen et al, 2020a ; Meng et al, 2020 ; Chen H. et al, 2021 ). Spraying with UASS has proven to be feasible in the prevention and control of crop diseases and pests by spraying insecticides or fungicides ( Meng et al, 2018 ; Yan et al, 2022 ). In the case of trees grown on steep slopes, the quality of the application is partially limited by the flight altitude of the sensor and terrain following technology with the help of lidar for example ( Meng et al, 2022b ; Wang C. et al, 2022 ).…”