Cottons grown in sandy soil with little nutrients, cotton easily suffers from malnutrition, causing fragile stem during growth period which will increase the risk of pest attacks. Prior to the harvest date, cotton producers usually apply defoliant to cotton to improve the harvesting efficiency with machineries.
In September, 2022 we went on to two cotton fields in Turkey with local plant protection team to see how different DJI Agras drones solve problems that cottons would encounter during different growing phase. The operation parameters as well as the chemical category and dosage were documented.
Growing phase troubleshooting: stem strengthening & pest control
Credit to SZR Tarım Drone Spraying
The first operation took place on September 28, 2022 in the cotton field of Küçükçıldırın Village in the city of Adana of Turkey.
When arriving at the cotton field, the plant protection team found that the cotton straws were weak and fragile due to lack of potassium. Some pests were also observed on the plants, including helicoverpa armigera (green worm) and gelechia gossypiella (pink bollworm) and Aphid.
Operation Parameters
| Type of Drone | DJI Agras T30 | Firmware Version | v.509 |
| Operation mode | Route Op. Mode | Operation Speed | 6.3 m/s |
| Operation height (from the top of the crop) | 3 Meters | Line spacing/ width | 8 Meters |
| Liquid amount sprayed per hectare (or per MU) | 10 Liters | Nozzle type | XR TEEJET11001V8 |
Chemicals used
Credit to SZR Tarım Drone Spraying
| Chemical commercial name | Formulation | Active ingredient and the percentage | Chemical amount (g or ml) used per hectare |
| Ekvator | 20 SL Fluent Concentrate Suspension Concentrate | 88 g/l MepiquatChloride + 22 g/l Cyclanilide | 400 ml |
| Liberator | 10 EC Emulsion Concentrate | 100g/1 Pyriproxyfen | 10 L water and500 cc chemical |
| Arrivo | 20 EL Emulsion | 200 g/l Cypermethrin | 10 L water and1000 cc chemical |
| Corragen | 20 SL Fluent Concentrate Suspension Concentrate | 200 g/l Chlorantraniliprole | 10 L water and200 cc chemical |
| Flash Kali | Emulsion Concentrate | Potassium Oxide | 10 L water and1500 cc chemical |
After the operation, pests were eliminated from the plants and the cotton stems have become stronger because of the added potassium. There were no damage on the cotton caused by tractor. As the client saw the effect of the spraying in time, he agreed on the effectiveness of drone spraying.
Mature Period: Bolls Started to Open 7 Days After Defoliant Application
The other operation took place on September 10, 2022 upon a client’s request. The defoliant application was scheduled 14 days prior to harvest, so that the cotton plant flowers would be opened totally and be ready for harvesting.
There were no damages observed on the plants. This defoliant application is made for drying the plant and opening the cottons’ bolls. The bolls on the field were observed to be open about 70% and this defoliant application is made for opening of the remaining bolls.
Before the defoliant application, credit to Çukurova Gübre Tarımcılık
Normal tractor spraying causes damages on the plant and reduces the amount as well as the quality of the harvest. So our client agreed to make this application from the air by drone.
Operation Result
After 7 days from the defoliant application, all the bolls were observed to be opened, leaves were dried and fell down so as a result all plants were ready for harvesting.
Day 7, credit to Çukurova Gübre Tarımcılık
Operation Parameters
| Type of Drone | DJI Agras T10 | Firmware Version | v.01.00.509 |
| Operation mode | Route Op. Mode | Operation Speed | 4.5 m/s |
| Operation height(from the top of the crop) | 2 Meters | Line spacing/ width | 4,25 Meters |
| Liquid amount sprayed per hectare (or per MU) | 14 Liters | Nozzle type | XR TEEJET11001V8 |
Info of Chemicals
Credit to Çukurova Gübre Tarımcılık
| Chemical commercial name | Formulation | Active ingredient and the percentage | Chemical amount (g or ml) used per hectare |
| Baystar | Defoliating Agent 10-14 before harvest | Thidiazuron + Diuron119.75 + 59.88 g/l | 600 ml |
| Extang | Boll Opener14 before harvest | Ethephol720 g/l | 2000 ml |
Operation Take-away:
We observed a better effect on the plants when spraying at a lower speed and with less concentration of the defoliant per hectare. These operation parameters used were 100% effective on site and on day 14, the client was able to harvest at great convenience.
