From Self-installed drone sprayer, MG-1 to DJI AGRAS T10: Mr. Hiraishi’s Endeavors Against Citrus Black Spot Diseases In Japan

 

Japan’s mandarin production continues to decline due to the overarching challenge in Japanese agriculture of aging farmers and a lack of successors. According to data from USDA FAS, orange production is forecast at 5,600 metric tons in 2022-23, with a decline of 2% from the previous year.

 

With refreshing aroma and sweet taste, citrus is not only attractive to human beings, but also pests, bacteria and fungus. Before and during the mature period which last for over half of a year, citrus is often exposed to attacks by scale insects and black spot disease caused by fungus.

 

Many of Ehime's mandarin orange are grown on slopes. It is a harsh environment for manual spraying.

 

In Japan, citrus is often cultivated in sloped orchards, which means that frequent application of pesticides is a huge challenge for farmers. Many agricultural machineries, such as speed sprayers which work well on plain fields are inaccessible on the slopes, especially under the circumstance of labor shortage. Additionally, sprinklers which need to be operated by multiple operators has been outdated because of their difficulties in maintenance while carrying portable kinetic sprayers and apply them on steep slopes is a labor-intensive solution.

 

Despite the challenge, Kichisaburo Hiraishi, 73-year-old fruit producer from Uwajima City, Ehime Prefecture in Japan, has discovered that the difficulties of year-round spraying against harsh pesticides on citrus can be overcome by agricultural drones that are capable of automatic navigation and spraying.

 

Mr. Kichisaburo Hiraishi, Citrus producer. He has been cultivating oranges since his grandfather's generation (130 years ago.) He manages 2ha of 17 orchards and 1ha of paddy fields.

 

"I've always been obsessed about things that can fly! With that passion, I gradually realized that I might be able to spray pesticides all year round from the air to make everything easier (laughs)."

 

In the 1970s, Mr. Hiraishi installed a self-made sprayer with a radio-controlled helicopter and tried to spray pesticides from the air. Unfortunately, the pilot flight resulted in a crash, which was reported by local newspapers and TV stations. “Since then, the media stopped coming even if I called them," he said with a wry smile.

 

Even so, Mr. Hiraishi did not give in to his dream of spraying from the air. With the help of the Agricultural and Wildlife Damage Prevention Board of Ehime prefectural, Mr. Hiraishi saved 2.5 million yen in two years. In 2016, Mr. Hiraishi was able to purchase an MG-1.

 

“My dream came true, and I excitedly started spraying with the MG1. While doing so, I manually operated the drone, making sure it stayed on the proper route and created some emergency landing sites to ensure a safe and stable flight. The drone works unstably under the manual control mode, and I was extremely worried about crashing again. I even went to a doctor because of the mental stress. I had a feeling that drone spraying would be effective against black spot disease, but it was impossible to spray with high precision under the manual mode because even spraying is unachievable.”

 

DJI AGRAS T10, an agricultural drone with compactness, automatic navigation, and high-precision spraying that meets the needs of farmers of all sizes, from beginners to veterans.

 

After overcoming a number of challenges, Mr. Hiraishi finally achieved effective and stable spraying with a drone. His partner is the DJI AGRAS T10, an agricultural drone capable of automatic surveying, which he purchased in 2022.

 

"Automatic navigation relieved me of all kinds of stress! With automatic navigation, the precision of spraying has dramatically improved, and I was finally able to spray pesticides all year round. For citrus farmers, the advantage of a drone is overwhelmingly prominent as it significantly improves the working efficiency. For example, in the past, you can't work continuously in hot summer, but with the drone you can spray 2 ha in 2 days. When the temperature is lower, you can finish the spray in 1 day. It takes 3 minutes to spray a narrow field, and 15 minutes for a wide field," said Ms. Yoko Motoyama, representative of Drone Works Uwajima, who provided training to Mr. Hiraishi and sold him the drone.

 

Mr. Kichisaburo Hiraishi of Hiraishi Farm and Ms. Yoko Motoyama, representative of Drone Works Uwajima.

 

“Mr. Hiraishi’s year-round spraying experience is useful for many citrus farmers. You can adjust the flight route based on actual needs while correctly observing how the plant disease develops from high above. The ease of use is another appeal of the AGRAS T10 as everyone is able to operate it after training.” Mr. Tsuchiyama, Mr. Hiraishi’s colleague who also produces citrus, agreed what Ms. Motoyama says, "It is easy to use and can be used by anyone."

 

Suggested Chemicals All-Year-Round Solution to Problems in Citrus Cultivation (T10)

Date (2022)	Active Ingredient	Dilution Factor	Chemical Amount (L/10a)	Targeted Pests/Diseases
Late May	Hasubananes (C21H27NO5)	50	8	Citrus Black Scale, Rust Mites, Quadraspidiotus pemiciosus (Comstock)
Around June 10	Mancozeb (C4H8MnN2S4Zn)	10	8	Citrus Black Spot
Early July	Mancozeb (C4H8MnN2S4Zn)	10	8	Citrus Black Spot
Late July	Mancozeb (C4H8MnN2S4Zn)	10	8	Citrus Black Spot
Mid-August	Hasubananes (C21H27NO5)	40	8	Unaspis yanonensis (Kuwana)
	Mancozeb (C4H8MnN2S4Zn)	10	8	Citrus Black Spot
Mid-September	Tebuconazole  (C16H22ClN3O), Trifloxystrobin (C20H19F3N2O4)	50	8	Primarily Citrus Black Spot
Late October	Thiophanate-methyl (C12H14N4O4S2)	20	10	Green mold etc.

 

Before & After the Spray

  

Before the spray: ruby beetle outbreak. After which they sprayed for about 40 times on the 10 acres orchard for about 8 liters.  

 

After the spray: By far the best sprayed tree as of June, 2022. This year, ruby beetles have not been seen. Parents of last year's outbreak have finished spawning and died. 

 

In Japan, aging is a prevalent social phenomenon, which is taking place in the agricultural industry too. There is no doubt that labor shortage will continue to be a trending situation.

 

“So, I have decided to purchase the T20 and continue my citrus production business, because I believe I could achieve that with an automated drone. I would ask Mr. Motoyama about the spraying tips,” said Mr. Hiraishi, who made up his mind to continue growing citrus fruits by making my daily routines less labor-intensive.

 

After overcoming a number of difficulties, Mr. Hiraishi benefited from a lot from the T10 agras drone. As he said, "Farming is inherently fun. The agricultural drones with automatic navigation and spray functions play an important role in the future of orange cultivation. Please don’t be afraid to go out of your comfort zone!”