Rice bacterial leaf blight has appeared; farmers, please strengthen prevention promptly
Recently, typhoons have brought days of overcast and rainy weather, and bacterial leaf blight has appeared one after another in rice paddies in Qiaotou and Wandan in the Gaoping area. To avoid a major outbreak, the Kaohsiung District Agricultural Research and Extension Station (hereafter referred to as the Kaohsiung Station) urges farmers to pay attention to the bacterial leaf blight situation in rice; once symptoms are found, control measures should be taken immediately. After bacterial leaf blight is found, avoid entering the fields after rain or before the morning dew has dried, in order to reduce human-mediated spread; in addition, avoid applying excessive nitrogen fertilizer to lower the severity of the disease.
The Kaohsiung Station points out that rice bacterial leaf blight is caused by pathogenic bacteria and is most easily contracted during windy and rainy periods. If it occurs during the peak tillering stage, it is even more severe. After infection, small water-soaked spots usually appear on the leaf margins a few centimeters from the leaf tip. The lesions usually spread along one or both leaf margins toward the midrib, and in severe cases can produce the typical wavy, grayish-white streaks with yellow halos.
Some fields in the Gaoping area are already affected, and with the recent impact of Typhoon Tembin, a major outbreak is possible. Therefore, farmers are urged to take control measures immediately before and after typhoons when the weather is clear, to avoid the expansion of the epidemic.
Bacterial leaf blight is one of the epidemic diseases of rice caused by bacteria. It mainly infects through wounds or natural openings in the leaves under conditions of strong wind and high humidity. If the peak tillering stage of rice coincides with a typhoon or heavy rain, severe disease often results. Under high-temperature and high-humidity conditions, the pathogen exudes bacterial ooze from diseased tissues, and strong wind causes diseased leaves to rub against nearby healthy leaves, creating wounds that help the bacteria invade; if battered by wind and rain, the bacteria can splash with the wind and rain and spread over long distances, causing large-scale outbreaks.
If one enters the field after rain or before the morning dew has dried, the bacterial ooze on diseased tissues is often carried by human contact and spread to healthy plants. Applying high amounts of nitrogen fertilizer reduces the disease resistance of rice plants.
If farmers have any questions about control, please contact 08-7389060 directly.
Contact: Zeng Minnan, Assistant Researcher
Tel: 08-7389158 ext. 757
Mobile: 0953-051931