Paenibacillus polymyxa: Biological control for rice plant disease

Securing the production of rice from the threat of plant pest organisms (OPT), rice farmers use the application of Paenibacillus polymyxa bacteria. A biological control for diseases that are easily obtained, more affordable than regular fungicide, and is ecologically safe.  

The bacteria was explored from healthy plants among plants affected by bacterial leaf blight. Exploration was done in 1996 by the Forecasting Center for Plant Pest Organisms (BBPOPT) under the Ministry of Agriculture in Jatisari, Karawang. Since then the bacteria have been used as a biological control to help fight diseases that can cause low production or even crop failure.

One of the diseases that occur on rice plants is the crackle or bacterial leaf blight disease caused by Corynebacterium. The Paenibacillus polymyxa acts as an antagonist to the Corynebacterium that causes wilting of seedlings and yellowing, drying leaves. Crackle or bacterial leaf blight disease attacks the plant on many of its phases from seedling, young until aged. Its symptoms are also often mistaken by farmers as a pest problem therefore the farmer will use pesticide to try and treat its crop. Resulting in a futile attempt. Without the Paenibacillus polymyxa treatment, crops that are affected by the crackle or bacterial leaf blight disease can stand to lose 70 percent of its produce.

The bacteria also help to fight the blast disease that is caused by the Pyricularia oryzae fungus. The disease can be identified by the spots on the leaf that are grey on the center with brown and green on the perimeter. Untreated the fungus can make the panicle of rice empty therefore reducing crop yields. This disease is faced by farmers all around and responsible for approximately 30 percent of rice production losses globally. As reported from Republika.com, Cahyadi, an officer from BBPOPT said that the Paenibacillus polymyxa has proven to suppress the intensity from blast disease.

“As a result, with just 4 applications, it was able to reduce the intensity of attacks from 15,11 percent to 0 percent,” said Cahyadi.

Other plant disease symptoms that can be controlled by using Paenibacillus polymyxa are the narrow spot disease and midrib rot. Plants without Paenibacillus polymyxa treatment can have the intensity of 60,1 percent narrow spot disease and 40 percent of midrib rot. With the treatment, that symptoms can be reduced to 11,3 percent and 1,5 percent respectively. 

Application of the Paenibacillus polymyxa solution can be done as early as the seed treatment process. Reported from WartaEkonomi.co.id, Sendy, POPT officer from BBOPT Jatisati, Karawang said to optimize the prevention of diseases, the selection of seed using salt water solution method can be used along with the Paenibacillus polymyxa. This method eliminates bad seeds or seeds that may carry disease by putting seeds in salt water solution. Seeds that float to the top are considered bad seeds and thrown away, while the seeds that sink into the bottom can be rinsed.

“The seeds that we have rinsed are then soaked for 1-2 nights until the seeds germinate. Do the soaking with a solution of Paenibacillus polymyxa at a dose of 5 cc per liter for 15 minutes before the seeds are sown,” said Sendy.

This treatment helps to restrain the development of disease and stimulate plant growth from 56 percent of germination without the Paenibacillus polymyxa treatment, to 82,7 percent with the treatment. 

One farmer from Kampung Babakan, Lemah Abanng, Karawang finds that propagating Paenibacillus polymyxa is easy to do. To make a liter of Paenibacillus polymyxa ready for application, farmers only need 300 grams of potato, 1 gram of sugar, and 1 liter of water. Ingredients are heated together to make sugar potato extract (EKG). After the mixture of sugar potato extract is cooled, a starter of Paenibacillus polymyxa is mixed into it and incubated for 14 days with the added air from the aerator. After that, the mixture is ready to be used.

Ministry of Agriculture’s efforts to maintain rice production

The introduction of Paenibacillus polymyxa as a biological control is part of the Ministry of Agriculture effort to help rice farmers and secure rice production. As reported from CNBC Indonesia, Angga, a freelance officer for POPT, BBOPT Ujung Jaya district, said that farmers in his region use Paenibacillus polymyxa that are environmentally friendly and easy to obtain to combat the worrying threat of blast disease. 

With the use of biological control bacteria such as Paenibacillus polymyxa, the Ministry of Agriculture through the Directorate of Food Crop Protection also tries to promote the Healthy Plant Cultivation campaign.

“With this cultivation pattern, farmers can obtain rice plants with high productivity and efficient work processes. In addition, the products produced are of high quality and chemically clean, so that product prices are able to compete in the free market,” said Angga.

Healthy plant cultivation patterns also mean that crop and soil management is carried out with organic matters and uses fungicide as the last resort. Head of Technical Information and Documentation Services, Forecasting Center for Plant Pest Organisms (OPT), Directorate General of Food Crops, Ministry of Agriculture, Suwarman said that the use of biological control on farming is per the principles of organic cultivation.

“This is in line with the message from the Director General of Food Crops, Suwandi during a working visit at the Forecasting Center for Plant Pest Organisms (OPT), that every disease and pest must have a remedy around it, in a natural way,” said Suwarman.

Paenibacillus polymyxa bacteria has proven its benefit as biological control for preventing and controlling disease in rice plants. With its organic nature and is easily obtained, it’s no wonder that Paenibacillus polymyxa is preferable to use among farmers.