Tuba vs rice pest

Powdered seeds of tuba (Croton tiglim) can effectively control the two major storage pests of rice, the rice weevil and lesser grain borer, findings of PhilRice researchers showed.

Evelyn S. Perialde, Jennifer J. Tagubase and Dr. Gerardo F. Estoy Jr. observed that tuba seed powder was even more effective than the commercial insecticides Deltamethrin and Pirimphosmethyl from one to five months in storage. Thus, this botanical pesticide could be developed and used as alternative control against insect pests in seed storage.

In their study, the researchers first soaked the rice seeds in hot water (60oC) for 30 minutes to kill the eggs, larvae and adults of storage insect pests that may be present in the seeds. The seeds were sun dried and then treated with tuba seed powder.

Lesser damage of 0.15 to eight percent was noted on rice seeds treated with tuba seed powder than on those treated with Deltamethrin (0.35 – 16 percent) from one to five months in storage. Although damage on seeds treated with tuba seed powder and Pirimphosmethyl had similar amounts of grain damage in the first month, the damage on tuba powder treated seeds became much lower in the succeeding four months of storage. 

The germination rate of the rice seeds was not affected by the tuba seed powder.

Dr. Madonna C. Casimero, PhilRice deputy director for research and development, however, warned that extreme care must be exercised when gathering tuba seeds and during the process of making the powder. Tuba juice can cause blindness if it gets into the eyes.– Sosimo Ma. Pablico