Scientists at the Department of Agriculture-Philippine Rice Research Institute (DA-PhilRice) are investigating how silicon (Si), a common soil mineral, could help rice plants resist lodging—the bending or toppling of plants caused by typhoons and heavy rains. Lodging often reduces grain yield and quality, posing long-standing challenges for farmers.
A recent study, “Silicon Mapping: A Potential Tool to Assess Lodging Resistance of Rice,” by Jan Nico A. Lazaro and their team, evaluated 101 rice lines and varieties to determine how efficiently they absorb silicon and how this affects stem strength.
“Rice that absorbs Si tends to develop stronger stems, which can improve its resistance to lodging,” Lazaro said.
The researchers measured silicon content in the plants’ flag leaves during the reproductive stage, assessed stem strength using a push meter, and examined leaf surfaces under an electron microscope with energy dispersive X-ray (SEM-EDX) to detect silica deposits.
Results showed that NSIC Rc 536 had the highest pushing resistance (1.11N), suggesting stronger stems, while Rc 298 recorded the highest silicon content (18.37% by weight) but displayed lower stem strength. According to the team, this indicates that factors beyond silicon—such as genetics and plant structure—also play a role in lodging resistance.
“Silicon is not yet classified as an essential nutrient, but it’s been shown to help cope with stress,” Lazaro explained. “We’re now moving toward testing these varieties in actual field environments to see how they perform.”
The findings may support breeders and researchers in developing rice varieties that are better equipped to tolerate physical stress and possibly even pest and disease pressures.
The study, conducted under controlled screenhouse conditions, is part of PhilRice’s ongoing Rice Diversity Panel (RDP), which seeks to identify rice lines with desirable traits like efficient silicon uptake. Field trials are planned next to see if the same patterns hold in real-world conditions, especially in areas prone to lodging.
The team also collaborated with the DA-Philippine Center for Postharvest Development and Mechanization for SEM-EDX analysis, which allowed the visualization and measurement of silica deposits on the surfaces of rice leaves.
The research has already gained recognition, bagging the 2nd Best Poster Award at the 25th Scientific Conference and Annual Meeting of the Philippine Society of Soil Science and Technology Inc., held at Visayas State University in Leyte.If proven effective in field trials, silicon mapping could aid breeders and researchers in developing rice varieties that can better withstand physical stress—and possibly even pest and disease pressure—helping secure higher yields for farmers.
