Varietal Mixture (VarMix) is viewed to be a possible solution to the vulnerability of single variety to diseases, especially under stress-prone areas.
The study To Mix or Not to Mix: Compatibility of Selected Rice Varieties to Increase Yield Stability under Stress-Prone Areas of the Philippine Rice Research Institute (PhilRice) showed that the mixture of selected released varieties has the mechanism to increase and stabilize yield, manage pests and diseases, and achieve desirable performance on limited water source. These varieties must have comparative qualities despite having dissimilar origins and varied functions.
“The novelty of this research is exploring the use of released varieties not only in an irrigated lowland where enough water is available, but also in unfavorable areas. VarMix is recommended as an alternative technology or a stop gap addressed to problematic locations,” Imeldalyn Pacada, project leader of VarMix said.
In cooperation with farmers, researchers, and extension officers, this project tested six varieties namely: NSIC Rc 216, Rc 298; Rc 300, NSIC Rc 238, Rc 214, and PSB Rc 82 in 13 selected areas of Luzon, Visayas, and Mindanao.
The selection of varieties was based on the similarities of their maturity, grain shape, amylose content, and genetic composition. No pesticide application was made and existing farmers’ practices were adapted in each experimental site.
In below ground environment, initial VarMix mechanism investigation was carried out through the following method: drought tolerance evaluation at seedling stage, salinity tolerance at seedling stage, and root system under changing soil moisture.
According to Roel Suralta who analyzed the root system development of VarMix, there were appropriate types of varieties that can be mixed. They discovered that the mixture of drought-tolerant and drought-susceptible varieties were compatible and aided each other to survive. Based on the results, drought-tolerant variety supplied water to the drought-susceptible variety when the soil dried out.
A farmers’ association in Brgy. Binangkilan, Sta. Barbara, Iloilo, one of the experimental set-ups of the study tried the VarMix technology and experienced positive results.
“Before when we used single variety and drought occurred, our harvest was not satisfying. However, when we tried VarMix, our neighboring farm was even surprised as our crops stood abundantly despite the dryness of the soil,” Aurelio Simora, Vice President of Binagkilan Farmers Association attested.
Aside from its good yield even in problematic conditions, the VarMix team also assessed if quoted prices and eating quality were comparable with the known single varieties in the market. Their survey concluded that in terms of the rice characteristics and properties, such as tenderness, color and eating quality, VarMix has no major difference compared to single varieties.
Accordingly, VarMix is a potential alternative rice technology for yield stability with the recommended right mix under stress-prone areas.