Author : Soriano, Randy T.

Summary : The study was conducted at Apita's Integrated Farm School located at Appas, Tabuk City, Kalinga from August to December 2024. A Randomized Complete Blocked Design (RCBD) with a two-factorial structure was employed. The study aimed to evaluate the agronomic and physiological response of inbred rice under different drone seeding parameters through two experiments. Study 1 investigated the effects of drone speed (5, 6, and 7 mis) and seeding rate (40, 60, and 80 kg/ha), while Study 2 examined drone flight altitude (2.5, 3.0, and 3.5 m) alongside seeding rate. In Study 1, results showed that drone speed significantly influenced plant density, with 6 m/s producing the highest density. However, seeding rate alone had no significant effect on plant density, panicle number, spikelet count, or yield. No significant interaction effects were observed between drone speed and seeding rate, indicating that these factors function independently. Physiological traits-such as harvest index (HI), leaf area index (LAI), crop growth rate (CGR), and net assimilation rate (NAR) - were not significantly affected by either factor. Correlation analysis showed that early vegetative traits (e.g., plant density and tiller number) were positively interrelated, while grain yield was more strongly associated with reproductive traits, particularly 1000-grain weight.

Study 2 found that neither drone flight altitude nor seeding rate significantly affected plant spacing, plant height, tillering, panicle production, or yield components. Similarly, physiological traits such as LAI, CGR, and NAR remained statistically unaffected. However, correlation analysis revealed that excessive vegetative growth negatively impacted yield, while early vigor, percent filled spikelets, LAI, and CGR were positively correlated with productivity.

Economic analysis identified the most profitable treatment in Study 1 as a drone speed of 7 m/s with a seeding rate of 60 kg/ha, yielding a net income of PhP26,166 and a benefit-cost ratio (BCR) of 1.51. In Study 2, the optimal treatment was 3.0 m altitude with a seeding rate of 60 kg/ha, generating a net income of PhP21,387 and a BCR of 1.43. Drone seeding also proved financially viable at scale, with estimated annual returns of PhP1.26 million over 1,000 hectares, a breakeven price of PhP720. 70/ha, payback period of 1.58 years, NPV of PhP2.39 million, and BCR of 1.40.

The study concludes that drone seeding is a promising and cost-effective approach for rice cultivation. It recommends the use of a 60 kg/ha seeding rate and mid-range drone speed or altitude for optimal performance. Further research is suggested across multiple cropping seasons and rice varieties to validate and refine these findings.