As the critical phase of seed management begins, the hybrid rice seed production bases in Heshui Town and Shazipo Town, Yinjiang Tujia and Miao Autonomous County, Tongren City, are now fully engaged in the core pollination and fertilization period. Expansive green rice paddies unfold across the landscape, with delicate rice flowers blooming in succession, marking the essential window for heading, flowering, and seed setting.

Unlike conventional rice, which self-pollinates, hybrid rice seed production relies on cross-pollination between male and female parent plants. The precision of field management directly determines the yield and quality of the autumn seed harvest. Taking advantage of the sunny, high-temperature weather, the seed production base in Xingwang Village, Heshui Town, is bustling with activity. Grower Zhang Guangning organizes workers to pair up, standing at both ends of the field ridges. They evenly pull long ropes to lightly sweep the rice panicles, using gentle vibrations to shake off pollen from the male parent plants, ensuring the pollen disperses evenly and attaches to the female parent panicles.

Key Pollination Window Requires Swift Action

"The rice is currently in its flowering stage, and with clear skies, the pollen is highly active. We are seizing this opportunity to artificially 'drive' the flowers through pollination, aiming to maximize the seed setting rate," explains Zhang Guangning. The flowering window for rice is only 7 to 10 days, making timeliness crucial. Continuous operation during favorable weather is essential.

Technician Wang Hui is stationed at the fields to guide growers on pollination techniques. In hybrid rice seed production, male and female parent plants are planted in separate rows. The female parent's stamens are degenerate, preventing self-pollination, so cross-pollination entirely depends on the male parent's pollen. The brief flowering window demands precise management. Wang Hui adjusts the timing of pollen dispersal based on daily temperature and humidity. The optimal time for pollination occurs when the male parent's panicles open and yellow pollen is exposed. The first round of pollen driving begins then, followed by a second round 20 minutes later. This cycle repeats three to four times daily, accumulatively totaling one to two hours, to ensure each batch of pollen effectively completes fertilization.

Drone Technology Enhances Pollination Efficiency

Traditional manual pollen driving is labor-intensive and time-consuming, and with rural labor shortages and fragmented mountain fields, its limitations are increasingly apparent. This year, Yinjiang County has shifted from traditional methods, introducing drone-based airflow pollination technology for the first time in hybrid rice seed production. This technique uses the stable airflow generated by low-flying agricultural drones to disturb the male parent panicles, lifting pollen efficiently over large areas.

"A single worker can manually cover only 10 to 15 mu per day, which has limited efficiency," says Ren Bin, Director of the Agricultural Machinery Center at the Yinjiang County Agriculture and Rural Affairs Bureau. He explains that this year, the county has implemented a classification-based approach: flat, contiguous fields are all pollinated by low-flying drones, using the stable airflow from the rotors to shake the panicles and release pollen. In contrast, scattered terraced fields inaccessible to machinery retain manual pollination using ropes and bamboo poles. Practical comparisons show that a single drone can cover 80 to 100 mu per day, matching the efficiency of 16 to 20 workers. This not only significantly reduces production costs and alleviates labor shortages but also effectively pushes rice seed production toward full mechanization.

Precise Flowering Timing and Field Purity Management

Beyond technological pollination efficiency, precise regulation of flowering timing is vital for stable seed production. Particularly, the persistent high temperatures after the hottest period of summer can cause uneven heading between male and female plants, misaligned flowering periods, or 'neck-clasping' of panicles, directly impacting pollination success. To address this, Yinjiang County implements precise chemical regulation. Zhang Xudong, Deputy Director of the Seed Management Station at the county's Agriculture and Rural Affairs Bureau, notes that field monitoring shows the optimal time to spray the growth regulator '920' is when the female parent has reached 5% to 8% heading. Currently, the female parent heading rate at the bases meets the standard. Agricultural technicians are guiding farmers to use drones for precise application, administering 20 grams per mu twice per season to help synchronize heading and ensure accurate flowering overlap. In cloudy or rainy weather, additional applications may be needed to avoid wasting the pollination window.

Ensuring stable yields begins with quality, and improving quality starts with purity. The flowering and pollination period is also a critical phase for field impurity removal and seed purification. At the seed production bases in Qingqiu and Shizi villages, Shazipo Town, technician Yang Songqing leads farmers in inspecting rows and plants, carefully identifying and removing off-types, variant plants, early-maturing plants, and late-maturing plants. These rogue plants, which differ in growth, color, and height from the seed-producing rice, compete for water, fertilizer, and light, interfering with normal pollen transmission and causing seed purity to fall short. Yang Songqing explains that the bases conduct at least three systematic impurity removal operations annually, filtering out undesirable plants to strictly ensure seed purity meets the national standard of over 98%.

From technological pollination efficiency and precise flowering regulation to manual impurity removal for purity, Yinjiang County employs superior methods, machinery, and meticulous management practices. By attending to every critical link in the seed production process, the county nurtures high-quality seeds through precise field cultivation, strengthening the foundation for seed industry revitalization and food security.