Ⅰ. INTRODUCTION

Barnyard millet (Echinochloa esculenta L.), also known as Japanese barnyard millet, is a summer annual C4 forage crop that grows well under high temperatures and poorly drained conditions. It has a short growing period (60–80 days) and demonstrates strong tolerance to waterlogging, making it suitable for paddy field utilization in East Asia (Lim et al., 2021;Park et al., 2022). Historically, E. esculenta is believed to have originated from the wild species E. crus-galli, and was cultivated as a staple food and forage crop in Japan and the Korean Peninsula, particularly in marginal environments with frequent flooding or poor soil fertility (Yabuno, 1987). Recent comparative genomics further clarifies the evolutionary history and domestication status of Echinochloa species, reinforcing the distinctiveness of barnyard millet within the genus (Wu et al., 2022). In Korea, research has shown that seeding dates significantly affect growth, yield, and nutritive value of barnyard millet, with delayed seeding after June resulting in a marked reduction in dry matter yield (Lee et al., 2013). Moreover, recent studies on forage cropping systems indicate that barnyard millet can be effectively integrated into multicropping systems with forage barley and whole-crop rice, thus providing flexibility in paddy field forage production (Oh et al., 2021;Jung et al., 2023). These findings highlight the potential of barnyard millet as a summer forage crop to fill the production gap in paddy-based cropping systems. Globally, breeding and genetic improvement efforts for barnyard millet have been actively reported. Genetic diversity studies using SSR markers confirmed the distinct separation between E. esculenta and E. crus-galli (Nozawa et al., 2006). More recently, omics-based approaches, such as genome sequencing, transcriptome analysis, and marker-assisted selection, have provided resources to improve traits such as lodging resistance, disease tolerance, and forage yield (Renganathan et al., 2020;Pradhan et al., 2024). These advances indicate that barnyard millet is now being considered not only as a underutilized cereal but also as a strategic crop for food and feed security in Asia. In Korea, government policy is also facilitating the expansion of summer forage crops. The Strategic Crop Direct Payment Program, initiated in 2023, aims to stabilize rice supply while promoting the utilization of paddy fields for summer crops such as barnyard millet, forage rice, and corn (MAFRA, 2023). This policy trend further underscores the importance of developing new cultivars with improved yield, quality, and adaptability. Therefore, the present study reports the breeding process and major agronomic and forage characteristics of the new barnyard millet cultivar ‘Da-on’, developed by the National Institute of Animal Science. The findings are expected to provide a scientific basis for strengthening the summer forage production system in Korea and enhancing domestic forage self-sufficiency.

Ⅱ. MATERIALS AND METHODS

This study was conducted from 2016 to 2024 by the Forages Production Systems Division of the National Institute of Animal Science (NIAS), Rural Development Administration (RDA), to develop a new barnyard millet (Echinochloa esculenta L.) variety with superior yield potential, forage quality, and adaptability to the domestic paddy-field production system.

1. Selection of superior individuals and line development

The barnyard millet (Echinochloa esculenta L.) cultivar ‘Da-on’ (line BM3) was bred using a stepwise pedigree selection scheme. The breeding program began in 2016 with the collection of a local landrace from Jeju Island, which served as the initial source population. Between 2017 and 2020, successive selection cycles were undertaken, emphasizing desirable agronomic attributes such as growth habit, heading date, panicle traits, and tolerance to lodging. This approach reflects conventional improvement methods previously applied to barnyard millet in East Asia (Yabuno, 1987;Lim et al., 2021). In 2022, the BM3 line was advanced to preliminary yield testing at Cheonan, where it demonstrated superior forage yield and quality relative to existing checks. Based on these results, BM3 was designated as a promising candidate for cultivar release.

2. Evaluation of agronomic characteristics of ‘Da-on’

A yield trial of the barnyard millet breeding line ‘Da-on’ (BM3) was carried out in 2022 at the experimental field of the Forages Production Systems Division, National Institute of Animal Science (NIAS). The agronomic characteristics of the new line were evaluated following the standard guidelines for crop characterization established by the Korea Seed and Variety Service (KSVS).

3. Regional adaptability trials

Regional adaptability trials of the barnyard millet line ‘Da-on’ (BM3) were carried out for two consecutive years (2023–2024) at three representative forage production sites: Cheonan, Jinju, and Gimje. The objective was to assess the adaptability, yield potential, and basic agronomic traits of ‘Da-on’ in comparison with the check cultivar ‘Borajik.’ Sowing was conducted on May 15 in Cheonan, May 20 in Jinju, and May 25 in Gimje, using a seeding rate of 20 kg/ha with drill sowing at 20 cm row spacing. Fertilizer management followed the official RDA guidelines for forage crops. A basal application of fertilizer (N–P₂O₅–K₂O = 80–120–120 kg/ha) was made at sowing, followed by a topdressing at 60–0–0 kg/ha. Morphological traits such as heading date, plant height, leaf size, stem diameter, and panicle structure were mainly recorded at Cheonan. Forage yield was measured by harvesting the whole plot at each of the three trial sites.

4. Forage nutritive value analysis

The forage nutritive value of the barnyard millet cultivar ‘Da-on’ was evaluated using standardized laboratory methods. Crude protein (CP) content was determined by the Kjeldahl method following the AOAC (1990) procedures with an automated nitrogen analyzer (Kjeltec™ 2400 Autosampler System, Foss Tecator, Sweden). Acid detergent fiber (ADF) and neutral detergent fiber (NDF) were analyzed using an Ankom Fiber Analyzer (Ankom Technology, Macedon, NY, USA), based on the sequential procedures described by Goering and Van Soest (1970). Total digestible nutrients (TDN) were calculated from ADF concentrations using the regression equations commonly employed in forage evaluation studies (Renganathan et al., 2020).

5. Statistical analysis

Data were subjected to statistical analysis using SAS software (ver. 9.4; SAS Institute, Cary, NC, USA). Differences between cultivar means were tested by Student’s t-test, with significance thresholds set at p<0.05.

Ⅲ. RESULTS AND DISCUSSION

1. Agronomic characteristics of the new barnyard millet cultivar ‘Da-on’

The agronomic characteristics of ‘Da-on’ are summarized in Table 1, based on observations conducted at Cheonan during 2023–2024. The cultivar exhibits an erect growth habit with elongated leaves and purple panicles. Its heading date (August 5) was ~11 days later than the check ‘Borajik,’ placing ‘Da-on’ in the mid-maturity group—a timing window that is generally favorable for maximizing summer biomass in paddy-field systems. This observation is consistent with previous reports indicating that later-heading barnyard millet types tend to secure greater dry-matter accumulation under May sowing in Korea (Park et al., 2022). Mean plant height was 178.8 cm in ‘Da-on,’ compared with 138.0 cm in ‘Borajik,’ and flag-leaf length was also greater (32.6 cm in ‘Da-on,’ compared with 21.8 cm in ‘Borajik’). These traits align with earlier studies that have linked canopy architecture, including leaf area and plant stature, to yield potential in barnyard millet. Despite a slightly smaller stem diameter 5.7 mm, ‘Da-on’ showed a tendency toward strong lodging resistance in field trials, a pattern that supports previous Korean agronomic findings showing that appropriate stand management (e.g., drill-sowing and density adjustment) can maintain standability even in tall barnyard millet canopies (Lee et al., 2021). Overall, the phenotype of ‘Da-on’ (upright habit, mid-maturity, good standability) corresponds well with broader syntheses describing Echinochloa esculenta as a short-season C4 forage adapted to humid, poorly drained paddy soils, where lodging-tolerant lines perform reliably (Lim et al., 2021;Renganathan et al., 2020).

2. Dry matter yield performance

Yield trials demonstrated that ‘Da-on’ exhibited outstanding productivity compared with the control variety ‘Borajik’ (Table 2). In the preliminary yield trial conducted at Cheonan in 2022, the dry matter yield of ‘Da-on’ reached 14,886 kg/ha, representing 192% of that of ‘Borajik.’ Furthermore, regional adaptability trials carried out from 2023 to 2024 across three sites Cheonan, Jinju, and Gimje showed that ‘Da-on’ achieved an average dry matter yield of 16,858 kg/ha, which was 130% higher than the control 7,338 kg/ha.

These findings demonstrate that newly developed barnyard millet cultivar exhibits superior biomass production compared with conventional varieties under both paddy and upland cultivation conditions during the summer growing season. The consistent yield stability observed across diverse environments further underscores the potential of ‘Da-on’ to serve as a reliable forage resource, thereby contributing to the enhancement of forage self-sufficiency in Korea (Fig. 2).

3. Forage nutritive value

The forage quality characteristics of ‘Da-on’ are summarized in Table 3. At the heading stage, crude protein (CP) content was 8.7%, which was nearly identical to that of the control cultivar ‘Borajik’ (8.5%), indicating that both cultivars provide similar protein levels. In contrast, the fiber composition of ‘Da-on’ was more favorable. The ADF and NDF contents of ‘Da-on’ were 34.0% and 63.7%, respectively, compared with 38.2% and 67.9% in ‘Borajik.’ Lower fiber fractions are generally associated with improved digestibility and higher voluntary intake, suggesting that livestock fed with ‘Da-on’ forage would benefit from enhanced feeding efficiency. As a result of the reduced fiber contents, the estimated total digestible nutrients (TDN) of ‘Da-on’ reached 62.0%, which was markedly higher than that of ‘Borajik’ (58.7%). This increase in TDN highlights the superior nutritional balance of ‘Da-on,’ combining adequate protein content with improved fiber composition. Taken together, these results indicate that ‘Da-on’ can provide higher-quality forage while maintaining high biomass yield, thereby offering a valuable option for summer forage production.

Ⅳ. CONCLUSIONS

The breeding and evaluation program for the barnyard millet cultivar ‘Da-on’ was carried out from 2016 to 2024 by the Grassland and Forage Division of the National Institute of Animal Science (NIAS), Rural Development Administration (RDA). ‘Da-on’ is characterized by an upright growth habit, long leaves, and purple panicles, with heading occurring on August 5, approximately 11 days later than the control cultivar ‘Borajik’. At this stage, the average plant height of ‘Da-on’ was 178.8 cm, significantly taller than ‘Borajik.’ In preliminary yield trials at Cheonan in 2022, ‘Da-on’ produced 14.9 tons/ha of dry matter, equivalent to 192% of the yield of ‘Borajik.’ Subsequent regional adaptability trials conducted from 2023 to 2024 in Cheonan, Jinju, and Gimje confirmed its yield advantage, with an average dry matter production of 16.9 tons/ha, 130% greater than the control. Yield superiority of ‘Da-on’ was consistent across locations, demonstrating its stability and adaptability to diverse environments. The forage nutritive evaluation at the heading stage revealed that ‘Da-on’ maintained a crude protein content of 8.7%, comparable to ‘Borajik’ (8.5%). However, ‘Da-on’ displayed a more favorable fiber profile, with lower ADF (34.0%) and NDF (63.7%) compared with ‘Borajik’ (38.2% and 67.9%). This resulted in a higher TDN value of 62.0%, compared with 58.7% for the control, suggesting improved digestibility and feeding value. Taken together, these results indicate that ‘Da-on’ offers both high productivity and enhanced forage quality. With its reliable performance in multiple environments and balanced nutritive traits, this new cultivar is expected to make a significant contribution to expanding summer forage production in Korea.