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ISSN : 2287-5824(Print)
ISSN : 2287-5832(Online)
Journal of The Korean Society of Grassland and Forage Science Vol.44 No.4 pp.279-286
DOI : https://doi.org/10.5333/KGFS.2024.44.4.279

Productivity of Sorghum-Sudangrass Hybrids in Cheonan Central Region, Korea

Palaniselvam Kuppusamy1, Ilavenil Soundharrajan1, Jeong Sung Jung1, Hyung Soo Park1, Yang Seung Hak1, Ouk Kyu Han2, Ki Choon Choi1*
1Grassland and Forages Division, National Institute of Animal Science, Cheonan 31000, Korea
2Department of Crops and Forestry, Korean National University of Agriculture and Fisheries, Jeonju 54874, Korea
* Corresponding author: Ki Choon Choi, Grassland and Forages Division, National Institute of Animal Science, Rural Development Administration, Cheonan 31000, Korea, Tel: +82-41‐580‐6752, E-mail: choiwh@korea.kr
December 11, 2024 December 24, 2024 December 24, 2024

Abstract


Forage crop cultivation and management are the greatest challenge under warm and dry climatic conditions. In this study, we estimated the productivity of three Sorghum-Sudangrass hybrids (SSH) cultivars in Cheonan, Korea, under different weather conditions during 2021-2023. The selected three cultivars performed well in the first and second cutting time during the experimental period and the plant growth characteristics were slightly different among cultivars. Particularly, the plant height was highest in Superdan cultivars (282 ± 24, 271 ± 30 cm), followed by Dairy mens dream (263 ± 39, 283 ± 29 cm) and Supergreen (270 ± 36, 264 ± 34 cm), for the first and second cuts respectively. The stem diameter slightly decreased in the second cut compared with the first cut of SSH cultivars. The highest stem diameter was found in Superdan cultivars (11.1 ± 1.7 mm), greater than Supergreen (10.2 ± 1.7 mm), and Dairy mens dream (9.5 ± 1.8 mm). Also, the total dry matter yield (DMY) was highest in Dairy mens dream (28,868 ± 6,653 kg/ha) followed by Supergreen and Superdan cultivars. In 2021 and 2023, the highest plant height, stem diameter and DMY were measured in the selected cultivars compared to 2022. The crude protein level was higher in the first cutting of all three cultivars at approximately 9-12%, in the order of Supergreen > Dairy mens dream > Superdan varieties. Moreover, the crude protein content was lowest in the second harvest of all cultivars, but the NDF and ADF levels did not alter in both harvest periods across different cultivars and years. In conclusion, the selected cultivars for SSH forage production could be efficient and recommended in the Cheonan region. However, the choice of cutting time and optimum precipitation should be considered to further increase SSH forage cultivation.


Sorghum-Sudangrass hybrids , Cultivars , Temperature , Dry matter yield , Crop growth , Cheonan region

초록

    Ⅰ. INTRODUCTION

    Agro-climatic factors such as heat, water and atmosphere conditions play important role in vegetation growth and better yields. Particularly, the fluctuations in temperature and precipitation may directly affect the development and suitability of crop production (Ray et al., 2015). The cultivation of forage crops may face yield reduction and nutritional losses due to climatic and environmental changes (Hatfield et al., 2011;Kim and Sung, 2023). Recently, sustainable farms and animals have been raised in livestock sector that extremely needed for the domestic supply of high-quality forage sources. As a result, the forage producers and scientific community have been focused on the different summer crops which can grow under abnormal weather condition (Kir and Sahan, 2018). Generally, forage crops cultivation depends on different factors including sowing time, resistance to drought, water supply, short growing season, plant density and harvest time which determining the forage quality and yields (Lee et al., 2019). Based on that, cultivation of the Sorghum-Sudangrass hybrid (SSH) would be advantageous in getting stable and robust forage production. SSH has better agronomic properties such as producing high dry matter yield and green biomass content like maize, alfalfa and legume crops. It can be tolerant in severe environmental conditions such as drought and high temperatures. Past five decades, the average annual temperature has risen at the rate of 0.23- 1°C in the Southern area of the Korean Peninsula and Jeju Island, which is slightly higher than the world average level. Also, the accumulated precipitation nationwide has been changed (IPCC,1995;Kang et al., 2011). Hence, many studies focusing on climatic factors impact on cultivation of summer forage crops and analysis extensively to achieve the optimum dry matter content and nutrient profile for ensiling process (Peng et al., 2017). Kim and Sung (2021) reported the expansion of grassland area in Korea, there is 9,162 ha (28.1%) of unused grassland that can be utilized as public pasture to enhance forage cultivation.

    Sorghum-Sudangrass hybrids (Sorghum bicolor L. × Sorghum bicolor ver. Sudanese) belong to Poaceae family which grows in semi-arid to warm temperature regions. SSH is high adaptability, resistant to various abiotic stresses and, lower production costs as compared to maize and legume crops (Atis et al., 2012;Venuto and Kindiger et al., 2008). The plants have regrowth potential and they can be harvested multiple times in a year. In addition, the SSH are good source for hay, silage and green chop and is widely used for silage in the US, Korea, China, and many other Asian countries. SSH could produce significant quantities of fresh biomass, normally around 3000 kg/ha. It can be able to optimize the production yield of up to 8000 kg/ha of fresh biomass (Choi et al., 2023). In Korea, there were fourteen SSH varieties used for the forage production, but all the cultivars have not been studied under the same environmental conditions, same years and same experimental sites (Choi et al., 2017). The SSH varieties differ in their chemical composition including the content of crude protein, sugars, neutral detergent fiber (NDF), acid detergent fiber (ADF) and lignin ratio (Seo et al., 2016). SSH is cultivating more than 26,491 ha, with the productivity of 3,97,372 tons in 2014, more than 50% of the total land area for summer forage crops in the Korean Peninsula and Jeju Island (RDA, 2012). The cultivation of the SSH forage crops was considered not only to improve the livestock feed production but also to partially replace the imported feed level. Therefore, this study was conducted to evaluate the performance of SSH growth characteristics, dry matter yield and nutritive content of three different cultivars in the Cheonan region during 2021-2023.

    Ⅱ. MATERIALS AND METHODS

    1. Study area and experimental set-up

    The trial experiment was conducted in Cheonan region from April 2021 to September 2023, and the site was located at Longitude 36°90'N, and Latitude 127°10'E. The average annual precipitation in Cheonan region was 900-1500 mm, on average more than 75% falls between June to September. The average annual temperature was 12°C usually ranges from 25-27°C in August month. The climatic data including average temperature, accumulated temperature, average precipitation and lowest average temperatures from sowing to first and second cut were derived from the Korean Meteorological Administration (KMA, 2020). Table 1-2 shows the average temperature and average precipitation-related variables in the SSH cultivation at the Cheonan site during 2021-2023. The SSHs seed sowing was conducted in early April every year with a drill seeding method used at 35 kg/ha. The plot size of the experimental unit was 12 m2 (3 M length, × 4 M width) with row spacing of 50 cm. This experiment was performed with three repetitions of randomized block design.

    In this study, three SSH varieties (Dairy mens dream, Supergreen and Superdan) were analyzed. The experimental field was chemically fertilized with approximately 250 kg/ha nitrogen (N), 150 kg/ha phosphate (P2O5) and 150 kg/ha potassium (K2O) applied on basal fertilizer of each year. Also, the same fertilizer 75% was applied after first harvest time.

    2. Agronomic characteristics study of SSH cultivars

    Plant growth parameters such as crop height and stem diameter were measured during harvest time, the plant was harvested above 10 cm from the soil and the crop growth height and stem diameter measured using Vernier calipers (Mitutoyo, Japan). Totally two cuts of SSH were taken during every year in the experimental period. The first cut was taken at 60 days after sowing and the second cut was taken at 55 days of ripening stage in SSH crops.

    3. Analysis of CP, NDF and ADF content

    The SSH samples were randomly selected three plants from the harvested SSH crops and cut into small pieces. Then, the chopped plants were dried in hot air oven at 55-65°C for 72 hr to analysis the dry matter content of the sample. The dried samples were ground and sieved to pass a 1mm mesh size to separate the bigger granules. Fiber content of samples was assessed with the Van-Soest method (Van-Soest et al., 1991), involving the sequential extraction of neutral detergent fibre (NDF) and acid detergent fiber (ADF) were measured. Crude protein content was determined with the method reported earlier by AOAC (1990).

    4. Statistical analysis

    Microsoft Excel 2010 ver 14.0 (Microsoft Corp. Redmond, WA, USA) was used to prepare the datasets. The datasets collected were statistically analysed using SPSS software (SPSS version 20.0, IBM Corp. NY, USA). The mean separation among treatment means was calculated using the Least significant difference (LSD) test and student t- test. P-value < 0.05 was considered a statistically difference between groups.

    Ⅲ. RESULTS

    1. Effect of temperature and precipitation on SSH cultivars

    Precipitation and temperature are considered key factors for forage vegetation and development. The meteorological data including monthly average temperature, lowest average temperature, accumulated temperature, average precipitation, and total precipitation from sowing to the first cut, and second cut were presented in Table 1-3. The average temperature in the summer season reached 27°C in July 2021, whereas the monthly lowest average temperature range was 20-22°C in June-August 2021. The monthly average temperature variations no significant effects on growth rate, dry matter yield and nutritive value of the SSH cultivars in Cheonan region, the details were discussed in the next chapters III. 2 and III. 3. Year-to-year accumulated temperature was significantly increased, 3182.4 °C recorded in September 2021 and gradually rose to 4039.6°C in September 2022 and followed by 4230.56°C in 2023. In this experiment, we noticed the average temperature was increased more quickly from the first harvest to second harvest time than the sowing to the first harvest time. However, the temperature range could stimulate the growth of SSH production in Cheonan region from 2021 to 2023.

    Based on the three-year experiment, the annual rainfall ranges fluctuated in the Cheonan region, the ranges of 1397, 1225 and 1059 mm for 2023, 2022 and 2021 respectively. Also, the Cheonan region have received much precipitation in 2021 compared to the other years, as total rainfall was received more than 90% during summer April – September of the year. Table 2 shows the monthly average precipitation in Cheonan region from 2021 to 2023. The maximum monthly rainfall is 474.7, 340 and 404 mm received during September 2021, July 2022, and September 2023, respectively. However, there was no precipitation was observed during July 2021 and September 2022. In 2022, there was erratic rainfall received; 825.4 mm precipitation received sowing to first cut and 122.2 mm fell between the first to second cutting time in Cheonan region (Table 3).

    2. Growth characteristics study on SSH cultivars

    Table 4 shows the agronomic characteristics and dry matter yield of different SSH cultivars in the Cheonan region from 2021 to 2023. The highest values of crop height were measured in Dairy mens dream (283 ± 29 cm, 2nd cut) and Superdan cultivars (282 ± 24 cm 1st cut) which is greater than the Supergreen variety. In 2021 and 2023, the SSH was found significantly taller plant in all cultivars than in 2022. The plant growth profile of SSH cultivation in the Cheonan region is similar like other subtropical parts such as Jeju Island and Southern area in Rep. Korea. The mean average of three years stem diameter was higher in Superdan (11.1 ± 1.7 mm) and followed by Supergreen (10.2 ± 1.7) cultivars. The lowest value of stem diameter was found in the Dairy mens dream (9.5 ± 1.8 mm) in the first harvest time. In the second harvest, the selected three cultivars were found lowest stem diameter ranges than the first harvest time and the stem diameter of Supergreen, superdan and Diary mens dream were 9.8 ± 1.5, 9.9 ± 1.9 and 9.7 ± 1.7 mm, respectively. Table 4 shows the SSH dry matter yield of two harvests in Cheonan region. Based on the average of three years, the dry matter yield varied between cultivars and the highest ranges were obtained in Dairy mens dream of first and second harvest times 16,567 ± 3952 and 12,300 ± 3368 kg/ha, respectively. In terms of quantity by cultivars (p<0.05), the Dairy mens dream exhibited the highest productivity. In addition, there is no significant changes between Supergreen (14,964 ± 3,715 and 11,505 ± 2,003 kg/ha) and Superdan cultivars (14,791 ± 4,087 and 10,921 ± 1,948 kg/ha) in first and second harvest time, respectively. The dry matter yield was not affected in the cultivars by rainfall, however, the Superdan cultivars was produced the lowest DMY among other cultivars. The Superdan cultivars was less resistant by precipitation in Cheonan climatic condition. Therefore, the harvest time and precipitation were significant effect for the dry matter content.

    3. Nutritional profile on SSH cultivars in Cheonan region

    The effect of climatic factors on SSH crude protein, ADF and NDF content in the Cheonan region was presented in Table 5. In our study, the crude protein values of Sorghum-Sudangrass cultivars showed no significant variation between cultivars, whereas the harvest time had strong differences in SSH CP content. The three-year average of CP content in Supergreen (10.57 ± 2.26 % DM) and followed by Dairy mens dream (9.87 ± 1.93 % DM) and Superdan (9.63 ± 2.91 % DM) cultivars in the first harvest time. In 2021, the CP content was highest in all cultivars at both harvest time than the other two years. Also, the SSH cultivars have least CP content in second cutting time (6-8 % DM, 3-year average). In the second cutting time, the total CP range of Supergreen cultivars was (6.80 ± 1.54 % DM) and followed by Supergreen was (6.41 ± 1.72 % DM) and Dairy mens dream was (6.05 ± 1.63 % DM) measured in the Cheonan region. Therefore, the CP ranges was approximately 30-40% higher in the first harvest time than the second harvest of SSH. In our study, we observed that the CP values were slightly different in the cultivation year, but three-year average CP content was almost similar in the all cultivars.

    The NDF and ADF content were no significant changes between cultivars in the three-year study but it had slight differences in the harvest time. The highest NDF value was Supergreen (61.91 ± 2.56 % DM, 3-year average) and followed by Superdan (61.84 ± 3.70 % DM) and Dairy mens dream (61.65 ± 2.68 % DM) determined in the second cutting time. In 2021, the cultivars are performed well and measured highest NDF values (60-63%) than other years which means the suitable precipitation and temperature enhances the nutrient profile of SSH cultivars in Cheonan region. The ADF amount was estimated in Dairy mens dream (38.31 ± 1.62 % DM), Supergreen (37.98 ± 2.09 % DM) and Supergreen (37.94 ± 2.92 % DM) cultivars in the second harvest time.

    Ⅳ. DISCUSSION

    Forage growth characteristic analysis is a fundamental factor in determining plant growth and physiology. The average temperature during the growth period of the SSH forage crop in the Cheonan region could be optimum for their demands. In 2021-2023, the average temperature was 12-18°C on April to May month, and the temperature gradually increased around 26-27°C from June to August. Peng et al. (2020) suggested the impacts of accumulated thermal climatic conditions is important during the forage SSH growth period. We found that the accumulated temperature gradually increased in the Cheonan region, Southern part of Rep. of Korea. In 2021, the accumulated temperature was 3182.4°C, which is less than the other two years (4039.6 and 4230.5°C in 2022 and 2023, respectively). The thermal factors may not affect the SSH plant growth characteristic and yield level in Nutrima, Nutri Honey and M81-E but, the nutrient content of forage has significantly decreased (Alaturk et al., 2024;Özyazıcı and Açıkbaş, 2019). Hyun and Kim (2007) reported that the arable lands in most regions of the Southern area of the Korean Peninsula, Jeju Island and some mountainous regions could be suitable for the cultivation of grain maize, Sorghum and grasses. Mainly, the appropriate precipitate during the crop growth cycle of Sorghum-Sudan grass is 500-800 mm. Hence, the total average precipitation was nearly 1000-1300 mm in Cheonan region during the 2021-2023 period. We observed the total precipitation from sowing to first harvest is more suitable for SSH crop growth and yield, the precipitation amount is 425.4 825.4 and 413.2 mm received in 2021, 2022 and 2023 respectively. The SSH cultivars can be resistant to high temperature and low water stress. More or less precipitation may affect the production of SSH forage crop (Venuto and Kindiger, 2008). However, we found that the SSH total dry matter yield and plant growth profile were not significantly affected in the Cheonan region during the experiment period.

    The plant height was slightly varied among cultivars, the tallest crop height was obtained from the Superdan (282 ± 24 cm, 1st cut) and Dairy mens dream (283 ± 29, 2nd cut). In 2022, the selected three cultivars showed the lowest plant height than the other two years. Previously, Celik et al. (2021) reported the different Sorghum species have obtained different values of plant height, for example, the Cukura sorghum cultivars plant heights were found 183-360 mm. The optimum precipitation and temperature can boost the plant growth rates and agronomic characteristics (Pupo et al., 2022). Recently, we also found that SSH cultivars produced good plant growth rates including crop height and stem diameter in the Jeju Island region. The Superdan and Supergreen cultivars had the highest plant height compared to the Dairy men dream cultivars which is attributed to the Jeju Island suitable climatic condition for SSH production. We also strongly suggest the high temperature and optimum precipitation strongly influence the plant agronomic behavior in the Southern area of Rep. Korea and Jeju Island (Kuppusamy et al., 2024). However, Miller and team (2011) found significance differences in the crop height between cultivars, for instance, Sugargraze (153.9 cm), Nutrifeed (76.9 cm) and Pac BMR (90 cm) have variations in growth profile. Therefore, the cultivars and climatic factors have a strong relationship for the better crop production. Also, the dry matter yield has significant differences among cultivars and harvest time. In the first cut, the mean dry matter yield of cultivars was slightly higher in all the cultivars than the second harvest time. The highest dry matter yield was measured in Dairy mens dream at each cut as well as the total of all cuts (28,868 ± 6,653 kg/ha) followed by Supergreen (26,469 ± 4,767 kg/ha) and least was measured in the Superdan cultivar (25,712 ± 4,885 kg/ha). In 2023, the dry matter yield of each cultivar was higher than those of the other years. Our study is similar finding of Wei et al. (2022), the forage dry matter yield was higher in the Sorghum-Sudangrass hybrid (23.5 t/ha) than in the corn (18.7 t/ha) and Proso millet (7.68 t/ha) crops. Atis et al. (2024) also suggested the dry matter yield can increase more than two-fold when the harvesting time is delayed in the SSH crops. In addition, the cultivars and environmental conditions might alter the SSH DMY and the yield ranges between 18,950-25,810 kg/ha (Gonulal et al., 2020).

    The crude protein content, NDF and ADF value could reveal the forage quality in the forage crops (Alatürk, 2024). In 2021, the crude protein content was more than 12 % in the SSH cultivars, but it was slightly reduced (1-3%) in the other two years. Also, the crude protein content in three cultivars showed significant differences in the first and second cutting time (12 vs 6 % DM respectively, 3-year average), the CP ranges were significantly lower in the second harvest time compared to the first cutting time. CP level in SSH may affected by increased average temperature and lower precipitation in the first harvest to second harvest time than the sowing to the first harvest time. In addition, the CP content was reduced in 2022 and 2023 in the Cheonan region. Therefore, the harvesting time, climatic factors influenced CP content of the selected three cultivars. We suggest that the first cut of SSH cultivars can achieve more CP content than the second cutting time. Crude protein content of around 10-15% is considered a good nutritional quality forage and less than 10% CP might considered that medium quality forage plant (Cherney and Hall, 2014). The season and environmental stress can affect CP concentrations, and eventually reduce the nutritional quality of the forage crops (Nohong et al., 2018;Pupo et al., 2022). In addition, Ozmen (2017) reported the different Sorghum species have different CP values due to the genetic changes. For example, the CP ratios in Bursa cultivars were found 7-8% and, 2.5–7% in Bingol variety. Furthermore, the NDF and ADF content in three SSH cultivars were not significantly influenced by the different cultivars such as Dairy mens dream, Superdan and Supergreen. But, the harvest times have slightly altered the ADF and NDF values in the SSH varieties. In the second cutting time, the NDF was higher in all three cultivars Dairy mens Dream (61.65 ± 2.68 % DM), Superdan (61.84 ± 3.70 % DM) and Supergreen (61.91 ± 2.56 % DM), that was 2-3% higher than first harvest time of SSH cultivars. Our findings obtained in this study are consistent with the work published earlier by Jung et al. (2019). The three SSHs cultivars had no significant differences in the NDF ratio, but the second cutting time was the highest NDF ranges of 58- 61% in the SSH cultivars.

    Ⅴ. CONCLUSION

    In conclusion, the study used three potent SSH cultivars for forage production in Cheonan region, Korea. It produced excellent dry matter yield and crop growth profile under the climatic conditions of the southern area. In 2022, the precipitation and temperature slightly altered the dry matter yield and plant growth characteristic of SSH, however, the nutrient content of selected SSH cultivars showed no significant changes throughout experimental periods from 2021 to 2023. Notably, the crude protein content was significantly higher in the first harvest time of all cultivars, but decreased by approximately 30-40% in the second harvest due to the increased average temperature and higher precipitation levels during the period between the first to second harvests. Overall, the climatic conditions of the Southern part of the Rep. Korea appear suitable for the cultivation of SSH hybrids. In addition, the effect of climatic factors on the long-term yields and growth characteristics of forage crops requires further localized studies for SSH production.

    Ⅵ. ACKNOWLEDGEMENT

    The research project was supported by the National Institute of Animal Science, Rural Development Administration, Republic of Korea, Project titled “Damage assessment of forages and development of cultivation technology for their damage reduction according to extreme weather (PJ01499601)”.

    Figure

    Table

    Meteorological data of monthly average temperature and the lowest average temperature during 2021-2023 of Sorghum-Sudangrass hybrids in Cheonan region

    Monthly average precipitation and accumulated temperature during 2021-2023 of Sorghum-Sudangrass hybrids in Cheonan region

    Monthly average temperature, the lowest average temperature and average precipitation by sowing to harvest time of Sorghum-Sudan hybrids in Cheonan region

    Sorghum-Sudan hybrids cultivars of growth characteristics and dry matter yields in Cheonan region during 2021-2023

    Nutritive contents of different Sorghum-Sudan hybrids cultivars in Cheonan region

    * Mean±SE, CP: Crude protein; ADF: Acid detergent fiber; NDF: Neutral detergent fiber.

    Reference

    1. Alaturk, F. 2024. Effects of harvest height and time on hay yield and quality of some Sweet Sorghum and Sorghum Sudangrass hybrid varieties. PeerJ. 12:e17274.
    2. AOAC. 1990. Official Methods of Analysis (15th ed.). Association of Official Analytical Chemist, Washington DC. USA.
    3. Atis, I., Konuskan, O., Duru, M., Gozubenli, H. and Yilmaz, S. 2012. Effect of harvesting time on yield, composition and forage quality of some forage sorghum cultivars. International Journal of Agriculture and Biology. 14:879-886.
    4. Celik, B.V. and Turk, M. 2021. The determination of forage yield and quality of some Sorghum and Sorghum Sudangrass cultivars in ecological conditions of Uşak Province. Turkish Journal of Range and Forage Science. 2:1-7.
    5. Cherney, J.H. and Hall, M.H. 2014. Forages. University Park: The Pennsylvania State University, pp. 1-100.
    6. Choi, G.J., Lee, S.H., Lee, K., Ji, H.C., Hwang, T.Y. and Kim, K.Y. 2017. Comparison of growth characteristics, productivity and feed values between varieties of Sudangrass and Sorghum-Sudangrass hybrids. Journal of The Korean Society of Grassland and Forage Science. 37:92-99.
    7. Choi, I.H., Choi, J.S., Kim, J.Y., Sung, K.I. and Kim, B.W. 2023. A study on the selection of manager and performance evaluation in management models for profitable structure of eco pastoral system in Alpine grassland. Journal of The Korean Society of Grassland and Forage Science. 43:248-256.
    8. Gonulal, E. 2020. Performance of Sorghum × Sudan Grass Hybrid (Sorghum Bicolor L. × Sorhgum Sudanense) cultivars under water stress conditions of arid and semi-arid regions. Journal of Global Innovations in Agricultural and Social Sciences. 8:78-82.
    9. Hatfield, J.L., Boote, K.J., Kimball, B.A., Ziska, L.H., Izaurralde, R.C., Ort, D., Thomson, A.M. and Wolfe, D. 2011. Climate impacts on agriculture: Implications for crop production. Agronomy Journal. 103:351-370.
    10. Hyun, S.W. and Kim, K.S. 2017. R based parallelization of a climate suitability model to predict suitable area of maize in Korea. Korean Journal of Agricultural and Forest Meteorology. 19:164-173.
    11. IPCC. 1996. Climate Change 1995: the IPCC Second Assessment Report, Volume 2: Scientific-technical analyses of lmpacts, adaptations, and mitigation of climate change, Watson RT, Zinyowera MC, and Moss RH (eds), Cambridge University Press, Cambridge, UK.
    12. Jung, J.S., Cho J.W. and Yamakawa, T. 2019. Effects of seeding date and cultivars on yield and growth characteristics of Sorghum × Sudangrass Hybrid [Sorghum bicolor (L.) Moench] cultivars in Central Region of South Korea. Journal of the Faculty of Agriculture, Kyushu University. 64:191-198.
    13. Kang, K., Lee, D., Na, Y., Sim, K., Choi, I., Lee, C., Park, K. and Kim, J. 2011. Climate change and Agriculture in Korea (33rd ed). Rural Development Administration, Seoul. Korea. pp. 1-25.
    14. Kim, M. and Sung, K. 2021. Comparison of forage production between extreme weather and normal weather for Sorghum-Sudangrass Hybrid (Sorghum bicolor L.) in Korea. Annals of Animal Resource Sciences. 34:54-70.
    15. Kim, M. and Sung, K. 2023. Assessment of weather events impacts on forage production trend of Sorghum-Sudangrass hybrid. Journal of Animal Science Technology. 65:792-803.
    16. Kir, H. and Şahan, B.D. 2018. The yield and agronomic characteristics of silage Sorghum and Sorghum-Sudangrass hybrid cultivars under Kirsehir ecological conditions. International Journal of Agricultural and Natural Sciences. 1:173-176.
    17. KMA (Korea Meteorological Administration). 2020. National typhoon center. Jeju, Korea. p.7.
    18. Kuppusamy, P., Soundharrajan, I., Jung, J.S., Hak, Y.S., Park, H.S., Han, O.K. and Choi, K.C. 2024. Growth characteristics and productivity of Sorghum-Sudangrass Hybrids in Jeju Island, Korea. Journal of the Korean Society of Grassland and Forage Science. 44:157-164.
    19. Lee, B.H., Kim, J.Y., Sung, K.I. and Kim, B.W. 2019. Investigation on the actual state of grassland in Republic of Korea. Journal of the Korean Society of Grassland and Forage Science. 39:89-96.
    20. Nohong, B. and Islamiyati, R. 2018. The effect of bio-slurry fertilization on growth, dry matter yield and quality of hybrid Sudangrass and Sorghum (Sorghum bicolor) Samurai-2 variety. Bulgarian Journal of Agricultural Science. 24:592-598.
    21. Ozmen, S. 2017. Determination of yield and quality features of different sorghum species in Bingol conditions. Bingöl Üniversitesi Fen Bilimleri Enstitüsü Tarla Bitkileri Anabilim Dalı, Yüksek Lisans Tezi, 63:S1.
    22. Özyazıcı, M.A. and Açıkbaş, S. 2020. The effect of harvest time on macronutrient concentrations in Sorghum × Sudangrass hybrid and Sudangrass varieties. Turkish Journal of Agricultural Research. 7:47-58.
    23. Peng, J., Kim, M. and Sung, K. 2020. Yield prediction modeling for Sorghum-Sudangrass hybrid based on climatic, soil, and cultivar data in the Republic of Korea. Agriculture. 10:137.
    24. Peng, J.L., Kim, M.J., Kim, Y.J., Jo, M.H., Nejad, J.G., Lee, B.H., Ji, D.H., Kim, J.Y., Oh, S.M. and Kim, B.W. 2015. Detecting the climate factors related to dry matter yield of whole crop maize. Korean Journal of Agriculture and Forest Meteorology. 17:261-269.
    25. Pupo, M.R., Wallau, M.O. and Ferraretto, L.F. 2022. Effects of season, variety type, and trait on dry matter yield, nutrient composition, and predicted intake and milk yield of whole-plant sorghum forage. Journal of Dairy Science. 105:5776-5785.
    26. Ray, D.K., Gerber, J.S., MacDonald, G.K. and West, P.C. 2015. Climate variation explains a third of global crop yield variability. Nature Communications. 6:5989.
    27. Rural Development Administration (RDA). 2012. Agricultural science and technology of analysis based on research(Ⅰ). pp. 315-374.
    28. Seo, S. Forage production, utilization, and animal husbandry in Korea. In Proceedings of the 6th Korea-China-Japan Grassland Conference, Jeju. Korea. 17-20 August 2016. pp. 5-15.
    29. Van Soest, P.J., Robertson, J.B. and Lewis, B.A. 1991. Methods for dietary fiber, neutral detergent fiber, and non-starch polysaccharides in relation to animal nutrition. Journal of Dairy Science. 74:3583-3597.
    30. Venuto, B. and Kindiger, B. 2008. Forage and biomass feedstock production from hybrid forage Sorghum and Sorghum–Sudangrass hybrids. Grassland Science. 54:189-196.
    31. Wei, S.N., Jeong, E.C., Li, Y.F., Kim, H.J., Ahmadi, F. and Kim J.G. 2022. Evaluation of forage production, feed value, and ensilability of proso millet (Panicum miliaceum L.) Journal of Animal Science and Technology. 64:38-51.
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