• Research Article

    Estimation of the Lodging Area in Rice Using Deep Learning

    딥러닝을 이용한 벼 도복 면적 추정목

    Ho-Young Ban, Jae-Kyeong Baek, Wan-Gyu Sang, Jun-Hwan Kim, and Myung-Chul Seo

    반호영, 백재경, 상완규, 김준환, 서명철

    Rice lodging is an annual occurrence caused by typhoons accompanied by strong winds and strong rainfall, resulting in damage relating to pre-harvest ... + READ MORE
    Rice lodging is an annual occurrence caused by typhoons accompanied by strong winds and strong rainfall, resulting in damage relating to pre-harvest sprouting during the ripening period. Thus, rapid estimations of the area of lodged rice are necessary to enable timely responses to damage. To this end, we obtained images related to rice lodging using a drone in Gimje, Buan, and Gunsan, which were converted to 128 × 128 pixels images. A convolutional neural network (CNN) model, a deep learning model based on these images, was used to predict rice lodging, which was classified into two types (lodging and non-lodging), and the images were divided in a 8:2 ratio into a training set and a validation set. The CNN model was layered and trained using three optimizers (Adam, Rmsprop, and SGD). The area of rice lodging was evaluated for the three fields using the obtained data, with the exception of the training set and validation set. The images were combined to give composites images of the entire fields using Metashape, and these images were divided into 128 × 128 pixels. Lodging in the divided images was predicted using the trained CNN model, and the extent of lodging was calculated by multiplying the ratio of the total number of field images by the number of lodging images by the area of the entire field. The results for the training and validation sets showed that accuracy increased with a progression in learning and eventually reached a level greater than 0.919. The results obtained for each of the three fields showed high accuracy with respect to all optimizers, among which, Adam showed the highest accuracy (normalized root mean square error: 2.73%). On the basis of the findings of this study, it is anticipated that the area of lodged rice can be rapidly predicted using deep learning. - COLLAPSE
    June 2021
  • Research Article

    Seeding Rate and Days for Low-density Transplant Cultivation

    드문모심기 적정 파종량 및 육묘일수 분석

    Woon-Ha Hwang, Jae-Hyeok Jeong, Hyen-Seok Lee, Seo-Yeong Yang, and Chung-gun Lee

    황운하, 정재혁, 이현석, 양서영, 이충근

    In order to develop a safe seeding technology for low-density transplantation, we analyzed the changes in seeding growth according to different seeding ... + READ MORE
    In order to develop a safe seeding technology for low-density transplantation, we analyzed the changes in seeding growth according to different seeding rates and seeding days. We detected changes in leaf number and shoot diameter on the 10th seeding day, and in plant height on the 20th seeding day according to seeding rate. The increase in shoot and leaf number, and shoot diameter per seeding day decreased with anincrease in seeding rate. On seeding day 20, the reductions in shoot and root dry weights according to seeding rate was lower compared with those recorded at seeding day 10. Shoot dry weight was significantly related to root dry weight, plant height, and shoot diameter. With an increase in seeding rate, seeding health decreased and there was an increase in the rate of seeding health per seeding day decreased. For low-density transplantation, the optimal number of seeds required for transplanting 3–5 plants per hill is 11,000, which is estimated to be approximately 280–300 g of seeds for 22 g brown rice. Furthermore, the appropriate number of seeding days is estimated to be 13 to 16 days, which corresponds to a small reduction in seeding health. - COLLAPSE
    June 2021
  • Research Article

    Annual Analysis of the Agronomic Traits of Global Wheat Germplasms in the Korean Environment

    국내환경에서 밀 유전자원의 연차간 농업특성 분석

    Jae-Han Son, Jinwoo Yang, Chon-Sik Kang, Kyeong-Hoon Kim, Kyeong-Min Kim, Han-Yong Jeong, Jinhee Park, Ji-Young Son, Tae-il Park, and Changhyun Choi

    손재한, 양진우, 강천식, 김경훈, 김경민, 정한용, 박진희, 손지영, 박태일, ChoiChanghyun

    Securing a range of wheat resources is of particular importance with respect to wheat breeding, as it provides a broad genetic foundation ... + READ MORE
    Securing a range of wheat resources is of particular importance with respect to wheat breeding, as it provides a broad genetic foundation. Although wheat breeders have used different wheat germplasms as material resources in current breeding systems, the traits of most germplasms collected from foreign countries differ from the unique traits that have evolved in the Korean environment. In this study, conducted over a 2-year period (2018 and 2019), we therefore evaluated the agricultural traits 1,967 wheat germplasms collected not only in Korea but also worldwide. During the period from sowing to February, the average temperature in 2019 was greater than 1°C, whereas from March to June, the average temperature was approximately 0.9°C higher in 2018. Compared with the growth recorded in 2018, the stem length in 2019 increased by approximately 20 cm in 2019, and there were notable differences heading date and maturation between 2018 and 2019. In 2019, the heading dates of 973 and 713 wheat resources were earlier and later than those in 2018, respectively. Moreover, stem length was found to be highly correlated with the heading date and maturation. In Korea, where the rainy season and tine of rice transplantation overlap with the time of wheat harvest, early flowering time with high grain yield has been the most important selection target with respect to wheat breeding. We anticipate that the findings of this study will provide would use a foundation for the selection of elite materials and the development of resource core-sets for Korean wheat breeding programs. - COLLAPSE
    June 2021
  • Research Article

    Evaluation of Regional Adaptability in Introduced Super Sweet Corn Hybrids and Heritability of Agronomic Traits

    도입 초당옥수수 교잡종의 지역 적응성 및 농업 형질의 유전력 평가

    Shin-Young Lee, Jong-won Kang, Seung-hyun Wang, Tai-choon Park, Jong-Wook Chung, and Yoon-Sup So

    이신영, 강종원, 왕승현, 박태춘, 정종욱, 소윤섭

    This study evaluated newly introduced, commercial super sweet corn hybrids (Zea mays L.) for their potential as breeding materials. Agronomic traits were ... + READ MORE
    This study evaluated newly introduced, commercial super sweet corn hybrids (Zea mays L.) for their potential as breeding materials. Agronomic traits were measured and variance components were obtained using a linear mixed model to estimate the heritability. The trials were carried out in 2018 at two locations (Haenam and Oksan in South Korea). All traits had low heritability, except for mid tasseling and silking days. These traits with low heritability mostly had low genetic variance component estimate. In case of ear height ratio, significant genotype by location appeared to be responsible for low genetic variance, which in turn led to low heritability. Low heritability estimates from the trials with commercial hybrids were perhaps because those hybrids were highly improved for commercial success. Hence, this does not necessarily point to them having poor potential as breeding materials. To overcome low heritability, significant genotype by environment interaction, and achieve high selection efficiency, intermating among hybrids is recommended to create new recombinants before inbred line development. - COLLAPSE
    June 2021
  • Research Article

    Effects of Seeding Date on Growth, Yield, and Fatty Acid Content of Perilla Inter-cropped with Sesame in Central Korea

    중부지역 참깨 간작 들깨 재배시 파종기가 수량 및 품질에 미치는 영향

    Young Sang Kim, Ki Hyeon Kim, Cheol Gu Yun, Yun Seon Heo, Ik Jei Kim, Young-Ho Kim, Yong-Sup Song, and Myoung Hee Lee

    김영상, 김기현, 윤철구, 허윤선, 김익제, 김영호, 송용섭, 이명희

    Perilla contains more than 60% of fatty acids. Linolenic acid is effective in preventing heart disease, improving learning ability, treating allergies, and ... + READ MORE
    Perilla contains more than 60% of fatty acids. Linolenic acid is effective in preventing heart disease, improving learning ability, treating allergies, and preventing cancer. This study was carried out to improve the cultivation method to aid the stable production of perilla by developing a suitable inter-cropping system with sesame in the central region as well as to report a suitable planting time. The test results are summarized as follows. As the planting time of perilla in the inter-cropping system with sesame was delayed, the number of clusters and capsules decreased. The perilla yields in this system showed significant differences compared to that with the previous crops (sesame varieties) and planting period. The yield of perilla was significantly lower in the characteristic-Type B variety than in the characteristic-Type A variety and decreased significantly as the planting time was delayed. With regards to the quality characteristics of perilla, such as crude protein, crude fat, etc., there were no differences between previous perilla crops and those inter-cropped with sesame. The perilla composition did not show any difference during the planting period; however, with delay in the planting time, crude protein content increased but crude fat content decreased. Yield of perilla was 38% higher in a two-row (40 x 40 cm) system, compared to a single-row cultivation (110 x 20 cm) of perilla inter-cropped with sesame. These results suggest that the suitable method for inter-cropping perilla with sesame in the central region is to sow the characteristic-Type A variety in early May, and cultivate the perilla in two lines (40 x 40 cm) in mid-June. This was judged to be the best cultivation method in the central region. - COLLAPSE
    June 2021
  • Research Article

    Evaluation of the Growth and Yield of Sweetpotato (Ipomoea batatas L.) at Different Growth Stages under Low Light Intensity

    생육시기별 차광 처리에 의한 고구마 생육 및 수량성 평가

    Won Park, Mi Nam Chung, Sang-Sik Nam, Tae Hwa Kim, Hyeong-Un Lee, San Goh, Im Been Lee, and Woon-Cheol Shin

    박원, 정미남, 남상식, 김태화, 이형운, 고산, 이임빈, 신운철

    This study was conducted to determine the degree of reduction in the yield of sweetpotato subjected to different shading treatments according to ... + READ MORE
    This study was conducted to determine the degree of reduction in the yield of sweetpotato subjected to different shading treatments according to the growing season of the typical viscous sweetpotato ‘Hogammi’ and the powdery sweetpotato ‘Jinyulmi’. Shading was provided using commercially available shading nets (55% and 75% shading level), and the treatments were applied at the following stages of storage root growth: SFS: the storage root formation stage (planting-50th day), SSS: the storage root swelling stage (50-90th day), and SAS: the storage root actively swelling Stage (90-120th day). The growth characteristics according to shading treatments during each growth period, the number of tubers obtained at harvest, and sugar contents were investigated. For both assessed cultivars, there was no significant difference between the control group and the 55% shading treated group with respect to the maximum quantum yield (Fv/Fm) of photosystem II under different shading treatments, whereas the 75% shading group showed slightly higher values than the control group. In both cultivars, the contents of chlorophyll a and b tended to increase in plants subjected to shading treatments compared with the control plants, particularly that of chlorophyll b. Compared with the control group, the chlorophyll b content of ‘Hogammi’ subjected to 55% and 75% shading increased by 47% and 41%, respectively, whereas that of ‘Jinyulmi’ increased by 39% and 34%, respectively. We also detected reductions in the dry weights of the above- and belowground parts of the two varieties in response to shading compared with the control, with the reduction in the dry weight of belowground parts being significant. Furthermore, in both varieties, the T/R rate tended to increase in response to shading treatment. Owing to the lack of sunlight, both cultivars tended to suppress the formation and enlargement of tuber roots. Consequently, post-harvest yield analysis revealed that under shading treatments, both cultivars were characterized by poor tuber root growth according to growing season, with the yield of ‘Hogammi’ showing a greater reduction compared with that of ‘Jinyulmi’. In addition, we found that the higher shading level also significantly reduced yields. Compared with the storage root formation and storage root actively swelling stages, shading treatments during the storage root swelling stage significantly affected yield reduction in both varieties. - COLLAPSE
    June 2021
  • Research Article

    Effects of Planting and Harvest Times on the Forage Yield and Quality of Spring and Summer Oats in Mountainous Areas of Southern Korea

    남부산간지에서 봄과 여름 조사료 귀리의 파종과 수확 시기에 따른 조사료 품질과 생산성 변화

    Seonghyu Shin, Hyunjung Lee, Jahwan Ku, Myungryeong Park, Kyungyoon Rha, and Byeongju Kim

    신성휴, 이현정, 구자환, 박명렬, 라경윤, 김병주

    Oats (Avena sativa L.) represent a good forage crop for cultivation in regions with short growing periods and/or cool weather, such ... + READ MORE
    Oats (Avena sativa L.) represent a good forage crop for cultivation in regions with short growing periods and/or cool weather, such as the mountainous areas of southern Korea. In this study, using the Korean elite summer oat varieties ‘High speed’ and ‘Dark horse’, we aimed to determine the optimal time to plant and harvest forage oats seeded in spring and summer in a mountainous area. Seeds were planted three times from late February and early August at 9- or 10-days intervals, respectively, and plants were harvested three times from late May to October at 10-day intervals. The experiment was carried out in an upland field (Jangsu-gun Jeonbuk) in 2015 and 2016. We investigated the changes in forage yield (FY) and quality [crude protein (CP) and total digestible nutrient (TDN) contents] based on the time of planting and harvest. Neither the forage quality nor yield of either spring and summer oats was significantly influenced by the time of planting. The CP of spring oats harvested three times at 10-day intervals from late May was 12.0%, 8.2%, and 6.5%, thereby indicating a reduction with a delay in the time of harvest. In summer oats, CP ranged from 8.4% to 8.7%, although unlike CP in spring oats, was not significantly influenced by the time of harvest. For both forage types, harvest time had no significant effect on TDN. The FY of spring oats harvested in late May and early and mid-June was 10.2, 18.7, and 19.5 ton ha-1, respectively, with that of oats harvested on the latter two dates being significantly increased by 83% and 91%, respectively, compared with that in late May. Similarly, the FY of spring oats harvested in late October and early and mid-November was 7.1, 12.5, and 12.1 ton ha-1, respectively, with that of oats harvested on the latter two dates being significantly increased by 75% and 71%, respectively, compared with that in late October. Taking into consideration forage yield and quality (not less than 8% CP), it would be profitable to plant spring oats in the mountainous areas of southern Korea until March 15 and harvest around June 10, whereas summer oats could be beneficially planted until August 25 and harvested from early November. - COLLAPSE
    June 2021
  • Research Article

    Differences in Seed Vigor, Early Growth, and Secondary Compounds in Hulled and Dehulled Barley, Malting Barley, and Naked Oat Collected from Various Areas

    맥종별 주산지와 재배한계지 수집종자의 활력, 초기생장 및 이차화합물 차이

    Hyung Hwa Park and Yong In Kuk

    박현화, 국용인

    The purposes of this study were to determine how changes in temperature affect germination rates and growth of hulled and dehulled barley ... + READ MORE
    The purposes of this study were to determine how changes in temperature affect germination rates and growth of hulled and dehulled barley, malting barley, and naked oat plants, and to measure chlorophyll content, photosynthetic efficiency, and secondary compounds (total phenol, total flavonoid, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity) in plants grown at 13°C or 25°C). Various types of barley seeds were collected from areas with ideal conditions for barley cultivation, hereinafter referred to as IA, and also from areas where barley cultivation is more difficult due to lower temperatures, hereinafter referred to as LTA. Seeds were tested for seed vigor. While there were significant differences in the electrical conductivity values between seeds collected from certain specific areas, no significant differences were evident between IA and LTA seeds, regardless of the type of barley seed. When plants were grown at 25°C, there were no significant differences in germination rates, plant height, root length and shoot fresh weight between plants originating from IA and LTA. However, there were differences in the measured parameters of some specific seeds. Similarly, under the low temperature condition of 13°C, no differences in the emergence rate, plant height, and shoot fresh weight were evident between plants originating from IA or LTA, regardless of the type of barley. However, there were differences between some specific seeds. One parameter that did vary significantly was the emergence date. Hulled barley and malting barley emerged 5 days after sowing, whereas naked oats emerged 7 days after sowing. There were no differences in the chlorophyll content and photosynthetic efficacy, regardless of the type of barley. There were no significant differences in total phenol, total flavonoid content, and DPPH radical scavenging activity between plants originating from IA and LTA, regardless of the type of barley. However, there were differences between some specific seeds. In particular, for malting barley the total flavonoid content differed in the order of Gangjin > Changwon > Haenam = Jeonju > Naju. The results indicate that crop growth, yield and content of secondary compounds in various types of barley may be affected by climate change. - COLLAPSE
    June 2021