• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.1
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• pp.32-37
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• 1998

The objective of this study was to analyze lodging-related traits using different cultivars from Korea, Japan, and the U.S. in direct seeded rice on dry paddy field. Stem diameter and culm wall thickness were highest in 'Caloro' followed by 'Nongan', 'M202', and 'Calrose'. All the U.S. cultivars were higher than the others in stem diameter and culm wall thickness. These two traits were important with regard to lodging. The highest breaking strength (1442g) was observed in Caloro. 'Gancheoek', 'Dongjin', and transplanted 'Hatsuboshi' showed more than 1000g in breaking strength. Lodging index was lowest in Hatsuboshi followed by Nongan and Gancheok. Even though breaking strength of the U.S. cultivars was higher than others, their lodging index values were high. There were no statistically significant differences in starch content. However, Calrose, Caloro, Dongjin, and Koshihikari were relatively higher than others in starch content. Positive correlations were found between culm base weight, lignin and breaking strength. High contents of lignin and cellulose were observed in Nongan, transplanted Hatsuboshi, Calrose, and Caloro. Traits such as stem diameter, culm wall thickness, bending moment, culm length, breaking strength, cellulose, lignin, and culm base weight were closely related to a lodging index. According to path coefficient analysis, most important traits were culm length, stem diameter, thickness of clum wall, and top plant weight.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.4
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• pp.319-323
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• 1991

To determine how closely related to field lodging for several characters affecting the field lodging for several characters affecting field lodging, and to obtain the basic information for selection of lodging resistance genotype, an experiment was conducted with 10 varieties from May to Oct., 1990 at the experimental field in Sunchon Xational University. Culm length, dry weight per unit culm length (W/1), bending moment per unit culm diameter (W1/d), lodging index (L), bending load ratio (W1/P), and index of critical lodging load(W$_{s}$$^{2}$/1$^4$) were the most closely related characters to field lodging. Culm length showed highly significant positive correlation coefficient with field lodging(r=0.7607), but it may be undesirable to judge lodging resistance of genotype by culm length itself without consideration of culm stiffness. Considering the difficulty and time-consuming to measure the character, clum length, W/1, W1/d, and W$_{s}$$^{2}$/1$^4$ were easy to measure and hence would be the most useful variables to judge the lodging resistance of genotype. Culm diameter, cross sectional area of culm, thickness of culm wall, and the second inertia moment of cross section of culm were not correlated with field lodging at all. Breaking strength of culm showed significantly negative correlation coefficient (r=-0.3986) with field lodging.ing.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.11
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• pp.105-117
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• 1972

This experiment has been made to study the relationship between several characters affecting the field lodging and to establish some useful standards for selection of lodging resistant varieties and to classify the degree of lodging resistance in wheat and barley varieties of different sources. The experiment was carried at the Crop Experiment Station, Suwon in 1968. The results obtained are summarized as followings. a. The lodging index modified with bending moment of culm at breaking seemed to be the most useful character in checking the lodging resistance. Highly significant positive correlation (Barley; r=0.40-0.67, Wheat; r=0.46-0.68) was obtained between the lodging index and actual field lodging. b. Between two essential components expressing bending stiffness of the culm, the bending moment at breaking and secondary moment of inertia, a highly significant positive correlation (Barley; r=0.59, wheat; r=0.46-0.53) was observed. c. The bending stiffness of culm got stronger as the dry weight per unit culm, which express the quantity of accumulated dry matters in culm, increased. The correlation coefficient between those two factors was 0.35 to 0.40 in barley and 0.33 to 0.76 in wheat respectively. d. In both wheat and barley, highly significant negative correlation between lodging index and the other factors such as dry weight per unit culm (Barley; r=-0. 51 to -0.70, Wheat; r=-0.65 to -0.83) and bending moment of culm at breaking (Barley; r=-0.29 to -0.69, Wheat: r=-0.54 to -0.89) were observed. Particulary, weight of culm at breaking, secondary moment of inertia and section modulus showed significant negative correlation with lodging index in wheat. e. Outside diameter of culm expressed more intimate relationship with physical characteristics of culm than inside diameter and also showed highly significant correlation with weight of culm at breaking (Barley; r=0.42-0.56, Wheat; r=0.39-0.44) and with bending moment of culm at breaking (Barley; r=0.40-0.41, Wheat; r=0.38-0.49) and with secondary moment of inertia (Barley; r=0.56-0.57, Wheat; r=0.28-0.98) and with section modulus (Wheat; r=0.22-0.96). Between the thickness of culm and physical characteristics of culm also showed the positive correlation. f. There was positive correlation between the culm length and actual field lodging in several groups of variety among the varieties tested. But the culm length seemed to undesirable as a selection measure for the selection of the lodging resistant variety considering the stiffness of culm. g. In classification of lodging resistance for the varieties tested, many Korean barley varieties expressed excellent lodging resistant than wheat, but most of the wheat and barley varieties from Japan considered quite resistant to lodging. h. In selection of lodging resistant varieties, lodging index lower than 1.67 in barley and 1. 76 in wheat considered highly resistant to actual field lodging.

• Korean Journal of Remote Sensing
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• v.37 no.5_1
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• pp.917-926
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• 2021

Lodging rice is one of critical agro-meteorological disasters. In this study, the UAV-based multispectral imageries before and after rice lodging in rice paddy field of Jeollanamdo agricultural research and extension servicesin 2020 was analyzed. The UAV imagery on 14th Aug. includesthe paddy rice without any damage. However, 4th and 19th Sep. showed the area of rice lodging. Multispectral camera of 10 bands from 444 nm to 842 nm was used. At the area of restoration work against lodging rice, the reflectance from 531 nm to 842 nm were decreased in comparison to un-lodging rice. At the area of lodging rice, the reflectance of around 668 nm had small increases. Further, the blue and NIR (Near-Infrared) wavelength had larger. However, according to the types of lodging, the change of reflectance was different. The NDVI (Normalized Difference Vegetation Index) and NDRE (Normalized Difference Red Edge) shows dome sensitivities to lodging rice, but they were different to types of lodging. These results will be useful to make algorithm to detect the area of lodging rice using a UAV.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.2
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• pp.157-167
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• 1996

The method of direct seeding on flooded paddy surface in rice is known to be the most labor saving cultural practice in rice. However, this method has a problem in practical use such as severe lodging occurring at the reproductive growth stage. The objectives of this study were observated degree of field lodging and variation of lodging-related characteristics with different seeding dates. The number of seedlings per m$^2$ were from 91 to 144 plants, and seedling ratios were from ranged from 61.7% to 91.8%. Days from seeding to flowering were shortened from 5 to 15 days by the later seeding dates. Heading dates of Ilpumbyeo, Seoanbyeo, Daecheongbyeo and Donjinbyeo on June 9 showed slightly elapsed on the critical stable heading time from, August 28 to 29. The culm length was effective in longer clum varieties than semidwarf varieties. The degree field lodging (degree of lodging: 0~9< 9 : complete lodging) in Obongbyeo and S101 with semidwarf varieties were 0.17, whereas 1.25 in Dongjinbyeo with long culm. The lodging resistant varieties and later seeding dates shortened the length of fibrous in the clum, and thickened fibrous in the clum, respectively. Obongbyeo and Sl0l showed stronger resistance to field lodging. The lodging resistant varieties, Obongbyeo and Sl0l, showed lower values of lodging index from 1.03 to 1.15 than those of lodging susceptible varieties, Daecheongbyeo and Palgongbyeo ranged from 1.42 to 1.70. Bending moment with leaf sheath were greater in lodging resistant varieties (Obongbyeo and Sl0l),1510.0~1930.4g.cm, than those in the lodging susceptible varieties (Daecheongbyeo and Palgongbyeo), 1127.2~1287.6g.cm.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.3
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• pp.226-235
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• 2002

This experiment was to evaluate lodging characteristics of 35 recommended rice varieties of Kyonggi-do at normal (110 kg N/ha) and hen (220 kg N/ha) nitrogen application rates during 1999 to 2000. At heavy N fertilization rate, varieties that were highly resistant to lodging were Obongbyeo, Daejinbyeo, Naepoongbyeo, Nonganbyeo and Ilpumbyeo. Fourteen varieties including Daeanbyeo were moderately resistant and 11 varieties including Jinbubyeo were susceptible to lodging. The lodging-related characters which showed the highest effect on lodging at lodging degree of 9 were culm length and height of center gravity, culm length at lodging degree of 5, and culm length and the third internode length at lodging degree of 3 or below. The difference in rice yield between normal and heavy nitrogen fertilization rate was within 5% in early-maturing varieties but there was great yield difference in mid- and late-maturing varieties depending on the degree of lodging. Consequently, stable rice yield could be obtained by selecting lodging-resistant varieties and lowering fertilization rate, specially in the paddy field where lodging occurrence is common.

• Plant Resources
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• v.8 no.1
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• pp.32-35
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• 2005

This study was conducted to investigate the influence of $K_{2}O$ fertilizer application on growth, yield and lodging resistance of rice. Culm length and panicle length were lowest at the treatment of fertilizer level, $N-P_{2}O_{5}-K_{2}O=16-8-8$ plot but number of panicle, percentage of fruitful culm, $1{\ell}$ grain weights of paddy rice and brown rice, 1,000 grains weight of brown rice, brown rice ratio, yields of paddy rice and brown rice were highest at the treatment of fertilizer level, $N-P_{2}O_{5}-K_{2}O=16-8-8$ kg/10a plot. Bending moment, breaking strength and lodging index were lowest at the treatment of fertilizer level, $N-P_{2}O_{5}-K_{2}O=16-8-8$ kg/10a plot. Judging from the results reported above, an optimum fertilizer level of rice for lodging resistance is most likely be $N-P_{2}O_{5}-K_{2}O=16-8-8$ kg/10a treatment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.3
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• pp.218-223
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• 1990

This experiment was carried out to obtain basic information on the lodging characteristics and yield components of rice plants by new anti-lodging reagent 'KIM-112' (3%, Wp) application at 30 days before heading (DBH) to 5 DBH under two dosage levels (lg 2g, a. i. /10a) at the Yeongnam Crop Experiment Station in 1989. Culm length was shortened by 10-17% at 1g, a. i. /10a and by 16-23% at 2g of KIM -112 applications. The shortening effect of internode was different by dosages and application times: 2g treatment was greater effect than 19 and early application resulted in shortening of lower internode while this was upper internode at the late application. There were positive correlation between culm length and lodging index, the 1st and the 4th internode lengths had on important effect to lodging index. Thickness of culm wall, culm diameter and weight of basal part of culm were not affected by KIM-112 application. However anti-lodging characters improved by increasing the breaking weight and by decreasing the moment. Lodging index was related to breaking weight, moment and weight of panicle. Heading date by KIM-112 application was delayed one to four days and number of grains per panicle was decreased by shortened panicle length as compared with untreated control, but yield capacity was high a little because of improvement ripening ratio by no lodging.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.4
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• pp.395-404
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• 1996

This experiment was to evaluate the growth characteristics of lodging resistance cultivated at sandbed in rice varieties. Five varieties were used in this studies. The leaf area, leaf dry weight, culm dry weight and total dry weight of cultivated rice seedling at sandbed showed the maximal values at heading stage, but decreased according to growth development. The number of newly developed roots of rice seedlings cultivated at sand pot were the most at the 30 days seedling stage, but those were decreasing at 40 to 45 days seedling stage. Cheongmyungbyeo and Dongjinbyeo showed the most vigor in newly developed roots. The bending moment at breaking of rice internodes were the largest at the 4th node, but decreased at the top internodes. Cheongmyungbyeo and Dongjinbyeo were proved lodging resistant varieties by the bending moment. The weight of culm base was positively correlated with bending moment at breaking of rice culm, but lodging index was negatively correlated weight of culm base and root dry weight, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.3
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• pp.186-190
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• 1999

The objective of this study was to ,determine trinexapac-ethyl [4-(cyclopropyl- $\alpha$ -hydroxy-me-thylene)-3,5-dioxocyclohexanecarboxylic acid ethyl ester] effects on lodging-related traits of rice varieties treated at different application rates and times. Trinexapac-ethyl WP was applied at the rate of 10, 20 and 30g ai/l0a to Heukjinjubyeo and Daeanbyeo, respectively. Effects of trinexapacethyl varied greatly with application time as well as application rate with little differences between rice varieties. As the application rate increased, lodging index, center of gravity and exsertion of panicle above flag leaf decreased, whereas breaking strength and phytotoxicity increased. Exsertion of panicle was greatly influenced by the application time with a little difference by application rate. The most effective application time of trinexapac-ethyl based on lodging index and total internode length (Ist-4th node) was 2DBH(days before heading) in Heukjinjubyeo and 17DBH in Daeanbyeo, resulting in reducing total internode length by 12.9 and 9.7cm, respectively. A significant reduction was found at the 1st, 2nd, and 3rd internodes in Heukjinjubyeo, while at the 2nd and 3rd internodes in Daeanbyeo. No significant difference was found among treatments in the panicle length of both rice varieties but the panicle fresh weights of Daeanbyeo were significantly greater in all trinexapac-ethyl treatments compared with that of the control when measured 20 days after heading. Consequently, trinexapacethyl treatment significantly improved lodging-related traits of rice plants without affecting rice yield and yield components.