• Research in Plant Disease
• /
• v.23 no.4
• /
• pp.314-321
• /
• 2017

Acidovorax valerianellae had been reported a causal agent of bacterial black spot disease on corn salad in France, 2003 and on watermelon in Korea 2011. In this study, difference in host specificity between 2 groups, corn salad strains and watermelon strains, of Acidovorax valerianellae was recognized and compared. In the pathogenicity test, all 5 watermelon strains showed pathogenicity on the 6 Cucurbitaceae plants but not on corn salad, whereas 4 corn salad strains showed pathogenicity only on the corn salad. Utilization of Biolog substrates was different between watermelon strains and corn salad strains on 4 substrates, Malonic Acid, ${\alpha}-Hydroxybutyric$ Acid, ${\alpha}-Keto$ Butyric Acid, and Glycyl-L Glutamic Acid. The phylogenetic tree built with the 16S rDNA sequences showed that all of A. valerianellae stains was grouped into 1 clade separating from the other species of Acidovorax genus. Within A. valerianellae clade, watermelon strains and corn salad strains were separated into 2 sub-groups. REP-PCR analysis also separated the two groups. Host specificity, substrate utilization, and some genetic characteristics suggested that there are two pathogenic groups, watermelon group and corn salad group in A. valerianellae.

• KSBB Journal
• /
• v.22 no.4
• /
• pp.201-206
• /
• 2007

The demand of L-arabinose has been increased recently because of its advantages including clinical effect. L-arabinose can be produced from dilute acid hydrolysis of agricultural wastes. In this study, optimum conditions of L-arabinose production using dilute acid hydrolysis of agricultural wastes and nutshells were determined. Among the tested various agricultural wastes and nutshells, corn fiber was selected as the best raw material for the production of arabinose. The highest arabinose production was achieved an acid hydrolysis of corn fiber for 1 h at 130$^{\circ}C$ with 0.4% sulfuric acid. Above optimal conditions, it was obtained 20.1 g/L glucose, 10.1 g/L xylose, 7.8 g/L arabinose and 1.8 g/L galactose from 90 g/L of corn fiber. For the purification of arabinose, it was carried out to remove all of sugars except arabinose by the Candida tropicalis cultivation of acid hydrolyzate and an organic contaminants such as pigments by the active carbon treatment of fermentation broth. Moreover, experiments were carried out to eliminate an ions by exchange chromatography. Finally, we obtained 3.1 g of partially purified L-arabinose powder with about 40% yield by evaporation and vacuum drying.

• Journal of Animal Science and Technology
• /
• v.64 no.1
• /
• pp.38-51
• /
• 2022

Whole-plant corn (Zea may L.) and sorghum-sudangrass hybrid [Sorghum bicolor (L.) Moench] are major summer crops that can be fed as direct-cut or silage. Proso millet is a short-season growing crop with distinct agronomic characteristics that can be productive in marginal lands. However, information is limited about the potential production, feed value, and ensilability of proso millet forage. We evaluated proso millet as a silage crop in comparison with conventional silage crops. Proso millet was sown on June 8 and harvested on September 5 at soft-dough stage. Corn and sorghum-sudangrass hybrid were planted on May 10 and harvested on September 10 at the half milk-line and soft-dough stages, respectively. The fermentation was evaluated at 1, 2, 3, 5, 10, 15, 20, 30, and 45 days after ensiling. Although forage yield of proso millet was lower than corn and sorghum-sudangrass hybrid, its relative feed value was greater than sorghum-sudangrass hybrid. Concentrations of dry matter (DM), crude protein, and water-soluble carbohydrate decreased commonly in the ensiling forage crops. The DM loss was greater in proso millet than those in corn and sorghum-sudangrass hybrid. The in vitro dry matter digestibility declined in the forage crops as fermentation progressed. In the early stages of fermentation, pH dropped rapidly, which was stabilized in the later stages. Compared to corn and sorghum-sudangrass hybrid, the concentration of ammonia-nitrogen was greater in proso millet. The count of lactic acid bacteria reached the maximum level on day 10, with the values of 6.96, 7.77, and 6.95 Log₁₀ CFU/g fresh weight for proso millet, corn, and sorghum-sudangrass hybrid, respectively. As ensiling progressed, the concentrations of lactic acid and acetic acid of the three crops increased and lactic acid proportion became higher in the order of sorghum-sudangrass hybrid, corn, and proso millet. Overall, the shorter, fast-growing proso millet comparing with corn and sorghum-sudangrass hybrid makes this forage crop an alternative option, particularly in areas where agricultural inputs are limited. However, additional research is needed to evaluate the efficacy of viable strategies such as chemical additives or microbial inoculants to minimize ammonia-nitrogen formation and DM loss during ensiling.

• The Korean Journal of Pesticide Science
• /
• v.3 no.3
• /
• pp.54-59
• /
• 1999

The objective was to know if corn growers at Hongchcel County, Kangwon-do, where corn is the major agricultural product, control weeds effectively and use herbicides properly to control weeds. Sixty-eight corn growers at Hongchon were participated in this survey. Corn growers have noxious weeds, such as hairy carbgrass, common purslane, lambsquarters, Asiatic dayflower, mugwort and barnyard grass in their corn fields. Forty-four percents of the answered corn growers control weeds by hand weeding, and the others by a combination of physical and chemical methods. Corn growers have a preference of paraquat and alachlor for a pre-emergence treatment (94% of the answered) and of paraquat, glufosinate, glyphosate and fluazifop-P-butyl for a post-emergence treatment (87% of the answered). Corn growers did not select and use herbicides in a proper manner. fifty-four percent of the answered corn fevers selected herbicides by their own experience and 18 percent by neighbors recommendation. Herbicides were not selected and used in a proper manner by corn growers: 54 percent of the answered selected herbicides by the experience of growers and 18 percent by the recommendation of neighbors. In addition, a half of the answered applied over two-fold higher amounts of herbicides than the recommended rate. With these improper- selection and use of herbicides, 37 percent of the answered have experienced the crop damage and 42 percent the herbicide poisoning. We conclude that the development of the educational program for the proper selection and use of herbicides is needed for corn growers in Kangwon-do.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.34 no.1
• /
• pp.30-39
• /
• 1989

Forage productivity of cropping systems of rye - silage corn, silage corn - oats, silage corn - rape was studied in the south-eastern part of Korea where rice black-streaked dwarf virus(RBSDV) infection of corn are severe. Rye(cv. Paldanghomil) was planted on Oct. 20 of 1986 and harvested 10 times from April 5 to May 5 at the 5-day intervals in 1987, corn (cv. Suweon 19 and Jinjuok) was planted 5 times from April 5 to May 15 at the 10-day intervals in 1987, and oats(cv. Megwiri) and rape (cv. Velox) were planted 4 times from Sept: 4 to 25 at the 7-day intervals and harvested 4 times from Nov. 10 to Dec. 10 at the 10-day intervals in 1987. Considering yield, nutrition value, and in vitro dry matter digestibility (IVDMD), forage productivity of the cropping systems was compared. As harvesting time of rye delayed, plant height, dry matter(DM) yield, percent DM, crude fiber, and digestible DM yield increased, but crude protein, crude fat, and IVDMD decreased. However, nitrogen free extract was not different among the harvesting dates. As planting date of corn delayed, RBSDV infection rate increased. but DM yield of silage decreased. However, silage yield of Jinjuok was higher, but RBSDV infection rate was lower compared with Suweon 19 at all planting dates. DM yield of oats and rape decreased as planting date delayed. However, at Sept. 4 and 11 plantings yield of oats on Nov. 10 was much lower than that of rape, but the differences in yield between two crops decreased with delayed harvesting, and yield was similar on Dec. 10. A cropping system harvesting rye around April 20 and followed by planting corn in late April was best among the rye-corn systems considering yield and nutrition value of both crops. However, among the corn-oats or corn-rape cropping systems early April planting of corn and followed by early Sept. planting of oats or rape showed best results with similar yield potential of the best rye-corn cropping system.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.19 no.3
• /
• pp.221-232
• /
• 1999

Dry matter yield and ear percent are commonly considered the most important factors for evaluating silage corn(Zea mays L.) hybrids for silage production. But quality of stover as well as forage production in important in identification of hybrids. The objective of this study was to evaluate nutritional value of stover, ear and whole plant from eight corn hybrids for silage at two dates of planting. In content of fiber components(ADF, NDF, ADL, hemicellulose and cellulose) from stover, ear and whole plant samples, optimum planting corn was lower than late planting one(P<0.01). Differences(P<0.01) in the content of fiber components in stover and whole plant were observed among the corn hybrids. Differences between different planting dates in TDN and $NE_1$ were detected in the stover and whole plant samples(P<0.05). Differences among the corn hybrids in TDN and $NE_1$ were also observed in stover, ear and whole plant samples. TDN and $NE_1$ of 'G4624', 'P3352' and 'P3394' for whole plant were higher than those of the other corn hybrids. ln vitro dry matter digestibility(IVDMD) at optimum planting date was higher than that of late(P<0.05), and there also were significant differences among the corn hybrids. Correlation coefficients for whole plant IVDMD with NDF, ADF, hemicellulose, and cellulose were $-0.82^{**}$, $-0.71^{**}$, $-0.63^{**}$, and $-0.69^{**}$, respectively. Results of this study indicate that optimum planting of corn resulted in increased quality of silage corn. Differences among corn hybrid, particularly, in nutritive value of stover and whole plant were also observed. Therefore, the nutritional value of stover and whole plant may be important in assessing the corn hybrids for silage.

• Journal of The Korean Society of Grassland and Forage Science
• /
• v.31 no.3
• /
• pp.251-260
• /
• 2011

This study was carried out to compare growth characteristics and yield of silage corn hybrids at four different regions (Hwaseong, Dangjin, Gochang and Pyeongchang). Two domestic corn hybrids, 'Kwangpyeongok' and 'Gangdaok', and two imported corn hybrids, 'P3394' and '32P75' were used in this study. Plant height and ear height ratio were not significantly different among corn hybrids. 'Kwangpyeongok' was the strongest of all corn hybrids for lodging. The others except 'Kwangpyeongok' were similar to lodging. All corn hybrids were excellent to stay-green. Incidence of southern corn leaf blight (Bipolaris maydis) was low at all corn hybrids. '32P75' was 10.1%, the most of all corn hybrids for incidence of BSDV (black streaked dwarf virus). 'Kwangpyeongok' and 'Gangdaok' were stronger than '32P75' for BSDV. Fresh yield of 'Kwangpyeongok' and 'Gangdaok' were the most of all corn hybrids as 74.85 and 76.68 ton/ha and 'P3394' was the least of all corn hybrids as 64.97 ton/ha. Dry matter yield as 18.83~21.92ton/ha and TDN yield as 12.73~14.52 ton/ha were not significantly different among corn hybrids.

• Korean Journal of Soil Science and Fertilizer
• /
• v.47 no.2
• /
• pp.85-91
• /
• 2014

Ground-based polarimetric scatterometers have been effective tools to monitor the growth of crop with multi-polarization and frequencies and various incident angles. An important advantage of these systems that can be exploited is temporal observation of a specific crop target. Polarimetric backscatter data at L-, C- and X-bands were acquired every 10 minutes. We analyzed the relationships between L-, C- and X-band signatures, biophysical measurements over the whole corn growth period. The Vertical transmit and Vertical receive polarization (VV) backscattering coefficients for all bands were greater than those of the Horizontal transmit and Horizontal receive polarization (HH) until early-July, and then thereafter HH-polarization was greater than VV-polarization or Horizontal transmit and Vertical receive polarization (HV) until the harvesting stage (Day Of Year, DOY 240). The results of correlation analysis between the backscattering coefficients for all bands and corn growth data showed that L-band HH-polarization (L-HH) was the most suited for monitoring the fresh weight ($r=0.95^{***}$), dry weight ($r=0.95^{***}$), leaf area index ($r=0.86^{**}$), and vegetation water content ($r=0.93^{***}$). Retrieval equations were developed for estimating corn growth parameters using L-HH. The results indicated that L-HH could be used for estimating the vegetation biophysical parameters considered here with high accuracy. Those results can be useful in determining frequency and polarization of satellite Synthetic Aperture Radar stem and in designing a future ground-based microwave system for a long-term monitoring of corn.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.58 no.2
• /
• pp.113-118
• /
• 2013

This study was carried out to evaluate the dyeing possibility of purple corn stem and leaf. The UV absorbance of the purple corn stem extract and leaf extract at different pH does not change. It is considered to use to efficiently measure the purple corn pigment content when using UV absorbance at 520~560 nm. By adjusting higher pH values in the extraction dyed fabrics, silk and cotton fabric used by the purple corn leaf extraction decreased lightness and redness. Extent for dyeing the fabric depending on the concentration, lightness and redness showed a tendency to increase color values when silk and cotton concentration increases. Also when the longer the dyeing time, silk and cotton increased lightness but redness decreased.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.58 no.2
• /
• pp.91-106
• /
• 2013

Exserohilum turcicum is considered serious destructive disease of maize (Zea mays L.) in North Korea. This study aimed to understand genetic inheritance and combining ability of newly bred lines of maize tolerant to E. turcicum by diallel crosses. Three diallel sets for two different ecological regions and one agronomic trait; eastern (E), northern (N) and stay green (SG) involving 29 inbred lines were tested in eight locations of 2000 and 2001. E. turcicum infections were under natural conditions, respectively. Lines used were selected for high yield potential in test crosses with good agronomic traits and tolerance to biotic and abiotic stresses. Selection for race specific high resistance to biotic stresses was avoided to select quantitatively inherited genes. Host plant responses to E. turcicum were rated on a scale of 1 (highly tolerant) to 9 (highly susceptible). Highly significant variations were recorded in all trials. General combining ability (GCA) mean square was roughly twice that of specific combining ability (SCA). The genotype (G) by environment (E) interaction was highly significant. The overall results of genetic studies in three diallel sets show that genetic control for inbred tolerance to E. turcicum is polygenic and quantitatively inherited. New inbreds; E-3, N-1 and SG-4 confer better tolerance to E. turcicum than the widely used inbreds; Mo17, and B73. Proper use of genetic information from this study shall increase of corn production under high E. turcicum infection in the Far Eastern Regions of Korea and China.