• Journal of Plant Biotechnology
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• v.49 no.4
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• pp.356-361
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• 2022

Bacillus sp. is a useful strain for agriculture because it promotes plant growth and controls plant pathogens through a variety of mechanisms. In this study, we obtained a microbial preparation with a high number of viable cells by culturing newly isolated soil bacteria on an optimized medium. Subsequently, we applied this preparation to lettuce to enhance its growth and yield. First, B. amyloliquefaciens ISP-5 was isolated from soil. Next, optimization of culture medium was carried out using 5 L scale fermenters. When culturing B. amyloliquefaciens ISP-5 on this optimized medium, the number of viable cells was approximately 1000 times higher than that obtained from culturing on the commercial medium. Afterwards, the plant growth promotion properties of the ISP-5 strain were evaluated using lettuce as a test plant. Foliar spray treatment of lettuce was carried out by inoculating half the standard concentration suspension (0.5 × 10⁷ cfu/ml). As a result, leaf width increased by 8.6% and leaf length increased by 12.9% compared to the control group. Live weight also increased by 24.2% and dry weight by 23.9%. Considering the results from field test, B. amyloliquefaciens ISP-5 showed potential as a plant growth-promoting bacteria.

• Food Science and Preservation
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• v.14 no.2
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• pp.119-123
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• 2007

Sprays containing chitosan, grain amino acids, or wood vinegar, were applied to vine leaves of the Campbell Early grape variety, and effects on the quality and storability of grapes were investigated. Weights of grape clusters and individual bemies did not differ significantly from the values seen when traditional agnicultural chemical treatment was used. The percentage of clusters over 300g in weight was, however, higher after spraying with chitosan, grain amino acids, or wood vinegar, than after agricultural chemical treatment, Grape moisture contents, levels of soluble solids, and reducing sugar concentrations, did not differ when the traditional treatment and the newer sparys were compared. Among minerals, the levels of potassium, iron and zinc measured in fresh grapes were increased by the clitosan, grain amino acids, and wood vinegar spray. After 8 weeks of MA storage, reducing sugar levels decreased, and titratable acidities increased, compared to levels measured at the beginning of storage. This was true regardless of the method of vine treatment the hardness of berries decreased slightly over 4-6 weeks of storage, and increased thereafter. The weight losses of grapes were relatively low(0.28-0.35%) on storage after any vine treatment tested. Grapes from vines sprayed with chitosan or grain amino acids showed a lower decay rate than did fruit from vines that had received a traditional agricultural chemical treatment. Sensory evaluation results indicated that the marketability of grapes from vines treated with traditional agricultural chemicals was better than that of grapes from vines sprayed with chitosan, grain amino acids, or wood vinegar.

• Korean Journal of Environmental Agriculture
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• v.15 no.4
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• pp.425-433
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• 1996

Pepper plants were water-logged at 0, 5, 10 and 15 cm at transplanting and flowering stages under the condition of greenhouse. Treatment of water-logging times were 6, 12, 24, 48 and 120 hours. The results obtained are summarized as follows. At the transplanting stage, plant height, number of leaves, shoot and root fresh weight decreased by water-logging at 0cm for 24 hours and at 5cm or more for 6 hours. Number of fallen leaf was negligible by 12 hours water-logging at 0cm, however, its increased by more increased the water-logging depth and time. Diffusion resistance and chlorophyll content of leaf, and root activity decreased at more than 24 hours of water-logging regardless of the water-logging depth treatments. Photosynthesis and respiration rate diminished by increased the water-logging depth at 120 hours water-logging treatment. Plant diseases, mainly anthracnose(Colletotrichum) occurred in proportion to increase the depth and time of water-logging. It was not possible to control the diseases by fungicides. At the treatment of foliar spray of urea for recovery to water-logging damage, the efficiency was not found on plant height, but the number of leaves. Number of fruit and weight of fruit per plant showed no difference from no water-logging to 24 hours water-logging at 0cm, but its decreased that more than 24 hours water-logging at 0cm and more than 6 hours water-logging at 5cm or more. The averaged weight of a fruit on survival plants increased by more hours and deeper water-logging. There was positive correlation between all the investigated characteristics of growth and yield. There was, however, negative correlation between the characteristics and diffusion resistance of leaf stomata. The correlation between number of fallen leaf and averaged weight of a fruit was not significant. At flowering stage, number of fruit and weight of fruit per plant showed a similar tendency to no water-logging and by 12 hours water-logging at 0cm and 5cm, but significantly decreased at more than 24 hours water-logging from 0 to 5cm, and more than 6 hours water-logging at 10cm or more. The averaged weight of a fruit on survival plants increased by more hours and deeper water-logging except for 120 hours water-logging at all water depths.

• Horticultural Science & Technology
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• v.29 no.6
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• pp.555-560
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• 2011

The objective of this study was carried out to investigate the proper plant growth regulator for increasing the number of flower, fruit set, and to enlarge the size of the berries in Ardisia pusilla. Flower bud formation was used rooted cutting, and fruit set, enlargement, and coloration of fruit were used with two years-old. $GA_3$ concentrations were treated with 0, 100, 200, or $400mg{\cdot}L^{-1}$. Flower bud formation was effective in $400mg{\cdot}L^{-1}$ $GA_3$ and it was 1.8 times greater than control. Plant growth regulators were applied by foliar spray at full bloom stage to increase the fruit set. As a result, $GA_3$ was the most effective for increasing fruit set. Also, auxins of 4-CPA (Tomatotone, Donbu hitech Co., Korea) and dichloprop triethanol amine (Antifall, Bayer Crop Science Co., Ltd., Korea) were effective. When $GA_3$ concentrations of 0.5 and $1.0mg{\cdot}L^{-1}$ were used, fruit set (%) reached to 70% and 77%, respectively. Effectiveness of $GA_3$ was 1.8 times greater than control. Also, auxins, dichloprop triethanol amine increased to about 7-12% during fruit setting, but cytokinin and anti-gibberellin were ineffective. To investigate the fruit enlargement and coloration, $GA_3$ was treated with 0.3, 0.6, and $1.2mg{\cdot}L^{-1}$. Fruit enlargement was achieved to about 15% by $GA_3$ $0.6mg{\cdot}L^{-1}$ when $GA_3$ was treated 3 times at the interval of 1 month per treatment when fruit size was about 2-3mm (after full-blooming two months). But anthocyanin contents for coloration of fruit skin were not significant according to $GA_3$ concentration. The results showed that $GA_3$ enhanced bud formation, fruit set and enlargement of fruit size in Ardisia pusilla.

• Journal of Bio-Environment Control
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• v.23 no.4
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• pp.329-336
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• 2014

As an abiotic stress, chilling stress is one of the major factors limiting plant growth and increasing susceptibility to pathogens. Therefore, enhancing stress tolerance in plants is an important strategy for their survival under unfavorable environmental conditions. The objective of this study was to determine the effects of the exogenous application of salicylic acid (SA) or nitric oxide (NO) on chilling tolerance in pepper seedlings. Pepper (Capsicum annuum L. 'kidaemanbal') seedlings were grown under normal growing conditions ($20/25^{\circ}C$, 15 hours photoperiod, $145{\pm}5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, fluorescence lamps) for 23 days after transplanting. The solution (3 mL) of 1 mM SA and 0.3 mM NO with surfactant triton 0.1% were sprayed two times a week, respectively. Right after the completion of chemical application, seedlings were subjected to chilling condition at $4^{\circ}C$ for 6 hours under dark condition and then the seedlings were recovered at the normal growing conditions for 2 days. In order to assess plant tolerance against chilling stress, growth characteristics, chlorophyll fluorescence (Fv/Fm), and membrane permeability were determined after chilling stress imposition. Total phenolic concentration and antioxidant capacity were measured during the whole experimental period. Disease incidence for pepper bacterial spot and wilt was also analyzed. Pepper seedlings treated with SA or NO were maintained similar dry mass ratio, while the value in control increased caused by chilling stress suggesting relatively more water loss in control plants. Electrolyte leakage of pepper seedlings treated with SA or NO was lower than that of control 2 days after chilling treatment. Fv/Fm rapidly decreased after chilling stress in control while the value of SA or NO was maintained about 0.8. SA increased higher total phenolic concentration and antioxidant capacity than NO and control during chemical treatment. In addition, increase in total phenolic concentration was observed after chilling stress in control and NO treatment. SA had an effect on the reduction of bacterial wilt in pepper seedlings. The results from this study revealed that pre-treatment with SA or NO using foliar spray was effective in chilling tolerance and the reduction of disease incidence in pepper seedlings.

• The Korean Journal of Pesticide Science
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• v.11 no.2
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• pp.106-116
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• 2007

Pesticide, chlorfluazuron was subjected to determine the safety of terminal residues at the harvesting date of perilla leaves cultivated in plastic house. After the pesticide applied on a foliar spray in 2005 and 2006, leaf persistence of its residue was analysed for 10 days before leaf harvest. The degradation rate of chlorfluazuron in the leaf was 32.3 %(standard application), 43.6 %(double application) and 78.0 %(standard), 80.4 %(double) at second and tenth day, respectively, under analysis of GC/ECD in 2005. The degradation rate of chlorfluazuron in the leaf was 33.1 %(GC/ECD analyze), 34.0 %(HPLC/UVD analyze) and 77.9 %(GC/ECD), 78.4 %(HPLC/UVD) at second and tenth day, respectively, under the standard level of pesticide in 2006. The biological half-life of the chlorfluazuron residue was estimated by the regression equation calculated from daily dissipation of pesticide in the perilla leaves. The longest half-life of the chlorfluazuron residue in perilla leaves was 5.5 days. The maximum residual limit(MRL) for chlorfluazuron based on the longest half-life was estimated 2.0ppm at harvesting day, 2.5ppm at second day and 7.1ppm at tenth day before leaf harvesting of perilla.

• Korean Journal of Weed Science
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• v.14 no.2
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• pp.120-127
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• 1994

To establish an efficient herbicide screening method for purple nutsedge(Cyperus rotundus) control, its sprouting characteristics, tuber production and responses on several herbicides were investigated under greenhouse condition. The tubers stored at $4^{\circ}C$ after sterilization with the diluted prochloraz(Spotac) solution showed higher sprouting than the non-sterilized did. The harvested tubers were not dormant, and the sterilized tubers which stored at low temperature had a sprouting capability of about 80% after 6 months. If the fresh weight of purple nutsedge tubers was decreased to below 48%, they could not sprout. However, the tubers soaked in water and then stored at low temperature could sprout by 88% even 6 months later. Sprouting and initial growth of tuber were much better at $35^{\circ}C$-day/$25^{\circ}C$-night than at 30/$20^{\circ}C$ or 25/$15^{\circ}C$. The half-sected tubers, which were prepared by setting the intact tuber of above 1.2g latitudinally, were shown similar initial growth to the intact but those sected crucifically were not. These results suggest that the half-sected tuber itself can be used as a material on herbicide screening. About 1000 tubers could be harvested when 10 tubers planted in a pot($56{\times}35{\times}16cm$) filled with the artificial soil were cultivated in greenhouse of $35^{\circ}C$-day/$25^{\circ}C$-night for 3 months(April-July, 1993). Chlorimuron, Bentazon and Norflurazon were selected as the standards for the screening because of providing relatively effective control on purple nutsedge in both soil-surface and foliar spray treatment.