• Proceedings of the Korean Society of Crop Science Conference
• /
• 2017.06a
• /
• pp.356-356
• /
• 2017

A field experiment was performed to evaluate the effects of tillage systems and fertilizer management on yield and nutrient uptake in Soybean. The plant height, fresh weight and dry weight of conventional tillage were much higher those observed for no-tillage. Significant differences in plant height were observed under tillage practices combined with fertilizer treatment. However, the greatest plant height (128.47 cm) was observed in conventional tillage with chemical fertilizer, and the lowest (45.4 cm) was observed in the no-tillage with green manure treatment. The highest fresh weight (172.4 g) and dry weight (44.1 g) were observed from the no-tillage chemical treatment in the late flowering stage of soybean. The plant concentration of nitrate was higher (2.29%) in no-tillage with green manure than it was with chemical fertilization. However, nitrogen increased steadily in all treatments, and the highest quantity of total nitrogen (476.7 Kg/ha) was observed in no-tillage with green manure. The N content in the soil decreased gradually just after the vegetative stage. Tillage practices and additional fertilizer application had an adverse effect on the uptake of N, P and K in soybean seeds. The nitrogen concentration in seeds was found to be increased in the no-tillage with green manure treatment. The uptake of more nitrogen induced a better yield. Thus, the no-tillage with green manure treatment had the greatest yield, although no significant difference was observed among foliar-applications and additional fertilization. Additionally, the phosphorus and potassium concentrations in seeds remained the same between the conventional tillage and no-tillage treatments. The results obtained in this study indicate that no-tillage strategies with fertilizers may influence the growth characteristics and mineral uptake in soybean.

• Korean Journal of Environmental Agriculture
• /
• v.30 no.4
• /
• pp.446-452
• /
• 2011

BACKGROUND: To investigate the dissipation patterns of 3 pesticides, azoxystrobin, difenoconazole and iprodione, on green garlic after field treatment pesticides were treated as foliar treatment by single application at recommended and double the recommended rates. METHODS AND RESULTS: Residue samples were harvested at 0, 1, 2, 5, 7 and 10 days post-treatment for azoxystrobin and 0, 1, 2, 5, 7, 10, 15 and 21 days post-treatment for difenoconazole and iprodione. After preparation the fortified samples were extracted and analyzed by gas chromotography-electron capture detector (GC-ECD) to determine the residue levels. Recoveries ranged from 87 to 109% for azoxystrobin, difenoconazole and iprodione at two different levels. The limit of Quantification (LOQ) values were 0.002 mg/kg for azoxystrobin and difenoconazole and 0.01 mg/kg for iprodione. CONCLUSION(S): Half-lives of azoxystrobin, difenoconazole and iprodione in green garlic after treatment were 1.2, 3.8 and 3.2 days at recommended and 1.4, 3.3 and 3.2 at double the recommended rate, respectively. Residue level of azoxystrobin, difenoconazole and iprodione in green garlic were below the maximum residue limits (MRLs) at 0 day, 0 day and 5 days, respectively. Therefore, these pesticide were considered that residues was satisfied to the requirement of domestic trade related to the consumer safety.

• FLOWER RESEARCH JOURNAL
• /
• v.18 no.1
• /
• pp.44-49
• /
• 2010

This study was carried out to investigate effect of low temperature and $GA_3$ treatment on flowering and cut flower yield of Limonium spp. 'Ocean Blue' and 'Fantasia' in summer and winter cultivations. Plants were kept at $3^{\circ}C$ for 4 weeks, and were treated with a foliar spray of $400mg{\cdot}L^{-1}$ $GA_3$ at seven weeks after transplanting in both seasons. The effect of low temperature $3^{\circ}C$ for two weeks $GA_3$ application was tested only in winter. In summer cultivation, 'Ocean Blue' and 'Fantasia' of cut flower production by low temperature treatment were increased about 16% and 53%, respectively, while bolting and flowering advanced significantly in 'Ocean Blue' as compared to those in the control. In winter cultivation, growth and development increased, especially, in 'Fantasia'. With low temperature treatment to 'Fantasia' for 4 weeks, cut flower production was increased about 35%. In addition, bolting and flowering were hastened by about 20 and 10 days, respectively. Combined treatment of low temperature and $GA_3$ advanced bolting and flowering with little difference among the cultivars, while, in 'Fantasia' it shortened days to flowering and produced more and best quality flowers as compared to the other treatments and the control.

• FLOWER RESEARCH JOURNAL
• /
• v.19 no.3
• /
• pp.127-138
• /
• 2011

Four different plant growth retardants (PGRs), paclobutrazol, flurprimidol, daminozide, and chlormequat, were applied to potted Saxifraga rosacea 'Kumoma' and 'Kumoma-Gusa' plants for control of the growth and flowering. Paclobutrazol (10, 20, 40, $80mg{\cdot}L^{-1}$), flurprimidol (5, 10, 20, $40mg{\cdot}L^{-1}$), daminozide (500, 1000, 2000, $4000mg{\cdot}L^{-1}$), and chlormequat (50, 100, 200, $400mg{\cdot}L^{-1}$) were applied to the plants by a foliar spray or drenching. In 'Kumoma', application of $40mg{\cdot}L^{-1}$ paclobutrazol by a foliar spray or drenching reduced plant height by 12.5 and 12.6 cm, and flower length by 3.4 and 3.3 cm, respectively. On the other hand, in 'Kumoma-Gusa', drenching of paclobutrazol reduced plant height by 10.7 to 12.6 cm and flower length by 2.0 to 3.9 cm with increasing concentration, but the number of florets almost fell to 20 as compared to 40.5 in the control. 'Kumoma-Gusa' plants drenched with $80mg{\cdot}L^{-1}$ paclobutrazol and sprayed with $40mg{\cdot}L^{-1}$ flurprimidol had the shortest heights of 10.7 and 9.9 cm, and floral length of 2.0 and 1.5 cm, respectively. A flurprimidol drenching at $40mg{\cdot}L^{-1}$ delayed the harvest by 3-13 days as compared to the control and the smallest number of florets, 15.6, was observed in this treatment. In both cultivars, chlormequat and daminozide did not effectively influence the growth and flowering. However, number of florets increased to more than 41 at all concentrations and up to 63, the greatest floret number, with chlormequat drench in 'Kumoma-Gusa'. These results demonstrated that over $40mg{\cdot}L^{-1}$ of paclobutrazol or 5 to $20mg{\cdot}L^{-1}$ of flurprimidol could be used as PGRs to control the growth of floral length and flowering for improving potted plant quality in S. rosacea 'Kumoma' and 'Kumoma-Gusa'.

• The Korean Journal of Pesticide Science
• /
• v.13 no.1
• /
• pp.39-44
• /
• 2009

This study was conducted to evaluate the actual risk of fipronil on worker honey bees (Apis mellifera L.) through acute contact toxicity test, acute oral toxicity test, toxicity of residues on foliage test, and small scale field test. The $48h-LD_{50s}$ of fipronil SC on honeybee were $0.005{\mu}g$ a.i./bee in acute contact toxicity test and $0.004{\mu}g$ a.i./bee in acute oral toxicity test, respectively. In toxicity of residues on foliage test, fipronil showed over 90% of mortality during 28days after treatment at recommended application rate. The $DT_{50}$ of dislodgeable foliar residue was 9 days. Finally, In small scale field test, fipronil showed similar toxicity in the residues on foliage test. It was concluded that fipronil has very high acute toxicity and long residual toxicity to honeybee. Therefore, fipronil is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops or weeds if bees are visiting the treatment area. To protect honeybee and wild pollinators from outdoor use of fipronil, ultimately it should need to limit for only indoor use to prevent pollinators from unintentionally exposure of fipronil.

• Korean journal of applied entomology
• /
• v.57 no.3
• /
• pp.221-231
• /
• 2018

The susceptibility of the western flower thrips, Frankliniella occidentalis and garden thrips, Frankliniella intonsa was evaluated using 51 commercial insecticides. 15 kinds of insecticides which showed more than 90% mortality against both thrips, F. occidentalis and F. intonsa was selected. Many active ingredients were misused and abused in commercial mixture formulation insecticides. Since the F. intonsa was more susceptible than F. occidentalis, it was considered that both thrips can be controlled by insecticides that showed insecticidal activity on the F. occidentalis. Lethal time ($LT_{50}$ and $LT_{95}$), systemic toxicity and residual toxicity of selected insecticides were compared. Both chlorpyrifos WP and chlorpyrifos + diflubenzuron WP revealed the fastest toxicity within 2 h ($LT_{95}$), while spinetoram WG revealed the slowest toxicity as 62.3 h ($LT_{95}$). Chlorfenapyr SC showed toxicity at foliar and drenching application while spinetoram WG was toxic only in foliar application. Chlorfenapyr SC showed residual effect at 3, 5, 7, 10, 15 days after treatment and both benfuracarb WG and chlorpyrifos WP showed residual effect at 3 days after treatment. As a result of treatment of selected insecticides for field population of F. occidentalis, the population collected from horticultural crops showed lower susceptibility than the population collected from vegetable crops.

• Journal of Animal Science and Technology
• /
• v.45 no.5
• /
• pp.865-874
• /
• 2003

Red sorrel, as one of exotic weeds in Korea, was introduced along with imported cereals for concentrate feed or within the seed for forage production. The plant was dominated in grassland and reduced the quality of forage. In particular, this weed cause severe problem in alpine grassland. This study was carried out to investigate the effect and response of red sorrel and forage crops by foliar and soil applied herbicide application. Mecoprop(MCPP) and pendimethaline were selected by pre-field experiment trials and applied to control the red sorrel in grassland. Herbicidal activity of MCPP was 77.2% at 500$m\ell$/10a level and 82.8% at 750$m\ell$/10a level. However, seeds of red sorrel from bare land formed after foliar applied herbicide treatment were germinated and covered bare land. Pendimethalin was not reduced the rhizome growth grown from red sorrel root but retarded seedling growth of germinated red sorrel. The herbicidal activity of pendimethalin to the red sorrel seedling was 83.0%. 2 times application of MCPP at the rate of 750$m\ell$/10a was effective to control of red sorrel regrown from root and herbicidal activity was 93.2%. MCPP and pendimethaline treatment was not reduced growth of grass and have no herbicidal injury to forage crop seedling. Amount of MCPP and pendimethalin remained in grass plant was decreased from 20 days after herbicide treatment and could not be problem in livestock feeding.

• Current Research on Agriculture and Life Sciences
• /
• v.4
• /
• pp.1-6
• /
• 1986

This study was conducted to find out the effect of $SiO_2$ treatment on the $SiO_2$ concentration in guttation liquid, the amount of guttation liquid exudated from the margin of rice leaves, and the relationships between $SiO_2$ concentration in guttation liquid and foliar burn during the rice seedling stage, using two rice varieties;Nagdong-byeo (a Japonica) and Samgang-byeo (a - Indica - Japonica hybrid). Seedlings were cultivated in water solution and enveloped in polyvinyl case ($50cm{\times}150cm{\times}70cm$). $SiO_2$ treatment increased the amount of guttation liquid, the amount of guttation liquid (Nagdong-byeo:4.30mg/plant, Samgang-byeo:4.34mg/plant)) treated with 200ppm of $SiO_2$ was greater than any other level, decreased over 200ppm of $SiO_2$. $SiO_2$ concentration in guttation liquid was increased as application rates of $SiO_2$ increased, showing the positive correlation, and $SiO_2$ in guttation liquid/$SiO_2$ in culture ratio decreased over 100ppm of $SiO_2$. The highest concenitration of $SiO_2$ (Nagdong-byeo:172.6ppm/lcc, Samgang-byeo:199.8ppm/lcc) in guttation liquid was obtained at 12 hrs after $SiO_2$ applied. Foliar burn seemed to be closely related with $SiO_2$ concentration in guttation liquid.

• Applied Biological Chemistry
• /
• v.11
• /
• pp.151-166
• /
• 1969

I. Fffects of nitrogen supplying level and culture condition on the top growth aod tubers formation of Ipomoea Batatas. 1) The low level nitrogen (A plot) 3 Milliequivalent per liter of nutrient solution stimulated tuber formation while the high level nitrogen ($B_1\;and\;B_2$ plot) of 10 milliequivalent per liter failed to form tuber though fibrous roots were seen much activated. The suppressive effect of nitrogen on tuber formation in presumed to result from the direct suppressive effect of nitrogen or a certain biocatalystic effect rather than from any indirect effect through the stimulation to growth of tops or the competition with carbohydrates. 2) The addition of milligram urea to nutrient solution stimulated the growth and increased fresh weight and dry weight of the aerial part while suppressed, a little, plant length. 3) The water culture method, which this experiment newly adopted, stimulated plant growth more than the gravel Culture method. And the treatment of low level nitrogen (A plot) in this water culture also saw a considerable degree of tuber formation, as in the case of gravel culture. 4) The foliar application of growth retardant B-nine suppressed the plant length only, with no other recognizable effect. II. Fffects of urea supplying level on the growth of IPOMOEA BATATAS. 1) The higher level of urea which was absorbed tby roots through nutrient solution suppressed top growth, such as plant length, number of leaves and fresh weight. And this can be attributed to the direct absorption of urea which was not ammonificated. 2) Although the higher level of nitrate nitrogen (B plot) made no tuber formation in previous experiment (Report-1), the higher level of urea nitrogen (A plot) made tuber formation possible in this experiment. The ratio of tuber to top was, however, less in higher level of urea than in lower level of urea, and the suppressing effect was larger on tuber than on top. 3) The foliar application of urea stimulated top growth while the higher level of urea absorbed by roots suppressed it, though the amounts of urea supplied in two experiments were same. Ratio of top to roots was larger in foliar application of urea (C plot) and less in root absorption of urea both of higher (B plot) and lower urea levels (A plot). III. Fffects of growth retardant etc. on the growth of IPOMOEA BATATAS in relation to urea application. 1) B-nine (N-dimethyl amino-succinamic acid) is recognized as a growth retardant, suppressed the plant length irrespective of urea levels. The treatment of gibberellin stimulated distinctly plant length, and the combined treatment of gibberellin and B-nine recovered completely the plant length which had been suppressed by B-nine. 2) B-nine increased fresh weight, especially, fresh weight of top both in lower and higher level of The degree of fresh weight increase varied according to concentrations of B-nine, of which the 0.15% of B-nine ($B_1$ plot) was the effective in higher level of urea. The effect of B-nine for increasing fresh weight was the largest in top next in tuber, and the least in fibrous roots. The ratio of fibrous roots to top was always decreased by B-nine application, which the ratio of tuber to top was contrary increased by B-nine in higher level of urea though decreased in lower level of urea. 3) Gibberellin treatment also increased fresh weight but the combined treatment ($B_3$+GA plot) of gibberellin and B-nine was even more effective than any of single treatments. Gibberellin and B-nine proved to be synergistic with fresh weight while reverse with plant length. 4) Considerable influences were abserved mainly in the length of plants and their fresh weight after B-nine treatment. So that B-nine may be reguraded as a metabolic controller rather than as an antimetabolite. 5) The surpressed growth of plants cause by higher level of urea was normalized by B-nine treatment. This fact suggested a further study on the applicability for practical use.

• Weed & Turfgrass Science
• /
• v.2 no.2
• /
• pp.111-121
• /
• 2013

Literatures were reviewed to understand the weeds occurring on the lawn and the effective control methods of them. Thirty-seven species of 16 families including three species of Cyperaceae for example Cyperus sanguinolentus, nine species of Poaceae including Digitalis ciliaris, Poa repens, etc., and 25 species of broad-leaved weeds such as Artemisia princeps, Draba nemorosa, Hydrocotyle sibthorpioides were occurred on the lawns. One hundred ninety-six weed species of 53 families were occurred on a tomb graveyard adjacent to the mountain. Therefore, it is possible to be infested by the weeds occurring on the graveyard on the golf course adjacent to the mountains. There are 67 items, 32 kinds of the soil treatment herbicides including dichlobenil GR, methiozolin EC, oxaziclomefone SC, imaxaquin GR et al, and 35 kinds of the foliar treatment herbicides including metamifop EC, bifenox flucetosulfuron WG, flazasulfuron WP, trifloxysulfuron-sodium WG et al. registered at the end of May 2012 for efficient management of the weeds occurring on the lawn. For effective management of the weeds, the herbicide can be generally applied twice a year on March to April and August to September for soil treatment and once a year on June to July for the foliage treatment.