• Korean Journal of Agricultural Science
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• v.38 no.2
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• pp.191-198
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• 2011

Herbicidal effects and crop selectivity of aqueous leaf extracts of sorghum (Sorghum bicolor L.) were evaluated against several weed species for developing sustainable weed management in organic farming. Aqueous sorghum leaf extracts were highly phytotoxic to different weed species. No broadleaf weeds were germinated in the concentration of 5 fold or higher concentrated sorghum leaf extracts and 90% of seed germination was inhibited within that range in grass species. Sorghum leaf extracts strongly inhibited the growth of different weeds by pre-emergence and foliar applications in greenhouse condition. Foliar application of sorghum leaf extracts had a higher inhibitory effect than the pre-emergence application. Broadleaf weed species were more susceptible than grasses to the application of sorghum leaf extract in foliar applications than grasses. Galium spurium, Erigeron candensis, and Rumex japonicus were completely killed at the highest concentrated sorghum leaf extract both in pre-emergence and foliar application. Most broadleaf weed species were inhibited more than 80% at pre-emergence application at 50 fold concentrated sorghum leaf extract. G. spurium, E. candensis, R. japonicus, Eclipta alba, Plantago asiatica and Portulaca oleraeea were most susceptible to sorghum leaf extract in foliar application. Growth of most broad leaf weed species was suppressed by greater than 90% at 50 fold concentrated sorghum leaf extract. Most crop species were tolerant to sorghum leaf extract but shoot growth was slightly reduced by the application of 40~50 fold concentrated extracts, Sorghum leaf extract may used to control weeds in organic fanning without affecting the growth of crop.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.2
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• pp.127-133
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• 2003

The purpose of this study is to investigate the positive or negative effects of 5-aminolevulinic acid(ALA) on the growth of several crops and weeds, by applying a seed soaking treatment, foliar treatment, and application timing, while comparing biological activity between ALA produced by chemical synthesis (Synthetic-ALA) and extracellularly-accumulated ALA by overexpressing the hemeA gene isolated from Bradyrhizobium japonicum(Bio-ALA). Seed soaking treatment of ALA in barley (five cultivars) and wheat (five cultivars) had not shown positive effects at lower concentrations, 0.05 to 0.5 mM as well as negative effects at higher concentrations, 1 to 30 mM. In rice, there also was no positive effect by seed soaking treatment of ALA at lower concentrations, although the rice became damaged by an application of 5 and 10 mM ALA. Growth in barley cultivars, Ganghossalbori, Naehanssalbori, Songhakbori, Saessalbori, and Daehossalbori were increased up to 14%, 19-51 %, 17-64%, 18-23%, and 22-38% by ALA foliar application at lower concentrations, 0.05 to 0.5 mM, respectively. On the other hand, the growth in barley cultivars was inhibited by ALA foliar application at higher concentrations. Barley responded more positively to ALA foliar application than wheat and rice. The growth stimulation caused by ALA seed soaking treatment was less than by ALA foliar treatment. ALA treatment at the 1.5-leaf stage increased growth of barley by 19-58%, while pretreatment to seeds, post-emergence treatment at 3 days after seeding, 3-leaf stages, and 5-leaf stages had not shown positive effects. Thus, the positive effects of ALA on barley were dependent greatly upon the timing of application and its concentration. Monocots weeds were more sensitive to ALA foliar treatment than dicotyledonous weeds. A monocot weed, Setaria viridis L. was the most susceptible plant to ALA while a dicotyledonous weed, Plantago asiatica L. was the most tolerant. No significant difference in biological activity between bio-ALA and synthetic ALA on barley, wheat, rice, and weed, Ixeris dentate tested was observed. Thus, ALA produced by microorganisms would be a potent substance to be used effectively in agricultural production.

• Korean Journal of Plant Resources
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• v.11 no.3
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• pp.301-306
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• 1998

In order to improve cultivation technuque of C. lanceolata, natural ABA was treated with foliar application periodically during differenctitation of node. The higher is concentration and the earier its foliar application was, the shoter plant height was. Especially, when $10mg;.L{-1}$ of ABA was treated at differentiated stage of 3rd node, plant height was inhibited to 60% of control. But leaf length, leaf width, and number of branches have no significant differnence in comparison wiht control. The fresh weight of subterranean part was similar to control independent of treat-time in the case of $10mg;.L{-1}$. When 1,5 and $10mg;.L{-1}$ of ABA were treated at initial differentiated node stage, plant height inhibited to 20~30% of control, but subterranean part was similar to control. All treatement showed slight antitumor activity by the P388 cytotoxic screening test.

• Korean Journal of Plant Resources
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• v.10 no.4
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• pp.411-417
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• 1997

In order to improve cultivation technique of Codonopsis lanceolata, uniconazol and paclobutrazol were treated periodically with foliar application during differentiation of node. Plant height, width and length of leaves decreased as the concentration of uniconazol and paclobutrazol increased independently of application period. Characteristics of subterranean part of all treatment by uniconazol foliar application did not show any significant difference to control, except when treated at the differentiated stage of 3rd node. But, when uniconazol was treated with the concentration of 10, 100mg $liter^1$, respectively at the differentiated stage of 12th node, fresh weight was increased to approximately 64%, 100% of control, respectively. Control and 10mg $liter^1$ treated at the differented stage of 6th node showed antitumor activity by the P388 cytotoxic screening test. Fresh weight of all treatment by paclobutrazol foliar application was not showed signigicant difference to control, except when treated at the differentiateed stage of 3rd node. But, when paclobutrazol was treated with the concentration of 10mg $liter^1$ at the differentiated stage of 12th node, fresh weight was slightly increased of control. All treatment showed slight antitumor activity by the P388 cytotoxic screening test.

• Korean Journal of Organic Agriculture
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• v.12 no.4
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• pp.427-436
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• 2004

This study was conducted to investigate the effect of microbial product on microorganisms in soil and the growth of leaf lettuce. The test material were treated with chitosan, wood vinegar and EM activity liquid, and treatment concentration was 50 times solution and 100 times solution level with foliar application. The results were summarized as follows : Among foliar application of microorganisms treatments diluted by chitosan 100 times solution level was effective considering growth of leaf lettuce as compared other dilutions and control plot. Change of microorganism number in the soil for cultivation of chinese cabbages and leaf lettuce was increased with microorganism treatment plot as compared with control plot. Specially chitosan 100 times solution level showes the most significant effect.

• Korean Journal of Weed Science
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• v.32 no.3
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• pp.263-272
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• 2012

The potential as natural herbicide of d-limonene natural agent was conducted on several weeds in a greenhouse and Sciyos angulatus in field condition. Herbicidal activity of foliar application at a concentration of 100 and 200 kg ai $ha^{-1}$ of d-limonene on seven weed species was completely killed in a greenhouse condition. Also, d-limonene at a concentration of 50 kg ai $ha^{-1}$ was completely killing on Abutilon theophrasti, Aeschynomene indica, Echinochloa crus-galli and Digitaria ciliaris 3 days after treatment. While pre-emergence treatment of d-limonene concentration of 12.5 to 200 kg ai $ha^{-1}$ showed not significant visible damages. Phytotoxic symptoms of d-limonene by foliar treatment were characterized by wilting and burn-down of leaves and stems followed by discoloration, finally, plant death. Crop selectivity at d-limonene concentration of 100 kg ai $ha^{-1}$ over to five main crops including Zea mays by foliar application was not at all. Field trial of foliar treatment with d-limonene 70 to 140 kg ai $ha^{-1}$ have effectively controled over 5~20 leaf stages of S. angulatus at the natural habitats. And herbicidal efficacy of foliar application on S. angulatus with carrier volume in field condition was increased with dose dependent manners. These results suggest that d-limonene is considered possible as herbicide, and may be further optimized for natural agent for environmental friendly natural herbicide.

• Journal of Sericultural and Entomological Science
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• v.20 no.1
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• pp.5-10
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• 1978

The effects of foliar spray of Kinetin (6-Furfurylaminopurine) on the growth of mulberry tree and the metabolic activities in the leaves were measured. The results of this experimented are summarized as follows: 1. Foliar application of Kinetin was effective in increasing of leaf area, the fresh and dry weight of the leaves, the length and diameter of shoots. 2. Chlorophyll content was generally increased in all treated leaves. 3. All the treated leaves were higher in GOT activity than the control leaves but were lower in GPT activities. 4. The activities of the carbohydrate metabolism in the mulberry leaves were higher than that of the control in all treated leaves.

• Korean Journal of Organic Agriculture
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• v.12 no.4
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• pp.399-409
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• 2004

This study was conducted to investigate the effect of different concentrations of microbial products on growth of chinese cabbage and microorganisms in soil. Two different levels of microbial products, such as 50 times and 100 times diluted solutions of chitosan, wood vinegar and EM activity liquid, were treated for foliar application. the results were summarized as follows : Among foliar applications of microbial products, 100 times diluted solution of chitosan was effective on growth of chinese cabbage comparing to other levels of dilutions and untreated control plot. The number of microorganism in the soil tended to increase under the treatment of microbial products compared to control plot. Especially, the numbers of the bacteria and actinomycetes were estimated $73.67{\times}10^3$ CFU/g and $34.00{\times}10^3$ CFU/g, respectively, under the treatment of 100 times diluted solution of chitosan.

• Journal of Radiation Protection and Research
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• v.23 no.4
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• pp.219-227
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• 1998

A solution containing $^{85}Sr$, $^{103}Ru$ and $^{134}Cs$ was applied to Chinese cabbage in a greenhouse via foliar spraying at 5 different times during its growth. Interception of the applied activity by plant showed no difference among radionuclides and increased with decreasing time interval between application and harvest. The maximum interception factor observed was 0.87. Percentages of the intercepted activity remaining in the whole leaves at harvest varied $16{\sim}58%$ for $^{85}Sr$, $15{\sim}73%$ for $^{103}Ru$ and $33{\sim}64%$ for $^{134}Cs$, with application time and those for the inner leaves (without 6 outmost leaves) varied $2{\sim}35%$, $0.4{\sim}46%$ and $14{\sim}40%$, respectively. It was demonstrated that rain plays an important role in weathering loss of the activity. Tying the upper end of the plant prior to the last application lowered interception and remaining activity in the inner leaves by factors of $3{\sim}4$. Present results can be referred to in predicting the radionuclide concentration in Chinese cabbage and deciding counter-measures at the time of an accidental release from the nuclear installation.

• The Korean Journal of Pesticide Science
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• v.2 no.3
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• pp.147-150
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• 1998

A series of new benzenesuIfonylurea derivatives possessing ${\alpha}$-diketone or ${\alpha}$-keto ester moiety as an ortho substituent were synthesized by employing new methodology starting from 2-bromophenyl methoxymethyl sulfide and some of them were found to have good herbicidal activity at foliar application.