• Journal of Sericultural and Entomological Science
• /
• v.36 no.2
• /
• pp.110-114
• /
• 1994

Abnormally cool and wet weather conditions during the summer of 1993 offered an opportunity to evaluate the effects of abnormal weather conditions on mulberry growth and to develop cultivation practicies to reduce leaf yield loss under the similar abnormal weather conditions. Different methods of nutrient supplementation were evaluated in Suwon and Kongju. Nitrogen was supplemented by foliar spray of urea(1.7%) or composite chemical fertilizer Jamsibiryo #8, or by the application of ammonium sulfate(60kg/ha) to the soil. During the period between the late June and the early September which corresponds to the mulberry growing season after summer pruning, mean temperature was 1.4$^{\circ}C$ lower and precipitation 83mm higher than normal year. This weather condition in 1993 caused reduction in leaf yield by 16.4% than common year. Soil nitrogen content decreased due to higher precipitation. Leaf yield loss was reduced by the supplementation of nitrogen to the soil. Leaf nitrogen content increased with the foliar urea spray and nitrogen supplementation to the soil.

• The Plant Pathology Journal
• /
• v.36 no.5
• /
• pp.476-490
• /
• 2020

The parasitic weed, Orobanche crenata, is one of the most devastating constraint for faba bean production in Mediterranean regions. Plant host defense induction was reported as one of the most appropriate control methods in many crops. The aim of this study was to elucidate the effect of salicylic acid (SA) and indole acetic acid (IAA) on the induction of faba bean resistance to O. crenata under the field and controlled experimental conditions. Both hormones were tested on two contrasting faba bean genotypes: Giza 843 (partially resistant to O. crenata) and Lobab (susceptible) at three different application methods (seed soaking, foliar spray, and the combination of both seed soaking and foliar spray). Soaking seeds in SA or IAA provided the highest protection levels reaching ~75% compared to the untreated control plants. Both elicitors limited the chlorophyll content decrease caused by O. crenata infestation and increased phenolic compound production in host plants. Phenylalanine ammonia lyase, peroxidase, and polyphenol oxidase activities were stimulated in the host plant roots especially in the susceptible genotype Lobab. The magnitude of induction was more obvious in infested than in non-infested plants. Histological study revealed that both SA and IAA decreased the number of attached O. crenata spikes which could be related to specific defense responses in the host plant roots.

• Asian Journal of Turfgrass Science
• /
• v.25 no.2
• /
• pp.195-201
• /
• 2011

The seaweed (Ascophyllum nodosum) extracts and chitosan formulations were sprayed on species of creeping bentrgass (Agrostis palustris Huds) cultivar "Penn A1" and species of Kentucky bluegrass (Poa pratensis L.) mixed cultivars (Midnight 33%, Moonlight 33%, Prosperity 33%) during fall season in sod farm. Turf color, chlorophyll contents and NDVI (Normalized Difference Vegetation Index) to affect turf qualities were investigated. There were detected significantly difference on chlorophyll contents and DNVI with seaweed extracts and chitosan formulations treatments. The contents of chlorophyll and NDVI on species of Kentucky bluegrass mixed cultivars and species of creeping bentgrass cultivar "Penn A1" were significantly increased by foliar spray with chitosan formulations and seaweed extracts. There was not a significantly difference on leaf color in two species within cultivars. These results suggested that chitosan formulations and seaweed extracts may help for turfgrass managements in the golf course during fall season.

• Horticultural Science & Technology
• /
• v.17 no.2
• /
• pp.134-135
• /
• 1999

In order to improve quality and to accelerate blooming time in potted Oncidium 'Aloha', foliar spray of $GA_3$, BA, zeatin, and kinetin were applied on June 1 and June 15. The plant growth regulators did affect the improvement of number of peduncles, pedicels and florets, and shortened flowering time. Especially, number of peduncles and of florets were remarkably increased by foliar application of BA solution. And the flower opening time were shortened 26 days by 100mg/L BA treatment compare with control.

• Korean Journal of Plant Resources
• /
• v.32 no.6
• /
• pp.677-682
• /
• 2019

Hand leaf thinning for improvement of fruit coloration and quality is one of the most labor-consuming works in Korean apple cultivation. The study was aimed at investigating whether foliar application of two chelate compounds (Cu-EDTA, Fe-EDTA) could defoliate effectively 'Hongro'/M.9 apple leaves and enhance fruit coloration and quality. At 30 days before harvest, foliar spray with two chelate compounds defoliated significantly the apple leaves. Chelate treatments did not affect the leaf chlorophyll content. High concentration of chelates decreased drastically photosynthetic rate of true leaves, and then it stayed in low levels, whereas low levels of chelates reduced sharply the photosynthetic rate but it was gradually restored over time. Cu-EDTA regardless of its concentration triggered higher defoliation compared to Fe-EDTA. Consequently, higher defoliation improved light interception of fruits and accumulated more anthocyanin. Particularly, Cu-EDTA could target mainly fruit cluster leaves which affect directly light interception of the fruits, i.e. more selective defoliants compared to Fe-EDTA. However, 3% Cu-EDTA rather defoliated excessively, accompanying with reduction of fruit weight and soluble solids. Therefore, our results suggest that 1% Cu-EDTA which defoliates properly the fruit cluster leaves could improve coloration and quality of 'Hongro'/M.9 apple fruits.

• Research in Plant Disease
• /
• v.22 no.2
• /
• pp.81-93
• /
• 2016

Out of plant-associated bacteria, certain plant growth-promoting bacteria (PGPB) have been reported to increase plant growth and productivity and to elicit induced resistance against plant pathogens. In this study, our objective was to broaden the range of applications of leaf-colonizing PGPB for foliar parts of road tress and pepper. Total 1,056 isolates of endospore-forming bacteria from tree phylloplanes were collected and evaluated for the enzymatic activities including protease, lipase, and chitinase and antifungal capacities against two fungal pathogens, Colletotrichum graminicola and Botrytis cinerea. Fourteen isolates classified as members of the bacilli group displayed the capacity to colonize pepper leaves after spraying inoculation. Three strains, 5B6, 8D4, and 8G12, and the mixtures were employed to evaluate growth promotion, yield increase and defence responses under field condition. Additionally, foliar application of bacterial preparation was applied to the road tress in Yuseong, Daejeon, South Korea, resulted in increase of chlorophyll contents and leaf thickness, compared with non-treated control. The foliar application of microbial preparation reduced brown shot-hole disease of Prunus serrulata L. and advanced leaf abscission in Ginkgo biloba L. Collectively, our results suggest that leaf-colonizing bacteria provide potential microbial agents to increase the performance of woody plants such as tree and pepper through spray application.

• Journal of Bio-Environment Control
• /
• v.29 no.4
• /
• pp.365-372
• /
• 2020

This study was conducted to compare the effects of foliar spray and sub-irrigation of the triazole fungicide diniconazole on the regulation of stem elongation and to investigate the stimulation of root system development during the seedling stage. Comparing the two application approaches, there were significant differences in the leaf area, leaf area ratio (LAR), plant height, compactness, fresh shoot and root production, relative growth rate (RGR), and root to shoot ratio (R/S). At the same application concentration, the sub-irrigation showed a better retarding effect on growth than the foliar spray, because the PGR activity of diniconazole in root absorption was higher than that in shoot absorption. For reaching a target of 20% to 30% inhibition rate of stem length, foliar application concentration of diniconazole exceeded 10, however, only approximately 1 was required in the sub-irrigation application. The root system of tomato seedlings responded strongly to diniconazole application. Total root length, root volume, root average diameter, and the number of root tips increased when diniconazole was sub-irrigation application at 1. A reduction in fine roots (diameter range of 0 to 0.3 mm) and an increase in the roots with a diameter range of 0.3 to 0.6 mm was observed, and this may contribute to the increase in average diameter. The increase in root average diameter may be positive because root penetration increases with root diameter. Our results suggested that sub-irrigation maximized the PGR activity of diniconazole to enhance the retarding effect. And it also possible to enhance the tomato seedling root system by diniconazole stimulating with a lower concentration.

• Horticultural Science & Technology
• /
• v.19 no.4
• /
• pp.564-567
• /
• 2001

This experiment investigated the dwarfing effect of daminozide and chlormequat to produce high quality of spray chrysanthemum. Long neck of cut-chrysanthemum break easily. Peduncle length of the cultivar 'Biarittz' and 'Vyking' were retarded by the foliar spray treatment of $1500mg{\cdot}L^{-1}$ daminozide. Daminozide application did not affect plant growth of 'Biarittz' and 'Vyking'. However, the number of days to flowering was delayed by 3 days by daminozide application of 'Biarittz'. Length of cut flowers of 'Vyking' was decreased by the application of daminozide, while chlormequat did not affect dwarfing of peduncle length in spray chrysanthemum.

• Korean Journal of Environmental Agriculture
• /
• v.25 no.3
• /
• pp.276-283
• /
• 2006

To evaluate the effectiveness of the foliar spray of calcium on "Baekdo" peach fruit, we carried out experiments in the orchards. The sprays were applied with $CaCl_2\;(Ca:\;400mg.kg^{-1})\;and\;CaCl_2$ with adjuvants (amino acid, $2g.kg^{-1}$; phytic acid, $2ml.kg^{-1}$ and wood vinegar, $2ml.kg^{-1}$) for four times from June 12 through July 4 at weekly intervals. The fruits and leaves were evaluated for Ca content, firmness and incidence of Brown rot caused by Monilinia fructicola at harvest To evaluate fruit quality included Ca content, firmness natural decay during the storage, the fruits were stored at room temperature for 14 days. The Ca content in leaf and fruit flesh at harvest was significantly increased (P=0.05) in $CaCl_2$ + amino acid treatment among $CaCl_2$ treatments. However, there was not significant Ca content in fruit peel. The firmness of flesh increased significantly (P=0.05) in $CaCl_2$ + amino acid treatment. The natural decay (Rhizopus stolonifers) during storage at the room temperature for 14 days, the fruit treated with $CaCl_2$ + wood vinegar exhibited lowest (P=0.05) incidence. Also, the firmness of the fruit during storage was firmer with treated $CaCl_2$ than untreated fruit. In the treatments of $CaCl_2$ + phytic acid and $CaCl_2$ + amino acid, it was possible to reduce incidence of Brown rot caused by M. fructicola most effectively in the field. In addition, inoculation with M. fructicola in fruits was also the most effective treatment for inhibiting disease development in vitro. These results suggested that the foliar spray of $CaCl_2$ with adjuvants increased the content of Ca and firmness of the fruits positively. It also inhibited the natural decay and the Brown rot effectively.

• FLOWER RESEARCH JOURNAL
• /
• v.19 no.2
• /
• pp.89-95
• /
• 2011

This study was conducted to improve commercial quality of cut spray chrysanthemums 'Charming Eye' and 'Pink Pride' bred in Korea by foliar application of daminozide, suppressing excessive elongation of peduncle caused by high temperature in greenhouse. Applications were made at two floral-bud-developmental stages and concentrations used were 0, 500, 1000, and $2000mg{\cdot}L^{-1}$. As for 'Charming Eye', cut flower length, peduncle diameter, stem diameter, flower bud diameter, and the number of flower buds did not show any significant difference among all treatments including control. However, the suppressing effect of peduncle elongation, widening angle of flower cluster arrangement on apical part, and increasing parallel flower buds in stage I showed better than those in stage II regardless of daminozide concentration. As for 'Pink Pride', cut flower length, peduncle diameter, and stem diameter did not show any significant difference among all treatments including control but angle of flower cluster on apical part increased compared to control as daminozide was sprayed at stage I and II except $2,000mg{\cdot}L^{-1}$ daminozide-sprayed at stage II. The number of flower buds and flower bud diameter showed the greatest increment through $1,000mg{\cdot}L^{-1}$ daminozide-sprayed at stage I and did the least values as sprayed with $2,000mg{\cdot}L^{-1}$ daminozide at stage II. Daminozide also gradually reduced peduncle length in a concentration-dependant manner but elongation of peduncle foliar-sprayed at stage I showed the more suppressing effect than that at stage II. Increasing the number of parallel flower buds showed the best results when sprayed with $2,000mg{\cdot}L^{-1}$ at stage I. In conclusion, we recommended that foliar spraying with $500-1,000mg{\cdot}L^{-1}$ daminozide at stage I and foliar spraying with $1,000-2,000mg{\cdot}L^{-1}$ daminozide at stage I improved cut flower quality of 'Channing Eye' and 'Pink Pride', respectively.