• Korean journal of applied entomology
• /
• v.21 no.4 s.53
• /
• pp.207-210
• /
• 1982

The studies were carried out to examine susceptibility or resistance of junipers as an inform ediate host of pear rust, to select effective fungicides to pear and juniper rust, and to determine their application time. The telia were formed abundanty on Juniperus chinensis var. kaizuka, moderately on J. chinensis, J. chinensis var. sargentii and J. virginiana, but little on J. chinensis var. globosa and J. utilis. The telia from the junipers were pathogenic to pear. Spraying juniper host with the fungicide Actidione in the 1st and End parts of April greaty inhibited swelling of telia as well as germination of teliospores. The two or three applications of Bayleton at the end of April to May 10 were remarkably effective for the control of pear rust. Fungicide sprays just before rain were more effective than those after rain.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.38 no.3
• /
• pp.213-218
• /
• 1993

An experiment was carried out to investigate the effects of plant growth regulators on the growth and fiber yield of ramie. Gibberellin (GA) and Atonic acid were applied at the various levels of application dates, application frequencies and concentration. Stem growth of ramie increased greatly by applying GA on the meristem of shoot apex. Among three treatments of application frequencies of GA, that is, one time application at the stage of stem length with 50cm, twice applications at the stem length of 50cm and 100cm, and three times applications at stem length of 50cm, 100cm and 150cm, stem growth increased more as application frequency increased. GA application is more effective on stem growth at the later stage of growth than the earlier growth stage. GA treatment of 100 to 300 ppm is more effective on stem elongation than 50 ppm, which was due on the elongation of internodes without increase in number of nodes. One time application of GA enhanced leaf growth more or less regardless of concentration, but GA was applied more frequently, leaf growth was inhibited more at higher concentration. Fiber yield was the highest at the treatment of three times application of GA with 100 ppm. This treatment also showed the highest percentage of fiber with 5.3%, which is much higher value compared with that of control treatment with 4.6%. Atonic acid was less effective on stem elongation than GA, but it also seemed to be effective on the enhancement of fiber development.

• The Korean Journal of Pesticide Science
• /
• v.20 no.1
• /
• pp.1-6
• /
• 2016

In order to obtain efficient control effect of the pesticide, it is important to ensure uniform adhesion to the desired plant parts at the right time. Pesticide spray method (application technology) is an important factor affecting the efficacy and crops persistent expression. The aim of this study was to develop an efficient system to investigate the coating weight distribution of citrus leaves due to the difference between the nozzle and spray sprinkler system using dithianon used in citrus scab. Other An, engine type sprayer was used as the control. Speed sprayer and different sprinklers were wsed to way the deposit amounts of dithianon on citrus leaves. The test was conducted at the National Institute of Horticultural Herbal Science Citrus Research Station, located in the circle citrus Jeju Island. In order to examine whether the citrus orchard spray and the evenl on the whole, dithianon (43% flowable 1000-fold dilution) was sprayed, filter paper and leaves were analyzed by the height as top, middle, bottom. Speed sprayer the was most effective on depositing at the middle position, of the leaves. All other sprays the leaces except the dry mist sprinkler were not effective enough to deposit on the back sides. To achieve more deposits on the high position leaves, an improve ment in the nozzle and an efficient power system of sprayer were needed.

• Korean Journal of Organic Agriculture
• /
• v.20 no.2
• /
• pp.243-258
• /
• 2012

These grafting seeding "Torobambica", rootstock "Chuk Yang" were tested to investigate the growth, yield, and quality of eggplants which can be influenced by the bumblebee pollination and plant growth regulators. The results were as follows: According to the treatment of bumblebee pollination and plant growth regulators, the yield of eggplant was good at bumblebee pollination with tomatotone flower spray at blooming time, and was good at foliage spray on the treatment of tomatotone and $GA_3$, and was good at flower clusters spray on the treatment of tomatotone. According to the treatment of bumblebee pollination and plant growth regulators, the ratio of marketable fruit was good at pollination bumblebee with tomatotone spray on the day they flowered, was good at foliage spray on the treatment of tomatotone and $GA_3$, and was good at flower clusters spray on the treatment of tomatotone. On the mineral element contents of eggplant stems, the contents of total nitrogen were good at tomatotone flower spray at blooming time, the ones of phosphorus, potassium, and magnesium were good at tomatotone foliage spray the rate of three days, the ones of calcium were good at tomatotone flower spray in two or three days before flowering, and ones of ash were good at tomatotone flower spray at blooming time, foliage spray the rate of three days. On the mineral element contents of eggplant fruits, the contents of total nitrogen were good at tomatotone and $GA_3$ foliage spray the rate of six days, the ones of phosphorus were good at tomatotone foliage spray the rate of three days, the ones of potassium, ash were good at tomatotone and $GA_3$ flower spray at blooming time, and the ones of calcium, magnesium were good at tomatotone an $GA_3$ flower spray in two or three days before flowering.

• The Korean Journal of Pesticide Science
• /
• v.14 no.3
• /
• pp.284-288
• /
• 2010

A series of experiments was carried out for selecting insecticides and determining proper spraying time to control pea weevil (Bruchus pisorum Linnaeus) in Jeonnam area. In the field trial two times spray with diazinon, carbaryl, imidacloprid, spinosad, etofenprox, clorpyrifos-methyl showed good control effect and threetimes spray showed the better control effect. The second spray (spraying on 10th of May) took the major role of insecticide effectiveness expression for controlling pea weevil. Further trial for selecting insecticides among organophosphates to control pea weevil in lab was conducted and every organophosphate insecticide tested was very effective to pea weevil even at the concentration of one forth of its recommending concentration.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.27 no.3
• /
• pp.247-253
• /
• 1982

This experiment was conducted to find out the optimum date for Combine harvesting of barley in the double cropping paddy field. By the consideration of moisture contents of grain, grain loss, rate of unhulled grain, and discoloring of external plant parts, the optimum date for harvesting was observed to be about 41 days after heading under natural condition. On the other hand, when desiccant was applied on the 34 days after heading, it could be shortened natural harvesting time for 3 days without any yield loss and grain qualities, too.

• Journal of Bio-Environment Control
• /
• v.30 no.4
• /
• pp.263-270
• /
• 2021

This experiment was carried out to determine the effect of CaCl₂ foliar spraying on the inhibition of blossom-end rot (BER) in hot summer paprika (Capsicum annum L. 'Special') cultivation. The effect of CaCl₂ application was examined by the foliar application based on different fruit size, frequency, and spraying time. Also, it was investigated the occurrence and alleviation effect of BER symptom. Foliar application of CaCl₂ (Ca 0.4%) was conducted by treating a fruit and leaf at 4 to 9 nodes above the crown flowers of each plant with 350 mL per week from June 3 to July 1. When the CaCl₂ was sprayed at 7-day intervals for 4 weeks, the Ca content was the lowest in the fruit harvested with BER symptom in 11 to 20 mm of fruit width (FW). Four different regions in both BER symptom and normal fruits showed significant differences of Ca content, the highest was in pedicel, followed by stem-end, middle, and blossom-end. The Ca content increased sharply in normal paprika with 31-40 mm FW, in which Ca content was 78% higher than that of BER. Ca content in the middle and blossom-end of paprika over 21 mm in FW ranged 19.8% to 28.8% in normal fruits and 15.7% to 18.5% in BER, respectively. The incidence of BER increased rapidly by more than 60% in fruits with 31-40 mm FW. While there was no difference in fruit weight among the FW treatment, marketable yield rate was highest in the 21-30 mm FW, and the sugar content was high in the 11-30mm FW. When CaCl₂ was applied three times for 7 days to a paprika having a 21- 30 mm FW, the cell wall-bound (CWB) Ca content was the highest and the rate of BER was lowest with 6.3%. After 10 days of CaCl₂ foliar spray treatment, the CWB Ca content of paprika increased by 2.9 to 3.5 times compared to the control in all treatments. At 7 days after the CaCl₂ foliar spraying once a day at varying spraying time, the leaf burn observed from 9:30 a.m. to 17:00 p.m. and the proline content increased as the spraying time was delayed. Therefore, the CaCl₂ foliar spraying method for reducing of BER occurrence during paprika summer cultivation seems to be appropriate to spray 2-3 times at intervals of 3 days and before 8 a.m. at the time when the FW is 21-30 mm.

• Korean journal of applied entomology
• /
• v.42 no.1
• /
• pp.85-89
• /
• 2003

Current status of pesticide applications in sweet persimmon orchards was investigated through the questionnaire and analysis of the pesticide application records from 62 growers in 2000 and 17 growers in 2001 in Jinju, Sacheon, Changwon, Changyoung, and Gimhae in Korea. Average yearly application was 7.6 times in 2000 and 7.7 times in 2001, concentrated in June and July. The kinds of fungicides and insecticides used were 36 and 34 items in 2000, and 22 and 23 items in 2001, respectively. Application of pesticides was mostly finished by mid-September. Fungicides such as mancozeb, thiophanate-methyl, and benomyl were most frequently used in 2000, and lime sulfur, benomyl and carbendazim in 2001. Insecticides such as deltamethrin, methidathion, and fenitrothion + fenvalerate were frequently used in both years. About one-half of the pesticides being used by the growers was not registered for persimmon in Korea.

• Korean Journal of Medicinal Crop Science
• /
• v.5 no.1
• /
• pp.62-66
• /
• 1997

This experiment was conducted to evaluated the effect of choline salt of maleichydrazide (C-MH) application on growth and root yield components of Bupleurum falcatum L. Flowering was delayed by C-MH application $17{\sim}35$ days. Twice application was more effective to delay flowering. Application of C-MH 2,000ppm at 30cm to 40cm of plant height reduced plant height 15cm, but increaced highly branches and the growth of root. The dried root yield per 10a was 27% higher in twice application of C-MH 2,000ppm than control plot.

• Journal of Korean Society of Forest Science
• /
• v.76 no.4
• /
• pp.357-360
• /
• 1987

1. The hair cells on adaxial surface turned out to be penetration way of Gleosporium Thea sinensis in tea plant. 2. The most parts of Gleosporium Thea sinensis generated in tea plant were young leaves with first-fifth leaves from tip of shoot. 3. The proper temperature for spore germination on leaf is $25-27^{\circ}C$, soaked by water for 12 hours. 4. For prevention of Gleosporium Thea sinensis the drug-spay in tea plant would be the most effective when sprayed at this temperature range, and the control of Gleosporium Thea sinensis would be possible through selection of tea plant with few hairs. 5. The treatment of bordeaux mixture to prevent growth of conidiospore was 48.3% more effective than in control plot which were not sprayed. 6. The effect of sprayed bordeaux mixture decreased to about 28.5% after one week of spray.