• Korean Journal of Environmental Agriculture
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• v.33 no.1
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• pp.24-29
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• 2014

BACKGROUND: Recently, as the consumption of fresh jujube is increased, fertilizer in jujube cultivation is excessively used to supply nutrient for large fruit produce. This study was conducted to obtain the useful data related to optimum nutrient management technique for fresh jujube cultivation. METHODS AND RESULTS: Nutrient contents of the jujube orchard soils were investigated at 30 different jujube orchards in Boeun, Chungbuk. Soil samples were collected from the different orchards in June, both 2012 and 2013. Soil chemical properties such as pH, organic matter, available phosphate, and exchangeable potassium, calcium, and magnesium were analyzed. Soil available phosphates in optimum level for jujube cultivation were 7% and 13% of total samples in the 2011 and 2012 respectively, and 73% and 57% were higher than optimum level. In Exchangeable K, 37%, 30% were optimum level, 63%, 67% were higher in the year 2011 and 2012 respectively. CONCLUSION: These results showed that nutrient contents of soils were accumulated in jujube orchard of Boeun area. Especially, available phosphate and exchangeable potassium were greatly higher than their optimum level for jujube cultivation respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.452-457
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• 2013

To obtain the useful data related to optimum nutrient management technique for pesticides-free jujube cultivation, nutrient contents of jujube leaves and fruits and the selected chemical properties of jujube orchard soils were investigated at 9 different orchards with pesticides-free cultivation in Boeun, Chungbuk, Korea. Soil and jujube leaf samples were collected from the different orchards in July and October, and jujube fruit samples were taken in October, 2012. Soil available $P_2O_5$ contents in the optimum level for jujube cultivation were 11% and 33% of total samples in July and October, respectively, but 56% of total samples was higher than the optimum level in both July and October. Exchangeable K and Ca ion contents were 44% and 67% of total samples, respectively, in both July and October, whereas exchangeable Mg ion content was 100% and 56% of total samples in July and October, respectively. Nutrient contents in jujube leaves were higher than those in fresh fruits. In addition, total nitrate, potassium and magnesium contents in the jujube leaves were higher in the samples collected in July than in October.

• Korean journal of applied entomology
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• v.56 no.4
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• pp.365-370
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• 2017

The flowering season of jujube (Zizyphus jujuba var. inermis (Bunge) Rehder) is overlaps with the rainy season and the abnormal weather conditions in Korea, thereby affecting pollination, fertilization, and fruit setting. We studied the pollinating activities of Apis mellifera L. and Bombus terrestris L. in rain shelter houses and their effects on fruit setting, with the ultimate aim of stabilizing fruit setting in Z. jujuba. A. mellifera and B. terrestirs were used for pollination in jujube orchard in the rain shelter house for approximately 55 days from June 1, 2016, to July 25, 2016. The peak time of the rate of outgoing and incoming A. mellifera was recorded in the afternoon. However, the diurnal activity of B. terrestris was constant between 09:30 and 17:30 h. The rate of jujube fruit set on current shoots by A. mellifera and B. terrestirs was 10.2 and 8.9%, whereas that in plots with no pollinators was 5.5%. Therefore, using pollinator in the rain shelter house in jujube orchard is effective in promoting jujube fruit setting.

• Horticultural Science & Technology
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• v.18 no.3
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• pp.399-403
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• 2000

Recently, abnormal leaf chlorosis has been observed in jujube trees of the major production area in Kyongbuk province. To determine possible causes for the observation, physico-chemical properties of the orchard soil and nutrient contents in the jujube trees were investigated. The chlorosis symptoms were categorized into three types based on the site of chlorosis initiation; leaf center, petiole, and intravein. Of the three, leaf center chlorosis was the most common. The symptom occurred more frequently in Ihyeon, Gyuam, and Geugrag soil series with previous history of apple orchard. In general, the soil and the tree showing leaf chlorosis had lesser nutrient contents than normal except P, Fe, and Zn. In particular, Mg contents in leaf, branchlet, and fruit of the tree were as much as 4 times lesser than those in normal tree; the soil also had 7.8 times lesser Mg contents. The results indicate that the abnormal leaf chlorosis in jujube tree may be caused by nutrient deficiency in soil and could be cured by proper fertilization.

• Korean Journal of Organic Agriculture
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• v.25 no.3
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• pp.619-630
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• 2017

In recent years, not only the cultivation area of Jujube in Korea but also the number of pest species has increased. The farmers farming environmentally friendly are in great difficulty because there are no effective control devices. This study was conducted to investigate the control effect of the insect screen net on three pest species (Apolygus spinolae, Dasineura sp. and Carposina sasakii) in Jujube orchard when the pests were blocked by insect screen net. For the first and second surveys, the damage rates by A. spinolae were 9.06, 13.95% in 50 mesh, 4.75, 10.17% in 25 mesh, 5.68, 11.84% in 18mesh mesh of insect screen net and 21.6, 36.34% in untreated insect screen net, respectively. The damage rates by Dasineura sp. were 0.54, 0.13% in 50 mesh, 0.93, 2.84% in 25 mesh, 1.05, 13.45% in 18 mesh mesh of insect screen net and 11.1, 26.65% in untreated insect screen net. Carposina sasakii were completely blocked in all the treatments. Damages on Jujube were not observed by insect screen net. Therefore, insect screen net is effective on insect pest control for Jujube.

• Korean journal of applied entomology
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• v.60 no.1
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• pp.79-90
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• 2021

Landscape composition and structure are important factors determining biological diversity including pests and natural enemires in agricultural ecosystem. This study was conducted to indentify effect of landscape composition on occurrence of lepidopteran pest population in Geochang, Gyoungdnam. For this, orchard characteristics and management practices were surveyed in 80 conventional apple orchards in Geochang, Korea, along with the monitoring of pest population densities. The landscape features of each surveyed orchard also obtained by extracting information from the public-service map. Grapholita molesta was the most dominat and damaging pest followed by Phyllonorycter ringoniella and Carposina sasakii in trap catches. Adoxophyes paraorana occurrences were low. Farmers spray insecticides and fungicides ap. 12.4 times per year respectively while acaricides were sprayed 2.4 times. Major landscape features such as surrounding apple orchard or paddy field did not influence the pest populations but presence of plum, peach, wild peach, graph, and even abandoned orchards significantly resulted in higher pest population mostly on G. molesta. C. sasakii population was higher in orchards with grape, peach, and P. ringoniella with peach, grape, abandoned orchards and jujube. Results highlight the need of landscape management not only for the rural amenity but also for increasing functional diversity of agroecosystem as well as reducing pest population.

• Korean journal of applied entomology
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• v.50 no.4
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• pp.367-372
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• 2011

An unknown planthopper was discovered in 2010 in an apple orchard in Sinpoong-myun, Gongju-si and in a blueberry orchard in Deogsan-myun, Yesan-gun. This pest have arrived 4 or 5 years ago and the population density then rapidly increased. It was identified as Ricania sp. by Dr. Murray J. Fletcher. Adult Ricania sp. was found on 26 plants including blueberry, grape, peach, sumac, japanese angelica, jujube, kiwi, Rubus coreanus, apple, apricot, plum and chestnut. Females lay eggs on 1-year-old branches. The mean number of eggs laid on apple and plum were 18.7 and 15.3, respectively. The mean length of egg masses on apple and plum were 12.35 and 11.45 mm, respectively. The distance between eggs laid on apple and plum branchs were 1.3 and 1.5 mm, respectively. The mean number of eggs in the same length of egg mass on apple and plum branchs were 17.1 and 13.3, respectively.