순환식 수경재배 시스템을 이용한 배액의 재활용은 수 자원 및 생산비 절감, 환경오염 방지를 위하여 중요하다. 따라서 일반 토마토인 ‘Bonus’를 110일간 반촉성 수경 재배하면서 생육 단계별 식물체, 공급액 및 배액의 무기 원소 농도 분석을 통하여 순환식 수경재배 시스템 개발 을 위한 기초 자료를 확보하고자 본 연구를 수행하였다. 착과절위에 따른 엽의 T-N 함량은 생육 초기에 약 4.1%로 높았으나 생육 후기로 갈수록 낮아져 8화방 개 화기에는 3.9%로 낮아졌다. P 함량은 초기에 높았으며, 3-7화방까지는 비슷하였고, 8화방에서 낮았다. Ca, Mg 및 Na은 생육초기보다 후기로 갈수록 함량이 높아져 8 화방 개화기에 가장 높았다. 토마토 생육 기간이 경과할 수록 공급 양액과 배액의 NO3-N, P, K, Ca 및 Mg 농 도는 정식 5주 후까지의 생육 초기에는 비슷하였으나 생육 후기로 갈수록 공급액보다 배액에서 농도가 높아지 는 경향이었다. B, Fe 및 Na의 경우 생육 초기에는 배 액의 농도가 약간 높았으며 중기 이후부터 공급액보다 배액의 농도가 높았다. 이상의 결과는 토마토 순환식 반 촉성 수경재배 시 배액의 무기원소 농도를 교정하기 위 한 기초 자료로 활용될 수 있을 것이다.

Changes in the pH, electrical conductivity (EC), and concentrations of essential nutrients have to be analyzed to enable reuse of the drainage solution (DS) in closed hydroponic cultivation of a crop because the chemical characteristics (CC) of drainage vary in relation to the kind of crop grown and the root media used. The objective of this research was to investigate changes in the CC of DS during cultivation of 'Seolhyang' strawberries. The root medium is composed of coir dust, peat moss, and perlite in the ratio 6:2:2 (v/v/v), and the composition of the nutrient solution applied for crop cultivation is N, P, K, Ca, and Mg at 15, 5, 7, 6, and 2 mg.L-1, respectively. The changes in the CC of the DS as well as the growth, yield, and fruit quality were investigated in relation to the number of years the root media used. The pH of the DS decreased as the number of years of root medium usage increased. The ECs of DS in all treatments were in the range of 0.8 to 1.5 dS.m(-1) during the growing season and tended to rise as the number of years of usage in the root medium increased. The concentrations of NO3 and Ca in the DS ranged from 200 to 600 mg.L-1 and 52 to 176 mg.L-1, respectively. The K concentration in the DS was in the range of 104 to 221 mg kg(-1) in all treatments during the growing season. The concentrations of P and Mg in the DS were 15 to 60 mg.L-1 and 18 to 48 mg.L-1, respectively. As the number of years of root media usage increased, the concentrations of NO3, P, Ca, and Mg tended to rise, whereas that of K tended to decrease. The different treatments with varying number of years of root medium usage did not lead to significant differences in plant growth, tissue nutrient content, budding and flowering date, and total yield. The results from this research, the changes in nutrient composition of the DS and their effect on tissue nutrient content, can be used to modify the nutrient composition in the DS when the solution is reused in closed hydroponic cultivation of 'Seolhyang' strawberries.

Recycling of drained nutrient solution in hydroponic cultivation of horticultural crops is important in the conservation of the water resources, reduction of production costs and prevention of environmental contamination. Objective of this research was to obtain the fundamental data for the development of a recirculation system of hydroponic solution in semi-forcing cultivation of ‘Bonus’ tomato. To achieve the objective, tomato plants were cultivated for 110 days and the contents of inorganic elements in plant, supplied and drained nutrient solution were analyzed when crop growth were in the flowering stage of 2nd to 8th fruiting nodes. The T-N content of the plants based on above-ground tissue were 4.1% at the flowering stage of 2nd fruiting nodes (just after transplanting), and gradually get lowered to 3.9% at the flowering stage of 8th fruiting nodes. The tissue P contents were also high in very early stage of growth and development and were maintained to similar contents in the flowering stage of 3rd to 7th fruiting nodes, but were lowed in 8th node stages. The tissue Ca, Mg and Na contents in early growth stages were lower than late growth stages and the contents showed tendencies to rise as plants grew. The concentration differences of supplied nutrient solution and drained solution in NO3-N, P, K, Ca, and Mg were not significant until 5 weeks after transplanting, but the concentration of those elements in drained solution rose gradually and maintained higher than those in supplied solution. The concentrations of B, Fe, and Na in drained solution were slightly higher in the early stages of growth and development and were significantly higher in the mid to late stages of growth than those in supplied solution. The above results would be used as a fundamental data for the correction in the inorganic element concentrations of drained solution for semi-forcing hydroponic cultivation of tomato. Additional key words : dry weight, EC, leaf area, pH, Solanum lycopersicum L., T-N content

The objective of this research was to obtain information on the changes in composition of drained nutrient solution (DNS), and the influence of reused drained solution on the growth and productivity of tomatoes. To achieve this, three treatments were prepared for hydroponic cultivation: 1) the Yamazaki nutrient solution for tomato (YNST); 2) 70% YNST with 30% DNS; 3) 70% YNST with 30% DNS with calibrated N and K ion concentrations (DNSC). Perlite was used as the root substrate and the frequency and amount of solutions supplied were equal for all treatments. Plant leaf area was not significantly different until 30 days after planting for treatments, but those treated with 70% YNST containing 30% DNS increased more rapidly than just YNST. The CGR was similar for all plants in the early growth stage, and faster 60 to 90 days, but the difference was not significant at 90 days after planting. The electrical conductivity (EC) of the DNS was higher than that of the supplied nutrient solution (SNS) during the entire tomato growing period. However, the pH of the DNS was lower than the SNS in the YNST treatment, but showed a rising tendency in the treatment with 30% DNS and DNSC as time went by. The concentrations of NO3-N, K, Ca, and Mg in the DNS were higher than those in SNS. The concentration of PO4-P was lower in the 70% YNST with 30% DNS and 30% DNSC than in the other treatments. The fruit yield after treatment with 70% YNST with 30% DNSC was higher than YNST alone, but statistically significant differences were not observed. The above results indicate that the reuse of DNS is better than an open system for the hydroponic cultivation of tomatoes.

Fusarium wilt on strawberry plants caused by Fusarium oxysporum f. sp. fragariae (Fof) is a major disease in Korea. The prevalence of this disease is increasing, especially in hydroponic cultivation in strawberry field. This study assessed the effect of nutrition solution pH and electrical conductivity (EC) on Fusarium wilt in vitro and in field trials. pH levels of 5.0, 5.5, 6.0, 6.5, 7.0, and 7.5 were assayed in vitro and in field trials. EC levels at 0, 0.5, 0.8, 1.0, and 1.5 dS∙m⁻¹ were assayed in field trials. Mycelial growth of Fof increased with increasing pH and was highest at 25°C pH 7 and lowest at 20°C, pH 5.0 in vitro. The incidence of Fusarium wilt was lowest in the pH 6.5 treatment and highest in the pH 5 treatment in field trials. At higher pH levels, the EC decreased in the drain solution and the potassium content of strawberry leaves increased. In the EC assay, the severity of Fusarium wilt and nitrogen content of leaves increased as the EC increased. These results indicate that Fusarium wilt is related to pH and EC in hydroponic culture of strawberry plants.

Production cost as well as environmental contamination can be reduced by reuse of drained nutrient solution in hydroponic.This research was conducted to obtain the information in changes in inorganic elements concentration of supplied and drained nutrient solution as well as of plant leaves.To achieve the objective, the samples of supplied and drained solution and cherry tomato leaf tissues were periodically collected and analyzed during the hydroponic cultivation.The electrical conductivity (EC) of supplied and drained nutrient solution in early growth stage of cherry tomato were measured as around 2.0 dS•m -1 , but those values move up with the passage of time reaching to 2.0 dS•m -1 at flowering stage of 9th fruiting node.The pHs of drained solution in early growth stage were 6.4 to 6.7, however those showed a tendency to get lowered to 5.9 to 6.1 as time passed during the crop cultivation.The concentration differences of NO 3 -N, P, K, Ca, and Mg between supplied and drained solution were not distinctive until flowering stages of 4th fruiting nodes, while those in drained solution moved up after the stage.The tissue N contents of leaves decrease gradually and those of K and Ca increased as crops grew.However, Tissue P and Mg contents were maintained similarly from transplant to end-crop.The above results would be used in correction of drained nutrient solution when element compositions are varied compared to supplied solution in hydroponic cultivation of tomatoes.

Dieback in strawberry (Seolhyang cultivar) was first observed during the nursery season (June to September) in the Nonsan area of Korea in the years 2012 and 2013. Initial disease symptoms included dieback on runners, as well as black rot on roots, followed by wilting and eventually blackened, necrotic discoloration in the crowns of daughter plants. A fungus isolated from the diseased roots, runners, and crowns is close to Lasiodiplodia theobromae based on morphological characteristics. Analysis of a combined dataset assembled from sequences of the internal transcribed spacer and translation elongation factor 1-alpha genes grouped nine fungal isolates with the type strain of L. theobromae. The isolates showed strong pathogenicity on strawberry cultivars Kumhyang, Seolhyang, and Akihimae, fulfilling Koch's postulates. Based on these results, the pathogen responsible for dieback on strawberry plants in Korea was identified as L. theobromae.

딸기 육묘기에 발생하는 주요 병해충은 íƒ„ì €ë³‘, 흰가루병, 시들음병, ì ë°•ì´ì‘ì• , 진딧물 등이 있다. 친환경과 ì•½ì œ 처리 ë°©ì œë ¥ì€ 병해충이 ë°œìƒí• ë•Œ 처리하는 ë°©ì œí”„ë¡œê·¸ëž¨ê³¼ 비교하여 ì ì€ ìœ ê¸°ë†ì— ìžìž¬ì™€ ì‚´ê· âˆ™ì‚´ì¶©ì œ 사용량으로 ë³‘í•´ì¶©ë°©ì œ 효과를 높일 수 있다. 2012ë „ê³¼ 2013ë „ 딸기 육묘기에 설향 í’ˆì¢ ì„ 대상으로 병해충 ë°©ì œë¥¼ 위한 친환경 ë°©ì œë ¥(EFSC)ê³¼ ì•½ì œ ë°©ì œë ¥(CSC)효과 시험을 실시하였다. EFSC는 육묘기간 동안 무처리 대비 병해충 발생이 감소되었다. íƒ„ì €ë³‘ê³¼ 흰가루병 발생은 EFSC와 CSC처리에서 2012ë „ê³¼ 2013ë „ 시험 동안 비슷한 이병율을 보였다. ì ë°•ì´ì‘ì• ë°œìƒì€ 2013ë „ì— EFSC와 CSC처리간 ë¹„ìŠ·í•˜ì˜€ê³ 6월 중순에 높은 피해율을 보였다. 진딧물 발생은 EFSC에서 6월 초중순에 높은 발생율을 보였다. 이러한 결과로 EFSC처리는 친환경으로 딸기에 발생하는 병해충을 íš¨ê³¼ì ìœ¼ë¡œ ë°©ì œí•˜ëŠ” 데 CSC를 ëŒ€ì²´í• ìˆ˜ 있을 ì •ë„ë¡œ 도움을 줄 수 있을 것이다.

Brassica rapa is an economically important crop with a wide range of morphologies. Developing a set of fixed lines and understanding their diversity has been challenging, but facilitates resource conservation. We investigated the genetic diversity and population structure of 238 fixed lines of leafy B. rapa with 45 new simple sequence repeat markers and 109 new NGS (next-generation sequencing)-generated single nucleotide polymorphism markers evenly distributed throughout the B. rapa genome. Phylogenetic analysis classified the vegetable fixed lines into four subgroups, with the three oil types forming a separate and relatively distant cluster. A model-based population structure analysis identified four subpopulations corresponding to geographical origins and morphological traits, and revealed extensive allelic admixture. In particular, the Chinese cabbage cluster was subdivided into three groups and showed considerable correlation with leaf- and heading-related traits (leaf and heading shape). The vegetable B. rapa fixed lines successfully developed in our study could be valuable materials for establishing a multinational Brassica rapa diversity resource. Understanding the genetic diversity and population structure could be useful for utilization of the representative genetic variation and further genomic analysis.