While potatoes are a representative crop in Bolivia, their cultivation requires a significant amount of chemical pesticides. Some seed treatment chemicals used for seed potatoes in Bolivia can be highly toxic. Additionally, farmers face financial constraints that make it difficult to use these pesticides. In this paper, we investigated the potential of applying plant ash to seed potatoes as an eco-friendly alternative for seed potato disinfection. We also examined the effects of seed tuber cutting in combination with the ash treatment. The potato variety used was “Jatun Puka,” a new variety developed in Peru that has been studied at the Bolivian National Institute of Agricultural and Forestry Innovation (INIAF). The experiment was conducted using a Randomized Complete Block Design (RCBD) with four repetitions in Sipe Sipe and Sapanani o f Cochab amb a, and Mairana of S anta Cruz. The r esults s howed that the e ffects of the ash treatment and tuber cutting were significantly influenced by the local environment of each region in Bolivia. The ash treatment was more effective than the others only in the Sapanani region, where the soil pH was low enough to fall within the optimal range for potatoes after the ash treatment. Generally, cutting seed potatoes had a negative effect on yield across all three regions, with the negative impact increasing in proportion to the humidity or precipitation of each area. However, considering the cost of seed potatoes per unit area, cutting them remains an adoptable option under certain circumstances. We hope this research will serve as an important reference for future studies on eco-friendly potato cultivation in Bolivia.

This study assessed the processing suitability and functional potential of sweet potato paste by comparing quality characteristics across different cultivars and heat treatment methods (steaming and baking). Generally, moisture content was higher after steaming, with the ‘Bodami’ and ‘Pungwonmi’ cultivars retaining more moisture, while ‘Jinyulmi’ and ‘Danjami’ had lower moisture levels. Purple-fleshed cultivars displayed negative a* and b* values, indicating bluish hues, whereas yellow-fleshed cultivars maintained stable b* values after heating. Both °Brix and free sugar levels increased after treatment, with baking significantly elevating maltose levels and enhancing sweetness. Apparent viscosity was higher in ‘Danjami’, ‘Jinyulmi’, and ‘Bodami’, while ‘Hogammi’, ‘Hopungmi’, and ‘Sodammi’ exhibited lower viscosity. Additionally, ‘Bodami’ and ‘Danjami’ demonstrated the highest levels of polyphenols, flavonoids, and antioxidant activities, confirming their potential as valuable functional ingredients. These findings underscore the importance of selecting appropriate cultivars and heat treatments to optimize the physicochemical and functional qualities of sweet potato paste.

A survey was carried out in Paraguay to investigate the prevalence and distribution of sweet potato virus diseases. Two DNA viruses, Sweet potato pakakuy virus (SPPV) and Sweet potato symptomless virus (SPSMV), and three RNA viruses, Sweet potato feathery mottle virus (SPFMV), Sweet potato virus G (SPVG), and Sweet potato virus C (SPVC), were detected. They were cloned and sequenced. Sequences were deposited in GenBank of the National Center for Biotechnology Information. Of 53 samples from which viruses were detected, SPVG was detected in 29, representing 57.6% of virus-detected samples. The second most common virus was SPFMV. It was detected in 23 samples. This is the first report of a sweet potato virus disease outbreak in Paraguay confirmed through viral sequence analysis.

본 연구는 고구마(Ipomoea batatas L.) 재배에서 토양 수분 함량별 고구마 괴근의 형태 및 수량 변화를 분석하기 위해 2023년부터 2024년까지 2년간 경상국립대학교 내동캠퍼스 부속농장에서 수행되었다. 시험 1년차(2023년) 처리구는 건조구(DD, dry)와 과습구(WW, wet), 대조구로 적습구 (N, normal)를 설정하였으며, 시험 2년차(2024년)는 건조구(DD), 반건조구(D, semi-dry), 과습구(WW), 반과습구(W, semi-wet), 대조구로는 적습구(N, Normal)를 설정하였다. 2년간 고구마 전 생육기간 평균 토양 수분함량은 반건조구 23.2%, 건조구 19.9%, 적습구 32.5%, 반과습구 43.3%, 과습구 47.6%로 나타났다. 2년간의 시험 결과, 괴근 길이는 적습구에서 각각 20.9, 21.3 cm로 가장 길었고, 괴근 직경 또한 적습구에서 각각 8.10 cm, 7.50 cm로 가장 길었다. 적습구의 장폭비는 2.58, 3.00으로 방추형으로 나타났고, 괴근 모양은 달걀형이 각각 주당 3.87, 5.06 개로 가장 높았고, 건조구와 과습구는 부정형 괴근의 발생 비율이 적습구 보다 증가하였다. 괴근 수량은 2년간 적습구에서 각각 3.15, 4.86 ton 10a-1로 가장 높았다. 반면, 적습구 대비 건조구에서는 평균 54.4%, 과습구는 평균 47.3% 감소하는 경향을 나타냈다. 본 연구를 통해 토양 수분 함량에 따라 다양한 형태의 괴근이 생산될 수 있으며, 용도에 맞춰 형태 조절이 가능함을 확인하였다. 특히, 토양 수분을 약 30% 내·외로 유지할 경우 괴근 형성과 비대가 촉진되며, 수량 증대와 함께 선호도가 높은 달걀형 고구마 생산이 가능할 것으로 사료된다.

This article aims to compile key information to describe the current production situation of potatoes f or c onsumption and v irus- free s eed potatoes i n Paraguay, and to identify the main challenges for developing a self-sufficient production system. The study describes the climatic conditions of the production of potatoes and the national production and distribution situation, highlighting the dependence on imports for more than 90% of market demand. It analyzed the issues surrounding the production and supply of virus-free seed potatoes, which depend on imports from Argentina, averaging 799.9 tons per year. Additionally, this study collects information on virus detection in local potatoes and the risks associated with introducing viruses through imported seeds. To address these issues, the Korea Partnership for Innovation of Agriculture (KOPIA) and the Paraguayan Institute of Agricultural Technology (IPTA) cooperation project promoted the production of virus-free seed potatoes for their distribution to smallholder farmers across various country regions, strengthening the foundations for future virus-free seed potato production and distribution systems. Improving self-sufficiency in potato production in Paraguay requires an integrated strategy that includes analyzing suitable regions for seed potato production, implementing advanced technologies, and strengthening farmers’ technical capacity. Establishing virus-free seed potato production areas and securing governmental and legal support are crucial steps toward achieving sustainable seed potato production and reducing dependence on imports.

The present study was undertaken to ascertain the temperature development characteristics of Phthorimaea operculella (Lepidoptera: Gelechiidae) across its various developmental stages. To this end, the insect was subjected to six constant temperature conditions (13, 17, 25, 27, 32, 34±1°C), relative humidity (RH) levels of 65±5%, and photoperiods of 16 : 8 h light/dark. The developmental time of larvae was longest at 13°C, and as the temperature increased up to 35°C, the developmental time tended to become shorter. At the pupal stage, all individuals developing at 13°C perished and were excluded from the calculation of the development period for the development model. To ascertain the relationship between temperature and development, a regression model was employed for analysis. The lower threshold temperature of the total immature stage was determined to be 9.4°C, and the thermal constant was found to be 454.5DD. In the analysis of the temperature-development experiment, the Lactin 2 model exhibited an optimal fit (R 2=0.90-0.98) for the total immature stage of P. operculella.

The leaves and stalks of sweet potato have attracted considerable interest as a health food due to numerous studies reporting the presence of functional compounds and various physiological activities. This study analyzed the functional components in the aerial parts of six domestically developed sweet potato cultivars and compared their antioxidant activities. The total polyphenol content, total flavonoid content, and total phenolic acid content ranged from 76.9 to 148.6 mg GAE/g, 3.98 to 11.90 mg CE/g, and 44.19 to 93.56 mg/100 g, respectively. Among the cultivars examined, 'Gogeonmi' and 'Tongchaeru' exhibited high levels of these compounds, and their DPPH and ABTS radical scavenging activities were superior to those of the other cultivars. The GABA content ranged from 0.59 to 2.55 mg/g, with 'Tongchaeru' and 'Jinhongmi' showing the highest levels. Lutein content ranged from 0.10 to 0.24 mg/g, with 'Tongchaeru' reaching its maximum concentration 90 days post-cultivation. Extracts from 'Tongchaeru' significantly inhibited the secretion of interleukin-6 (IL-6) inflammatory cytokines, with the water extract demonstrating a stronger effect than the pretanol extract. These findings suggest that the aerial parts of sweet potato could serve as excellent functional vegetables and bioactive ingredients for health food applications.

This study assessed dried vegetables derived from sweet potato petioles to promote the use of typically discarded aerial parts. The length (18.25 to 35.00 cm) and thickness (4.59 to 6.66 mm) of the petioles varied by variety, with ‘Hophungmi’ and ‘Tongchaeru’ showing promise for dried vegetable processing due to their longer and thicker petioles. In terms of color, ‘Hophungmi’ and ‘Shinmi’ exhibited high lightness, ‘Tongchaeru’ and ‘Hayangmi’ displayed strong redness, and ‘Pungwonmi’ had high yellowness. Rehydration rates and hardness increased over the harvest period, with ‘Pungwonmi’ and ‘Tongchaeru’ demonstrating excellent rehydration capacity. Additionally, ‘Hayangmi,’ ‘Shinmi,’ ‘Tongchaeru,’ and ‘Hophungmi’ maintained lower hardness levels, appealing to consumers who prefer a softer texture. Notably, the substantial polyphenol content (10.70 to 16.20 mg GAE/g) and flavonoid content (4.79 to 8.11 mg CE/g), along with antioxidant activity (DPPH: 1.11 to 2.14 mg, ABTS: 5.51 to 7.78 mg TE/g), indicate their potential as antioxidant-rich functional foods. This research supports the development of dried vegetable products tailored to consumer preferences.

Within the framework of a project entitled “Development of Advanced Sweet Potato Cultivation Technology for Smallholder Farmers in Paraguay” implemented by KOPIA Paraguay Center (Korea Partnership for Innovation of Agriculture) in collaboration with Paraguayan Institute of Agricultural T echnology (I PTA) d uring the period 2021-2024, r esults o f four m ain e xperiments are described in this research: selection of suitable varieties, optimal planting and harvesting times, the use of ridges, and optimal chemical fertilization doses. In the selection of suitable varieties for Paraguay, 11 sweet potato varieties were evaluated in departments of San Pedro and Misiones. As a result, varieties Andaí, Jety Paraguay, and Chaco I showed the highest productivity in San Pedro, while varieties Jety Uruguayo, Chaco I, and Taiwanés showed higher productivity in Misiones. The other three experiments were carried out in San Pedro only. Optimal planting and harvesting times were determined with three varieties: Andaí, Pyta Guasu, and Jety Paraguay. For Andaí and Jety Paraguay varieties, they should be planted in December and harvested at 122 days post planting (DPP). For Pyta Guasu, it should be planted in October and harvested at 124 DPP. Regarding productivity response with soil preparation methods, the use of ridges showed higher yields in all planting methods, with the curved method planting being the most productive. Finally, optimal chemical fertilization doses were established in order to improve the total yield. The optimal nitrogen fertilizer dose (urea 45% N) was 40 kg/ha. The optimal phosphorus fertilizer dose (triple superphosphate 45% P2O5) was 80 kg/ha and the optimal potassium fertilizer dose (potassium chloride 60% K2O) was 120 kg/ha.

Sweet potato (Ipomoea batatas L.) is an essential crop in the Paraguayan diet. It plays a crucial role in food security. It is a source of income for family agriculture. It has a significant potential to adapt to various climatic and soil conditions in Paraguay, making it a promising crop for improving productivity. However, Paraguay faces a deficit in the development of sweet potato cultivation technology, resulting in a low productivity of 5.3 ton/ha. Efforts have been made to collect and characterize sweet potato genotypes, covering a diversity of native varieties. These efforts have laid the groundwork for future sweet potato research and development. Still, ongoing research and development of strategies are needed to address existing challenges of improving genetic resource traits and developing cultivation technology and to fully exploit growth opportunities in this sector. This review summarizes sweet potato cultivation in Paraguay, focusing on several key technical aspects. It analyzes current market situation and production conditions as well as the availability of genetic materials adapted to different ecoregions. Additionally, it explores prospects for the development of advanced sweet potato crops, including the production of high-quality, virus-free sweet potato plants with improved productivity.

지구온난화로 인한 물 부족에 대응하고, 작물 생산의 극대화를 위한 효율적인 방법의 하나로 지중점적 관비 시스템이 주목받고 있다. 하지만, 우리나라에서 식량작물에 적용된 지중점적 관비 효과에 대한 이해 및 이와 관련 시스템 개발은 아직 부족한 실정이다. 본 연구는 지중점적 시스템을 이용한 관수 및 관비처리(SF)가 감자(Solanum tuberosum L.)의 생장 및 수량에 미치는 영향을 알아보기 위하여 수행되었다. 지중점적 처리를 위해, 경상국립대학교 시험포장(600 m2)에서 점적관(Ø 14.1 ㎜, 1.6 L h-1)을 80 ㎝ 간격으로 40 ㎝ 깊이에 매설하였다. 감자의 표준시비량(N-P-K: 100-88-130 ㎏ ha-1) 중의 일정량을 기비로 시용한 후, 잔여 시비량인 N-P-K: 50-40-40 kg ha-1을 절반씩 괴경형성기(4월 29일)와 괴경비대기(5월 17일)에 각각 나누어 관비하였다. 대조구(CF)는 전량 기비로 시용하였다. 지중점적 관비 처리시 토양 20㎝ 깊이의 수분함량은 대조구 9.6%, 지중점적 처리구 55.1%로 지중점적처리구의 수분함량이 45.5% 더 높았기 때문에, 관비처리가 잘 수행되었다고 판단되었다. 관비 후 생육특성 조사에서 지중점적처리구와 대조구 간 차이가 없었지만, 수량특성 조사에서는 지중점적처리구가 괴경 직경이 56.0 ㎜로 가장 굵었고, 괴경수 또한 11.6개로 가장 많게 나타나 대조구와 약 12~18%의 차이를 보였다. 상서용 수량 또한, 지중점적처리구가 3,402 kg 10a-1로 대조구 대비 약 10% 더 많았다. 따라서, 봄 감자 재배시 지중점적시스템을 이용한 관비처리가 수량 향상에 도움을 주는 것으로 판단되나, 토성에 따른 투수성 등의 차이로 인한 여러 문제점이 존재할 수 있어, 국내의 노지재배 작물에 지중점적시스템을 적용하여 다양한 토성에서의 체계적인 연구가 필요할 것으로 생각된다.

The key to invasive pest management lies in preemptive action. However, most current research using species distribution models is conducted after an invasion has occurred. This study modeled the potential distribution of the globally notorious sweet potato pest, the sweet potato weevil (Cylas formicarius), that has not yet invaded Korea using MaxEnt. Using global occurrence data, bioclimatic variables, and topsoil characteristics, MaxEnt showed high explanatory power as both the training and test areas under the curve exceeded 0.9. Among the environmental variables used in this study, minimum temperature in the coldest month (BIO06), precipitation in the driest month (BIO14), mean diurnal range (BIO02), and bulk density (BDOD) were identified as key variables. The predicted global distribution showed high values in most countries where the species is currently present, with a significant potential invasion risk in most South American countries where C. formicarius is not yet present. In Korea, Jeju Island and the southwestern coasts of Jeollanam-do showed very high probabilities. The impact of climate change under shared socioeconomic pathway (SSP) scenarios indicated an expansion along coasts as climate change progresses. By applying the 10th percentile minimum training presence rule, the potential area of occurrence was estimated at 1,439 km2 under current climate conditions and could expand up to 9,485 km2 under the SSP585 scenario. However, the model predicted that an inland invasion would not be serious. The results of this study suggest a need to focus on the risk of invasion in islands and coastal areas.

The fungus Alternaria alternata, responsible for causing brown to black spotting on numerous fruits and vegetables globally, was identified in 2022 as the causative pathogen of brown spot disease in potatoes in Korea. In pursuing potential inhibitors against A. alternata growth, we evaluated 15 mushroom culture filtrates: eight from Trametes spp. and seven from Polyporus spp., known for their antibacterial and anticancer properties. Antifungal activity was assessed by exposing each filtrate to A. alternata on a paper disc. Four filtrates displayed inhibitory action against the fungus, albeit with mild effects. Our findings highlight the potential of Trametes and Polyporus fungi as emerging antifungal candidates, offering promise in preventing potato brown spots.

This study investigated the antioxidant characteristics of sweet potato according to different plant parts and drying methods. The sweet potato plant parts were divided into root tubers, stems, stalks, leaves, and tips, and the drying methods were freeze-drying and hot air drying. Total polyphenol and flavonoid contents and radical scavenging activity of the sweet potato plant parts were significantly different depending on the plant parts and drying methods. The total polyphenol content of freeze-dried sweet potato leaves and tips were 52.76 and 46.19 mg chlorogenic acid equivalents/g sample, and the total flavonoid contents were 222.47 and 214.12 mg quercetin equivalents/g sample, respectively, and decreased with hot air drying. DPPH radical scavenging activity was higher in freeze-drying than hot air drying and was significantly different depending on the plant parts. The ABTS radical scavenging activity of freeze-dried sweet potato leaves and tips were 43.48 and 44.68 mg Trolox equivalents/g sample, respectively, and decreased with hot air drying. Therefore, additional studies on the functionality of using by-products from sweet potato cultivation are needed.