Potato Production Areas Research Articles

Effects of Organic Fertilizer Replacing Some Nitrogen Fertilizers on the Structure and Diversity of Inter-Root Soil Fungal Communities in Potato

The aim of this study was to investigate the effects of organic fertilizer replacing part of the nitrogen fertilizers on the structure and diversity of the inter-root soil fungal communities of potatoes. By carrying out a field trial in Gaoquan Village, Tuanjie Town, Dingxi City, Gansu Province, the main potato-producing area in China, the optimal proportion of organic fertilizer to replace nitrogen fertilizer was determined to provide a scientific basis for the rational use of organic fertilizer to improve the structure and function of soil fungal communities. The experiment was laid out with six treatments: CK (no nitrogen fertilizer, phosphate and potash fertilizer applied), CF (nitrogen fertilizer alone, control), T1 (25% replacement of nitrogen fertilizer), T2 (50% replacement of nitrogen fertilizer), T3 (75% replacement of nitrogen fertilizer), and T4 (100% replacement of nitrogen fertilizer). A systematic study of the inter-root soil fungal community structure, diversity, and soil physicochemical properties during potato harvesting was conducted using high-throughput sequencing technology. The results show that the organic fertilizer replacing part of the nitrogen fertilizer significantly increased the content of alkaline dissolved nitrogen, quick-acting potassium, quick-acting phosphorus, and organic matter in the inter-root soil of the potatoes, and significantly reduced the pH value of the soil. There was a trend of decreasing soil fungal abundance and a significant decrease in the Alpha diversity of the soil fungi. The treatment groups in the soil had as their core fungi Acomycota, Mortierellomycota, Basidiomycota, and others. The organic fertilizers replacing the nitrogen fertilizers significantly altered the structural composition of the inter-root soil fungal community of the potatoes, and increased the differential fungi in the soil. The number of functionally diverse and complex fungi in the soil gradually increased, and the function of the fungal community gradually changed from Singularity to diversification and complexity. A redundancy analysis showed that the soil pH was the main environmental factor affecting the inter-root soil fungal communities of potatoes under organic fertilizer replacing N fertilizer.

Comparative Study of Income of Sweet Potato Farmers' in Different Trade Channels in Bandorasa Wetan Village, Cilimus District, Kuningan Regency

This study aims to analyze the income of sweet potato farmers in Bandorasa Wetan Village, Kuningan Regency, by comparing different trading channels, specifically sales to middlemen and direct sales to the processing industry. Sweet potato farming plays a crucial role in supporting local and national economies, with Kuningan being a major sweet potato production area in West Java. Using a quantitative comparative approach with survey techniques, data was collected from 83 farmers, with 49 selling to middlemen and 34 to the industry. The results show that the average income of farmers selling to the industry (IDR 3,468,222) is significantly higher than those selling to middlemen (IDR 2,812,569), as evidenced by the independent sample test (p = 0.000). However, income from industry sales shows greater variability. This research contributes by highlighting the income disparities across trading channels, offering valuable insights for farmers and stakeholders in optimizing trading practices to maximize profitability. Future research should explore factors influencing channel selection, including market conditions and trading strategies, to enhance the overall sustainability and profitability of sweet potato farming.

Non-invasive, pre-symptomatic detection of potato cyst nematode infection in tomato using chlorophyll fluorescence analysis.

Potato cyst nematodes (PCN) are notorious pathogens in all major potato production areas worldwide. Mainly due to the low mobility of this soil pathogen, PCN infestations are mostly observed as patches ('foci') that only cover a fraction of the acreage. In-field pre-symptomatic localization of this pathogen is valuable as it would allow for the localized application of control measures. Although the mapping of foci is technically feasible, it is unpractical as it would take the analysis of numerous soil samples. We investigated whether chlorophyll fluorescence (Chl-F) could be suitable as a rapid, non-destructive method for early PCN detection. To this end, the impact of four Globodera pallida densities on the Chl-F of tomato was investigated in a phenotyping greenhouse for 26 days. Furthermore, classical plant performance indicators biomass and root surface area were compared with Chl-F. Thermal dissipation ('NPQ_Lss') and actual photosynthetic rate ('QY_Lss') responded at 1 DPI, while QY_Lss was most sensitive to low PCN infection levels. Chl-F parameters responded more readily to PCN infection than biomass and root surface area. The efficiency of photosystem II (QY_max) and the potential activity of photosystem II (Fv/Fo) initially increased at low PCN infection levels, whereas a sharp decrease was observed at higher infestation levels. Hence, our data suggest that low PCN levels promoted plant performance before becoming detrimental at higher levels. While Chl-F allowed for early and sensitive PCN detection, it remains to be investigated whether these signals can be distinguished from those produced by other below-ground stressors in the field.

Collaborative Network, Technological Progress and Potato Production in China

AbstractThe development of science and technology is one of the vital driving forces for the Chinese agricultural development. Based on 2,513 valid potato invention patents from 1986 to 2019 in China, a social network analysis is applied to investigate the effects of the network changes in potato patents on the innovation activities and potato production. The results show that China has formed a status quo of separation between potato-producing areas and patent-invention places. The collaborative relationships of potato patents are mainly distributed in non-main production areas. Most of the collaborations are intra-provincial rather than inter-provincial. The correlation relationship between potato innovation and potato yield is positive. But the density and cluster coefficients of collaborative networks in potato research affect the potato innovations differently. Considering the variation in collaborative networks and different technology progress in potato production across regions, a cross-regional exchange platform is needed to promote the dissemination and extension of potato patents in the main potato-producing areas.

First Report of Dickeya dadantii Causing Potato Blackleg in Fujian Province China.

Blackleg and soft rot are harmful diseases in potato (Solanum tuberosum) caused by Pectobacterium spp. and Dickeya spp. (Czajkowski et al. 2015). The occurrence of potato blackleg was serious in potato-producing areas around Xiapu County in Fujian Province, China, in 2021 (6 ha) and 2022 (7 ha), with an incidence of approximately 5%, which reached nearly 23%. Three diseased plants were collected to isolate the pathogen. Single colonies from each sampled plant were isolated and streaked onto fresh plates. DNA from three colonies from different plants was PCR amplified with primer pair 27F/1492R (Lane 1991) for the 16S rRNA gene. Since the sequences were identical, we selected strain M2-3 for further analysis. The strain M2-3 was gram-negative, pectolytic on CVP, grew at 37°C and 5% NaCl. The bacterium was positive for phosphatase activity, erythromycin sensitivity, indole production, gelatin liquefaction, malonic utilization, and acid production from, melibiose, raffinose, and arabinose. The bacterium was negative for sucrose, α-methyl glucoside, sorbitol, trehalose, lactose, and sodium citrate (Fujimoto et al. 2018;),although sucrose and lactose did not provide the expected results, there are exception in all species. The genome of strain M2-3 was sequenced and deposited in the NCBI database under accession numbers: CP077422. An Average Nucleotide Identity (ANI) analysis showed that M2-3 clustered with other D. dadantii strains and has a 98.39% identity with D. dadantii strain DSM 18020 (CP023467). The housekeeping genes (recA, dnaX, acnA, gapA, icd, mdh, mtlD and pgi) were amplified with primer pairs designed previously(Fujimoto et al. 2018; Ma et al. 2007) and sequenced. A multilocus sequence analysis (MLSA) was performed by concatenating the 8 gene sequences and constructing a maximum likelihood phylogenetic tree using PhyloSuite version 1.2.1 (Zhang et al. 2020) and IQ-tree version 1.6.8 (Nguyen et al. 2015) software. Strain M2-3 was clustered together with Dickeya dadantii. For the pathogenicity test, three plants per treatment, totaling nine plants, were used. Bacterial suspensions (1×10^8 CFU/mL) were made in a 10mM PBS buffer. 10 μL of M2-3, D. dadantii type strain 18020 (positive control), and buffer (negative control) were injected into the plant stems near the base. Water stains appeared at the site of inoculation after 2 days and they gradually became black and rotten. The leaves became yellow and wilted, and the petiole base rotted within 5 days of inoculation completing the Koch postulate. According to average nucleotide identity and housekeeping gene sequence analysis, strain M2-3 was identified as Dickeya dadantii. Previous studies have reported several pathogens that cause potato blackleg in China, including P. atrosepticum, P. carotovorum, P. brasiliense, P. parmentieri, P. polaris, and P. punjabense (Li-ping et al. 2020; Wang et al. 2021). To the best of our knowledge, this study is the first to report potato blackleg disease caused by Dickeya dadantii in Fujian Province, China. This finding suggests that this pathogen may cause a threat to potato production in Fujian Province.

Opportunity of the NEGFRY Decision Support System for the Sustainable Control of Potato Late Blight in A Limia (NW of Spain)

The NEGFRY system is presented in this research work as a novelty strategy for the control of potato late blight in A Limia (NW Spain). The aim was to analyse the number of fungicide applications established by NEGFRY (Decision Support System, DSS) with respect to the routine calendars of this potato production area. This approach is in accordance with the requirements imposed by European policies, participating in more profitable and environmentally friendly agriculture. For this purpose, the relationships between the pathogen and the environmental conditions and epidemiological parameters were analysed in different plots compared to late blight infection in both Routine and DSS strategies. In addition, economic and environmental impacts of fungicide sprays were also analysed to check the adaptability of the decision support system to late blight in the area. Results confirmed that it is possible to reduce sprays following the NEGFRY model by more than 50% compared with Routine applications. Therefore, NEGFRY is a promising strategy to achieve lower footprint potato yields through a reduction in applied pesticides and water, lower gas emissions and less soil compaction due to a reduction in the number of tractor passes over the soil. The commitment to this strategy contributes to improving the economy of farmers, the health of the biodiversity, the environment and consumers, as well as to comply with demands of global economies in terms of more sustainable and resilient agriculture.

Inhibition of Potato Fusarium Wilt by Bacillus subtilis ZWZ-19 and Trichoderma asperellum PT-29: A Comparative Analysis of Non-Targeted Metabolomics.

Potato Fusarium Wilt is a soil-borne fungal disease that can seriously harm potatoes throughout their growth period and occurs at different degrees in major potato-producing areas in China. To reduce the use of chemical agents and improve the effect of biocontrol agents, the inhibitory effects of the fermentation broth of Bacillus subtilis ZWZ-19 (B) and Trichoderma asperellum PT-29 (T) on Fusarium oxysporum were compared under single-culture and co-culture conditions. Furthermore, metabolomic analysis of the fermentation broths was conducted. The results showed that the inhibitory effect of the co-culture fermentation broth with an inoculation ratio of 1:1 (B1T1) was better than that of the separately cultured fermentation broths and had the best control effect in a potted experiment. Using LC-MS analysis, 134 metabolites were determined and classified into different types of amino acids. Furthermore, 10 metabolic pathways had the most significant variations, and 12 were related to amino acid metabolism in the KEGG analysis. A correlation analysis of the 79 differential metabolites generated through the comprehensive comparison between B, T, and B1T1 was conducted, and the results showed that highly abundant amino acids in B1T1 were correlated with amino acids in B, but not in T.

Multi-omics approaches to understand pathogenicity during potato early blight disease caused by Alternaria solani.

Potato early blight (PEB), a foliar disease of potato during the growing period, caused by Alternaria sp., is common in major potato-producing areas worldwide. Effective agents to control this disease or completely resistant potato varieties are absent. Large-scale use of fungicides is limited due to possibility of increase in pathogen resistance and the requirements of ecological agriculture. In this study, we focused on the composition and infection characteristics of early blight pathogens in Yunnan Province and screened candidate pathogenesis-related pathways and genes. We isolated 85 strains of Alternaria sp. fungi from typical early blight spots in three potato-growing regions in Yunnan Province from 2018 to 2022, and identified 35 strains of Alternaria solani and 50 strains of Alternaria alternata by morphological characterization and ITS sequence comparison, which were identified as the main and conditional pathogens causing early blight in potato, respectively. Scanning electron microscope analysis confirmed only A. solani producing appressorium at 4 h after inoculation successfully infected the leaf cells. Via genome assembly and annotation, combine transcriptome and proteomic analysis, the following pathogenicity-related unit, transcription factors and metabolic pathway were identified: (1) cell wall-degrading enzymes, such as pectinase, keratinase, and cellulase; (2) genes and pathways related to conidia germination and pathogenicity, such as ubiquitination and peroxisomes; and (3) transcription factors, such as Zn-clus, C2H2, bZIP, and bHLH. These elements were responsible for PEB epidemic in Yunnan.

Impact of Urbanization on the Sustainable Production of Regional Specialty Food: Evidence from China’s Potato Production

The rapid urbanization process has gradually deepened its role in the sustainable development of agriculture, especially in the sustainable supply of food in poor areas, and has attracted more attention from international academic circles. However, the impact mechanism of different dimensions of urbanization on food sustainability in poor areas has not yet been fully unpacked. Therefore, this study focuses on potatoes as a specialty food mainly grown in poor areas of China, explores the impact mechanism of urbanization on the carbon emission intensity of potato production (CEIPP) with the spatial Durbin model, and compares with the carbon emission intensity of staple grain (CEISG) results. The main conclusions are as follows: the urbanization of main potato-producing areas developed rapidly from 2002 to 2020, which is in line with the decrease in CEIPP. The decrease in CEIPP has a significant impact on slowing down the growth of total carbon emissions and has greater potential for reduction, especially in Central and Western China, which has a large poverty-stricken population. Compared with traditional staple grain, urbanization has become a key factor influencing CEIPP. The results indicate that different dimensions of urbanization have varying degrees of impact on the sustainable production of regional specialty foods in China. The improvement of comprehensive urbanization, population urbanization, and economic urbanization reduces CEIPP, while land urbanization increases CEIPP. Therefore, to reduce CEIPP and promote its sustainable development, it is necessary to improve population urbanization and economic urbanization, properly avoid the disorderly expansion of land urbanization, and improve the quality and level of comprehensive urbanization.

A Genome Resource for 192 Verticillium dahliae Isolates Infecting Potatoes Across Canada

Verticillium dahliae is an important soilborne pathogen causing Verticillium wilt. It is also the primary causal agent of potato early dying, a disease complex involving the root-lesion nematode. Here, we report the whole-genome sequencing of 192 isolates of V. dahliae originating from the major potato production areas across Canada. Our results yielded a resource of 277,010 genetic variations that will be useful for genetic analyses and revealed the presence of two major lineages, both present in all provinces but exhibiting differences in regional prevalence. [Formula: see text] Copyright © 2023 His Majesty the King in Right of Canada, as represented by the Minister of Agriculture and Agri-Food Canada. This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Examining the Division of Housework among Potato Farmers in Serang Village Karangreja District Purbalingga Regency

Karangreja Sub-District is a potato-producing area. One of the producing areas is in Serang Village. Potato production in the sub-district has fluctuated due to several factors, namely fertilizers, pesticides, land area, and labour. Fertilizers and pesticides do not affect potato production. Potato farmers in Serang Village collaborate with the company so that the amount and type of fertilizers and pesticides used are the same. The land area also does not affect potato production because the land used is always the same. Labour is a factor that needs to be investigated further. This study examines the distribution of housework among potato farmers in Serang Village, Karangreja Sub-District, Purbalingga Regency. The research focuses on three aspects: 1) the distribution of productive housework, 2) the distribution of reproductive housework, and 3) the distribution of social housework. A qualitative descriptive approach is used, and the sample consists of 35 potato farmers selected through simple random sampling. Data is collected through questionnaires, observations, and document analysis. The Moser approach and work time outlay are used for data analysis. The findings reveal that productive housework, such as land preparation, planting, and harvesting, is predominantly carried out by husbands. Reproductive housework, including cooking, cleaning, and childcare, is mainly performed by wives. Social housework varies between husbands and wives, such as participation in recitation activities and farmer group meetings. The study contributes to understanding potato farmers' division of labour and housework.

Response of potato (Solanum tuberosum L.) varieties to blended NPSB fertilizer rates on tuber yield and quality parameters in Gummer district, Southern Ethiopia

Potato is an important food security and cash crop in Southern Ethiopia, including Gurage Zone. However, the productivity of the crop in the zone is far below its potential due to an array of factors. For instance, inappropriate selection of varieties and lacking information regarding the actual rate of the newly recommended blended NPSB fertilizer in the potato-producing areas, including Gummer district. Cognizant of this, the present experiment was initiated and conducted in Gummer district under supplementary irrigation, during the 2021 Belg season, with the objective of assessing the response of different potato varieties to blended NPSB fertilizer rates. The experiment was laid out in randomized complete block design (RCBD) with the factorial arrangement and having three replications. There were 12 treatment combinations, comprising three potato varieties (namely; Belete, Gudanie and a local check, Askot) and four blended NPSB fertilizer rates (0, 119, 238 and 357 kg NPSB ha-1). The analysis of variance showed that the two main factors (blended NPSB fertilizer rates and potato varieties) had a statistically significant effect on all tested parameters except the effect of the blended NPSB fertilizer rates on days to 50% emergence. The interaction of the two factors had also showed a statistically significant effect on days to 90% maturity, plant height, main stem number per plant, total tuber number/hill, tuber yield per hill, large-sized tuber yield, marketable and total tuber yields (t ha-1) and tuber dry matter content. Days to 90% maturity were delayed with increased rates of blended NPSB fertilizer for all tested varieties. The highest mean plant height (69.54 cm) and number of main stems per hill (8.38) were obtained at 357 kg ha-1 NPSB with Belete variety. The highest marketable tuber yield (34.40 t ha-1), total tuber yield (35.84 t ha-1) and tuber dry matter content of (26.75%) were obtained from belete variety with the application of 238 kg ha-1 NPSB fertilizer. The results of the economic analysis indicated that the maximum net benefit (180660.7 Birr ha-1) with a 3405.23% marginal rate of return was obtained from Belete variety with the application of 238 kg NPSB ha-1. Hence, the application of 238 kg ha-1 with belete variety can be recommended for optimum potato production with acceptable economic benefit in the study area and similar agroecology. However, since the result is only of one season and location, further research is recommended to be carried out across more seasons and locations

How to Break the Bottleneck of Potato Production Sustainable Growth—A Survey from Potato Main Producing Areas in China

China is the world’s largest potato producer, and the potato’s role in ensuring food security and rural development is irreplaceable. Therefore, how to achieve sustainable growth in potato production has attracted widespread attention from academia. However, few existing studies have analyzed how to achieve sustainable growth in main potato-producing areas based on farmers’ micro perspectives in terms of both technical efficiency and output elasticity of input factor. This paper investigates the output elasticities of input factors, technical efficiency, and its influencing factors among 398 potato farmers from China’s main potato-producing regions in 2021 to fill this knowledge gap. The stochastic frontier production is applied to calculate the technical efficiency and elasticities of input factors in main potato-producing areas. The Tobit model is utilized to analyze influencing factors of technical efficiency. Our findings indicate that the technical efficiency of the main potato production regions is 0.67, with an efficiency loss of 0.33. And, the output elasticity of land input and labor input is negative, and the output elasticity of capital input is positive. Moreover, the factors that affect the technical efficiency in main potato-producing areas include age, whether to be a village leader, income from other crops, labor input, potato price, and disaster impact. Our findings suggest that the agricultural authorities should strengthen the cultivation of potato producers, control the scale of potato production, and optimize the allocation of input factors.

Profitability analysis of potato growing in Ödemiş district of Izmir province

The aim of this study is to perform an economic analysis of potato growing in Ödemiş district of Izmir province. For this aim, data were collected from 90 farmers by proportional sampling and face-to-face survey methods. Potato production in 2019 was included in the study. In the study, yield, production cost, gross production value, gross and net profit calculations were performed in order to reveal the profitability level of potatoes for entrepreneurs and farmers. According to the results of the study, the average potato production area is 41.88 decares, the average potato yield is 3875.79 kg/da and the potato price received by the farmers is 1.43 TL/kg. It was determined that the farmers used 392.74 kg of seeds, 39.72 kg of nitrogen and 746.89 g of pesticides per decare. The production cost per decare for potatoes is 3274.44 TL and 85.69% of it is variable costs. The gross and net profit from potato production was calculated as 2736.55 TL/da and 2267.94 TL/da, respectively. The results of this study show that potatoes can be grown economically in the district. But, the biggest expectation of the potato farmers included in the research is sustainable and planned production. At this point; there is a need to establish cooperation and coordination among farmers, processors, industrialists, universities and exporters.

Identifying the Influencing Factors of Plastic Film Mulching on Improving the Yield and Water Use Efficiency of Potato in the Northwest China

Potato is an important crop in the Northwest China, however, its production is constrained by water scarcity. Plastic mulching film is an efficient technical measure to alleviate potato production restrictions. Therefore, studying the response of potato yield and water use efficiency to plastic mulching film is of great significance. The study conducted a meta-analysis to quantify the effect of plastic film on potato yield and water use efficiency in the Northwest. The study then quantified the effects of different levels of natural conditions (mean annual precipitation, mean annual accumulated temperature ≥ 10 °C), fertilizer application (nitrogen fertilizer, phosphate fertilizer, potassium fertilizer), cultivation measures (planting density, cultivation method, mulching method), and mulching properties (mulching color, mulching thickness) through subgroups analysis. Finally, the random forest model was used to quantify the importance of factors. Plastic film mulching increased yield by 27.17% and water use efficiency by 27.16%, which had a better performance under relatively lower mean annual precipitation, low mean annual accumulated temperature ≥ 10 °C, relatively lower fertilizer application, planting density of 15,000–45,000 plants·ha−1, ridge, and black mulching. Natural conditions, fertilization measures were vital to improve productivity. The research results can provide reference for agricultural management strategies of potato cultivation using plastic film in the Northwest China and other potato-producing areas.

A large-scale assessment on spatial variability of potato yield and soil chemical properties in northern China

Understanding the spatial variability of potato yield and soil chemical properties is critical for designing management strategies and ensuring potato sustainable production. However, there has been no detailed investigation on a large-scale variation in yields and soil nutrients in potato production areas of China. In this study, 938 soil samples and potato production information were collected from the main potato-producing areas in northern China. The results showed that potato yields and selected soil properties varied considerably, with coefficients of variation ranging between 12.2% and 110.8%. Potato yield, pH, soil organic matter (SOM), total nitrogen (TN), available potassium (AK), and electrical conductivity (EC) showed strong spatial correlations, while mineral nitrogen (MN) and available phosphorus (AP) had moderate spatial correlations based on semi-variograms analysis. The spatial distribution of yields indicated that 83.3% of potato yields ranged from 20 to 60 t ha−1. The SOM, TN, AP, and AK showed similar spatial distribution trends with high concentrations in the northeast, while pH showed the opposite trend. EC was found to be highly variable with high values in the west. The high soil pH and low SOM were the most important constraints limiting potato productivity, and the high MN implied excessive nitrogen fertilizer application. The soil quality index (SQI) was calculated using selected soil properties, and a significant correlation between SQI and potato yield was observed. The spatial distribution of SQI showed that 42.2% of the study area was of low soil quality (SQI less than 0.6). A relatively low SQI indicated that there was great potential for increasing potato productivity in northern China. After dividing soil samples into rainfed and irrigated, the effect of soil nutrients on potato yield was found to become weaker at irrigated sites, where there was no correlation between SQI and yield, suggesting that the role of soil moisture overshadowed the role of nutrients. The spatial variability of soil chemical properties provided essential information for developing rational nutrient management strategies and regional planning to achieve sustainable potato production in China.

First report of potato (Solanum tuberosum L.) blackleg disease caused by Dickeya solani in Mayabeque, Cuba.

Blackleg, caused by Pectobacterium spp. and Dickeya spp., is an important disease of potatoes. During the period from November 20 and March 2021, stems of potato plants showing necrosis and rot symptoms, and chlorotic leaves, were collected from commercial production areas of the Mayabeque province of Cuba (Fig. 1A). After disinfestation of affected stems, small fragments of the stem were cut and macerated in a sterile 0.85% NaCl solution. Serial dilutions of bacterial suspension were prepared and streaked onto nutrient agar in Petri plates. Two colonies per sample showing the characteristic of "fried egg" were selected for further investigation, and an isolated was selected and named D7. The isolated bacterium was rod shaped, gram-negative, motile, oxidase and indole production negative, with anaerobic growth, and able to use lactose as carbon source in Mac Conkey Agar medium. One colony of the isolate D7 was selected and multiplied. Total DNA of the bacteria cells was extracted and used to amplify the genes pelADE (Nassar et al., 1996) and gapA (Cigna et al., 2017), to differentiate Dickeya from Pectobacterium. The sequence obtained showed 99.75% and 99.88% nucleotide identity with Dickeya solani for pelADE (Genbank accession number ON644347) and gapA (Genbank accession number ON644346), respectively. To confirm the pathogenicity of the isolate D7, four 15-day-old potato plants, including two plants of each 'Otolia' and 'Naima' potatoes were inoculated with a bacterial suspension of the isolate D7 (108 CFU/ml) in sterile water by stabbing. Control plants were stabbed with sterile water. Inoculated plants were maintained at 28°C, relative humidity of about 90%, and at 12 h light/12 h dark, as described by (Chen et al. 2014). After 3 to 5 days, typical blackleg disease symptoms (water-soaked lesions and necrosis) developed at the inoculated areas of plants (Fig. 1B). No symptom was observed in the control plants. Bacterium was re-isolated from symptomatic plants and the isolates had the same cultural, physiological, and biochemical characteristics to the isolate D7. To our knowledge, this is the first report of D. solani causing blackleg in potato fields in Cuba. Further studies to determine the spread of this pathogen in potato producing areas in Cuba is underway.

Entrepreneurial competencies and farm management performance of potato farmers in Solok Regency

Solok Regency has excellent potential in growing vegetables and fruit, which significantly contribute to West Sumatra’s economy. Solok Regency is the largest potato-producing area in West Sumatra. However, since 2015 there has been a drastic decline in potato production. The negative growth of potato production was affected by several factors, including sub-optimal farming management. Farmers’ lack of passion and entrepreneurial ability is one of the socioeconomic factors that hinder the development of their potential in managing productive businesses in rural areas. This paper analyses the entrepreneurial competency of potato farmers in Solok Regency and examines the effect of entrepreneurial competency on the farm management performance of potato farmers in Solok Regency. This study finds that the level of entrepreneurial competency of potato farmers is at a moderate level. Moreover, PLS path analysis found that the variables of individual characteristics of farmers, entrepreneurial characteristics, and business environment are a reference in measuring the entrepreneurial competency of Potato Farmers. Furthermore, entrepreneurial competency, individual characteristics of farmers, entrepreneurial characteristics, and business environment positively and significantly affect the farm management performance of Potato Farmers in Solok Regency. Farmer entrepreneurs do not work alone. However, they operate in a complex and dynamic environment. Despite the level of farmers’ competency ranging from moderate to high, it needs support from other parties to give farmers access to superior seeds and better prices for inputs and output.

PERFORMANCE OF EXPERIMENTAL ORANGE-FLESHED SWEET POTATO GENOTYPES IN THE WESTERN REGION OF SÃO PAULO

The orange-fleshed sweet potato has interesting nutritional characteristics, as it has a high concentration of β-carotene, which is a precursor of vitamin A. Vitamin A deficiency is a public health problem and can be avoided by adequate intake of β-carotene-rich foods, like the orange-fleshed sweet potato (OFSP). However, few OFSP genotypes are available to growers. The objective of this study was to evaluate the agronomic performance of OFSP experimental genotypes under the edaphoclimatic conditions of Western São Paulo. The experiment was carried out in the municipality of Álvares Machado-SP in a sweet potato production area on a commercial scale. Planting was carried out in October 2021 using a randomized block design with four replications. Five experimental genotypes of OFSP were evaluated, namely: F-09, F-34, U2-05, U2-19 and C-14. The cultivar Beauregard was adopted as control. At 139 days after planting, the tuberous roots were harvested and the following were assessed: total tuberous root production in Kg ha-1; number of commercial tuberous roots in roots ha-1, production of commercial tuberous roots in Kg ha-1; average mass of commercial tuberous roots in g; dry mass percentage of commercial tuberous roots; length of roots in cm, diameter of roots in cm and soluble solids, in °Brix, appearance of roots using a scale of grades, and resistance to damage caused by insect pests. The commercial yield of the evaluated genotypes ranged from 38,27 t ha-1 (Beauregard) to 89,25 t ha-1 (F-34). The experimental genotypes present tuberous root quality similar to the commercial control 'Beauregard'. Genotypes F-34 and C-14 have flesh color similar to 'Beauregard', and genotype F-09 has dark orange flesh, a class above the control. All evaluated genotypes can potentially contribute to the increase in yield in Western São Paulo.

Identification and characterization of opportunistic pathogen Pectobacterium polonicum causing potato blackleg in China.

Blackleg and aerial stem rot of potato (Solanum tuberosum L.), caused by soft rot enterobacteria of the genera Pectobacterium and Dickeya, has recently increased years in Hebei Province, China. Field surveys were performed during the 2021 potato growing season in Hebei to identify and characterize bacterial pathogens. Sixteen potato plants showing blackleg or aerial stem rot were collected from three potato-producing areas, and ten representative pectinolytic bacteria were isolated from symptomatic plants. 16S rDNA sequencing and multilocus sequence analysis were performed to determine the taxonomic position of the bacterial isolates. The isolates belonged to the genus Pectobacterium, including Pectobacterium atrosepticum, Pectobacterium carotovorum, Pectobacterium brasiliense, and Pectobacterium parmentieri. The exceptions were isolates BY21311 and BY21312, which belonged to a new species of Pectobacterium polonicum previously found in groundwater. The taxonomy of isolate BY21311 was confirmed using whole genome-based analysis. P. polonicum has only been identified in potato plants on one farm in Baoding region in China. Isolates BY21311 and BY21312 displayed similar physiological and biochemical traits to the type strain DPMP315T. Artificial inoculation assays revealed that isolate BY21311 fulfilled Koch's postulates for potato blackleg. These findings represent the first time P. polonicum, a water-associated Pectobacterium species may be the cause of blackleg in the field. Interestingly, P. polonicum BY21311 has reduced ability to macerate potato tubers when compared to P. atrosepticum, P. brasiliense, P. versatile, and P. parvum, which is more virulent in tubers than the type strain DPMP315T. The host range of isolate BY21311 was determined by injection method, which can impregnate five plants. Although the genome of isolate BY21311 harbors gene clusters encoding a type III secretion system, it did not elicit a hypersensitive response (HR) in Nicotiana benthamiana or N. tabacum leaves. T3SS effector AvrE and T4SS effector PilN were obtained by predicting isolate BY21311 genome. P. polonicum appears to show significant variations in gene content between two genomes, and gene content varies between isolates BY21311 and DPMP315T, with strain specific-genes involved in many aspects, including lipopolysaccharide biosynthesis, substrate translocation, T4SS and T6SS among others, suggesting that isolates BY21311 and DPMP315T might represent distinct clades within the species.