Epidemic networks and potential sources of bacterial wilt infection in a potato seed network in Kenya.

Potato seed systems in Kenya are largely informal, characterized by high seed degeneration due to the buildup of seed- and soil-borne diseases, including bacterial wilt caused by Ralstonia solanacearum. Informal sources of seed include neighbors, local markets and farmer-saved seed, and present a risk for spread and establishment of disease. To understand the larger context of potato disease risk in Kenya, we used network analysis to evaluate (1) epidemic risk through potato trade networks centered around East Africa, and (2) locations in East Africa likely to be particularly important for epidemic management because of their high potato cropland connectivity. We evaluated the interactions of the key stakeholders in a potato seed system and used network analysis to identify locations that are likely to be important for the spread of infection of R. solanacearum in a potato seed distribution network in Meru, Kenya. Household details, seed sources, quantities sold, pest incidence and management practices, knowledge about seed degeneration and farmers' sources of information on potato production were obtained and analyzed. The survey revealed that self-saved, neighbors, seed companies, friends, exchange, and markets are the main seed sources. Only 43% of total seed transacted was certified. Users of uncertified seeds have high disease risk, and this is an especially important risk if their roles in the network give them the potential to be 'superspreaders' of disease.

On the assessment of the sources of inoculum of bacterial wilt in Brazil.

Dispersal of Ralstonia spp. cells by water and contaminated plant material and the importance of weeds as inoculum sources have been poorly investigated. Water of rivers, soil from fields of diverse crops and areas of natural vegetation both from the Amazonia, Cerrado and Mata Atlantica biomes, besides soil of the rhizosphere of weeds present in tomato fields with records of bacterial wilt were sampled and analyzed to detect Ralstonia spp. Seeds of tomato plants artificially and naturally infected with Ralstonia spp. were also processed. All samples were enriched a priori in selective medium South Africa (SMSA) and colonies were isolated in plates containing solid SMSA. Detection of Ralstonia spp. was confirmed by polymerase chain reaction with specific primers. The Co-operational PCR (CO-PCR) was also used to detect Ralstonia spp. Colonies were obtained from soil samples and from a commercial substrate sample. Five soil samples from eggplant fields, one from coffee field, one substrate from potato seed tuber production, two soil samples from the rhizosphere of Amaranthus spp., one from Bidens pilosa and one from Solanum americanum tested positive for Ralstonia spp. Besides these soil samples, five water samples of rivers were positive for CO-PCR detection: two samples from Amazonia, one from Cerrado and two samples from irrigation water collected from tomato fields located in the Mata Atlantica biome. Ralstonia spp. were not detected in tomato seeds. These results revealed potential inoculum sources, especially weeds, in areas with historical records of bacterial wilt. Additionally, rivers may act as dispersal agents of inoculum of Ralstonia spp.

GO potato aeroponic seed production in Indonesia, producers’ perception toward the benefits and challenges

The high-quality potato seed availability in Indonesia always to be attempted continuously by Indonesian governments to encourage national potato production optimization. One of the efforts is through aeroponic potato seed production. The G0 (zero generation seed) aeroponic potato produces a better yield and healthier tuber compare to G0 conventional potato production. IVegRI has undertaken studies related to G0 potato aeroponic. The results have been disseminated and some of them have been adopted by the potato producers in various regions in Indonesia. The study aimed to investigate the potato aeroponic seed production in Indonesia based on the producers’ perception of the benefits and challenges. The study was conducted from April to December 2017, in 8 districts from 6 provinces, engaging 18 G0 aeroponic potato producers. Data were analyzed descriptively. The resulting study showed that G0 aeroponic producers perceived the production of G0 aeroponic potato as more profitable compared to G0 conventional. The advantages covered: the production was higher, the yield tuber was healthier and sterile, and also it could be produced anytime. Meanwhile, challenges faced were: initially investment cost was quite expensive, electricity installation frequently was unstable and, the challenge concocted a suitable potato aeroponic nutrition.

The development of farmers cooperative in the potato agribusiness system in Batur Subdistrict, Banjarnegara

Farmers’ corporations are a form of farmer economic empowerment that unites all farmer resources and manages them in an integrated management. Batur Subdistrict, is one of the potato-producing centers in Banjarnegara District. This paper aims to analyze the potential for developing farmer corporations in the potato agribusiness system in Batur Subdistrict, Banjarnegara. The Farmer Corporation Model developed refers to the Ministry of Agriculture No. 18 of 2018, which is in the form of cooperatives or other legal entities with the majority of capital ownership by farmers. The data comes from the results of the 2020 study. Respondents consist of potato farmers, administrators of the Dieng Farmers Union (SPD), owners of subsidized fertilizer shop, potato seed breeders, agricultural extension workers, potato marketing actors, and managers of Agribusiness Microfinance Institutions (LKMA). Data analysis was carried out qualitatively and quantitatively descriptively by taking into account technical, economic and management aspects. The results of the study indicate that the existing farmer institutions in Batur Subdistrict, both technically, economically, and management have the potential to develop farmer corporations. The corporate model formulated is the growth of primary and secondary cooperatives which include potato seed cooperatives, farming capital cooperatives, potato production facilities cooperatives, and potato marketing cooperatives. The amount of economic value that can be obtained by each potato farmer with the existence of a corporation ranges from Rp. 1.04 - 2.07 million per year. In order for a farmer corporation to run and provide benefits to farmers, support from the government is needed in the form of assistance, business training, and initial capital.

Microtubers production by using Temporary Immersion System (TIS) bioreactor to potato varieties

As the national potatoes growth has become lower from year to year, it is now known that the problems came from the lack of certified potato seed varieties and the minimum access to sophisticated technology to make a good potato variety. The solution that can be made is to utilize microtubers as an efficient factor. The purpose of this research is to find the most effective method in micro tubers cultivation in vitro by comparing the conventional tissue culture method and the Temporary Immersion System (TIS) bioreactor method to four different potato varieties (Granola L., Dayang Sumbi, Atlantic Malang, Maglia). This research uses a split-plot design with a completely randomized design by using two factorial. The result of this study shows that the microtubers in the multiplication and production step using the TIS bioreactor method has a higher average compared to the conventional tissue culture method. As the various details, Dayang Sumbi has the highest parameter such as most sprouts, primer roots, diameter, wet weights, and fastest time growth. Granola L. excel in planlet height and most tubers. Atlantic Malang in the most multiplication and nodus. Meanwhile Maglia excel in most leaves.

Cultivation method for revitalized potato material in the system of original seed production

To arrange a system of virus-free potato seed production in the Sakhalin region, a series of studies undertaken to come up with a method towards potato material cultivation in film-gauze greenhouses. At the initial stage, the key agrotechnical methods were developed for growing test-tube microplants, including optimal planting plans – 70×15 cm (the highest yield derived from a standard mini-tuber fraction pcs/m2), 70×30 cm (for clone selection); spraying with insecticides (Aktellik – 3 l/ha, Rogor – 2 l/ha) and fungicides (Ridomil – 1 kg/ha, Tsineb – 2.4 kg/ha) to combat agents transmitting viral and fungal infections; chlorocholine chloride treatment (1.1%) to reduce the growth of the vegetative mass; serological analysis of plants for latent infection with viruses X, Y, S, M, F; burning tops with Reglon (2 l/ha) 2 weeks before harvesting. A set of agrotechnical methods used for producing healthy seed tubers on the Timiryazevskoye seed farm made it possible to reduce the elite cultivation cycle from 5 to 4 years, increase the yield by 57.2%, and reduce the production cost by 43.5%. Subsequently, the methods worked out for producing potato seeds were improved based on modern breeding varieties and phytoregulators (Azolen, Elena, Extrasol, Epin-Extra, Zircon) in spray mixtures with the fungicide Shirlan, contributing to an increased yield up to 34% and efficiency of a standard seed fraction up to 33%. Under production conditions, this method provided a conditionally net income of 450-700 thousand rubles/ha.

Study of suitability postharvest handling level of potatoes in Kerinci District

Almost 60% of Jambi Province’s potato production comes from Kerinci District. As well as other food crop products, productivity must be balanced with the quality of the produced. Postharvest handling based of Good Handling Practices concept is the key to producing high quality and competitive potatoes and optimizing the results obtained. The data obtained showed that there was a decrease in potato seed yield around 16% during the storage. The loss was contributed by rotten and moisure migration tubers. Very few studies have been conducted to evaluate the appropriateness of postharvest handling of potatoes according to GHP concept in Kerinci District. Therefore, purpose of the study was to determine the level of suitability of postharvest handling of potatoes in Kerinci District. The research method is descriptive exploratory by making hostages systematically, factually and accurately. The data were obtained through observation, interviews and calculating the percentage of postharvest handling suitability based of the GHP concept. The results showed that the level of suitability for postharvest handling of potatoes in Kerinci District was around 69% with the average improvement that had to be done at the cleaning, storehouse handling, sanitation and packing type stages around 31% and digging tube loss reaching 100%. In principle, carrying out potato postharvest activities based of the GHP recommendations is an effort to minimize yield losses. The results of this study are expected to be a solution for improving the quality and competitiveness of potato commodities in Kerinci District, Jambi Province.

Assessing the national seed production system of potato, shallot, and garlic

A good seed production system results in quality seed. Subsequently, quality seed produces high yield, good quality, and uniform crop performance. This paper aims to assess the national vegetable seed system, especially those seeds produced using vegetative propagation, i.e. potato, shallot, and garlic. The study was conducted in 2019 in West Sumatera, West Java, Central Java, and Northern Sulawesi Provinces. Using primary data from the respondents and secondary data from related institutions, both data were analyzed descriptively. Indonesian Vegetable Research Institute (IVEGRI), universities, and seed companies produce various vegetable seeds. Community in groups or personals as well as regional governments may register their varieties to the Center for Crop Variety Protection and Agriculture Permit (PVTPP). Potato seed producers deal with higher production cost and the farmers have to pay more expensive seed since the Ministry of Agriculture (MoA) implemented the policy on shifting extension potato seed from G4 (fourth generation) to G2 (second generation). The farmers cope with quality and volume of garlic seed supply. Shallot seed adopted by the farmers are generally not certified. Farmers usually adopt certified shallot seed if they receive the government seed assistance. TSS (true shallot seed) has been introduced but farmers’ adoption is limited. Garlic seed certification through post-harvest observation in the seed warehouse without field supervision was valid until the end of 2019 leading to low garlic yield. MoA should facilitate farmers with quality seed of improved vegetable varieties to enhance vegetable production as well as to improve farmers’ profit.

Development of new immunoanalytical test systems for diagnostics of potato blackleg caused by Dickeya spp. bacteria

Potato blackleg caused by Dickeya spp. bacteria is one of the most important bacterial diseases of potatoes. The rapid spread of this disease in the territory of Russia requires new effective diagnostic tools for the timely detection of infection. To solve this problem, antisera specific to Dickeya spp. were obtained. Polyclonal antibodies isolated from antisera have shown high affinity for the main species of Dickeya spp. ( D. solani, D. dianthicola, D. chrysanthemi, D. dadantii, D. paradisiaca ). Enzyme linked immunosorbent assay (ELISA) and lateral flow immunoassay (LFIA) test systems have been developed based on specific and high affinity antibodies that were obtained. For ELISA, the detection limit was 0.8 105 cells/mL for D. solani and 2 104 cells/mL for D. dianthicola . For LFIA, suitable for use in non-laboratory conditions, the detection limit of D. solani was 2 105 cells/mL and the analysis time was 15 minutes. When testing potato seed material, LFIA test system confirmed positive results of ELISA determination in 75 % of samples, and negative - in 100 % of samples.