ABSTRACT: The average yield of sweet potato (Ipomoea batatas (L.) Lam.) in Brazil is below the crop potential, and appropriate cultural practices and more productive cultivars are needed to improve crop yield. The Beauregard sweet potato cultivar, originally from the United States, has shown high productive potential. This study evaluated the performance of features of agronomic importance of the Beauregard cultivar in comparison to local cultivars and eight sweet-potato clones in Brazilian regions. For that purpose, two sets of experiments were carried out. The first set evaluated eight sweet potato clones and cultivars Beauregard, Olho Roxo and Ourinhos in Brasília–DF and Itabaiana–SE using as criteria two foliage and six root traits. In the second set, two sweet potato clones (9 and 75), and Beauregard, Brazlândia Branca and Canadense cultivars were evaluated in Piacatú–SP, Brasília–DF, PAD–DF, Canoinhas–SC and Altamira–PA, for the traits: commercial, non-commercial, and total yield. Beauregard presented little foliage production but great root yield across the different environments. Since it has low dry matter content, acceptance of this cultivar may be limited in some regions. None of the sweet potato clones showed stable yield to justify a commercial launch.

Potatoes (Solanum tuberosum L.) are the fourth largest crop in the world after rice and corn. In Azerbaijan, the yield of potatoes per unit area is very low compared to other countries of the world. There are many factors that reduce crop productivity, among which diseases such as late blight of potato (Phytophthora infestans) play an important role. Therefore, the fight against this disease is very important. Late blight of potato can be controlled by the following control strategies: use of biological control agents, use of resistant varieties, crossbreeding, use of certified disease-free seeds, use of selective fungicides and agronomic practices such as destruction of cull heaps by freezing or deep burial, destruction sprouting voluntary potato plants in nearby fields during the season, killing infested plants to avoid spreading, shortening periods of leaf wetness and high canopy moisture through proper irrigation times, applying the recommended fungicide spraying program (program must be started before pathogen is detected).

We conducted a baseline survey to appraise the current potato practices and farming systems in the Adamawa and West regions of Cameroon where a GIZ-funded project (ONE WORLD – No Hunger, or SEWOH) titled "Green Innovation Centers for the Agricultural and Food Sector" (ProCISA) is being implemented. We employed a mix of qualitative and quantitative methods to gather and analyze data/information. This study focused on potato farmers that have been into potato production for at least two years. We developed a structured questionnaire which was administered to small- and medium-sized potato growers based on a literature review and consultation with key stakeholders. The questionnaire was pretested through ten in-depth interviews with selected farmers in the Adamawa and West regions. Local enumerators were recruited in each region and trained to administer the questionnaire in the field. In total, 341 questionnaires were completed (141 in Adamawa and 200 in the West region) in 133 villages (35 in Adamawa and 98 in the West region) using a modified systematic random sampling technique to ensure even representation. The collected data was then coded and analyzed. Farmers in both regions cultivate an area typically not more than 1 hectare (ha), but in Adamawa, farmers grow only one round of potatoes, while in the West they cultivate two in a year (i.e., during the rainy season from March to October). Top challenges to farmers in our survey area include low access to quality seed, poor management and agronomic practices, and limited access to credit, fertilizers and pesticides. In Adamawa, just over half of the farmers (51%) reported having received no agricultural training in the past, compared to just 43% in the West region. Thus, interest in and willingness to participate in future trainings are high.

This data study contains data related to participatory variety selection (PVS) and double cropping of cereals, broad beans, and potato. Project title: Second Agreement Africa RISING (Research in Sustainable Intensification for the Next Generation: ILRI Contract No. ASSP-14/2014 Project abstract: The Ethiopian highlands are characterized by cereal-food legume production system where the productivity is very low due to pests, poor agronomic practices and growing of unimproved cultivars. Potato is becoming an integral parts of the production system of the highlands. Sustainability of cereals (wheat and barley) and potato is maintained through regular rotation with food legumes in small and main rainy seasons of the highlands. During the implementation of Africa RISING (AR) in Bale highlands and other projects, it was possible to identify high yielding cereal, broad beans and potato cultivars that can provide high yield and contribute to food security. However, many varieties are not tested in all the four AR sites. Moreover, there are early maturing legumes that can be used in double cropping with cereal and potato to increase land productivity in the highlands. Most of the wheat, barley, potato and broad beans cultivars released are developed with little or involvements of farmers and hence there is a need to put these varieties under PVS where farmers? inputs will be considered. Therefore, this study/intervention is designed to evaluate cultivars of the four commodities following PVS approaches as well as testing double cropping to increase land productivity. Project website: http://africa-rising.net | IFPRI1; Africa Rising

Late blight, caused by Phytophthora infestans (Mont.) de Bary, is a devastating disease of potato (Solanum tuberosum L.). To identify potential sources of resistance to the disease, 32 clones received from the National Potato Research Program (NPRP) were evaluated under natural conditions at the National Maize Research Program Rampur, Chitwan in 2018 and 2019. Potato cultivars Desire, Kufri Jyoti, and Farmers local were used as moderately resistant, susceptible, and highly susceptible checks, respectively. The experiments were laid out in α-lattice design with two replications. Each experimental plot of 3.6 m2 was seeded as two 3m long rows with 0.6 and 0.25 m row and plant spacing, respectively. Agronomic practices were followed as recommended by NPRP. The disease severity was measured based on a percentage of leaf area infected using disease scale of (1 to 9) at three times in seven days intervals. Disease severity values were converted into the area under disease progress curve (AUDPC). During harvest, the total yield and its components were recorded. Potato clones differed significantly (P ≤ 0.01) for disease severity, yield, and yield components. The results revealed high genetic variability, heritability, and genetic gain for disease parameters, tuber yield, and its components. Six clones (CIP311622.9, PRP277072.122, PRP146971.135, PRP147072.27, CIP311350.27, and PRP146971.117 had lower area under disease progress curve AUDPC) values (274.25 to 421.03), showed higher resistant in both years and yielded more tuber yield (~20 t/ha) than other clones. These clones could be used to develop late blight resistant, high yielding potato varieties

Potatoes are one of the main sources of carbohydrates in human diet, however they have a high glycaemic index (GI). Hence, developing new agricultural and industrial strategies to produce low GI potatoes represents a health priority to prevent obesity and related diseases. In this work, we investigated whether treatments of potato plants with elicitors of plant defence responses can lead to a reduction of tuber starch availability and digestibility, through the induction of cell wall remodelling and stiffening. Treatments with phosphites (KPhi) and borate were performed, as they are known to activate plant defence responses that cause modifications in the architecture and composition of the plant cell wall. Data of suberin autofluorescence demonstrated that potato plants grown in a nutrition medium supplemented with KPhi and borate produced tubers with a thicker periderm, while pectin staining demonstrated that KPhi treatment induced a reinforcement of the wall of storage parenchyma cells. Both compounds elicited the production of H₂O₂, which is usually involved in cell-wall remodelling and stiffening reactions while only KPhi caused an increase of the total content of phenolic compounds. A two-phase digestion in vitro assay showed that treatment with KPhi determined a significant decrease of the starch hydrolysis rate in potato tubers. This work highlights the ability of cell wall architecture in modulating starch accessibility to digestive enzymes, paving the way for new agronomic practices to produce low GI index potatoes.

The development of precision agricultural technologies for an adequate potato tuber yield requires knowledge and understanding of significant factors affecting crop growth and its yield. This study was designed to identify the significant factors responsible for fluctuations in tuber yield within the potato fields. The field experiments were conducted during potato growing seasons of 2017 and 2018 in the region of Souris alongside the LaPierre Lane in Prince Edward Island (PEI), Canada. Both fields were under conventional farming and received traditionally recommended agronomic practices and amounts of agrochemicals over the past decade. Grids of 25 x 25 m2 were established to collect horizontal coplanar geometry of ground electrical conductivity (HCP). The soil samples were collected from the same grids to determine soil organic matter content (SOM), pH, Lime Index (LI), phosphorous (P), potassium (K), calcium (Ca), Iron (Fe), cation exchange capacity (CEC) and %P/Al (P aluminum ratio). The soil moisture content (θ) was recorded using time domain reflectometry (TDR) probes. The normalized difference vegetative index (NDVI) was recorded using GreenSeekerTM. Potato tuber yield was collected manually from 0.91 x 3 m2 strips at the same grids. Results revealed that the selected soil and crop properties showed a low, moderate, and high variability and spatial dependence within the fields. Tuber yield had significant (p < 0.001) correlations with HCP, θ, SOM, and P during the first sampling at the beginning of the growing season. However, during the second sampling, the tuber yield was significantly correlated with HCP, θ, NDVI, SOM, P, and K. Stepwise regression (through backward elimination at α = 0.01) excluded the low important variables namely P and K leaving HCP, θ, SOM, and NDVI as the most influential variables for tuber yield. However, these influential variables had significant correlations with soil P and K. Results of this study suggested that managing the crop inputs based on these influential variables has a significant potential to enhance tuber yield.

Background China is the leading consumer of plastic film worldwide. Plastic film mulched ridge-furrow is one of the most widely adopted agronomic and field management practices in rain-fed agriculture in dry-land areas of China. The efficiency of plastic film mulching as a viable method to decrease evapotranspiration (ET), increase crop yields, and water use efficiency (WUE), has been demonstrated extensively by earlier studies. Methods A comprehensive evaluation of how co-application of plastic-film mulch and biochar in different agro-environments under varying climatic conditions influence ET, crop yield, WUE, and soil microbial activity were assessed. We performed a meta-analysis using the PRISMA guideline to assess the effect of plastic-film mulched ridge-furrow and biochar on ET, yield, and WUE of wheat (Triticum aestivum L.), potato (Solanum tuberosum L.), and maize (Zea mays L.) in northern China. Results The use of plastic film increased average yields of wheat (75.7%), potato (20.2%), and maize (12.9%) in Gansu, Ningxia, Shaanxi, and Shanxi provinces, respectively due to the reduction in ET by 12.8% in Gansu, 0.5% in Ningxia, and 4.1% in Shanxi, but increased in Shaanxi by 0.5% compared to no-mulching. These changes may be attributed to the effect of plastic film mulch application which simultaneously increased WUE by 68.5% in Gansu, 23.9% in Ningxia, 16.2% in Shaanxi, and 12.8% in Shanxi, respectively. Compared to flat planting without mulching, in three years, the yield of maize increased with the co-application of plastic film and biochar by 22.86% in the Shanxi and Shaanxi regions. Conclusion Our analysis revealed co-application of plastic film with biochar is integral for improving soil and water conservation in rain-fed agriculture and as an integrated practice to avert drought while simultaneously mitigating runoff and erosion.