Quality Of Sweet Potato Research Articles

Effects of Roasting Sweet Potato (Ipomoea batatas L. Lam.): Quality, Volatile Compound Composition, and Sensory Evaluation

Roasting can increase the Maillard reaction and caramelization of sweet potatoes to create an attractive appearance, color, aroma, and taste, and is rapidly increasing in the commercial market. This study mainly analyzed the influence of roasting sweet potatoes, with and without the peel, on sweet potato quality and flavor characteristics combined with sensory qualities. The results showed that the a* value (1.65–8.10), browning degree (58.30–108.91), total acidity (0.14–0.21 g/100 g, DW), and maltose content (0.00–46.16 g/100 g, DW) of roasted sweet potatoes increased with roasting time. A total of 46 volatile compounds were detected and 2-furanmethanol, furfural, and maltol were identified as the main sources of the aroma of roasted sweet potatoes. A sensory evaluation based on a comprehensive nine-point acceptance test and descriptive analysis showed that roasting for 1 to 2 h resulted in the highest acceptance score (6.20–6.65), including a golden-yellow color, sweet taste, and fibrous texture. The sweet potatoes became brown after roasting for 2.5 to 3 h and gained a burnt and sour taste, which reduced the acceptance score (4.65–5.75). These results can provide a reference for increased quality in the food industry production of roasted sweet potatoes.

Imaging Spectroscopy and Machine Learning for Intelligent Determination of Potato and Sweet Potato Quality.

Imaging spectroscopy has emerged as a reliable analytical method for effectively characterizing and quantifying quality attributes of agricultural products. By providing spectral information relevant to food quality properties, imaging spectroscopy has been demonstrated to be a potential method for rapid and non-destructive classification, authentication, and prediction of quality parameters of various categories of tubers, including potato and sweet potato. The imaging technique has demonstrated great capacities for gaining rapid information about tuber physical properties (such as texture, water binding capacity, and specific gravity), chemical components (such as protein, starch, and total anthocyanin), varietal authentication, and defect aspects. This paper emphasizes how recent developments in spectral imaging with machine learning have enhanced overall capabilities to evaluate tubers. The machine learning algorithms coupled with feature variable identification approaches have obtained acceptable results. This review briefly introduces imaging spectroscopy and machine learning, then provides examples and discussions of these techniques in tuber quality determinations, and presents the challenges and future prospects of the technology. This review will be of great significance to the study of tubers using spectral imaging technology.

Effect of Integrated Nutrient Management Practices on Yield and Quality of Sweet Potato [Ipomoea batatas (L.) Lam] cv. Kanjangad

The investigation was carried out to study the “Effect of integrated nutrient management practices on yield and quality of sweet potato [Ipomoea batatas (L.) Lam] cv. Kanjangad” at Elavuvilai village, Kanyakumari District, Tamil Nadu during Kharif season of 2020. The experiment was laid out in randomized block design with nine treatments replicated thrice. Sweet potato vine cuttings of about 15 cm with 4 nodes were used for the study. The treatments comprised of two levels of recommended dose of fertilizers (RDF - 40:80:120 kg NPK ha-1) viz., 50 and 100% along with FYM, poultry manure, gibberellic acid and seaweed extract. The treatments comprised of half dose of nitrogen and full doses of phosphorous and potassium were applied as basal and remaining half dose of nitrogen was applied at 60 days after planting. Organic inputs viz., FYM (25 t, 12.5 t ha-1), poultry manure (5 t, 2.5 t ha-1) as were applied as basal application, gibberellic acid (200 ppm) and seaweed extract (2%) were applied as foliar application at 40, 55 and 70 days after planting were also used. The observations were recorded at 180 days after planting. The results indicated that the maximum values for yield parameters viz., number of tubers plant-1 (3.02 g), tuber length (19.02 cm), tuber girth (15.58 cm), tuber weight (138.36 g), tuber dry weight (66.73 g), tuber yield [plant-1 (417.84 g), plot-1 (12.18 kg), hectare-1 (30.45 t)], whereas quality parameters such as total soluble solid (9.210 Brix) and starch content (12.24%) of tuber, post harvest soil available nutrient (245.00 N; 21.93 P and 278.00 K kg ha-1), maximum net income (Rs. 5,16,050) and B: C ratio (3.23) were recorded in the plots which received 50% RDF + FYM 12.5 t ha-1 + Poultry manure 2.5 t ha-1 + Seaweed extract 2% (T9). This was followed by (T6) 50% RDF+ FYM 12.5 t ha-1 + Poultry manure 2.5 t ha-1 + GA3 200 ppm.

Combination of wound healing with 1-methylcyclopropene and wound detection by iodine solution to maintain the quality of sweet potato during long-term storage

Wound healing treatment after harvest is a critical step to protect sweet potatoes from pathogens. The method of phloroglucinol staining is commonly used for detecting callus. However, this method is not easy to identify the degree of callus as the color change is not obvious compared with non-curing roots for some cultivars. A new method based on the principle of starch test by iodine was developed for the detection of wound healing. After healing, the reducing sugar content increased while the starch content decreased to a lower level compared to that of the non-curing roots. Moreover, the antioxidant capacity of the sweet potato after wound healing was higher than that in the control. Wound healing combined with ethylene, 1-methylcyclopropene (1-MCP), chlorpropham or abscisic acid were studied for inhibiting sprout of sweet potato root caused by high temperature during curing. The results showed ethylene and 1-MCP treatment had no negative effect on wound healing. Moreover, 1-MCP treatment was the most effective one on the suppression of sprouting and decay of sweet potato. The results indicate that iodine solution staining is a useful and rapid method to identify the wound healing extent, and 1-MCP treatment can effectively inhibit root sprouting during wound healing and the subsequent long-term storage. Keywords: sweet potato, wound healing, iodine staining, sprouting inhibition, decay rate DOI: 10.25165/j.ijabe.20211403.5735 Citation: Cao J X, Liu P, Wang X J, Wang Q G, Shi J Y. Combination of wound healing with 1-methylcyclopropene and wound detection by iodine solution to maintain the quality of sweet potato during long-term storage. Int J Agric & Biol Eng, 2021; 14(3): 241–246.

Impact of nitrogen and green manure on yield and quality of sweet potato in sandy soil: A Brazilian case study

A field experiment was conducted to evaluate the effects of mineral N rates on the yield, morphological traits, quality, and mineral content of the storage roots of sweet potato grown after different green manure sources. Treatments included the application of N at four rates (0, 50, 100, and 200 kg ha−1) to sweet potato grown after the control (indigenous weeds) or the legumes showy crotalaria and velvet bean. PCA revealed that in the treatments with previous showy crotalaria cultivation, there was a low incidence of defects in the storage roots and the storage roots weighed more than they did in the control or in the velvet bean treatments. The current study also showed that legume cultivation only in the previous season was not enough to improve the yield and quality of sweet potato. Therefore, it is necessary to combine previous legume cultivation with the application of 100 or 200 kg N ha−1 in sweet potato to achieve higher levels of yield, quality, and mineral contents, such as Cu, Zn, K, Ca, and Mg, in storage roots. The current research has indicated that future studies should investigate whether the benefits of previous legume cultivation for sweet potato are restricted only to the current growing season.

Breeding process of high quality sweetpotato lines with low soil temperature tolerance

Breeding process of high quality sweetpotato lines with low soil temperature tolerance

Farmers’ Preference, Yield, and GGE-Biplot Analysis-Based Evaluation of Four Sweet Potato (Ipomoea batatas L.) Varieties Grown in Multiple Environments

The study aimed to select high-yielding, farmers-preferred quality sweet potato varieties that are suitable to grow in various environmental conditions in Bangladesh. In this context, four popular sweet potato varieties (viz., ‘BARI Mistialu-8′, ‘BARI Mistialu-12′, ‘BARI Mistialu-14′, and ‘BARI Mistialu-15′) were used in the study. These varieties were released by Bangladesh Agricultural Research Institute (BARI). In the first season (2018–2019), these varieties were evaluated at nine locations, and in the second season (2019–2020), the same varieties were tested further, but only in three locations. The trial was set up in a randomized complete block design and repeated three times. After two years of observation, it was found that the fresh root yield was varied significantly due to the environment (E), genotypes (G), and their (G × E) interaction (p ≤ 0.01) by using genotype and genotype x environment (GGE) biplot analysis. The E and G × E interaction effects were found to the greater than the genotypes effect solely. In the first year, three varieties, namely ‘BARI Mistialu-8′, ‘BARI Mistialu-12′ and ‘BARI Mistialu-14′, were identified as balanced and comparatively higher in yield in nine locations. These three varieties also showed a similar trend with respect to root yield in tested three locations in the second year. Among the four varieties, ‘BARI Mistialu-12′ was found to be the highest root yielder, followed by ‘BARI Mistialu-8′ and ‘BARI Mistialu-14′. Across the locations, these varieties showed 57.89%, 61.50% and 44.30% higher yield than the local check cultivar. Therefore, these three varieties may be recommended as the best varieties of sweet potato throughout the country.

Physical, chemical and organoleptic quality of sweet potato leaves (Ipomoea batatas L.) ice cream

During the Covid19 pandemic, many people are looking for healthy foods to boost their immune systems. The immune system can be boosted by consuming foods that contain vitamins, phenols, flavonoids and antioxidants, and one of these foods is sweet potato leaves. Sweet potato leaves have not been utilised optimally. So, to increase its utilisation, sweet potato leaves can be processed into a popular product, one of which is ice cream. The purpose of this study was to make healthy ice cream with the addition of sweet potato leaves extract. This study used a Completely Randomised Design (CRD) 2 factors. The first factor was the concentration of skim milk (10%, 13%, 16%). Meanwhile, the second factor was the sweet potato leaves extract 5%, 10%, 15%. Each treatment was repeated three times. The test parameters used in this study were physical analysis, namely overrun; chemical analysis, namely antioxidants (IC50), fat content, protein content, carbohydrate content, and crude fibre content; and organoleptic tests, including taste, colour, aroma, and softness. The results proved that S3D1 treatment with a concentration of 16% skim milk and 5% sweet potato leaves extract was the best treatment. This treatment obtained the highest Result Value (RV), which is 0.78. The other parameter results obtained were the taste test 6.44 (like); overrun 65%; softness 5.96 (like); IC50 value 112.30 ppm; protein content of 5.63%; fat content 0.76%; carbohydrate content 10.02%; crude fibre content 5.27%; vitamin C content16.79 mg; aroma 5,52 (like); and colour 5.59 (like).

Role of sucrose phosphate synthase and vacuolar invertase in postharvest sweetening of immature sweetpotato tuberous roots (Ipomoea batatas (L.) Lam cv ‘Xinxiang’)

Postharvest sweetening can improve the eating quality of sweetpotato, particularly of immature sweetpotato. In this study, soluble sugar content, activities of sucrose phosphate synthase (SPS) and vacuolar invertase (VIN) enzymes and expression of three IbSPSs, five IbVINs and two vacuolar invertase inhibitory factor (IbVIFs) genes were examined in immature sweetpotato cv ‘Xinxiang’ during 30 days storage at 20, 13 and 4 °C. Results showed that sucrose content increased at all temperatures, while glucose and fructose mainly increased at 4 °C. However, chilling injury developed at 4 °C and postharvest sweetening at 20 °C is potentially a safer option. The sucrose level was correlated with SPS activity and SPS activity is not manipulated at transcriptional stage. Fructose/glucose content was correlated with VIN activity. Transcript level of IbVIN1 was correlated with VIN activity and sweetness index in sweetpotato roots. Therefore, IbVIN1 could be a candidate gene in cultivating variety high in sweetness.

Estimation of Starch Hydrolysis in Sweet Potato (Beni Haruka) Based on Storage Period Using Nondestructive Near-Infrared Spectrometry

Sweet potatoes are a substantial source of nutrition and can be added to processed foods in the form of paste. The moisture and starch contents of these potatoes affect the physicochemical properties of sweet potato paste. In this study, the changes in the moisture, starch, and α-amylase content of sweet potatoes were measured for eight weeks after harvest. Using nondestructive near-infrared analyses and chemometric models, the moisture and starch contents were predicted. The partial least squares (PLS) method was used for prediction, while linear discriminant analysis (LDA) was used for discrimination. To increase the accuracy of the model, the near-infrared spectrum was preprocessed using the Savitzky–Golay derivative (S–G), standard normal variate (SNV), and multiplicative scattering correction methods. When applying PLS to the moisture content, the best calibration model accuracy was obtained using the S–G preprocessed spectrum. Furthermore, the best calibration model accuracy for starch content was obtained using the SNV preprocessed spectrum. The moisture and starch contents were categorized into five classes for LDA, with results indicating that the internal quality of sweet potatoes can be predicted and classified using chemometric models through nondestructive detection.

Effects of Different Skin Processing Conditions of Japanese Sweet Potato Powder (Ipomoea batatas) on Physicochemical Properties

Sweet potato (Ipomoea batatas) is among the most popular crop around the world. Physicochemical properties are an important element in the sweet potato processing industry. However, little knowledge is known about this variety of sweet potatoes. In this study, colour, moisture, ash, protein, fat, crude fibre and carbohydrate were studied subjected to three different conditions of Japanese sweet potato; whole tuber (C1), peeled tuber (C2) and skin of tuber (C3). Colour and proximate analysis were determined using the lightness (L), red/green (a) and yellow/blue (b) system and AOAC method, respectively. The result indicated that L, a* and b* ranged from 68.0–89.2, 0.48–5.65 and 11.67–13.27, respectively. The highest values of L, a and b were observed in C1, C3 and C1, respectively. Moisture, ash, protein, fat, carbohydrate and fibre were ranged from 5.93–7.86%, 2.64–8.11%, 4.64–5.47%, 0.06–0.70%, 65.96–86.96% and 1.00–2.43%, respectively. C1 had the highest value of moisture content while C2 showed to have the highest values of protein and carbohydrate. C3 was observed to have the significantly highest (p < 0.05) content of ash, lipid and crude fibre. Overall, the differences in the physicochemical properties of three different conditions of sweet potato are significant in certain properties. C1 was suggested to be the best selection for producing better quality sweet potato products. Therefore, the result obtained from this study becomes useful for further processing of sweet potatoes.

Methyl jasmonate controls sprouting incidence in stored sweet potatoes and preserves overall quality for fried chips

ABSTRACT High incidence of sprouts and loss of quality of sweet potato is one of the negative aspects that compromises the commercialization most, and the methods of sprout control are still very limited. The appearance of sprouts promotes the wilting of sweet potato roots, reducing their commercialization period. The main objectives of this study were to evaluate sprout control and physiological and biochemical changes, in addition to the impact on the quality of postharvest chips in sweet potato roots cultivar BRS Cuia treated with methyl jasmonate (MeJa) and nonanoic acid (NA). Roots were fogged with 10 μmol·L–1 MeJa or 5 μmol·L–1 NA applied at first sprout initiation and control. Physiological and biochemical alterations such as fresh weight loss assessment, sprouting incidence and sprout length, total soluble sugars, reducing sugars, nonreducing sugars, enzymatic peroxidase and polyphenol oxidase, chips quality after frying were then assessed. Besides that, to determine the influence of treatments and storage periods, multivariate analysis was also performed using the main components. The MeJa reduced the incidence of sprouting and maintained the root quality during storage at room temperature. Notably, such events led to an increased both shelf life and potential of commercialization. Moreover, MeJa-treated chips displayed lighter color appearance after frying than control and NA-treated roots. Roots fogged with NA did not suppress the growth of sprouts, which consequently triggered a higher browning intensity in fried sweet potato chips.

Combination of wound healing with 1-methylcyclopropene and wound detection by iodine solution to maintain the quality of sweet potato during long-term storage

Wound healing treatment after harvest is a critical step to protect sweet potatoes from pathogens. The method of phloroglucinol staining is commonly used for detecting callus. However, this method is not easy to identify the degree of callus as the color change is not obvious compared with non-curing roots for some cultivars. A new method based on the principle of starch test by iodine was developed for the detection of wound healing. After healing, the reducing sugar content increased while the starch content decreased to a lower level compared to that of the non-curing roots. Moreover, the antioxidant capacity of the sweet potato after wound healing was higher than that in the control. Wound healing combined with ethylene, 1-methylcyclopropene (1-MCP), chlorpropham or abscisic acid were studied for inhibiting sprout of sweet potato root caused by high temperature during curing. The results showed ethylene and 1-MCP treatment had no negative effect on wound healing. Moreover, 1-MCP treatment was the most effective one on the suppression of sprouting and decay of sweet potato. The results indicate that iodine solution staining is a useful and rapid method to identify the wound healing extent, and 1-MCP treatment can effectively inhibit root sprouting during wound healing and the subsequent long-term storage. Keywords: sweet potato, wound healing, iodine staining, sprouting inhibition, decay rate DOI: 10.25165/j.ijabe.20211403.5735 Citation: Cao J X, Liu P, Wang X J, Wang Q G, Shi J Y. Combination of wound healing with 1-methylcyclopropene and wound detection by iodine solution to maintain the quality of sweet potato during long-term storage. Int J Agric & Biol Eng, 2021; 14(3): 241–246.

Effects of combined radio frequency with hot water blanching on enzyme inactivation, color and texture of sweet potato

Sweet potato is an important food crop with rich nutritional value, and also a commonly used feed and industrial raw material. However, the quality of sweet potatoes may decline during storage and thermal processes because of enzymatic reaction induced by peroxidase (POD). Radio frequency (RF) blanching was thus proposed to reduce POD activities. Effects of electrode gaps and sample thicknesses on the RF heating rate and uniformity in sweet potato were studied. Influences of hot water blanching and combination of RF heating with hot water blanching on enzyme inactivation and physiochemical properties of sweet potatoes were also analyzed. Results showed that the optimum RF heating uniformity was obtained at an electrode gap of 90 mm and a sample thickness of 60 mm. Combined RF with hot water blanching effectively inactivated POD in sweet potatoes. Compared to hot water blanching, combined RF with hot water blanching gave better sample color, texture values, and lower weight loss when achieving the same level of enzyme inactivation (< 10%). Therefore, combined RF with hot water blanching is recommended as an effective, uniform and high-quality blanching technology for sweet potatoes.

Skrining Golongan Senyawa Kimia dan Pengujian Aktivitas Antioksidan Ekstrak Ubijalar (Ipomoea batatas (L.)Lam.) Varietas Lokal di Distrik Skanto Kabupaten Keerom Provinsi Papua

Sweet potato (Ipomoea batatas) is native plant comes from the American continent. It began to spread throughout the world, especially in the tropical countries in the 16th century. Papua Province is one of the regions with the largest area of harvested sweetpotato in Indonesia, therefore there is a high chance to develop food independence in Papua. Because of the Papuan people are accustomed consuming non-rice food. The study was conducted in the Biology Laboratory and the Pharmacy laboratory of MIPA Faculty Cenderawasih University and also the supporting Laboratory of The Papua Agricultural Research and Development Center (Balitbangtan). The purpose of this research is to test the quality of flour of Keerom sweet potato varieties. Method for flour of sweet potato quality testing were using phytochemical screening to determine the chemical compound group and using antioxidant test with the DPPH (1-diphenyl-2-picrylhydrazyl) method. The results of the description of the Skanto District Keerom sweet potatoes in the field were three (3) local varieties including Weayuken (purple sweet potato), Musanaken (yellow sweet potato) and Hiho (white sweet potato). The result of phytochemical screening show that the purple sweet potato variety has more chemical compounds consist of tannins, quinones, flavonoids, terpenoids and alkaloids compared to white sweet potato consist of alkaloids only and yellow sweet potato consist of tannins, flavonoids, terpenoids and alkaloids. The result of antioxidant activity tests to flour extract ethanol has IC50values of 299.82 ppm (purple sweet potato), 301.18 (yellow sweet potato), 1027.98 ppm (white sweet potato) respectively. So can be conclude that the purple sweet potato variety is the best. It was suggested for further research to isolate bioactive compounds and test antioxidants to other varieties in other centers areas of sweetpotato culture which have potential to develop for food, supplement and tradisional drugs.Key words: Sweet potato; local varieties; flour quality; phytochemical screening; antioxidant test

Fried sweetpotato user preferences identified in Nigeria and Ghana and implications for trait evaluation.

Fried sweetpotato quality is important for variety adoption in West Africa. To inform breeding efforts, the study developed a product profile for sweetpotato chunk fries using mixed qualitative and quantitative methods. Root characteristics, processing attributes, in-mouth attributes and appearance of fried product were critical to final product quality. Raw roots should be hard, have smooth skin and no off-odours. Peeled roots should be hard to slice and not sticky. Stickiness and moist surface indicate high moisture content, associated with excessive oil absorption during frying. Hard to slice roots connote high dry matter. Fried product should be crisp, slightly sugary and mealy, have a uniform colour with brown tint and not be soggy. Crispness, mealiness and short frying time with limited oil absorption may be functions of starch. Understanding starch characteristics and other attributes that contribute to quality fried sweetpotato is critical for breeding sweetpotato genotypes with superior quality for frying.

Changes in cell wall components and polysaccharide-degrading enzymes in relation to differences in texture during sweetpotato storage root growth

Sweetpotato has special texture characteristics, which directly affect the eating quality and post-production processing quality of sweetpotato. To investigate the texture change mechanism of sweetpotato during the growth process, this study selected two varieties with significant differences in texture from 35 varieties. The storage roots were sampled at 50, 80, 110, and 140 days after planting. Measure the texture parameters, the cell wall composition content, cell wall-related enzyme activities and the expression of expansin genes of sweetpotato storage roots. The results show that the hardness, adhesiveness and chewiness parameters of ‘Yushu No 10′ were significantly lower than those of ‘Mianfen No 1′, they have significantly different texture properties. In terms of cell wall composition, the soluble pectin content of ‘Yushu No 10′ was more than twice that of ‘Mianfen No 1′, whereas the insoluble pectin content was lower than that of ‘Mianfen No 1′, with the cellulose content of ‘Yushu No 10′ being significantly higher than that of ‘Mianfen No 1′. In terms of cell wall-related enzymes, ‘Yushu No 10′ hardness gumminess and chewiness had a significant correlation with hemicellulose activity, and ‘Mianfen No 1′ had insignificant correlation with four cell wall-related enzymes. Expansin genes were also expressed differently during the various stages of root tubers expansin. The expressions of IbEXP1, IbEXP2 and IbEXPL1 were significantly correlated with the changes in cell wall component content, and were related to the qualitative structure changes. The research conclusion shows that the texture changes during the growth of sweetpotato are related to cell wall composition, cell wall-related enzyme activity changes, and the expression of expansin genes. This study provides theoretical guidance for in-depth study of texture changes of sweetpotato, post-harvest processing and utilization and quality improvement of storage roots.

Potential Utilization of Low Quality Sweet Potato for Bioethanol Production by Saccharomyces cerevisiae TISTR5339

This study was aimed to investigate the optimal condition of ethanol production that has 2 major stages: acid hydrolysis and fermentation processes. These processes came from low quality sweet potato (LQSP) which was destroyed by the sweet potato weevil. The main compositions of LQSP were starch and fiber which consist of 55.25 and 10.29 %, respectively. In this case, the starch can be hydrolyzed to reduce the sugar, followed by the fermentation of the reduced sugar to ethanol. For this experiment, the effecting factors on acid hydrolysis of LQSP and the ethanol fermentation condition were optimized by S. cerevisiae using Response Surface Methodology (RSM) with Box-Behnken design in order to maximize ethanol yield. It was found that the maximum reducing sugar concentration of 390.99 ± 5.35 g/L was obtained from the hydrolysis condition with 1 % (v/v) of sulfuric acid and 25 % (w/v) of LQSP. Accordingly, the effects of ammonium sulphate content (0.05 - 0.15 %), pH (4.5 - 5.5) and inoculum content (5 - 10 %) on ethanol production was determined by RSM using Box-Behnken experiment design with a total 17 sets of all trials. The results were found that the maximum experimental ethanol productivity of 5.98 g/L was obtained from the condition at 0.05 % of ammonium sulphate, pH 5.5 and 5.0 % of inoculum size to 90 mL LQSP based medium and incubated at 30 °C for 48 h. In addition, the scale-up of ethanol production was studied in 9 L fermenter which provided the maximum ethanol yield of 5.04 g/L. Therefore, it can be concluded that LQSP had a potential as a substrate for ethanol production.

Pengaruh Pengaturan Komposisi Media Tanam Organik Terhadap Pertumbuhan Dan Hasil Tanaman Ubi Jalar ( Ipomoea batatas L.) Dengan Sistem Tabilampot

Sweet potatoes are an alternative source of carbohydrates that have high nutritional content. Development of sweet potato cultivation methods needs to be done to overcome the decrease of productive agricultural land due to land conversion. This study aimed to test the effect of differences in the composition of the growing media on the growth, yield, and quality of sweet potato. This study was a pot experiment using a Randomized Block Design (RBD) with 7 treatments and 5 replications. The types of treatments tested were P0: 100% soil + inorganic fertilizer; P1: 50% soil + 50% cow manure; P2: soil 50% + vermicompost 50%; P3: soil 50% + biochar rice husk 25%, cow manure 25%, P4: soil 50% + biochar rice husk 25% + vermicompost 25%, P5: soil 50% + cocopeat 25% + cow manure 25%, P6: soil 50% + cocopeat 25% + vermicompost 25%. The research results showed that the composition of the growing medium significantly affected plant growth and yield. The results of the statistical analysis showed that the treatments of P4 and P6 gave the highest growth, while the high yield of fresh weight of tubers per pot were found in the treatments P1, P2, P3, and P4 by 165.59 g, 143.38 g, 171.56 g, and 144.80 g, respectively. The highest number of tubers was found in treatment P6 by 7.66 tubers. The highest yield of dry matter was also found in treatments P1, P2, P3, and P4 by 59.91 g, 51.73 g, 59.02 g, and 48.59 g, respectively. Based on the research results, it can be recommended that the cultivation of sweet potato plants in pots can be carried out using porous growing media in a container that is sufficient and available balanced nutrients for the development of plant tubers.Keywords: Vermicompost, composition of growing media, Sweet Potatoes, Yield, Quality

Effect of Combined Organic and Inorganic Fertilizer Application on Soil Attributes, Yield and Quality of Sweet Potato (Ipomoea batatas L.)

The use of organic fertilizers in adequate doses is an alternative to reduce the use of inorganic inputs, improving the soil chemical attributes, and increasing the production and quality of sweet potato. In this perspective, the objectives of this study were: (i) to evaluate the effects of fertilization with poultry and bovine manure, Ribumin®, and of conventional fertilization on soil attributes, production, and quality of sweet potato; and (ii) to evaluate the residual effect of organic fertilization on the production components and quality of sweet potato, in the second crop cycle. The two experiments were developed in the 2018/2019 crop year at the Agrotechnical School of the Federal University of Roraima (UFRR), Brazil. The treatments were arranged in a randomized block design with three replications, using a (2 × 5 × 2) + 1 factorial arrangement referring to two manure sources (bovine and poultry manure) and five doses, aiming at increasing the content of soil organic matter (1.35%) to 2.35; 3.35; 4.35, and 5.35%, in the absence and presence of Ribumin®, and an additional treatment referring to organomineral fertilization. For the evaluation of the second cycle, the residual effect of the manure was evaluated by applying only Ribumin® and conventional fertilizers. In the first cycle, the addition of 50.4 t ha-1 of bovine manure without Ribumin® provided the highest values of total (14.7 t ha-1) and marketable yield (14.6 t ha-1). However, the addition of poultry manure associated with the application of Ribumin® provided no increments in the sweet potato production components. Under the same experimental conditions, chemical fertilization can be replaced by fertilization with organic sources.