Sweetpotato Yield Research Articles

Potassium Positively Affects Skin Characteristics of Sweet Potato Storage Roots

Sweet potato (Ipomoea batatas) growth faces two critical problems: variability in storage root (SR) number and size among individual plants, and skinning injuries that render the SR susceptible to pathogen infections during storage. We hypothesized that application of potassium (K) fertilizer, an essential mineral for sweet potato, would contribute to increased yield, uniformity, and skin quality of SRs. Sweet potatoes were grown in sandy soil, which is poor in K, and in loess soil. The fertilizers potassium chloride (KCl) and polyhalite were applied before planting. Polyhalite is a hydrated sulfate of K, calcium, and magnesium that has been shown to improve potato skin appearance. Soil type was the major factor affecting SR yield—higher in sandy vs. loess soil. The K fertilizers did not affect yield in either soil type, or improve SR uniformity. However, the skin of the SRs from loess soil had more phellem layers and larger phellem cells following fertilization, mainly with KCl. Accordingly, the expression of suberin marker genes was significantly higher in mature vs. immature skin of SRs fertilized with KCl. Overall, soil type was the major factor affecting sweet potato yield, and addition of K positively affected skin morphology and related gene expression.

Influence of morpho-physiological traits on root yield in sweet potato (Ipomoea batatas Lam.) genotypes and its adaptation in a sub-humid environment

Sweet potato is a crop with a wide morpho-agronomic variation among genotypes. Source-sink relationship is determined by the regulation capacity of heterotrophic and autotrophic organs. To understand the influence of morphological traits, biomass allocation, and plant growth on sub-humid adaptation, eighteen genotypes were morpho-agronomically characterized under three texture soils (Cerete, Carmen de Bolivar, and Corozal). Subsequently, selected genotypes were evaluated to determine growth rates and, source and demand potential. Morphological features seem to significantly influence the agronomic performance of sweet potato genotypes, especially those related to leaf description and plant architecture. Efficiency of cover ground was a determinant trait for sweet potato yield, but, it was not completely related to above-ground biomass yield. Through growth rate analysis and morphological features description, the negative influence of excessive accumulation of foliar biomass on production of storage roots of sweet potato was confirmed. In soils with low water holding capacity, the genotypes with higher cover ground efficiency at establishment phase showed major adaptation and root biomass accumulation. Morpho-physiological evaluation of sweet potato genotypes could be considered as a helpful strategy to improve varietal selection with tolerance to limited water availability.

Effects of wheat straw incorporation and nitrogen application on sweetpotato yield and quality and soil fertility

ABSTRACT The study was aimed to determine the effect of wheat straw incorporation and nitrogen (N) fertilization on soil fertility and enzyme activity, as well as sweetpoato yield and quality. Field experiment was conducted in the summer seasons of 2017 and 2018, and four treatments were set: zero straw +50 kg·ha−1N (S0N50), 50% straw return +50 kg ha−1N (S1N50), 100% straw return +50 kg·ha−1N (S2N50), 100% straw return+150 kg ha−1N (S2N150). The aboveground yield, storage roots yield and single root fresh weight increased with the increase of straw returning quantity(S2N50> S1N50> S0N50). The storage root yield ofS2N150in 2017 was higher than that ofS2N50,but lower than that ofS2N50in 2018. Two years of nitrogen/straw incorporation also increased the starch content of sweetpotato, but decreased the reducing sugar, soluble sugar and protein content. The available N, total N, available P, available K and organic matter content, as well as catalase, alkaline phosphorylase, urease and invertase activity in soil were enhanced by nitrogen/straw incorporation. The results indicated that the conjoint application of full amount of straw and appropriate amount of N had the best effect on increasing the yield and starch content of sweetpotato.

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

Split Application under Reduced Nitrogen Rate Favors High Yield by Altering Endogenous Hormones and C/N Ratio in Sweet Potato

A process for reducing the nitrogen (N) application rate while maintaining sweet potato yield urgently needs to be determined. A two-year pot experiment was conducted with three N management strategies to explore the mechanism underlying yield increase caused by a split application under a reduced N rate through an investigation of the changes in the carbon (C)-N metabolism and endogenous hormone. Results revealed that, compared with conventional basal N management, split application under a reduced N rate increased storage root yield by 22.1% through improving the storage root number and mean storage root weight by 12.3% and 10.2%, respectively. During the storage root formation period, split application under a reduced N rate decreased the soil-available N (AV-N) content and N content in storage root, inducing elevated C content, C/N ratio, auxin (IAA) content, zeatin and zeatin riboside (Z + ZR) content and reduced abscisic acid (ABA) content in storage roots, promoting storage root formation. During the storage root bulking period, split application under a reduced N rate appropriately elevated the soil AV-N content and N content in the storage root which, together with increased ABA content, which enhanced C content and C/N ratio in the storage root, resulted in an improved mean storage root weight. These results will facilitate the generation of appropriate N management strategies to improve sweet potato productivity.

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.

Photosynthesis product allocation and yield in sweet potato with spraying exogenous hormones under drought stress

This study investigated the alleviation effects of spraying phytohormones on the physiological characteristics and yield of sweet potato under drought stress during the early vine development and storage root bulking stage, respectively. The endogenous hormone contents, photosynthetic fluorescence indexes, photosynthetic products transfer allocation (based on 13C labeling method), and yield of sweet potato were studied by spraying water, 6-benzylaminopurine (6-BA), abscisic acid (ABA), and combined with the two exogenous hormones under artificial dry shed and dry pond. Results indicated that the yield was increased by spraying 6-BA or ABA separately in comparison with the control treatment under drought stress, and the alleviation effects of spraying 6-BA at the early stage were better than at the storage root bulking stage, while spraying ABA at the storage root bulking stage was better than at the early stage. The sweet potato yield increased when sprayed with 6-BA, especially at the early vine development stage, and sweet potato yield was further enhanced by the addition of ABA. When sprayed together, exogenous 6-BA and ABA increased plant shoot and storage root biomass, as well as leaf area and yield, at both stages. The combination of exogenous 6-BA and ABA also increased shoot 13C accumulation at the early vine development stage and storage root 13C accumulation at the storage root bulking stage, in comparison with 6-BA or ABA alone under drought stress. Spraying exogenous hormones under drought stress increased the endogenous hormone contents, enhanced carbon metabolism enzyme activities, improved the photosynthetic fluorescence characteristics of leaves, and regulated the source-sink balance, all of which alleviated the yield reduction caused by drought stress. Application of the combination of 6-AB and ABA yielded better results than that of the 6-BA or ABA alone.

Sustainable sweetpotato farming systems to improve soil health and reduce losses caused by root-knot nematode

Australia produces some of the highest sweetpotato yields in the world but the health of the soil used to produce the crop is declining because it is repeatedly tilled to kill volunteer sweetpotatoes, incorporate cover crop residues and prepare beds for planting. Additional disturbance occurs when the swollen roots are harvested. An on-farm study showed that it is possible to replace this tillage-dominated farming system with an alternative that is not only productive, but is also likely to be sustainable in the long-term. When the soil was amended with organic matter, beds were formed 10 months prior to planting, two cover crops (forage sorghum followed by oats) were grown on the beds, residues from those crops were retained on the soil surface as mulch, and sweetpotato cuttings were planted into the mulched, undisturbed beds using strip tillage, the crop established well and yielded 93 t/ha. The only detrimental effect was that root-knot nematode (Meloidogyne incognita) caused severe damage. In contrast, a trial in the same field showed that when organic amendments were placed in a furrow in the centre of the bed so that the swollen roots were surrounded by the amendment as they developed, nematode control was much better. Sawdust and a mixture of sawdust and chicken litter were the most effective amendments, as they both reduced root-knot nematode populations and the severity of nematode damage, and increased marketable yield by 29%. The wide range of natural enemies found in soil collected from the amended furrow at harvest, and the results of a suppression assay in the laboratory suggested that the soils amended with sawdust and sawdust /chicken litter were biologically suppressive to root-knot nematode.

Effects of Cattle-Cud Digester on Soil Properties and Yield of Sweet Potato on Acid Sand of Akwa Ibom State, Nigeria

Effects of Cattle-Cud Digester on Soil Properties and Yield of Sweet Potato on Acid Sand of Akwa Ibom State, Nigeria

Pengaruh Dosis Pupuk Kandang Ayam Terhadap Pertumbuhan Dan Hasil Ubi Jalar (Ipomea batatas L) Varietas Cilembu

The study aims at determining, firstly, the effect of chicken manure dose on the growth and crop result of sweet potato (Ipoma batatas), Cilembu Variety, secondly, determining the optimum dose of chicken manure which can lead the best of growth and yield of sweet potato (Cilembu variety). The method used at this research is completely randomized design, and the treatments are K0 (non-fertilizer), K1 (dose of 10 tons/ha), K2 (dose of 20 tons/ha), K3 (dose of 30 tons/ha). Observation variables in this study are the length of the rod, number of leaves, leaf area, number of wet bulb per plant, berangkasan weight, wet weight of bulb per plant, length of the bulb, the diameter of the bulb, and weight of wet bulb per hectare. The result of this research indicates that the giving of chicken manure, giving a good influence at the growth and yield of Cilembu sweet potato and real affect long stem at the age of 2, 6, and 8 mst of age, and wide leaf index at age 2, 4, and 6 mst. Production components have significantly affected for berangkasan weight, wet weight of bulb per plant, length of the bulb, the diameter of bulb and weight of wet bulb per hectare. The optimum dose of chicken manure was obtained with a dose of 20 tons per hectare which can raise the growth of stem length of Cilembu Sweet Potato (80,85 cm) and the crop of Cilembu sweet potato (731, 72 kg/ha).

Sweetpotato leaf curl virus decreased storage root yield and quality of edible sweetpotato in China

AbstractSweetpotato leaf curl virus (SPLCV) causes leaf curl symptoms in sweetpotato [Ipomoea batatas (L.) Lam]. These symptoms disappear under high temperature. Previous studies have shown that SPCLV reduces storage root yield in sweetpotato. However, knowledge of SPLCV's effect on root quality is limited. In this study, we surveyed the effect of SPLCV on storage root yield and quality in edible sweetpotato. Quantitative real‐time reverse transcriptase–polymerase chain reaction and leaf paraffin section results showed that the SPLCV mRNA level and the distribution density of spongy mesophyll cells in SPLCV‐infected plants were significantly higher than in healthy control plants (CK). Leaf net photosynthetic rate, vine length, and storage root yield were reduced in SPLCV‐infected plants during the growing period, and the shoot/root ratio was significantly increased compared with CK. Additionally, root abscisic acid, auxin, and zeatin riboside contents under SPLCV infection were higher than the CK, whereas root gibberellic acid content was lower. Root dry matter, starch, and carotenoid contents were lower in the infected plants than in the CK. Moreover, SPLCV‐infected plants showed reduced expression of starch and carotenoid metabolitic genes, such as ADP‐glucose pyrophosphorylase‐ß, granule‐bound starch synthase I, starch branching enzyme I and II, and carotenoid isomerase, and increased expression of α‐amylase, ß‐carotene hydroxylase, and zeaxanthin epoxidase. These results suggest that sweetpotato infected by SPLCV had decreased storage root yield and decreased starch and carotenoid contents through reducing photosynthetic capacity, regulating starch and carotenoid degradation, and changing endogenous hormone contents. Therefore, effective management should be taken to prevent SPLCV epidemics during sweetpotato production.

EFFECT OF POPULATION DENSITY OF SWEET POTATO ON THE YIELD OF MAIZE-SWEET POTATO INTERCROP FOR WEEDS SUPPRESSION IN SOUTHERN GUINEA SAVANNAH NIGERIA

ABSTRACT Maize–sweet potato intercropping often results in weed suppression and increased crop productivity. This study was designed to determine the appropriate planting time and optimal density of sweet potato in a maize-sweet potato intercropping system that will minimize weed infestation and improve yield of the component crops in a drought-prone southern Guinea savanna of Nigeria. The experiment was laid as a randomized complete block design with a split-plot arrangement and 3 replications in 2018 and 2019 growing seasons. The main plots were planting time (May, June and July) while the sub-plots consisted of 3 maize-sweet potato intercropping populations(maize at 53,333 plants/ha + 33,333 plants/ha of sweet potato, maize at 53,333 plants/ha + 66,666 plants/ha of sweet potato and maize at 53,333 plants/ha +99,999plants/ha of sweet potato), sole maize at 53,333 plants/ha and sole sweet potato at 33,333 plants/ha. The results revealed that, 7 weed species were the most prevalent and there was inconsistent effect of planting date on weed flushes while weed smothering efficiency of intercropping was between 31 to 49 % and 48 to 73% for weed density and weed biomass, respectively. Intercropping resulted in land equivalent ratios (LER) of 1.29 to 1.74 while the competitive ability of maize was increased with an increase in sweet potato density. Planting in the month of June had significantly higher tuber yield of 9.56 t/ha of sweet potato and maize grain yield of 3.28 t/ha while intercropping 33,333 plants/ha of sweet potato (1 vine of sweet potato planted at 0.40m apart on the ridge and 0.75m between ridges) and maize at 53,333 plants/ha (0.25m x 0.75m) gave an intercrop yield of 7.32 t/ha tubers and 3.46 t/ha grain yield with highest LER of 1.74, a net profit of ₦566,435.00 and benefit cost ratio of 1.44 was relatively similar to sole sweet potato. Therefore, the above intercropping pattern established in the month of June will minimize weed infestation and improve productivity of maize and sweet potato in the southern Guinea savanna of Nigeria.

A reliable method for predicting bioethanol yield of different varieties of sweet potato by dry matter content

Abstract In this study, we analyzed the potential of using dry matter content for determining ethanol yield of sweet potatoes as one of the raw materials for bioethanol production. We tested dry matter content, total starch content, crude protein content, glucose content, fructose content, sucrose content and fermentation indicators of 29 sweet potato varieties in Henan province. Correlation analysis between main component contents of sweet potato and the fermentation indicators were carried on. The results showed that there was strong linear correlation between dry matter content and bioethanol yield (R2 = 0.935). In order to prove the conclusion, we also tested dry matter content and ethanol yield of another 24 sweet potato varieties. Based on the dry matter content and linear correlations, we predicted the ethanol yields. We performed correlation analysis between the predicted values and the measured values of bioethanol yield of the 24 sweet potato varieties, and found highly significant positive correlation between the predicted values and the measured values. These results confirmed the reliability of using dry matter content for bioethanol production prediction for sweet potatoes.

Effects of Cattle-Cud Digester on Soil Properties and Yield of Sweet Potato on Acid Sand of Akwa Ibom State, Nigeria

Holistic management of arable soil is key to dealing with the most complex [1], dynamic, and interrelated soil properties, thereby maintaining sustainable agricultural...

Herbicide systems including linuron for Palmer amaranth (Amaranthus palmeri) control in sweetpotato

AbstractField studies were conducted to determine sweetpotato tolerance to and weed control from management systems that included linuron. Treatments included flumioxazin preplant (107 g ai ha−1) followed by (fb) S-metolachlor (800 g ai ha−1), oryzalin (840 g ai ha−1), or linuron (280, 420, 560, 700, and 840 g ai ha−1) alone or mixed with S-metolachlor or oryzalin applied 7 d after transplanting. Weeds did not emerge before the treatment applications. Two of the four field studies were maintained weed-free throughout the season to evaluate sweetpotato tolerance without weed interference. The herbicide program with the greatest sweetpotato yield was flumioxazin fb S-metolachlor. Mixing linuron with S-metolachlor did not improve Palmer amaranth management and decreased marketable yield by up to 28% compared with flumioxazin fb S-metolachlor. Thus, linuron should not be applied POST in sweetpotato if Palmer amaranth has not emerged at the time of application.

The effect of cattle manure and mineral fertilizers on soil chemical properties and tuber yield of purple-fleshed sweet potato in the dryland region of East Nusa Tenggara, Indonesia

Abstract. Nur MSM, Arsa IGBA, Malaipada Y. 2019. The effect of cattle manure and mineral fertilizers on soil chemical properties and tuber yield of purple-fleshed sweet potato in the dryland region of East Nusa Tenggara, Indonesia. Trop Drylands 3: 56-59. A field experiment was carried out to study the effect of combination of cattle manure and mineral fertilizer on the soil chemical properties and yield of purple-fleshed sweet potato in the Integrated Field Laboratory of Archipelagic Dryland Center of Excellence, Universitas Nusa Cendana during November 2017 to March 2018. The experiment was arranged in a Randomized Block Design, with six treatments and four replicates. The assigned treatments were P0 = without manure and without mineral fertilizer, P1 = 100% recommended dosage of manure (20 tons ha-1), P2 = 75% recommended dosage of manure (15 tons ha-1) + 25% recommended dosage of mineral fertilizer (25 kg urea ha-1, 25 kg SP-36 ha-1 and 37.5 kg KCl ha-1), P3 = 50% recommended dosage of manure (10 tons ha-1) + 50% recommended dosage of mineral fertilizer (50 kg urea ha-1, 50 kg SP-36 ha-1 and 75 kg KCl ha-1), P4 = 25% recommended dosage of manure (5 tons ha-1) + 75% recommended dosage of mineral fertilizer (75 kg urea ha-1, 75 kg SP-36 ha-1 and 112.5 kg KCl ha-1), and P5 = 100% recommended dosage of mineral fertilizer (100 kg urea ha-1, 100 kg SP-36 ha-1, 150 kg KCl ha-1). The results showed that P1 and P2 treatments produced the highest contents of organic-C, total-N, available-P, exchangeable-K and soil Cation Exchange Capacity. However, the highest tuber weight was obtained in the treatment P3. These results indicated that the combination of 50% recommended manure dosage (10 tons ha-1) + 50% recommended mineral fertilizer dosage (50 kg urea ha-1, 50 kg SP-36 ha-1 and 75 kg KCl ha-1) could provide a balanced nutrient content in sufficient quantities that meet the sweet potato requirements from the early growth stage to the tuber formation stage, and create soil physical conditions that support the sweet potato tuber development.

Yield potential of sandponically produced sweetpotato (Ipomoea batatas (L.) Lam) pre-basic seed for selected genotypes

Abstract Sufficient sweetpotato (Ipomoea batatas (L.) Lam) pre-basic seed at the start of the “seed” value chain is critical and often a bottleneck in the production of sweetpotato in Sub-Saharan Africa. Predominantly, pre-basic seed is multiplied in screenhouse using the conventional soil substrate method which is costly, is untenable, and achieves sub-optimal yields. The sandponics system is a better alternative for sweetpotato pre-basic seed multiplication in the screenhouse attributed to increased yields and cost-effectiveness. This experiment compared sweetpotato yield- and growth-related traits of planting materials sourced from the sandponics system with conventional soil substrate planting materials for four genotypes when grown in the field. A randomized complete block design was used with three replicates. Results showed a significant difference (p ≤ 0.05) between sources of planting materials and among genotypes for the measured traits. The interaction of source of planting materials and genotype was significant (p ≤ 0.05) for harvest index. Vine survival, storage root yield, number of storage roots per plant, and vine yield were higher by 4.1%, 24%, 27%, and 24%, respectively, in favor of planting materials sourced from the sandponics system. Sandponically multiplied planting materials showed superior performance for yield and most of the measured growth-related traits to planting materials multiplied by the conventional soil substrate method.

Impact of reduced rates of 2,4-D and glyphosate on sweetpotato growth and yield

AbstractCommercialization of 2,4-D–tolerant crops is a major concern for sweetpotato producers because of potential 2,4-D drift that can cause severe crop injury and yield reduction. A field study was initiated in 2014 and repeated in 2015 to assess impacts of reduced rates of 2,4-D, glyphosate, or a combination of 2,4-D with glyphosate on sweetpotato. In one study, 2,4-D and glyphosate were applied alone and in combination at 1/10, 1/100, 1/250, 1/500, 1/750, and 1/1,000 of anticipated field use rates (1.05 kg ha−1 for 2,4-D and 1.12 kg ha−1 for glyphosate) to ‘Beauregard’ sweetpotato at storage root formation (10 days after transplanting [DAP]). In a separate study, all these treatments were applied to ‘Beauregard’ sweetpotato at storage root development (30 DAP). Injury with 2,4-D alone or in combination with glyphosate was generally equal or greater than with glyphosate applied alone at equivalent herbicide rates, indicating that injury is attributable mostly to 2,4-D in the combination. There was a quadratic increase in crop injury and quadratic decrease in crop yield (with respect to most yield grades) with increased rate of 2,4-D applied alone or in combination with glyphosate applied at storage root development. However, neither the results of this relationship nor of the significance of herbicide rate were observed on crop injury or sweetpotato yield when herbicide application occurred at storage root formation, with a few exceptions. In general, crop injury and yield reduction were greatest at the highest rate (1/10×) of 2,4-D applied alone or in combination with glyphosate, although injury observed at lower rates was also a concern after initial observation by sweetpotato producers. However, in some cases, yield reduction of U.S. no.1 and marketable grades was also observed after application of 1/250×, 1/100×, or 1/10× rates of 2,4-D alone or with glyphosate when applied at storage root development.

Reduced Rates of Glyphosate in Combination with 2,4-D and Dicamba Impact Sweetpotato Yield

Commercialization of crops tolerant to application of 2, 4-dichlorophenoxyacetic acid (2,4-D) and dicamba is a cause of major concern for sweetpotato (Ipomoea batatas) producers regarding potential negative impacts due to herbicide drift or sprayer contamination events. A field study was initiated in 2016 and repeated in 2017 to assess impacts of reduced rates of combinations of glyphosate with 2,4-D or dicamba on sweetpotato growth and production. Reduced rates of 1/10x, 1/33x, 1/66x, and 1/100x of a 1x rate of glyphosate at 1 lb/acre plus 2,4-D choline at 0.94 lb/acre and glyphosate at 1 lb/acre plus diglycolamine salt of dicamba at 0.5 lb/acre were applied to ‘Beauregard’ sweetpotato at 10 or 30 days after transplanting. With respect to visual injury, in general glyphosate plus dicamba proved to be more injurious than glyphosate plus 2,4-D, especially within the lower rate range. In most cases injury was greater at the later application timing. In either case, typical hormonal herbicide symptomology was quite evident 35 days after application. With respect to U.S. No. 1 and total (U.S. No. 1, canner, and jumbo grade) sweetpotato yield, greatest negative impact was observed with herbicide application at the upper rate range, particularly the 1/10 and 1/33x rates, and at the later application timing regardless of herbicide applied.

Efforts to increase production sweet potato as raw materials Kaya Beta Karoten flour by using compost baglog mushroom waste

Research-based community partnership program activities involve two partners, namely the Murti Lestari Farmer Group and Agrina Creation UKM in Helvetia Village, XI Gang Sawit Hamlet, Labuhan Deli District Deli Serdang Regency. This dedication activity is the application of the results of research that had been carried out two years earlier which was USU's Talent Grants in 2017 and 2018. The problem faced was the lack of understanding of oyster mushroom baglog waste management techniques that have the potential to pollute the environment, on the other hand the farmer group Murti Lestari also experienced difficulties in increasing the quantity and quality of sweet potato production which is also widely cultivated in this village. The low interest of farmers is also encouraged because of the low price of sweet potato products and a relatively limited shelf life. The method implemented for training and discussion, accompanied by the practice of making compost from mushroom baglog waste, the practice of preparing planting material in the form of local sweet potato clones with high beta carotene content, compost application in sweet potato cultivation, maintenance to harvesting and post-harvest process using processing equipment into sweet potato flour rich in beta carotene and various other processed food products. Activities that have been carried out are training on composting of baglog mushroom waste using compost counting machines and bioactivators introduced in this activity so that the composting process goes faster, training on technical culture of orange sweet potato cultivation by applying mushroom baglog compost, training on mushroom making mushrooms and composting Oyster mushroom cultivation using shelves made of mild steel and fogging using a sprayer. Production and quality of yields of sweet potatoes that were given compost baglog oyster mushroom waste increased compared without the provision of compost. The next crop is processed into sweet potato flour with high beta carotene content and various food products using an introduced machine, which is a sweet potato slicing machine, flour machine, macaroni making machine and equipment for making sweet potato flour based food processing products.