Sweetpotato Yield Research Articles

IbNF-YA1 is a key factor in the storage root development of sweet potato.

As a major worldwide root crop, the mechanism underlying storage root yield formation has always been a hot topic in sweet potato [Ipomoea batatas (L.) Lam.]. Previously, we conducted the transcriptome database of differentially expressed genes between the cultivated sweet potato cultivar "Xushu18," its diploid wild relative Ipomoea triloba without storage root, and their interspecific somatic hybrid XT1 with medium-sized storage root. We selected one of these candidate genes, IbNF-YA1, for subsequent analysis. IbNF-YA1 encodes a nuclear transcription factor Y subunit alpha (NF-YA) gene, which is significantly induced by the natural auxin indole-3-acetic acid (IAA). The storage root yield of the IbNF-YA1 overexpression (OE) plant decreased by 29.15-40.22% compared with the wild type, while that of the RNAi plant increased by 10.16-21.58%. Additionally, IAA content increased significantly in OE plants. Conversely, the content of IAA decreased significantly in RNAi plants. Furthermore, real-time quantitative reverse transcription-PCR (qRT-PCR) analysis demonstrated that the expressions of the key genes IbYUCCA2, IbYUCCA4, and IbYUCCA8 in the IAA biosynthetic pathway were significantly changed intransgenic plants. The results indicated that IbNF-YA1 could directly target IbYUCCA4 and activate IbYUCCA4 transcription. The IAA content of IbYUCCA4 OE plants increased by 71.77-98.31%. Correspondingly, the storage root yield of the IbYUCCA4 OE plant decreased by 77.91-80.52%. These findings indicate that downregulating the IbNF-YA1 gene could improve the storage root yield in sweet potato.

Impact of biochar and organic fertilizers on sweet potato yield, quality, ascorbic acid, β-carotene, sugars, and phenols contents

ABSTRACT The demand for food is increasing and the use of soil organic amendments in agricultural management practices has been instructed to increase crop yield and reduce dependence on synthetic inorganic fertilizers at low cost to limited resource farmers. However, the effect of organic amendments on the quality and nutritional composition of edible plants has received little attention. Locally available organic amendments (sewage sludge SS, chicken manure CM, cow manure Cow, vermicompost Vermi, and biochar Bio) were chosen to test their impact on field-grown sweet potato, Ipomoea batatas L. yield, root quality, and root nutritional composition. The results indicated that utilizing Cow manure in growing sweet potatoes significantly promoted root yield and root nutritional composition. Cow treatment produced the greatest number of roots compared to Bio, CM, SS, and the control treatments. The results also revealed that the concentrations of vitamin C (260. 3 µg g−1), β-carotene (45.4 µg g−1), soluble sugars (16.7 mg g−1), and total phenols (196.3 3 µg g−1 fresh roots) were greater in the roots of plants grown in Cow compared to the roots of the control treatment. The results indicated the low impact of biochar whereas Cow is recommended for enhancing sweet potato yield and nutritional composition.

Effect of potassium fertilization on storage root number, yield, and appearance quality of sweet potato (Ipomoea batatas L.).

Increasing storage root number is a pivotal approach to enhance both storage root (SR) yield and appearance quality of sweet potato. Here, 2-year field experiments were conducted to investigate the effect of 0 (K0), 120 (K1), 240 (K2), and 360 (K3) kg ha-1 potassium fertilizer (K2O) on lignin metabolism, root growth, storage root yield, and uniformity. The results demonstrated that potassium (K) application led to a decrease in the activities of key enzymes involved in lignin biosynthesis, including phenylalanine deaminase (PAL), 4-coumarate coenzyme A ligase (4-CL), cinnamic acid dehydrogenase (CAD), polyphenol oxidase (PPO), and peroxidase (POD). This resulted in a significant reduction in lignin and G-type lignin contents in potential SRs compared to K0 treatment within 10-30 days after planting (DAP). BJ553 exhibited a significant decrease in PAL activity, as well as lignin and G-type contents at 10 DAP, whereas YS25 showed delayed effects until 20 DAP. However, the number and distribution of secondary xylem conduits as well as the mid-column diameter area in roots were increased in K2 treatment. Interestingly, K2 treatment exhibited significantly larger potential SR diameter than other treatments at 15, 20, and 25 DAP. At harvest, K2 treatment increased the SR number, the single SR weight, and overall yield greatly compared with K0 treatment, with an average increase of 19.12%, 16.54%, and 16.92% respectively. The increase of SR number in BJ553 was higher than that of YS25. Furthermore, K2 treatment exhibited the lowest coefficient of variation for both SR length and diameter, indicating a higher yield of middle-sized SRs. In general, appropriate potassium application could effectively suppress lignin biosynthesis, leading to a reduction in the degree of pericycle lignification in potential SRs. This promotes an increase in the number of storage roots and ultimately enhances both yield and appearance quality of sweet potato. The effect of potassium fertilizer on lignin metabolism in BJ553 roots was earlier and resulted in a greater increase in the SR number compared to YS25.

Sweet potato yield and quality characteristics affected by different late-season irrigation levels.

Seasonal late-season water deficits negatively affect the yield and quality of sweet potatoes in northern China. However, the amount of late-season irrigation to achieve high yield and consistent quality storage root remains undetermined. We assessed the yield and some qualitative traits of sweet potatoes such as size, shape, skin/flesh colour and nutritional content, as influenced by five irrigation levels (T0: unirrigated control; T1: 33% ETc; T2: 75% ETc; T3: 100% ETc; and T4: 125% ETc). Late-season irrigation significantly increased yield and marketable yield. Yields for T2 and T3 were significantly higher than other treatments, whereas T2 had the highest Grade A rating in a 2-year test. The vertical length of storage roots gradually increased with an increase in irrigation level, whereas the maximum width remained unchanged. The proportion of long elliptic and elliptic storage roots also increased, whereas the proportion of ovate, obovate and round storage roots gradually decreased. The skin and flesh colours became more vivid as the level of irrigation increased, with the skin colour becoming redder and the flesh colour becoming more orange-yellow. The levels of carotenoids, vitamin C and soluble sugar were significantly higher in irrigated crops, with the highest vitamin C and soluble sugar levels in T2 and the highest carotenoid levels in T3 treatment. Taken together, these results demonstrate the potential of moderate irrigation in the late-season to improve both yield production and quality potential. The results are of great importance for improving the market value of sweet potatoes and increasing grower profits. © 2024 Society of Chemical Industry.

Selection for representative environment to identify high yielding and sweetness levels of sweet potato (Ipomoea batatas L.) in Indonesia

Abstract. Solihin E, Santosa DA, Nugroho B, Purwono, Sudirja R, Maulana H, Kamaluddin NN, Karuniawan A, Anwar S. 2024. Selection for representative environment to identify high yield and sweetness levels of sweet potato (Ipomoea batatas) in Indonesia. Biodiversitas 25: 386-391. Sweet potato is one of the important and commercial agricultural commodities in the world. Yield and sweetness levels are important traits that can influence consumer preferences. Environment is an important factor in the development of sweet potatoes. A suitable environment will provide high yields and good quality. The objectives of this study were to examine the significance and relevance of sweet potato yield and sweetness levels in two locations (Sumedang and Bandung District) and to select representative environments for sweet potato yield and sweetness levels. The research was conducted in Sumedang and Bandung districts on lowland paddy field and dry land. The field experiment used a factorial randomized completed block design with three repetitions. The significance and relevance of sweet potato yield and sweetness levels was analysis using T-test. Representative environments were identified by GGE biplot. The results showed that the Bandung and Sumedang environments showed significant differences in yield but not in sweetness. The Bandung paddy field is the most representative environment for yield, while the Sumedang dry field and Bandung dry field are the most representative environments for sweetness. The results of this research can be used by researchers, farmers and industrial users in the sweet potato development program, especially the yield and yield quality.

Effects of Agricultural Photovoltaic Systems Development on Sweet Potato Growth

Agricultural Photovoltaic (APV) has become more popular worldwide. Its core idea is to generate electricity and grow crops simultaneously on the same farmland. We developed two APV, Spectrum Splitting and Concentrated APV (SCAPV) and Even-lighting Agricultural Photovoltaic (EAPV). Our previous studies have investigated electricity generation, enhanced growth of plants/crops, and reduced water evaporation simultaneously on the same farmland. Furthermore, SCAPV and EAPV examined the better quality and increased yield of many plants, such as lettuce and cucumber. However, the effects of SCAPV and EAPV on sweet potato quality and yield have not been studied. Therefore, this study aims to investigate the impact of SCAPV and EAPV on evapotranspiration (ET) and sweet potato quality and yield. We conducted three treatments: SCAPV, EAPV, and open-air (CK). We planted 32 m2 of sweet potatoes and placed a weather station in each treatment. Our results showed that the 32 m2 of sweet potato yield under SCAPV, EAPV, and CK were 121.53 kg, 99.55 kg, and 77.84 kg, respectively. The dry rate in CK was 11.75% lower than 13.41% and 13.81% under SCAPV and EAPV, respectively. Soluble sugar content increased under EAPV. Anthocyanin content under SCAPV improved. Therefore, SCAPV and EAPV positively affect dry matter accumulation and enhance the sweet potato's growth. Average ET under SCAPV and EAPV compared with CK significantly reduced by 31% and 23%. SCAPV and EAPV could reduce irrigation and provide feasible green energy and sustainable APV solutions.

Different regions and environments have critical roles on yield, main quality and industrialization of an industrial purple-fleshed sweetpotato (Ipomoea batatas L. (Lam.)) “Xuzishu8”

Purple-fleshed sweetpotato (PFSP) (Ipomoea batatas (L.) Lam), whose flesh is purple to dark purple, is a special variety type of sweetpotato, which has the characteristics of food crop, industrial crop and medicinal crop. The storage root (SR) of PFSP is rich in anthocyanins, starch, protein, soluble sugar, mineral elements, polyphenol, dietary fiber and so on, which has balanced and comprehensive nutritional value. And in recent years, its unique nutritional elements are increasingly known for their health functions. At present, there is no article on the characteristics and quality analysis of industrial xz8 variety. To explore the influence of different environments on the processing quality of xz8, we selected nine regions (Xuzhou, Jiawang, Pizhou, Xinyi, Peixian, Sihong, Yanchen, Xiangyang and Tianshui) to measure its yield and quality changes. The data demonstrated that xz8 has a very consistent high yield performance. In Tianshui, the anthocyanins, protein and minerals contents were significantly higher and yield also above average. Moreover, the variety with the lowest starch content exhibited the best taste. On the basis of the above results, it suggested that quite practicable to promote xz8 cultivation and suitable for processing in these areas. Thus, our present findings improve our understanding of xz8 variety and provide the basis for the industrial production of PFSP with strong prospects for success.

Relationship of potassium doses with bioethanol yield in sweet potato in Cerrado soil

Sweet potato-bioethanol yield was evaluated in response to potassium fertilizer application. Experiments were performed using a 5 × 2 factorial design in which factors included the amount of K2O applied to the soil, with five levels (0, 30, 60, 120, and 240 kg ha-1) and genotype, with two levels (industrial genotype BDGPI #25 and table genotype BDGPM #04). Root yield, root starch and soluble solid contents, bioethanol yield, and economic viability of potassium application for bioethanol production were evaluated. Potassium affected root yield of both genotypes, with the highest yield observed at 140 kg K2O ha-1. Root starch concentration at harvest depended on genotype potential rather than potassium dose. Soluble solid content in fresh roots was lower than that in cooked roots, in which case, maximum conversion efficiency was observed at 109,69 and at 123.75 kg K2O ha-1 for BDGPM#04 and BDGPI#25, respectively. Bioethanol yield reached 10,484 and 9,839 L ha-1 at 151.87 and 136 kg K2O ha-1 for BDGPI#25 and BDGPM#04, respectively. Genotype BDGPI#25 was more efficient than sugarcane in converting potassium to bioethanol at 151.87 kg K2O ha-1, producing 10,484.29 L of bioethanol. In turn, BGDPM#04 showed maximum conversion efficiency relative to sugarcane at 122 kg K2O ha-1.

Tripartite Introductions of PGPR, Humic Acid, and N-Fertilizer Improve the Growth and Yield of Sweet Potato Under Glasshouse Conditions

This study was undertaken to investigate the effects of plant growth-promoting rhizobacteria (PGPR) with humic acid (HA) as amendments on the morphological and physiological growth characteristics and yield of Sepang Oren sweet potato (Ipomoea batatas[L.] Lam). The experiment was conducted under glasshouse conditions at the Faculty of Agriculture, Universiti Putra Malaysia, for 110 days. Two factors were used in this experiment: The first factor was PGPR-HA inoculations (UPMB10, UPMRB9, and mixed strains) and non-inoculation-HA, and the second factor was the Nitrogen fertilizer levels (50, 75, and 100%). The treatments were replicated three times and arranged factorially in a randomized complete block design. The results showed that inoculations with PGPRs-HA (UPMRB9 and UPMB10 strains) positively affect the plant growth significantly (SPAD measurements, number of leaves, vine length, root length, leaf area index, root dry weight, shoot dry weight, and root: shoot ratio) of sweet potato upon addition of 50% and 75% of N-fertilizer, respectively. The nutrient content of soil and plant leaf significantly increased by 12-15% and 14-18%, respectively, compared to the uninoculated, when applied with the same inoculation. After 30 days, the population of soil bacteria increased, reaching a value of 8.65 log10 CFU/g soil. The use of PGPR-HA inoculations with N-fertilization resulted in a considerable rise in the majority of plant and soil parameters compared to the treatments without PGPR inoculation. Therefore, PGPR supplemented with humic acid (HA) may be considered a viable and sustainable strategy for enhancing sweet potatoes' morphological and physiological attributes. This technique can result in increased crop productivity and serve as a substitute for nitrogen-based fertilizers.

Effect of Different Tillage Practices on the Growth and Yield of Sweet Potatoes (Ipomoeo Batata L) in Asaba, Delta State Nigeria.

The research was carried out to determine the effect of different tillage practices on the growth and yield of sweet potatoes (Ipomoeo batata L) in Asaba, Delta State Nigeria. Field experiment was carried out at the teaching and research farm of Federal College of Education (Technical),Asaba, Delta State Nigeria. The experiment was laid out in a randomized complete block design (RCBD) made up of four treatments: To – control (ridge tillage), T1 – Zero tillage, T2 – Mound tillage, T3 – Flat tillage and was replicated three times (4 x 3). Land area of 100m x 100m was cleared and divided into three to represent, replicates 1, 2 and 3. Random samples of five plants were tagged for data collection at four, six and eight weeks’ intervals after germination of plants to measure the growth parameters, while yield was measured in kg using weighing scale. Data analysis was carried out using the statistical package of social science (SPSS) with general linear model procedure analysis of variance (ANOVA) to determine the treatment effect and Duncan Multiple Range Test was used for mean separation difference in mean were considered significant at an alpha level of 95% or higher (p ≤ 0.05). Findings from the study revealed that tillage practices had significant effect (p<0.05) on the growth and yield of sweet potatoes. The study recommended the adoption of ridge tillage practices for increased growth and yield of sweet potatoes.

Effects of pesticide treatment against nematode disease on soil bacterial community structure and sweet potato yield and quality

AbstractSweet potato stem nematode disease is a devastating disease, which seriously affects the yield and quality of sweet potato (Ipomoea batatas (L.) Lam.). At present, soil treatment with pesticides is mainly used to prevent sweet potato stem nematode disease. In this study, Illumina MiSeq high‐throughput sequencing technology was used to analyze the diversity of soil bacterial and fungal communities treated with different pesticides. At the same time, high performance liquid chromatography was used to determine the pesticide residues in soil and sweet potato, and the impact on sweet potato yield was investigated. Kruskal–Wallis test was used to analyze the four α‐diversity indexes of soil under different pesticide treatments, and the differences were not significant (p > 0.05), indicating that there was no significant difference in the diversity and abundance of bacterial and fungal communities in soil under different pesticide treatments. The results of principal coordinate analysis showed that there was no significant difference in bacterial and fungal community structure among different pesticide treatments (p > 0.05). Pesticide residue analysis and yield statistics of sweet potato showed that the residual amount of three kinds of pesticides in sweet potato did not exceed the maximum limit stipulated by the current National Standards for Food safety (GB2763‐2021). When 5% chlorpyrifos phoxim particles were applied at 15.18 kg/acre, sweet potato was unaffected by pests and diseases basically, and the yield was the highest.

Effects of Various Potassium Fertilizer Dosages on Agronomic and Economic Assessment of Sweet Potato Fields

To explore the effects of various potassium fertilizer dosages on sweet potatoes, field experiments were conducted in 2018 and 2019 using a randomized block design. In the experiment, the control (completely blank, no fertilizer), KS0 (potassium blank, no potassium fertilizer), KS100 (100 kg K2O ha−1), KS200 (200 K2O ha−1), and KS300 (300 K2O ha−1) treatments were set up. The application of potassium fertilizer increased the potassium content of sweet potato plants, thereby increasing the chlorophyll content, net photosynthetic rate, and the fluorescence chlorophyll parameters. It also increased the amylose content in tuber roots to increase the total starch content and yield of sweet potatoes. Specifically, the KS200 treatment significantly improved the soil potassium content, potassium absorption, potassium agronomic efficiency, and potassium recovery efficiency. Compared with the other treatments, the yield and net profit of the KS200 treatment increased by 0.89–27.05% and 2.34–30%, respectively, on average, over two years. Based on factors such as sweet potato yield and starch content, the recommended amount of potassium fertilizer was 200 kg ha−1, which has significant economic benefits and theoretical value.

Effect of S-metolachlor and flumioxazin herbicides on sweetpotato treated with and without activated charcoal applied through transplant water

Abstract Flumioxazin and S-metolachlor are widely used in conventional sweetpotato production in North Carolina and other states; however, some growers have recently expressed concerns about potential effects of these herbicides on sweetpotato yield and quality. Previous research indicates that activated charcoal has the potential to reduce herbicide injury. Field studies were conducted in 2021 and 2022 to determine whether flumioxazin applied preplant and S-metolachlor applied before and after transplanting negatively affect sweetpotato yield and quality when activated charcoal is applied with transplant water. The studies evaluated five herbicide treatments and two activated charcoal treatments. Herbicide treatments included two flumioxazin rates, one S-metolachlor rate applied immediately before and immediately after transplanting, and no herbicide. Charcoal treatments consisted of activated charcoal applied at 9 kg ha−1, and no charcoal. No visual injury from herbicides or charcoal was observed. Likewise, no effect of herbicide or charcoal treatment on no. 1, marketable (sum of no. 1 and jumbo grades), or total yield (sum of canner, no. 1, and jumbo grades) was observed. Additionally, shape analysis conducted on calculated length-to-width ratio (LWR) for no. 1 sweetpotato roots found no effect from flumioxazin at either rate on sweetpotato root shape. However, both S-metolachlor treatments resulted in lower LWR of no. 1 sweetpotato roots in 2021. Results are consistent with prior research and indicate that flumioxazin and S-metolachlor are safe for continued use on sweetpotato at registered rates.

Effect of in-row spacing on weed suppression and yield of ‘Covington’ and ‘Monaco’ sweetpotato

Abstract Organic sweetpotato growers have limited effective weed management options, and most rely on in-season between-row cultivation and hand weeding, which are time consuming, are costly, and deteriorate soil quality. Studies were conducted at the Samuel G. Meigs Horticulture Research Farm, Lafayette, IN, and at the Southwest Purdue Agricultural Center, Vincennes, IN, in 2022 and 2023 to determine the effects of in-row plant spacing and cultivar selection on weed suppression and organic sweetpotato yield. The experiment was a split-split plot design, with in-row spacings of 20, 30, and 40 cm as the main plot factor, weeding frequency (critical weed-free period and weed-free) as the subplot factor, and sweetpotato cultivar (‘Covington’ and ‘Monaco’) as the sub-subplot factor. However, in 2022, we evaluated only in-row spacing and weeding frequency because of the poor establishment of ‘Monaco’. In 2023, sweetpotato canopy at 5 wk after transplanting (WAP) decreased as in-row spacing increased from 20 to 40 cm, and sweetpotato canopy cover of ‘Monaco’ (62%) was greater than that of ‘Covington’ (44%). In-row spacing did not affect weed density at 4, 5, and 6 WAP. As in-row spacing increased from 20 to 40 cm, total sweetpotato yield pooled across both locations in 2023 decreased from 30,223 to 21,209 kg ha−1 for ‘Covington’ and from 24,370 to 20,848 kg ha−1 for ‘Monaco’; however, jumbo yield increased for both cultivars. Findings from this study suggest that an in-row spacing of 20 cm may provide greater yield than the standard spacing of 30 cm for both ‘Monaco’ and ‘Covington’.

Effect of anti-ethylene and cytokinin biostimulants on flowering and yield of Sweetpotato (Ipomoea batatas L.)

Breeding is needed to enhance the poor agronomic and qualitative attributes of the majority of sweetpotato cultivars grown in Nigeria. Even though the majority of cultivars don't often flower, the flowers are essential for genetic advancements. This study aimed to assess the effect of anti-ethylene (Silver-thiosulphate) and cytokinin (6-benzyladenine) biostimulants for induction of flowering and yield, to encourage early flowering of delayed sweetpotato genotype, and to ascertain the ideal concentration of growth regulators for sweetpotato flowering induction. A randomized complete block design with three replications was fitted with a 3x3x2 factorial arrangement. The first factor consisted of three different concentrations of two plant growth regulators (PGR): silver thiosulphate (STS) and 6-benzyladenine (BA) (0, 50, and 100 ppm). Three types of sweet potatoes (Umuspo3, Buttermilk, and Tis87) constituted the second factor. After planting, the BA and STS were administered three weeks later. The sweet potato varieties sprayed with STS and BA displayed morphological and physiological challenges, such as stem drooping (Temporal) (Page 1A), which recovered in 24 hours, root swelling, stem splitting, bud and flower production, vine branching, and elongation (Plate 1B). Varieties sprayed with high concentrations of STS (100 ppm) displayed significant morphological and physiological abnormalities, while those sprayed with BA displayed a significant increase in all growth metrics. However, two of the varieties Umuspo3 and Tis87 that were sprayed with STS and BA began buds and set flowers within two weeks after the treatment, whereas the plants that were not sprayed did not flower at all. The results of the interactions showed that the combination of benzyladenine + Umuspo3 at 100% (100T1V1) was superior for yield, whereas the combination of silver thiosulphate + Umuspo3 at 100% (100T2V1) was superior for the total number of flowers/plant. The vegetative growth parameters and the flowering characteristic exhibited a substantial positive connection (P<0.05), however the correlation between the vegetative growth traits and the yield traits was negative. As a result, the higher dosage of BA and STS (100 ppm) that was employed in this experiment is most likely quite near to the ideal concentration for sweet potato flower induction. Despite not being the ideal concentration, sweet potatoes can currently be induced to flower at this level, enabling the start of breeding programs for the crop.

Genome-Wide Analysis of Sweet Potato Ammonium Transporter (AMT): Influence on Nitrogen Utilization, Storage Root Development and Yield.

Ammonium, as a major inorganic source of nitrogen (N) for sweet potato N utilization and growth, is specifically transported by ammonium transporters (AMTs). However, the activities of AMT family members in sweet potatoes have not been analyzed. In the present study, the sweet potato cultivar 'Pushu 32', which is planted in a large area in China, was used in field experiments at the Agricultural Base of Hainan University (20°06' N, 110°33' E) in 2021, and Sanya Nanfan Research Institute of Hainan University (18°30' N, 109°60' E) in 2022. Four N levels were tested: 0, 60, 120, and 180 kg ha-1. The results are as follows. Twelve IbAMT genes were identified in the sweet potato genome, which were classified into three distinct subgroups based on phylogeny; the same subgroup genes had similar properties and structures. IbAMT1.3 and IbAMT1.5 were mostly expressed in the storage roots under N deficiency. Compared with the NN and HN groups, IbAMT1.3 and IbAMT1.5 expressions, N content in storage roots, N uptake efficiency at the canopy closure, N fertilization contribution rates, number of storage roots per plant, storage root weight, and yield were all increased in the MN group. Furthermore, there was a significant positive correlation between the expressions of IbAMT1.3 and IbAMT1.5 with N content in the storage roots of sweet potato. In a word, IbAMT1.3 and IbAMT1.5 may regulate N utilization, affect the development of the storage root. and determine the yield of sweet potato. The results provide valuable insights into the AMT gene family's role in the use of N and effects on storage root development and yield in sweet potatoes.

Effect of Foliar Spray with Zinc, Boron, Calcium and Potassium on Growth, Yield, and Tuber Root Quality of Sweet Potato.

Effect of Foliar Spray with Zinc, Boron, Calcium and Potassium on Growth, Yield, and Tuber Root Quality of Sweet Potato.

Nutrient Uptake and Efficiencies of Orange-Fleshed Sweet Potato (Ipomoea batatas L.) Varieties under Different Rates of Nitrogen and Phosphorus Fertilizers

Sweet potatoes serve as a staple food and animal feed in Africa and serve as a source of raw materials for the food, feed, pharmaceutical, cosmetic, chemical, and energy industries. The yield of orange-fleshed sweet potatoes is increased when nitrogen (N) and phosphorus (P) are added to low-fertility soils. The objective of this study was to evaluate the nutrient uptake and use efficiency of orange-fleshed sweet potato varieties under applied N and P. The experiment was conducted for two growing seasons (2019 and 2020) under rain-fed conditions in the field. The study included five orange-fleshed sweet potato varieties (Kulfo, Kabode, Alamura, Dilla, and NASPOT-12), three N levels (0, 23, and 46 kg·N·ha−1), and two levels of P (0 and 46 kg P2O5·ha−1) fertilizers designed in 5 × 3 × 2 with α-lattice design in factorial arrangement using 3 replications. The interaction effect of variety, N, and P fertilizers affected nutrient uptake, physiological efficiency, and agronomic efficiency of sweet potatoes. NASPOT-12 was the better variety in nutrient uptake but poor in apparent recovery at all levels of N and P. The highest nutrient uptake, agronomic efficiency, and physiological efficiency were observed on NASPOT-12 when subjected to 23 kg N·ha−1 and 46 kg P2O5·ha−1. Overall, NASPOT-12 with 23 kg·N·ha−1 and 46 kg P2O5·ha−1 could be recommended for its high nutrient uptake, agronomic, and physiological efficiencies.

Effects of plant spacing and rates of NPK application on the growth and yield of sweetpotato var NSIC SP30

Sweetpotato yield may be increased through effective crop management practices including plant spacing and fertilization. This study was conducted in an alluvial soil (Inceptisol) to evaluate the effects of plant spacing and rates of NPK application on the growth and yield of NSIC Sp30 sweetpotato. The experiment was laid out in a split plot arranged in RCBD with three replications. Three plant spacing treatments were designated as the main plot D1(75cmx25cm), D2(100cmx25cm), and D3(100cmx50cm). The rates of NPK application were designated as the subplot: F0(no NPK), F1(40-40-60kg ha-1 NPK), F2(60-60-90kg ha-1 NPK), and F3(80-80-120kg ha-1 NPK). Plant spacing significantly affected the number of lateral vines, weight of marketable roots, number of marketable roots, root length, and the total root yield of NSIC Sp30 sweetpotato. An interaction effect was observed between the plants spaced at 100cmx50cm with NPK application resulting in more medium-sized roots. Plants spaced at 75cmx25cm produced the highest total root yield of 7.67t ha-1. Application of NPK significantly influenced the length of main vines, fresh herbage yield, the weight of marketable roots, number of marketable roots, root length, root diameter, total root yield, LAI and HI. A higher yield of marketable roots 7,208.85kg ha-1 and a total root yield of 8.51t ha-1 were observed for plants applied with 40-40-60 kg ha-1 NPK. The growth and yield performance of NSIC Sp30 is better when plants are spaced at 75cmx25cm with 53,333 plants ha-1 and fertilized with 40-40-60kg ha-1 of NPK.

Large-scale and cost-efficient agrivoltaics system by spectral separation

Agrivoltaics (AV) offers a promising solution to address both food and energy crises. However, crop growth under photovoltaic (PV) conditions faces substantial challenges due to insufficient light transmission. We propose a large-scale and cost-effective spectral separated concentrated agricultural photovoltaic (SCAPV) system. The system utilizes concentrator modules, cell components, and dual-axis tracking systems to enhance power conversion efficiency (PCE), achieving a maximum PCE of 11.6%. After three years of successful operation, a 10kWp power plant achieved an average annual electricity generation exceeding 107 MWh/ha. The results showed higher yields of various crops, including ginger and sweet potatoes, and significant improvements in soil moisture retention compared to open air. The improvements in PCE and microclimate validate the scalability of the SCAPV, which provides better plant conditions and cost-effectiveness, with an estimated cost reduction of 18.8% compared to conventional PV power plant. This study provides valuable insights and directions for improvement in AV.