Storage Root Quality Research Articles

Pre-harvest application of sodium nitroprusside enhances storage root quality in red beet cultivated under normal and drought conditions.

The role of nitric oxide (NO) in plant stress tolerance, as well as in increasing post-harvest quality, has been extensively demonstrated in several fruits and vegetable crops; however, the effects of its pre-harvest application on post-harvest quality are still poorly documented. Therefore, the pre-harvest application of NO in red beet (Beta vulgaris subsp. vulgaris) plants cultivated under well-watered and drought conditions was evaluated to assess whether it improves the post-harvest quality of their storage roots. Red beet plants cultivated under well-watered (80% of water holding capacity) or drought condition (15% of water holding capacity) were sprayed weekly with water (control) or 100 μmol L-1 sodium nitroprusside (SNP), an NO donor. Sixty-six days after sowing, red beet roots were harvested, and root yield, total sugar yield, reducing sugars, non-reducing sugars, proteins, lipids, root ashes, root moisture, soluble solids, titratable acidity, pH, vitamin C, total phenolics, total betalains, betacyanins, betaxanthins and antioxidant capacity were determined. While drought led to a reduction in root yield, sugars, lipids and titratable acidity, it increased phenolic compounds, betalains and the antioxidant capacity of beets. SNP reversed the negative effects of drought on sugar, lipid and organic acid contents and increased antioxidant capacity independent of stress. Pre-harvest SNP treatment reversed drought-induced yield reductions in beets, while boosting bioactive compounds and antioxidant capacity. It also enhanced vitamin C content independently, indicating its dual role in stress mitigation and beet quality improvement. Future research should explore other crops and stress conditions. © 2024 Society of Chemical Industry.

Enhancing Reniform Nematode Management in Sweetpotato by Complementing Host-Plant Resistance with Nonfumigant Nematicides.

The reniform nematode (Rotylenchulus reniformis Linford and Oliveira) adversely impacts the quality and quantity of sweetpotato storage roots. Management of R. reniformis in sweetpotato remains a challenge because host plant resistance is not available, fumigants are detrimental to the environment and health, and crop rotation is not effective. We screened a core set of 24 sweetpotato plant introductions (PIs) against R. reniformis. Four PIs were resistant, and 10 were moderately resistant to R. reniformis, suggesting these PIs can serve as sources of resistance for sweetpotato resistance breeding programs. PI 595869, PI 153907, and PI 599386 suppressed 83 to 89% egg production relative to the susceptible control 'Beauregard', and these PIs were employed in subsequent experiments to determine if their efficacy against R. reniformis can be further increased by applying nonfumigant nematicides oxamyl, fluopyram, and fluensulfone. A 34 to 93% suppression of nematode reproduction was achieved by the application of nonfumigant nematicides, with oxamyl providing the best suppression followed by fluopyram and fluensulfone. Although sweetpotato cultivars resistant to R. reniformis are currently not available and there is a need for the development of safer yet highly effective nonfumigant nematicides, results from the current study suggest that complementing host plant resistance with nonfumigant nematicides can serve as an important tool for effective and sustainable nematode management.

Optimizing sweet potato production: insights into the interplay of plant sanitation, virus influence, and cooking techniques for enhanced crop quality and food security.

This study investigates the impact of sweet potato plant sanitation on the yield and external and internal quality root storage exploring the nutritional content affected by various cooking methods (raw, boiled, and oven-cooked). The presence of viruses, and concretely of the sweet potato leaf curl virus (SPLCV), in sweet potato propagation material is shown to significantly reduce yield and modify storage root quality. Notably, the research reveals a substantial improvement in crop yield and external quality, reinforcing the efficacy of plant sanitation methods, specifically apical meristem culture, in preserving the overall productivity of sweet potato crops. Furthermore, the investigation identifies a noteworthy decrease in starch content, suggesting a dynamic interaction between plant sanitation and starch metabolism in response to viral diseases. The study also delves into the alteration of mineral absorption patterns, shedding light on how plant sanitation influences the uptake of essential minerals in sweet potato storage roots. While the health status of the plants only slightly affected magnesium (Mg) and manganese (Mn) accumulation, indicating a potential resilience of mineral balance under virus-infected conditions. Moreover, the research identifies significant modifications in antioxidant levels, emphasizing the role of plant sanitation in enhancing the nutritional quality of sweet potatoes. Heat-treated storage roots, subjected to various cooking methods such as boiling and oven-cooking, exhibit notable differences in internal quality parameters. These differences include increased concentrations of total soluble solids (SS) and heightened levels of antioxidant compounds, particularly phenolic and flavonoid compounds. The observed increase in antioxidant capacity underscores the potential health-promoting benefits associated with plant sanitation practices. Overall, the study underscores the critical importance of plant sanitation in enhancing sweet potato production sustainability, contributing to food security, and supporting local agricultural economies. The results emphasize the need for further research to optimize plant sanitation methods and promote their widespread adoption globally, providing valuable insights into the complex relationships in food quality.

Assessing socioeconomic impact of pathogen tested and conventional practice sweet potato production in the highlands of Papua New Guinea

Sweet potato (Ipomoea batatas) is a major staple food crop in Papua New Guinea (PNG), grown extensively in the high-altitude Highlands as a subsistence food crop by smallholder farmers and it is developing into commercial production for cash income. However, pests and diseases attack remain a major challenge. Most of the PNG farmers do not practice an active pests and diseases management, which has a significant impact on the yield and farmers' income. Few farmers have opted to use cultural practices, though these methods are ineffective and expensive. An alternative intervention technology through Pathogen Tested (PT) seeds as a part of Integrated Pest and Disease Management (IPDM) technology was trialed in three different zones in the Highlands of PNG and compared with the Conventional Practice (CP). The study was done using farmer participatory research approach (FPR). Pre-designed structured questionnaires were administered to collect data for yield, costs, income, and farmer's perception. The Benefit Cost Ratio (BCR) analysis was used to compare the costs, benefits, and net incomes. T-test statistics was used to compare the mean yield. The farmer perception was summarized using descriptive statistics. Results revealed that marketable sweet potato yield was significantly (P < 0.01) improved with implementation of the PT practice compared to the CP. The improvement in storage root yield had subsequent result in the net income doubled for the farmers. The yield and quality of storage roots had significant influence on the farmers' perception towards adoption of the IPDM technology.

Influence of flower bud removal on the growth and anti-inflammatory properties of Platycodon grandiflorus roots

Platycodon grandiflorus roots have been used as a popular food additive and traditional medicinal product because of their therapeutic effects. During cultivation of this crop, flower bud removal has been used to increase root yield. However, the underlying mechanisms by which flower bud removal increases the yield of P. grandiflorus roots are still unknown. In this study, to investigate the effect of flower bud removal, we analyzed the level of gibberellic acid 3 (GA3) production, anti-inflammatory properties, and polyphenolic compounds in P. grandiflorus roots. Flower bud removal led to reduced GA3 content, resulting in increased root yield. In addition, we found that the accumulation of polyphenolic compounds through induction of the phenylpropanoid pathway is presumably a positive effect of flower bud removal that improves the anti-inflammatory properties of P. grandiflorus roots. Our results revealed that flower bud removal is a promising strategy for improving yield and quality of storage roots by rebalancing the assimilate exchange between sink organs.

COMPARACIÓN DE CLONES MEJORADOS DE CAMOTE (Ipomoea batatas [L.] Lam) EN EL RENDIMIENTO Y CONTENIDO DE BIOETANOL DE RAÍCES RESERVANTES

&lt;p&gt;&lt;strong&gt;Background:&lt;/strong&gt; Sweet potato (&lt;em&gt;Ipomoea batatas&lt;/em&gt; L.) is a crop of great importance in social, economic and industrial terms due to its forage aptitude, high yield potential and quality of storage roots, necessary as human food and also as raw material for bioethanol production a promising substitute for fossil fuels or to boost alcohol production. &lt;strong&gt;Objective:&lt;/strong&gt; To compare improved sweetpotato clones under different growing seasons and to select a promising new cultivar with high yield potential and bioethanol production from storage roots in Peru. &lt;strong&gt;Methodology:&lt;/strong&gt; The combined analysis of variance was used during two seasons (summer and spring) in Lambayeque, Peru. The yield of storage roots was evaluated, with respect to the quality, the percentage of dry matter and the production of bioethanol were evaluated, which was analyzed by the enzymatic hydrolysis of the starch of four clones and a control variety. &lt;strong&gt;Results:&lt;/strong&gt; The combined analysis of variance shows that the clones presented a significant effect on the variables under study. Likewise, the clone CIP 199071.8 with the highest yield of storage roots was identified during season 1 (summer) with an average of 67.4 ± 1.2 t ha&lt;sup&gt;-1 &lt;/sup&gt;and in season 2 (spring) with 73.4 ± 0, 8 t ha&lt;sup&gt;-1&lt;/sup&gt; regarding the combined analysis obtained 70.4 ± 1.1 t ha&lt;sup&gt;-1&lt;/sup&gt;. In addition, the present clone with an average of 28.9 ± 1.4% of dry matter stands out statistically, in fact the same clone 199071.8 reported the highest bioethanol production in season 1 (summer) with an average of 7089.6 ± 2, 2 L ha&lt;sup&gt;-1&lt;/sup&gt; of bioethanol and in season 2 (spring) it reached the highest bioethanol production with an average of 7875.1 ± 1.9 L ha&lt;sup&gt;-1&lt;/sup&gt;. Regarding the combined analysis, it obtained 7553.2 ± 1.7 L ha&lt;sup&gt;-1&lt;/sup&gt; of bioethanol.&lt;strong&gt; Implications:&lt;/strong&gt; The sweet potato clones had a significant effect on the yield and quality of the storage roots, a necessary source for human food or industrial input. &lt;strong&gt;Conclusion:&lt;/strong&gt; The clone CIP 199071.8 reached the highest yield of storage roots, dry matter and bioethanol production during the two growing seasons (summer 2019 and spring 2019), therefore, it will be released as a new cultivar.&lt;/p&gt;

Stimulating the growth, storage root yield and quality of carrot plant by phosphoric acid, potassium and boric acid foliar applications

Stimulating the growth, storage root yield and quality of carrot plant by phosphoric acid, potassium and boric acid foliar applications

Discovery of a major QTL for root-knot nematode (Meloidogyne incognita) resistance in cultivated sweetpotato (Ipomoea batatas)

Key messageUtilizing a high-density integrated genetic linkage map of hexaploid sweetpotato, we discovered a major dominant QTL for root-knot nematode (RKN) resistance and modeled its effects. This discovery is useful for development of a modern sweetpotato breeding program that utilizes marker-assisted selection and genomic selection approaches for faster genetic gain of RKN resistance.The root-knot nematode [Meloidogyne incognita (Kofoid & White) Chitwood] (RKN) causes significant storage root quality reduction and yields losses in cultivated sweetpotato [Ipomoea batatas (L.) Lam.]. In this study, resistance to RKN was examined in a mapping population consisting of 244 progenies derived from a cross (TB) between ‘Tanzania,’ a predominant African landrace cultivar with resistance to RKN, and ‘Beauregard,’ an RKN susceptible major cultivar in the USA. We performed quantitative trait loci (QTL) analysis using a random-effect QTL mapping model on the TB genetic map. An RKN bioassay incorporating potted cuttings of each genotype was conducted in the greenhouse and replicated five times over a period of 10 weeks. For each replication, each genotype was inoculated with ca. 20,000 RKN eggs, and root-knot galls were counted ~62 days after inoculation. Resistance to RKN in the progeny was highly skewed toward the resistant parent, exhibiting medium to high levels of resistance. We identified one major QTL on linkage group 7, dominant in nature, which explained 58.3% of the phenotypic variation in RKN counts. This work represents a significant step forward in our understanding of the genetic architecture of RKN resistance and sets the stage for future utilization of genomics-assisted breeding in sweetpotato breeding programs.

Nutraceutical Content and Daily Value Contribution of Sweet Potato Accessions for the European Market

Sweet potatoes (SPs) are considered by the FAO as a primary crop for “traditional agriculture” in the tropics, but in Europe, its consumption is not widespread. However, consumer demand has grown exponentially over the past five years. This study has evaluated the quality and nutrient contents of storage roots of 29 SPs accessions to characterize their role in improving the human diet. Roots were analyzed for nutraceuticals, sugars, and minerals. Results underlined a considerable variability of nutrient content related to color among SPs accessions. The deep-orange-fleshed SPs showed a higher content of β-carotene compared to the light orange- and cream-fleshed ones; 100 g of edible product of HON86 can supply 32.3% of the daily value contribution of vitamin A, followed by the pale orange-fleshed BRA32 and BRA54. The total phenolic content of the purple ecotypes was about two to five times higher than the other genotypes. The calcium content was generally low, whereas, in many accessions, magnesium and phosphorus content reached 20%, or higher of the contribution to the daily value. Such a high variability suggests different use of the different accessions according to their strengths, but might also be used for breeding to improve quality traits of the commercial varieties.

Beetroot response to sodium chloride as a component of fertilizers

Sodium use combined with NPK fertilizers can potentially increase beetroot (Beta vulgaris L.) yield and quality. This hypothesis was studied in three field experiments with beetroot in Western Transbaikalia throughout the seasons 2012-2014. The effects of a combination of fertilizers and different Na amounts (10, 20, and 40 kg Na/ha) combined with the chloride on beetroot yield, storage root quality, and sugar accumulation were estimated. As a result, Na application increased beetroot yield by 13-22%, as compared to the mineral fertilizers along, and the highest Na dose contributed to the maximum beetroot yield. The rising of the root mean weight was detected. Also, crude protein and vitamin C were increased in beetroots, while crude fibre and nitrates were decreased. Along with increased sodium concentration, potassium amount in dry matter of roots and tops were declined. Both roots and tops were found to have more efficient P and N uptake.

Sweetpotato production practices, constraints, and variety evaluation under different storage types

AbstractSweetpotato plays an important role in ensuring food security and household income sources for local communities in Ethiopia. It is dominantly grown in southern parts of Ethiopia. However, its production and productivity over the last few years has declined due to the limited access of quality planting materials at the onset of the rainy season, disease, and severe pest infestation. Therefore, it was imperative to carry out this study to identify the main constraints related to the recent decline of the crop in Misrak Badawacho District. The survey result revealed that many varieties of sweetpotato were grown in the district; mainly, Awassa‐83, Ogan‐Sagan, and Wolaita‐local were the most preferred variety by producers. The main sweetpotato production and storage constraints in the study district are as follows: rodents, disease and insect pests, heat and drought, shortage of quality planting materials, and absence of best methods for long‐term storage. Awassa‐83, Ogan‐Sagan and Wolaita‐local were evaluated under different storage types (straw, soil, ash, sawdust, and sand storage). The combination of Awassa‐83 variety and sand storage was performed better in percentage of decay, weight loss, and weevil damage, whereas length and number of vine per storage roots were performed better in the separate treatment. Thus, Awassa‐83 variety and sand storage can be recommended for maintaining the storage roots during dry periods and access of quality vines at the onset of the rainy season. More importantly, sand storage provides an opportunity to maintain the quality of sweetpotato storage roots for a long period of time and producers can easily and timely access quality vines at the onset of rainy season.

Vine Removal Prior to Harvest, and Curing Duration and Temperature Affect the Incidence and Severity of Internal Necrosis in ‘Covington’ Sweetpotato

Internal necrosis (IN) is a physiological disorder that affects Covington, the most commonly grown sweetpotato (Ipomoea batatas) cultivar in North Carolina. Because IN affects the quality of sweetpotato storage roots, studies have been conducted since the first report of IN in 2006. Field studies (three in 2016 and two in 2017) were conducted to evaluate preharvest and postharvest treatments on the occurrence of IN in ‘Covington’ storage roots. Four preharvest treatments consisted of combinations of high chlorine or minimal chlorine potash fertilizer and mowing vs. not mowing before harvest. For postharvest treatments, 30 storage roots were obtained at harvest from each preharvest treatment plot and immediately cured in 75 and 85 °F rooms for a duration of 0.5, 1, 2, 3, and 5 weeks in 2016, and 0.5, 1, and 2 weeks in 2017. Shorter curing durations (0.5 and 1 week) coincided with industry recommendations while longer durations mimicked the challenges that some commercial facilities face when cooling down temperatures of rooms after curing is supposed to be concluded. Once curing temperature and curing duration treatments were completed, roots were placed in a 58 °F storage room at 85% relative humidity until cut. A control comparison was included in which harvested roots were placed in a 58 °F storage room (no curing) immediately after harvest. The storage roots from all temperature treatments were then cut 49 to 80 days after harvest, and incidence and severity of IN visually rated. Preharvest potash fertilizer treatments had minimal or no effect on occurrence of IN. However, mowing vines before harvest in several studies reduced IN incidence when roots were cured for more than 0.5 week at temperatures of at least 75 °F. Lower temperature (75 vs. 85 °F) and shorter curing duration (0.5 vs. 1, 2, 3, or 5 weeks) resulted in reduced IN occurrence in ‘Covington’ sweetpotato.

Response of sweetpotato to diquat applied pretransplanting

AbstractField trials were conducted in North Carolina in 2017 and Louisiana and Mississippi in 2018 to determine the effect of pretransplanting applications of diquat on sweetpotato crop tolerance, yield, and storage root quality. In North Carolina treatments consisted of two rates of diquat (560 or 1,120 g ai ha−1) alone or mixed with 107 g ai ha−1 flumioxazin and applied 1 d before transplanting (DBP), sequential applications of diquat (560 or 1,120 g ha−1) 1 and 17 DBP, 107 g ha−1 flumioxazin alone, and a nontreated check. In Louisiana and Mississippi treatments consisted of diquat (560 or 1,120 g ha−1) applied 1 DBP either alone or followed by (fb) rehipping rows or 107 g ha−1 flumioxazin immediately prior to transplanting. Additional treatments included 546 g ha−1 paraquat applied 1 DBP and a nontreated check. In North Carolina injury was ≤3% for all treatments through 23 d after transplanting (DAP), and no injury was observed after 23 DAP. Visual sweetpotato stunting pooled across the Mississippi and Louisiana trials ranged from 1% to 14%, 0% to 6%, and 0% to 3% at 2, 4, and 6 wk after planting (WAP), respectively, and no crop injury was observed after 6 WAP. Diquat applied 1 DBP and not fb rehipping resulted in greater crop injury (12%) than comparable treatments that were rehipped (2%). In North Carolina single and sequential diquat applications resulted in reduced No. 1 sweetpotato yield (24,230 and 24,280 kg ha−1, respectively) compared with the nontreated check, but No. 1 yield when diquat plus flumioxazin (26,330 kg ha−1) was used was similar to that of the nontreated check. No. 1 yield did not differ by treatment in Louisiana and Mississippi.

Response of sweetpotato to pendimethalin application rate and timing

AbstractField trials were conducted near Pontotoc, Mississippi; Chase, Louisiana; and Clinton, North Carolina, in 2017 and 2018 to determine the effect of pendimethalin rate and timing application on sweetpotato crop tolerance, yield, and storage root quality. Treatments consisted of five pendimethalin rates (266, 532, 1,065, 1,597, and 2,130 g ai ha−1) by two application timings (0 to 1 or 10 to 14 d after transplanting). Additionally, a nontreated check was included for comparison. Crop injury (stunting) was minimal (≤4%) through 6 wk after transplanting (WAP) and no injury was observed from 8 to 14 WAP, regardless of application timing or rate. The nontreated check yielded 6.6, 17.6, 5.5, and 32.1 × 103 kg ha−1 of canner, no. 1, jumbo, and total grades, respectively. Neither pendimethalin application timing nor rate influenced jumbo, no. 1, marketable, or total sweetpotato yield. Overall, these results indicate that pendimethalin will be a valuable addition to the toolkit of sweetpotato growers.

Impacts of &amp;lt;i&amp;gt;S&amp;lt;/i&amp;gt;-Metolachlor Application Timing on Sweetpotato Growth and Development

S-metolachlor is used to control/suppress yellow nutsedge, annual grasses and several broadleaf weeds in sweetpotato. However, a decline in storage root quality is suspected when excessive rainfall occurs within 24-h after application. A greenhouse study was conducted to determine the effect of S-metolachlor application timing on sweetpotato growth and development. S-metolachlor treatments (0 and 1 kg·ha-1) were applied over-the-top at 0, 5 and ten days after transplanting (DAT) and a simulated rainfall treatment delivered 25 mm of rain, 51 mm·h-1 intensity, immediately after herbicide application. Plants were harvested at 5, 10, 15, 20 and 80 DAT. During the first four harvests, roots were scanned and analyzed with WinRHIZO-Pro image analysis system to estimate root number, length, volume, and surface area along with aboveground growth parameters. At the final harvest, plant growth and biomass components, and quality of storage roots were recorded. Plants treated with S-metolachlor on day 0 and 5 DAT were significantly less than those of 10 DAT and untreated control for all measured parameters for the initial 20 days of plant growth. Even though vine length, leaf number, stem biomass, and total storage roots were not different among the treatments at 80 DAT, all other plant components and total biomass production and leaf area development for plants treated at 0 and 5 DAT were significantly (P % and 16% for plants treated at 0 and 5 DAT, respectively, relative to the untreated check. These results indicate that delaying S-metolachlor application to 10 DAT will be less damaging to sweetpotato growth and development, particularly marketable storage roots and yield.

PRODUTIVIDADE E QUALIDADE DE RAÍZES DA MANDIOQUINHA-SALSA EM DIFERENTES NÍVEIS DE ADUBAÇÃO NPK

The storage roots of arracacha have high nutritional value, being rich in carbohydrates, minerals, vitamins A and C, and starch of high digestibility. However, in this crop one of the decisive factors for the production of roots with higher nutritional value is the balanced fertilization. The aim of this study was to evaluate the yield and nutritional quality of storage roots of arracacha, grown at increasing levels of NPK fertilization. The experiment was conducted in the randomized blocks design, with eight replications. The treatments consisted of three NPK levels (AD0 = unfertilized cultivation, AD1 = cultivation with 50% of recommended fertilization, and AD2 = cultivation with 100% ofrecommended fertilization). It was observedthat higher levels of NPK fertilization increase the number, size and marketable yield of storage roots of arracachacrop. NPK fertilization also increases the size and contentsof K, Mg, and Mn of storage roots, without interfering with the pulp pH and contentsof protein, Ca, Cu, and Fe. However, when the increase in root size is not accompanied by an increase in dry matter content, the starch, P, and Zn contents of the roots reduce with increasing levels of NPK fertilization.

Sugar beet response to different K, Na and Mg ratios in applied fertilizers

Potassium (K) in sugar beet can be partly replaced by magnesium (Mg) and sodium (Na). This hypothesis was verified based on 12 field experiments conducted on four farms in Poland during the seasons 2010–2012. The effect of different K, Na and Mg ratios in fertilizers applied in the total rate of 3205 mol/ha on beet yield (BY), storage root quality and white sugar yield (WSY) was determined. The tested K:Mg:Na cation ratios were as follows: 1:0:0; 1:0.11:0.09; 1:0.16:0.54 and 1:0.33:2.19. BY and WSY were affected by the total rate of the applied cations. The optimum ratio of K:Mg:Na was different with respect to the site and the growing season. The K rate reduction from 125 to 24 kg/ha combined with the simultaneous increase in the rate of Mg and Na did not result in lower BY. However, a too narrow K:Na ratio in applied fertilizers resulted in a decrease of sucrose content in storage roots. The fertilization cost for sugar beet production could be reduced through the application of fertilizers that contain fixed amounts of Na on soils rich in available K.

EFFICIENCY OF NATURAL GROWTH REGULATORS IN CARROT PRODUCTION

Utilization of natural biostimulators- secondary metabolits of plants in carrot production was studied. Purified fractions with glycoside content are characterized with extraction and adsorption chromatography from the next plants: linarosides – from Linaria vulgaris Mill. L., melampyrosides - from Melampyrum nemorosum L., genistifoliosides - from Linaria genistifolia L., verbascosides - from Verbascum phlomoides L., melongosides - from Solanum melongena L. and tomatoside – from Solanum lycopersicum L. The former substance was registered under market mark “ecostim”. Prospective preparations for the improvement plant resistance to abiotic and biotic stresses have been identified in laboratory tests. Treatment of carrot seeds with water solutions of such substances accelerates plant growth, increases yield and improves quality of storage roots. We determined regimes of seed treatment (substance concentration, time of exposition) and gave recommends by using of natural regulators in the technologic scheme of carrot cultivation. Using secondary metabolites of higher plants stimulates the energy of germination (on 1,5-6,7%) and increases the field germination of carrot seeds (on 23-40%). It accelerates leaves growth and increases the mass of storage roots, improves biochemical characteristics of storage roots (accumulation the β- carotene and decreasing of nitrates content). Yield of storage roots increases on 4,2-8,5 t/ha, and yield of market quality roots increases on 4-6 t/ha.

RESPONSE OF SWEET POTATO PLANT TO THE SAME SOURCES OF ORGANIC MANURE AND APPLICATION METHODS OF POTASSIUM HUMATE UNDER SANDY SOIL CONDITIONS.

Two field experiments were performed during two consecutive summer seasons of 2014 and 2015 at El-Kassasien Hort. Res. Station, Ismailia Governorate, Egypt, to study the effect of organic manure sources (recommended chemical fertilizers, FYM, compost and chicken manure) and potassium humate ( without, soil application and foliar application) at the rate of 2 g/L ,as well as, different combination between them on plant growth, chemical constituents, yield and its components and storage root quality of sweet potato (Ipomoea batatas, L.) cv. Abees grown under sandy soil condition with drip irrigation system. Application of organic manure fertilizers caused significant increases in growth parameter, yield and its components and mineral contents compared to control treatment (without organic fertilization). meanwhile, application of chicken manure at the rate of 5 m3/fed. achieved highest values of all aforementioned parameters, followed by the application of compost at the rate of 15 m3/fed and FYM at the rate of 15 m3/fed, in a descending order, respectively. Spraying sweet potato plants with potassium humate significantly enhanced plant growth, yield and its components and mineral contents (NPK content in tuber root TSS, reducing and total sugar as well as total carbohydrate contents). In this respect, spraying plants with 2 g/L potassium humate attained the superiority impacts comparing the other treatments. Hence, it can be concluded that fertilizing sweet potato plants by chicken manure at the rate of 5 m3/fed. in combined with spraying plants by potassium humate at the rate of2 g/L gave the highest values of growth, yield and its components and chemical constituents as compared to other interaction treatments. Conclusively, this study showed that the highest yield of sweet potato storage roots and storage roots quality were obtained from chicken manure at 5 m3/fed., foliar application was potassium humate (2 g/L). The interaction between 5 m3 chicken manure and potassium humate as foliar application at the rate of2 g/L.

Epigenetic map and genetic map basis of complex traits in cassava population

Cassava (Manihot esculenta Crantz) is an important tropical starchy root crop that is adapted to drought but extremely cold sensitive. A cold-tolerant, high-quality, and robust supply of cassava is urgently needed. Here, we clarify genome-wide distribution and classification of CCGG hemi-methylation and full-methylation, and detected 77 much candidate QTLsepi for cold stress and 103 much candidate QTLsepi for storage root quality and yield in 186 cassava population, generated by crossing two non-inbred lines with female parent KU50 and male parent SC124 (KS population). We developed amplified-fragment single nucleotide polymorphism and methylation (AFSM) genetic map in this population. We also constructed the AFSM QTL map, identified 260 much candidate QTL genes for cold stress and 301 much candidate QTL genes for storage root quality and yield, based on the years greenhouse and field trials. This may accounted for a significant amount of the variation in the key traits controlling cold tolerance and the high quality and yield of cassava.