The metabolic profiling of Chinese yam fermented by Saccharomyces boulardii and the biological activities of its ethanol extract in vitro

Chinese yam(Dioscorea opposita Thunb.),as one of the medicinal and edible homologous plants,is rich in various nutrients and functional factors.In this study,Chinese yam fermented by Saccharomyces boulardii was performed to investigate its bioactive components and metabolic profile.And then,the main bioactive components and biological activities of fermented Chinese yam ethanol extract(FCYE)were evaluated.Results showed that there were 49 up-regulated metabolites and 52 down-regulated metabolites in fermented Chinese yam compared to unfermented Chinese yam.Besides,corresponding metabolic pathways analysis initially revealed that the distribution of bioactive substances was concentrated on alcoholsoluble small molecular substances.Ulteriorly,the total polyphenol content and the total flavonoid content in FCYE were significantly increased,and the corresponding antioxidant and immunomodulatory activities in vitro were also significantly enhanced.Our study provided a new reference for the comprehensive utilization of Chinese yam and laid a theoretical foundation for the development and application of natural probiotic-fermented products.

Production of Yam Tubers Using Seed Tubers from Vitroplants Regenerated from Aerial Stems in the Yam Species Dioscorea alata (L.) and Dioscorea cayenensis-rotundata (L. & P.) in Côte d’Ivoire

The aim of this study is to produce large quantities of yam tubers in the field from seed tubers derived from vitroplants regenerated from aerial stem cuttings and farmers’ tuber seeds. Seed tubers from ten yam cultivars, including five from Dioscorea alata (cDa083, cDa053, cDa115, cDa150 and cDa266) and five from Dioscorea cayenensis-rotundata (cDr015, cDr027, cDr150, cDr206 and cDr148) with distinct agro-morphological characteristics, were used as material. A completely randomized block design with 3 replications was used. In each block, all cultivars and seed types were represented. When put into cultivation, the tubers produced by the vitroplants all germinated and gave 100% healthy plants, compared with 86% to 100% healthy plants for the seed tubers produced by the farmers. Yields per hectare ranged from 10 to 25 tonnes for seed tubers produced by in vitro plants, and from 4 to 9 tons for seed tubers produced by farmers. Seed tubers from vitroplants can therefore be recommended to farmers as a solution to the problem of seed tuber unavailability.

Efficiency of Legumes in Increasing Yam Yield under Sandy Ferrasol in the Forest Zone of Southwestern Côte d’Ivoire

The cropping system is based on traditional farming in rural areas. In this way, yields of some food crops like yam are very low considering their high need for nutrients. The nutrient-rich land is under high land pressure as it is occupied by cash crops such as oil palm and rubber at the expense of food crops and soil fertility is declining. The study was conducted in Grand-Lahou to assess the effect of organic matter provided by legumes in increasing yam yield. The randomized complete block design included four (4) treatments: Arachis hypogaea + yam association (T1), Acacia mangium + yam association (T2), Arachis + Acacia mangium + yam association (T3) and pure yam crop (T0). The parameters measured were: the soil nutrients content, the rate of mineralization of organic matter through the C/N ratio as well as the yield of yam through different techniques that allowed the objective of the study to be achieved. It was noted a slight improvement of nitrogen and organic carbon in all treatments with a higher value recorded in the T2 treatment. The C/N ratio decreased to 12 in all treatments compared to the control, which reflects a normal decomposition of the organic matter. Treatment T1 increased yam yield (8.4 t/ha) in contrast to treatments T2 (4.1 t/ha) and T3 (2.8 t/ha). Legume-based treatments T2 and T3 were associated with a significant decrease in yam yield, resulting in losses of −46.34% to −25.09%, while treatment T1 resulted in a gain of 28.57%. As a result, the treatments involving legumes contributed to normalizing the organic matter content of the soil. The simultaneous association of these two legumes led to a decrease in yam production, contrary to the treatment associating only groundnut.

Assessment of Microbial Changes and Nutritional Qualities of Extruded White Yam (<i>Dioscorea rotundata</i>) and Bambara Groundnut (<i>Vigna subterranean</i>) Blends

Two flavoured extruded products were developed by co-extruding yam grits (750 μm) obtained from white yam (Dioscorea rotundata) and bambara groundnut flour (250 μm) in 160:40 respectively obtained from white bambara groundnut with added flavouring agents of salt (1% - 3%) and sugar (4% - 6%) in the feed blends at screw speed of 70 rpm, 17.5%, feed moisture and at the barrel temperature of 145℃. The extruded products were packaged in low density polyethylene bag (0.02 μm gauge size) and stored at room temperature (28℃ ± 2℃) and at refrigeration temperature (9℃ ± 2℃) for a period of twenty weeks. The microbiological changes in the extruded products as determined by the total plate under both storage conditions showed that maximum total plate counts were 0.5 × 104 and 5.4 × 104 cfu/g at 9℃ ± 2℃ and 28℃ ± 2℃ respectively. Nutritional evaluation studies of extrudates were comparable (p ≥ 0.05) with standard casein diet with minimum crude protein content of 13.51% providing 1707.2 KJ energy per 100gof diet and supported weight gain and growth of laboratory animals.

Effect of Curing Treatments on Seven Key Farmers’ Yams (<i>Dioscorea</i>spp.) in Ghana

Curing of freshly harvested yams (Dioscorea spp.) is a process for wounded yams during harvest to heal. In this work the effectiveness of straw, polypropylene and jute sack on curing of seven key farmers’ yam varieties over a duration of 7, 14 and 21 days was studied. Seven key farmers’ yam varieties identified as Pona, Lariboko, Dente, Mutwumudoo, Serwah belonging to D. rotundata, Matches and Akaba belonging to D. alata were studied under different curing treatments. The percentage weight loss of yam tubers varied among the treatments over curing period. Curing under jute sack showed all yam varieties had weight losses less than 2.0%, within 7 days of curing. Five different varieties had weight loss less than 2.0% except Dente under the straw treatment. Mutwumudoo variety showed the highest water loss (8.4%) for polypropylene sheet and 6.9% for Lariboko in the control treatment. During 7 days curing the control and polypropylene treatment did not support yam curing. After 14 days of curing of tubers, similar tends were observed as in 7 days curing. After 14 days of curing under jute sack, percentage weight loss of the tubers ranges from 2.0% - 3.7%. In the straw treatment, the percentage weight loss ranges between 1.0% - 4.7% in all other varieties except Dente (D. rotundata) (8.2%). Polypropylene sheet treatment showed the highest percentage weight loss in Mutwumudoo variety (18.4%). A similar trend was observed for the yam tubers cured for 21days as percentage weight loss of tubers under jute sacks was 2.5 – 9.8%. Curing temperature and humidity ranged between 27&degC - 40&degC and 87% - 100% rh for yam tubers under the three different treatments of polypropylene, jute and straw. However, the control treatment recorded lower humidity of 60% - 80% rh. Curing material, duration, climatic conditions and yam varieties influenced curing and Serwah variety, which is a D. rotundata is the best bet yam variety to cure under jute sack for 7, 14 and 21 days of curing.

DPPH Radical Scavenging Capacity of Phenolic Extracts from African Yam Bean (<i>Sphenostylis stenocarpa</i>)

The phenolic extracts of the seeds of African yam bean (Sphenostylis stenocarpa) were studied using different extraction solvents (70% ethanol, 80% acetone and acidic 70% acetone) and two heat treatment methods (dry heating on a hot plate with acid-washed sea sand at 135℃ for 25 min and wet heating in an autoclave at 120℃ for 20 min). The study examined the total phenolic content (TPC), total flavonoid content (TFC), and condensed tannin content (CTC) of the seed extracts, as well as their free radical scavenging and antioxidant properties. The raw African yam bean seed was dry heated in air oven at 100℃ for 5 min (control). Heat treatments application affected the phenolic contents of the seeds significantly (p < 0.05). The free radical scavenging activity of the phenolics were done using 2,2-diphenyl- 1-picrylhydrazyl (DPPH). The effectiveness of the extract was determined using DPPH at 50 mg/g, 10 mg/g and 5 mg/g of the extracts. At 5 mg/g, the extract was most effective indicating that higher concentration of extract gave higher antioxidant activity. The seed has high antioxidant capacity and an appreciable amount of phenolic extracts.

Formulation factors affecting the binding properties of Chinese yam(Dioscorea oppositifolia) and corn starches

Objective:The quantitative effects of formulation and processing variables affecting the binding properties of Chinese yam starch（Dioscorea oppositifolia） in chloroquine phosphate tablet formulations have been investigated in comparison with corn starch using a 23 factorial experimental design.Methods:Chinese yam starch,representing the "low" level,and corn starch,representing the "high" level were used as binders at concentrations of 2.5%w/w and 10%w/w in chloroquine phosphate tablet formulations.The mechanical properties of the tablets,measured by the tensile strength（T） and brittle fracture index（BFI） as well as the release properties measured by the disintegration time（DT） and dissolution time(t80- time for 80%drug release),were used as assessment parameters.Results:The ranking of the individual coefficient values for the formulations on T was D 】 N 】】C,on BFI was N 】 D 】】C,on DT was D 】 N 】 C and on t80 was C 】 N 】 D while the ranking of the interaction coefficient on T was N-D 】 C-D 】】 N-C,on BFI was N-D 】 N-C = C-D,on DT and t80 was N-C 】 N-D 】 C-D.Changing the binding agent from Chinese to corn starch,led to a decrease in T,DT and t80 but increase in BFI of the tablets.There were significant（P 【 0.001 ） interactions between the nature of binder,N and the other two variables,C and D.Conclusion:The result showed that Chinese yam possessed stronger binding capacity than corn starch and could be useful as an alternative binder when tablets with high mechanical strength with minimal problems of lamination,and slow release are required.

Effect of 24-Epibrassinolide on Growth of <i>in Vitro</i>Shoot Tips of Different Yam (<i>Dioscorea</i>Spp.) Species

In this work we compared the effect of the growth regulator content of the culture medium on the growth of in vitro shoot tips of five yam accessions belonging to four yam species (one Dioscorea alata, one D. rotundata, one D. cayenensis and two D. trifida). Medium S contained 0.6 μM benzyl adenine, 1.07 μM naphthalene acetic acid and 0.23 μM gibberellic acid while medium EBR contained 0.23 μM gibberellic acid and 0.1 μM 24-epibrassinolide. After 2 months of culture, oxidation level was significantly reduced on medium EBR compared to medium S for four of the five accessions tested. By contrast, medium EBR did not have any positive effect on shoot length since length of shoots produced after 2 months of culture on medium S and EBR were similar, except with accession 3-45T, for which shoot length was shorter on medium S compared to medium EBR. These results underline the potential of 24-epibrassinolide to reduce oxidation phenomena during in vitro culture and call for its utilization for regeneration of cryopreserved yam shoot tips, which is often impeded by oxidation phenomena.

Reproductive and Growth Performance of Rabbit Fed Different Inclusion Levels of African Yam Bean (<i>Sphenostylis stenocarpa</i>)

A feeding trial was conducted to determine the effect of dietary inclusion of Processed African Yam Bean (AYB) at 0%, 10%, 20% and 30% levels respectively, on the growth and reproductive performance of Rabbits. The AYB inclusion was to ascertain the best (%) level that would give better performance in rabbits. Complete randomized design was used to allot twenty (20) grower rabbits of both sexes into four treatments in three replicate with each group having three does and two bucks. Each of the treatment diets formulated at different growth stages was fed to the rabbits. The rabbits were kept in hutches inside the rabbit house and given feed and water ad libitum. Growth and reproductive parameters were measured. The proximate analysis and anti-nutritional factor of processed AYB showed that it contained values of 26.88%, 92.97%, 5.26%, 61.89%, 7.04%, 3.79% and 2.17% for Crude protein, Dry matter, Crude fibre, Nitrogen-free extract, Moisture content, Ash content and Ether extract respectively while the anti-nutritional factor contained 0.11%, 14.02 mg/g, 0.19 mg/g, 0.21 mg/g, 0.14 mg/g, 0.21 mg/g, 0.13 mg/g and 0.01 mg/g of Tannin, Alkaloid, Oxalate, Phytate, Saponin, Flavonoids, Trypsin inhibitor and Lectin. From this study, the rabbit group on 10% AYB inclusion significantly (p 0.05) affected by the diets. The results of this experiment concluded that AYB can be included in the diet of rabbits with 10% inclusion giving a better reproductive performance and growth rate without any negative effect.

First Report of a Successful Development of Yam Hybrids(Dioscorea alata L.)from Lyophilized and Long-Term Stored Pollens

Various biological constraints including erratic and asynchronous flowering between male and female plants hinder successful hybrid development and genetic gains in greater yam breeding programs.Therefore,pollen storage has gained much attention to facilitate artificial pollinations and increase the genetic gains.This 4-year study aimed at developing a practical long-term pollen storage technique for the successful development of yam hybrids.Fresh pollens were collected from two Dioscorea alata males,then lyophilized(two lyophilization treatments were applied),followed by storage at room temperature(24℃–25℃)for 12 months.Moreover,the lyophilized and stored pollens were tested for viability by crossing with four female varieties.Our results showed that lyophilization is effective for achieving viable pollens after 12 months of storage.Treatment 1(48 h drying)showed higher pollen germination and fertility rates than Treatment 2(72 h drying).Although we observed a reduction in viability of lyophilized pollens after 12 months of storage,we generated hybrid seedlings with success rates from 12%to 21%compared to 21%–31%when using fresh pollens.Paternity testing based on molecular genotyping confirmed the hybrid status of the obtained seedlings,which grew well in a greenhouse.Lyophilization is a practical approach for a long-term storage of greater yam pollen samples.This protocol will positively impact yam breeding programs particularly in developing countries.

Quality and Storage Characteristics of Hot Press Tortilla Prepared from Yam-Wheat Composite Flour

Mixtures of refined wheat flour (RWF) with flours from different sources could impact the functional qualities and shelf life of wheat-based products. Storage stability is one of the most critical factors for tortilla quality. Tortillas made from yam (Dioscorea sp.) wheat composite flours were characterized. RWF was substituted with 5%, 10%, 15%, and 20% of fermented yam flour-brown (FYF) and unfermented yam flour-white (UYF). Farinograph water absorptions of UYF-composite flours (65.5% - 77.1%) were significantly (P < 0.05) higher than FYF-composite flour absorptions (60.5% - 61.5%). During storage, moisture contents of composite flour tortillas increased while the RWF-tortilla decreased. Tortilla from FYF-composite flour exhibited greater strength (3.1 N at day zero on average) compared to UYF-composite tortillas (2.1 N at day zero on average), while UYF-composite flour tortillas had good extensibility and rollability properties. The properties and composition type and ratios of flour blends affected tortilla quality during the storage period. The substitution of RWF with 15% or 20% UYF would be more suitable for making tortilla with improved properties compared to that of FYF.

Effect of Plant Growth Hormones and Liquid Fertilizer on Rooting and Tuberization of Yam (<i>Dioscorea rotundata</i>Poir.) Vine Cuttings

Vine cutting is an effective solution to solve the problem of seed availability in yam cultivation. This study was conducted to improve the recovery and rooting rate of vine cuttings of Dioscorea rotundata. Two-node cuttings from five (5)-month-old hybrid plants were grown in liquid media consisting of phytohormones (AIA3 and GA3) and liquid fertilizer (NPK 8-8-8) at different concentrations. Observations were made weekly from the 21st day after transplanting and focused on the survival rate of the cuttings, the number of roots emitted and the number of minitubers initiated. The results obtained showed a significant effect of the different growing media on the survival rate, rooting and production of minitubers. The best survival rates were obtained for cuttings grown in NPK (8-8-8) at 0.25% (100%) and AIA3 at 25 ppm (93.3%). The highest averages root number was recorded with growing media containing 0.25% NPK 8-8-8 (20.3) and 25 ppm AIA3 (17.7). Growing media with 0.25% NPK (8-8-8) and 25 ppm AIA3 provided the highest average numbers of minitubers initiated, respectively 5 and 4.6. Growing medium containing 0.25% NPK 8-8-8 has been identified as the one that allows better roots emission and minitubers production by yam vines cuttings.

Composition and Functional Properties of Yam Bean (<i>Pachyrhizus</i>spp.) Seed Flour

Yam bean (Pachyrhizus spp.) is legume crop that not only produces edible roots but also has a high yield of unutilized seeds. Although the yam bean seeds are rich in protein, they are not used due to a high content of toxic rotenone. In this study, yam bean seeds were detoxified and the nutritional and functional properties of their protein determined to assess the proteins’ potential for applications. Seeds of 10 accessions (2 accessions of P. erosus, 4 accessions of P. ahipa and 4 accessions of P. tuberosus) were analyzed for proximate composition, pasting and functional properties (bulk density, least gelation concentration, water absorption capacity, oil absorption capacity, emulsifying capacity, emulsion stability, foaming capacity, foam stability and protein solubility). The results showed that yam bean seeds contained: 29.2 - 32.1 g/100g proteins, 31.3 - 33.0 g/100 g carbohydrates, 24.1 - 25.6 g/100g total fat, 7.5 - 8.1 g/100g crude fiber and 3.4 - 4.1 g/100g ash. The defatted P. erosus seed flour contained 45.6 - 48.8 g/100g protein, 32.6 - 36.5 g/100g total carbohydrate, 6.7 - 7.1 g/100g crude fiber, 6.0 - 6.4 g/100g ash and 5.2/100 g crude fat. The defatted yam bean seed flour exhibited relatively high protein solubility (68.0% - 70.4%), least gelation concentration (14%), water absorption capacity (2.8% - 2.9%) and oil absorption capacity (1.5%). The defatted flour exhibited emulsifying capacity of 35.7% - 36.0%, emulsion stability of 33.2% - 33.5%, foaming capacities of 42% and foam stability of 25.1% - 25.8%. With respect to pasting properties, the defatted yam bean seed flours exhibited pasting temperature of 80.0?C - 81.3?C, peak viscosity of 145.5 - 146.7 RVU, trough viscosity of 95.1 - 102.0 RVU, break down of 43.5 - 51.6 RVU, set back of 252.9 - 258.1 RVU and final viscosity of 348 - 360 RVU. The results show that yam bean seed has potential for use in both food and non-food applications.

Assessment of Seed and Tuber Production Potential in Varieties of <i>Sphenostylis stenocarpa</i>(Africa Yam Bean)

Twenty accessions of African Yam Bean, grown at the Teaching and Research Farm of Ladoke Akintola University of Technology, Ogbomoso during the cropping seasons of May to November, 2014 and 2015 were assessed for genetic diversity and Genotype × Environment interaction effects on trait performance and their ability to produce tuber. The first six Principal Components jointly explained 70.30% of the total variation among the accessions. Vine length, branching pattern, pod number, pod length, seed number, and seed yield contributed mostly to the observed variations. Seed biometric traits were most variable and contributed 52% of total variation. Variance due to genotype accounted for 54.2%, environment 10.5% and G × E interaction accounted for 30.1% of the interaction sum of squares. Accessions, G2, G4, G47, G49 and G50 produced tubers, while accessions G6, G15, G31, G32 and G33 nodulated extensively. Conversely, there was a marginal reduction in seed yield in accessions that either produced tubers or nodules.

Isolation of Nine Microorganisms from Rotten <i>Dioscorea rotundata</i>(White Yam) and Antimicrobial Sensitivity Test with Five Plant Extracts

Five yam tuber varieties were investigated for microorganisms that cause yam tuber rot from five local government areas of Benue State, Nigeria, between the months of March 2014 to March 2015. Five fungi species: Aspergillus niger, Rhizopus stolonifera, Botryodiplodia theobromae, Fusarium oxysporum, Penicillium marnessei and four bacteria species: Serratia marcescens, Erwinia caro-tovora, Klebsiella oxytoca and Pseudomonas aeruginosa were consistently isolated. Pathogenicity test carried out confirmed these organisms as the pathological agent of the rot. Antimicrobial activity of five plant aqueous extracts: Terminalia catapa (common name fruit), Passiflora edulis (passion fruit), Daniella oliveri (Chiha-Tiv), Ceiba pentandra (Vambe-Tiv), Jatropha tanjorensis (Catholic plant) was carried out on the isolated microorganims and they showed varing degrees of inhibition, the aqueous extract from Passiflora edulis, Ceiba pentandra and Jatropha tanjorensis were able to inhibit all the fungi completely.

Postharvest Loss Control: Synergistic Plants Extract Inhibition of Ten Microbial Yam Rot Organisms

Nine microorganisms were isolated from four varieties of Dioscorea rotundata (gbongu, ogoja, Amula, Hembamkwase);four bacteria, Erwinia carotovora, Pseudomonas aeruginosa, Serratia marcescens, Klebsiella oxytoca and five fungi, Rhizopus stolonifera, Aspergillus niger, Aspergillus flavus, Fusarium oxysporum, Penicillium marneffei, from five local government areas of Benue State (Vandeikya, Ukum, Katsina Ala, Guma and Logo). Pathogenicity test on the isolates confirmed them to be the cause of rot. The nine plants extract (Ceiba pentandra, Jatropha tanjorensis, Azadirachta indica, Moringa oleifera, Carica papaya, Mangifera indica, Daniella oliveri, Terminalia catapa and Passiflora edulis) synergistically added inhibited all the four bacteria isolates completely. The five fungi were inhibited by 60% (c) - 80% (b);Rhizopus stolonifera, Aspergillus flavus, Fusarium oxysporum;and Aspergillus niger, Penicillium marneffei, respectively.

Isolation of Six Microorganisms from Rotten <i>Dioscorea alata </i>(Water Yam), and Antimicrobial Sensitivity Test with Nine Plant Extracts

Six microorganisms: four fungi—Aspergillus niger, Aspergillus flavus, Rhizopus stolonifera, Penicillium marneffei, two bacteria—Erwinia carotovora and Pseudomonas aeruginosa were isolated and identified from three rotten Dioscorea alata (water yam) varieties from two sites each in two local government areas of Benue State, Nigeria, in West Africa, between the months of May 2014 and May 2015. Pathogenicity test carried out using the microorganisms confirmed them to be the pathological agents of the rot. Antimicrobial activity test with aqueous extracts of nine plants: Terminalia catapa, Passiflora edulis, Daniella oliveri, Ceiba pentandra, Jatropha tanjorensis, Azadirachta indica, Carica papaya, Moringa oleifera, and Mangifera indica of fresh and dry material showed that three pathogens, Rhizopus stolonifera (fungi), Erwinia carotovora and Pseudomonas aeruginosa (bacteria) isolated were completely inhibited each by a plant. The result obtained shows that Passiflora edulis had the best antimicrobial activity for both fungi and bacteria;indeed it inhibited completely Rhizopus stolonifera which was stubborn with most of the other plants. Azadirachta indica, Carica papaya, Moringa oleifera, and Mangifera indica were also able to inhibit most of the fungi but not completely. Terminalia catapa and Jatropha tanjorensis were most effective against the bacteria. Erwinia carotovora was completely inhibited by Terminalia catapa and Pseudomonas aeruginosa was completely inhibited by Jatropha tanjorensis. Daniella oliveri and Ceiba pentandra had the least inhibition against the isolates. Generally, the fresh plant extract shows more activity as compared to the dry plant extract.

Effect of Extrusion Cooking of White Yam (<i>Dioscorea rotundata</i>) and Bambara-Nut (<i>Vigna subterranean</i>) Blend on Some Selected Extrudate Parameters

The effect of thermo-extrusion processing of white yam (Dioscorea rotundata) and bambara nut (Vigna subterranean) on some selected extrudate parameters of residence time, throughput and moisture content were investigated in this study. Both yam and bambara nut were processed into meals of 750 μm and 500 μm respectively. Extrusion was carried out following a three variable response surface methodology using a Box Behnken design. Blend of yam meal and Bambara nut meal at ratio 80:20 respectively was conditioned into 12.5, 15.0 and 17.5% moisture content (dry basis) and allowed to equilibrate for 4 h. Extrusion was carried out on a single screw extruder at 50, 60 and 70 rpm screw speed and 130oC, 140oC and 150oC barrel temperatures. The study revealed that the extrusion time varied between 13.1 and 29.7 sec, throughput varied from 13.3 to 34.4 kg/h and product moisture ranged from 11.1 to 16.8% dry basis). All investigated extrudate parameters were significantly affected (p< 0.05) by the process variables of screw speed, barrel temperature and feed moisture content, and their interactions. The results were indicative that the second order polynomial was adequate to model the dependence of the extrudate parameters of residence time, throughput and moisture content on extrusion variables of barrel temperature, feed moisture content and screw speed.

Extraction Methods and Inhibition Studies of Ten Plant Extracts on Nine Yam Rot Pathogenic Microorganisms

Nine microorganisms, comprising of four bacteria, Erwinia carotovora, Pseudomonas aeruginosa, Serratia marcescens, Klebsiella oxytoca and five fungi, Rhizopus stolonifera, Aspergillus niger, Aspergillus flavus, Fusarium oxysporum and Penicillium marneffei, isolated from rotten yam tubers of 2016 harvest year, were treated with ten plants extracts (Passiflora edulis, Daniella oliveri, Ceiba pentandra, Jatropha tanjorensis, Azadrichta indica, Carica papaya, Moringa oleifera, Mangifera indica, Terminalia catapa and Senna alata), singly and synergistically by incorporation of extract in media for inhibition test. Two plant extracts singly and completely inhibited the growth of three organisms: Terminalia catapa at 100% and 10-1 showed complete inhibition (a) of Erwinia carotovora. Passiflora edulis at undiluted (100%) concentration completely inhibited Rhizopus stolonifer and Penicillium marneffei, respectively. Synergistic plant extract recorded complete inhibition (a) of all the four bacteria isolates at 2 mL extract incorporation;ten (10) mL extract incorporation in media recorded complete inhibition (a) of three out of the five fungi isolates: Rhizopus stolonifer, Fusarium oxysporum and Penicillium marneffei, respectively;the other two fungi recorded high inhibition (b) of Aspergillus niger and Aspergillus flavus, respectively. Hot aqueous synergistic plants extract recorded poor inhibition of the isolates as compared to the cold. Soxhlet solvent extracted synergistic plants extract, however, recorded lower inhibition as compared to hot aqueous synergistic plants extract and cold aqueous synergistic plants extracts. Room temperature solvent extracted synergistic plants extracts recorded inhibition that was same as that obtained with cold aqueous synergistic plants extract. This research indicates that heat employed extractions recorded less inhibition activity.

Breeding and Mechanized Cultivation of the New Bulk Purple Yam Variety Suyu 2

The new bulk purple yam variety Suyu 2,which had high quality,efficiency and was suitable for production in a highly mechanized cultivation,was bred by special and was suitable for whole-course mechanized cultivation.Integrated with agricultural machinery and agricultural trait,four kinds of machines produced by two factories from Jiangsu and Shandong could complete 10 kinds of main production processes,including rotary tillage,ridging,sowing,intertillage,topdressing,drug delivery,weeding,hilling,vine cutting and harvest.The work efficiency of single machine was 4-5 hm^2/d,and the production pattern got the cost saving and effectiveness increasing in the main yam producing area.The benefit reached over RMB 37500 yuan/hm^2 in special vegetable area.It was simple,feasible and easy to popularize the mechanization cultivation technique.