Recovery of Protease Inhibitors from Potato Fruit Water by Expanded Bed Adsorption Chromatography in Pilot Scale

The current study was conducted to investigate the recovery of native potato protein from potato fruit water (PFW) by expanded bed adsorption (EBA) chromatography. The eluted proteins were concentrated by ultrafiltration and spray-dried into powder. The SDS-PAGE showed that the recovered proteins were potato protease inhibitors (PPIs). The trypsin and chymotrypsin inhibitor activities of the recovered PPIs were 377.93 ± 8.22 and 12.90 ± 0.03 mg g^?1 protein, respectively. The recovery yield of protease inhibitors was 74.88%. The glycoalkaloid assay showed that the recovered PPIs contained 30.31 ± 0.15 μg g^?1 of α-chaconine and 92.77 ± 0.52 μg g^?1 of α-solanine, and these values were much lower than those in potato protein concentrate (PPC) obtained by traditional thermal coagulation. The most abundant amino acid in the PPIs was serine. The results indicated that the EBA can be used to effectively recover native potato protein from PFW.     

Sugar-Starch Metabolism and Antioxidant Potential in Potato Tubers in Response to Different Antisprouting Agents During Storage

Single applications of different antisprouting agents like hot water treatment, spearmint oil and clove oil were carried out on potato cultivar “Lady Rosetta” to compare their efficacy with that of synthetic chloro isopropyl N-phenyl carbamate (CIPC). The tubers were stored at ambient storage conditions (25?±?2 °C) for 81 days to assess changes in their sugar-starch concentrations and antioxidant potential. Antioxidant potential in the tubers was assessed as their total phenolic concentrations and radical scavenging activities. In addition, the enzymatic activities were also determined in order to evaluate the possible depletion of these antioxidants as substrate during storage. Results revealed significant response of stored potatoes to all antisprouting agents compared with the control (P?≤?0.05). CIPC and clove oil applications maintained tuber dormancy almost twice as long (81 days) as observed in the control (45 days). Application of spearmint oil and hot water treatment maintained tuber dormancy for almost 2 months. However, it was associated with an increased percentage sprouting during the last weeks of storage. At the end of storage, the highest starch (16.83%) and lowest sugar (0.99%) concentrations were estimated after CIPC application and maximum total phenolic concentration (143.57 mg gallic acid equivalent (GAE)/100 g), and highest antioxidant activity (39.73%) were found after clove oil application. Enzymatic activities were not statistically different between CIPC and clove oil application during most of the storage period. Results showed that efficient replacement of CIPC with clove oil in the premium potato cultivar might be useful; this may avert related food safety and environmental issues and would also ensure organic potato storage.     

Specific Gravity,Dry Matter and Starch Concentration of Different Potato Cultivars as Affected by Arsenic Contamination

Arsenic (As) contamination of the soil may affect the quality of potato tubers. When assessing the processing quality of potato cultivars, specific gravity (SG) is the measurement of choice for estimating dry matter (DM) and starch concentrations in the potato tubers. In this study, effects of the As concentration in the soil on quality parameters (SG, DM, starch concentration and total soluble solids (TSS)) of 11 potato cultivars in Bangladesh were investigated in an outdoor pot experiment with a randomized complete block design (RCBD) and three blocks, at Sher-e-Bangla Agricultural University, Dhaka, Bangladesh, from November, 2012 to March, 2013. The results showed highly significant differences between cultivars in quality parameters, except SG. Both As levels (25 and 50 mg As kg^?1 soil) reduced the DM and starch concentration in the tubers of the potato cultivars compared to the control (0 mg As kg^?1 soil), but had no significant effects on SG and TSS. ‘Lady Rosetta’ showed the highest SG (1.093 g cm^?3), DM (23.02%) and starch concentration (16.60%). The lowest SG (1.065 g cm^?3), DM (17.04%), and starch concentration (10.96%) was found in ‘Granola’. Highest TSS (5.91) was found in ‘Jam Alu’ while ‘Meridian’ had the lowest °Brix value (3.76). Bangladeshi potato farmers will benefit from the information generated regarding potato cultivation under As affected areas.     

Modelling the distribution of isopropyl N-(3-chlorophenyl) carbamate [CIPC] in box potato stores

Summary A numerical model has been produced to predict the distribution of deposits of the sprout suppressant isopropyl N-(3-chlorophenyl) carbamate [CIPC] in box potato stores. The model considers the movements of the CIPC by forced convection, sedimentation, natural convection and diffusion. Measurements have mostly shown high levels of CIPC on the top of the uppermost box, with levels decreasing towards the floor of the store. The model predicts this pattern and indicates that particle size, the temperature difference between the air inside and around the boxes, and the application rate of the chemical have a large effect on the levels and uniformity of CIPC deposits. Smaller particles (2 μm) can lead to better uniformity of distribution, but they are prone to natural convection effects which are difficult to control and they are slow to deposit which could lead to greater losses from the store.     

Isopropyl N-(3-chlorophenyl) Carbamate (CIPC) Residues in Potatoes Stored in Commercial Cold Stores in India

Since no attempt has been made so far in India to determine isopropyl N-(3-chlorophenyl) carbamate (CIPC) residues in potatoes, it became necessary to determine its residues in potatoes which are being used for table and processing purposes. Using high-performance liquid chromatography, CIPC residues were determined in peels, peeled tubers and unpeeled tubers periodically during storage at 10–12 °C in commercial cold stores. The highest concentration of CIPC found in potato peels was 20.17 mg/kg fresh wt, whereas in unpeeled and peeled tubers the residue levels were very low ranging from 0.29 to 1.13 and 0.05 to 0.24 mg/kg, respectively. However, all residue levels observed were within the maximum residue level prescribed by the US Environmental Protection Agency. The experiments done to determine the dispersal and concentration of CIPC applied as an aerosol fog with respect to location and time showed that the distribution of CIPC within the cold store was uneven leading to large variations in residue levels in samples drawn from different parts of the store.     

Effects of Foliar and Tuber Sprout Suppressants on Storage of Ware Potatoes under Tropical Conditions

Potato (Solanum tuberosum L.) is an important source of dietary carbohydrate and cash income generation for farmers in the tropical highlands of Kenya. The feasibility for cold storage at the farm level is limited due to the high costs of maintaining such a facility and there is limited data on the long-term post-harvest storage and quality of tubers of tropical-adapted cultivars. Application of sprout suppressants to control premature sprouting of ware potato is an attractive proposition. The objectives of this study were to evaluate the efficacy of pre-harvest foliar applications of paclobutrazol (PBZ) and ethephon for sprout suppression on ware potato tubers in storage. Post-harvest spray applications of Isopropyl N-(3-chlorophenyl carbamate) chloropropham (CIPC) and 1,4-dimethylnaphthalene (DMN) on tubers as fog was also evaluated. Potato cultivars had varying levels of tuber dormancy. The tubers were stored at ambient temperature (23 C) and evaluated weekly for 24 weeks for percent of tubers sprouting, length of longest sprouts, tuber weight loss and assessed for dormancy for 24 weeks. Paclobutrazol prolonged tuber dormancy by 21–31 days and reduced tuber weight loss. Ethephon treatment had no effect on dormancy and tuber weight loss. Potato tubers treated with CIPC had greater sprout control than the other treatments in storage. Tuber response to DMN treatment varied among the three potato cultivars evaluated. The findings from this study imply that PBZ is effective in prolonging potato tuber dormancy for short-term basis at 23 C, while CIPC applied on tubers was effective for long term storage. Optimization of post-harvest potato storage can improve food security in the highland tropics.     

Analysis of Polyphenols, Anthocyanins and Carotenoids in Tubers from Solanum tuberosum Group Phureja, Stenotomum and Andigena

Sixty-five Solanum tuberosum group Andigena, Phureja and Stenotomum genotypes from an initial population of 1,500 were analyzed for phenylpropanoids, carotenoids, and antioxidant capacity. Total phenolic content ranged from 3 to 49 mg g^?1 DW, total carotenoids from 4.1 to 154 μg/g DW, anthocyanins from 0.27 to 34 mg g^?1 DW and antioxidant capacity from 60 to 1,767 μmol TE/g DW. HPLC analysis of phenolic extracts revealed that 5-O-chlorogenic acid (5CGA) was the most abundant polyphenol in all genotypes. Ten genotypes were independently grown out for more in-depth phytonutrient analysis. The Phureja genotypes RN 27.01 had the highest polyphenol, anthocyanin and antioxidant content, while RN 39.05 had the highest carotenoid content. The tuber percentage dry matter varied markedly among the ten genotypes, influencing the phytonutrient values when expressed on a dry weight basis. Chlorogenic acid concentrations ranged from 1.7 to 29.4 mg g^?1 DW and kaempferol-3-rutinose was present up to 3 mg g^?1 DW. Petunidin-3-O-coum-rutinoside-5-O-glu or pelargonidin-3-O-coum-rutinoside-5-O-glu were the most abundant anthocyanins. The principal carotenoids were lutein, zeaxanthin, violaxanthin, and antheraxanthin, but no one carotenoid was predominant in all genotypes. These findings further support utilization of Phureja group germplasm for phytonutrient enhancement efforts.     

Effects of early planting and cultivars on the yield and agronomic traits of soybeans grown in southwestern Japan

Early planting contributed to increased soybean yields in the U.S. Because a double-cropping system dominates in southwestern Japan, early planting is not performed; it is thus unclear how much the yield potential could be increased by early planting. To address this question, we planted seven U.S. and five Japanese cultivars on around 20 May (early planting), measured the agronomic traits, including yield, yield components, and oil and protein contents, and compared these traits with those of the same cultivars planted on around 20 July (normal planting). In the early planting, the yields of the U.S. cultivars were 322–453 g m^?2, whereas the highest yield among the Japanese cultivars was only 315 g m^?2, which is significantly lower than those of the top five U.S. cultivars, indicating the adaptability of U.S. cultivars to early planting. The increases in yield obtained with early planting were 99–199 g m^?2 and ?26–144 g m^?2 for the U.S. and Japanese cultivars, respectively. The yield obtained by early planting was positively correlated with the pods m^?2, seeds pod^?1, and oil contents, but negatively correlated with the sterile pod rate, 100 seed weight and protein content. In the early planting, the U.S. cultivars had greater pods m^?2, seeds pod^?1 and oil content and less sterile pod rate, 100-seed weight, and protein content than the Japanese cultivars. These results suggest that early planting can increase the yield in southwestern Japan, if cultivars with agronomic traits observed in the U.S. cultivars of this study are grown.     

Phenolic Compounds Determined by LC-MS/MS and <Emphasis Type="Italic">In Vitro</Emphasis> Antioxidant Capacity of Brazilian Fruits in Two Edible Ripening Stages

The aim of this study was to investigate the free individual phenolics and the in vitro antioxidant capacity of blackberry, acerola, yellow guava, guabiju, jambolan and jabuticaba fruits in two edible stages. Of the thirty-three phenolics investigated by liquid chromatography - tandem mass spectrometry (LC-MS/MS), twenty-five were quantified and the major ones were catechin, isoquercitrin, epicatechin and gallic acid. The highest values for the total phenolic content (in dry matter) were observed for acerola (83.6 to 97.7 mg gallic acid equivalents g^?1 DM) and blackberry (18.9 to 28.3 mg gallic acid equivalents g^?1 DM); however, acerola, jabuticaba, and blackberry showed the highest antioxidant capacities (134.6 to 1120.4 mg Trolox equivalents g^?1 for 2,2-diphenyl-1-picrylhydrazyl and 43.6 to 501.8 μmol Trolox equivalents g^?1 for ferric reducing antioxidant power). For most fruits, the antioxidant capacity decreased during the ripening, possibly due to a decrease in the concentration of most of the phenolics.     

Alkaline phosphatase activity and its relationship to soil properties in a saline–sodic soil reclaimed by cropping wolfberry (Lycium barbarum L.) with drip irrigation

In order to ascertain the alkaline phosphatase (ALP) activity and its relationship with soil properties in saline–sodic soils during reclamation, a study was conducted in a saline–sodic soil reclaimed by cropping wolfberry (Lycium barbarum L.) with drip irrigation, in Ningxia Plain, Northwest China. The soil EC_e, pH and SAR in 0–30 cm were 12.3 dS m^?1, 9.4 and 44.1 (mmol/L)^0.5, respectively. Soil transects with different planting years were intensively sampled, which had a wide gradient of salinity and sodicity. Ranging from 1.1 to 42.4 μg g^?1 h^?1, soil ALP activities increased with the increasing planting years, and showed a large spatial variability within transect. The higher ALP activities were always found beneath the drip emitters. More soil physicochemical properties became related significantly to the ALP activities as the planting years increased, indicating that the ALP activities could be better predicted by other properties after reclamation. Path analyses showed that the negative direct effects of soil pH on ALP activities became clearly dominant as the planting years increased. The positive effects of organic matter on ALP activities exerted indirectly, mainly through pH, total N, and available P. Soil ALP activities decreased exponentially with pH, which varied from 7.38 to 10.00. Our findings demonstrated that soil pH was the limiting factor for improving soil ALP activities in this saline–sodic soil, and after three planting years, soil biological activities and fertility level increased significantly.     

Changes in chlorpropham residues in stored potatoes

Chlorpropham (CIPC)³ concentrations were measured in peel samples of tubers taken from large commercial potato storages and from test bins after aerosol application. Tuber samples were taken at different levels within the pile and at numerous sites near the surface. The minimum concentration of CIPC in the peel layer for complete inhibition of sprouting was estimated to be 20 ppm. Immediately after commercial application of CIPC, 99% of the sample sites had concentrations high enough to completely inhibit sprouting, and residues in the peel were generally highest in samples obtained from the surface and from the bottom of the pile. CIPC concentrations decreased during the storage season in nearly all sites tested. Storages differed in the rate at which CIPC was lost. Mean peel residues fell below the level necessary for sprout inhibition in some storages but not in others. The rate of CIPC loss increased at the same time that air movement to maintain the desired temperature increased. With the 20 ppm threshold level as a guide, it is possible to monitor commercial storages for sprout-inhibition status. Retreatment before peel residues drop below 20 ppm can extend sprout inhibition in storage.     

Assessment of soil enzyme activities of saline–sodic soil under drip irrigation in the Songnen plain

A field experiment was carried out to research the changes and spatial distributions of soil enzyme activities in saline–sodic soil for a different number of cultivated years under drip irrigation. The distributions of alkaline phosphatase, urease, and sucrase activities within 40 cm in both horizontal and vertical directions of the emitter in saline–sodic soils planted with Leymus chinensis for 1st, 2nd, and 3rd year were studied. A mathematical method was used to determine the relationships between soil enzyme activities and soil environmental factors contain the electrical conductivity of saturated-soil extract, pH value, available nutrient, and organic carbon. Alkaline phosphatase, urease, and sucrase activities all increased with cultivated years in saline–sodic soil under drip irrigation: from 4.5, 1.39 and 19.39 to 20.25, 3.17, and 61.33 μg g^?1 h^?1, respectively, after planting L. chinensis for 3 year. Alkaline phosphatase, urease, and sucrase activities all decreased with increased horizontal and vertical distance from the emitter. After 3 year of drip irrigation, the correlations between soil enzyme activities and soil environment factors had stronger correlations than in the unreclaimed land. After 4–6 years, the soil enzyme activities should attain the level of the natural L. chinensis grassland.     

Effect of Cooking and Processing on CIPC Residue Concentrations in Potatoes and Processed Potato Products

Residue concentrations of the sprout suppressant chlorpropham (or CIPC) were determined in raw and cooked potatoes and processed potato products, 48 h after CIPC aerosol treatment and after 30 days of subsequent storage at 4 or 12 °C. In the raw (uncooked) tuber, 48 h after CIPC treatment, the CIPC residue in the peel was 4.7 mg kg^-1, while in the peeled tuber it was 0.1 mg kg^-1. Boiling resulted in a decrease in residue concentration in the peel, but no significant differences in the residue concentration of the peeled tuber were observed. Pressure cooking resulted in a significantly increased residue concentration in the peel, but no significant change in the peeled tuber, whereas microwave cooking also did not increase the residue concentration in the peel significantly compared with that in raw tubers. Also the trend towards increases in residue concentration in microwave-cooked peeled tubers was not significant. The CIPC residue concentration detected in peeled tubers was 0.4–0.7 mg kg^-1 after boiling, 0.4–1.5 mg kg^-1 after pressure cooking and 0.4–3.8 mg kg^-1 after microwave cooking. The highest values were always found for tubers stored for 30 days at 4 °C. Processed products such as crisps, French fries, dehydrated sliced potatoes and starch contained different concentrations of CIPC residue, which was also detected in the cooking water and frying oil. The highest residue concentrations detected were 0.7, 4.7, 1.3 and 0.2 mg kg^-1 in crisps, French fries, dehydrated sliced potatoes and starch, respectively. The highest CIPC residue concentration observed in raw potatoes was much lower than the maximum residue level of 10 mg kg^-1 prescribed by the European Union.     

Effects of soil types and fertilizers on growth,yield, and quality of edible Amaranthus tricolor lines in Okinawa,Japan

Soil types and fertilizer regimes were evaluated on growth, yield, and quality of Amaranthus tricolor lines, IB (India Bengal), TW (Taiwan), BB (Bangladesh B), and BC (Bangladesh C) in developing management practices in Okinawa. Growth and yield of all amaranth lines were higher in gray soil (pH 8.4) than in dark red soil (pH 6.6) and red soil (pH 5.4). The combined NPK fertilizer resulted in highest growth parameters and yield of amaranths in all soils. Nitrogen fertilizer alone did not affect growth parameters and yield of amaranths in dark red and red soils. Growth parameters and yield increased similarly with the 30, 40, and 50 g m^?2 of NPK fertilizer in BB line, and with the 20, 30, 40, and 50 g m^?2 in BC line. Agronomic efficiency of NPK fertilizer at 50 g m^?2 was not prominent on the amaranths, compared to the fertilizer at 40 g m^?2. Amaranth lines had higher Na in dark red and red soils, while K and Mg in gray soil, Ca in gray and red soils, and Fe in dark red soil. The NPK fertilizer resulted in higher Na, Ca, Mg, and P in BB line in glasshouse. These minerals in BB line were not clearly affected, but in BC line were lower with NPK fertilizer at 20–50 g m^?2 in field. These studies indicate that gray soil is best for amaranth cultivation and combined NPK fertilizer at 20–40 g m^?2 is effective in gray soil in Okinawa for higher yield and minerals of amaranth.     

Radiation utilization efficiency,latent heat flux,and crop growth simulation in irrigated rice during post-flood period in east coast of India

To study the radiation utilization efficiency, latent heat flux, and simulate growth of rice during post-flood period in eastern coast of India, on-farm trial was conducted with three water regimes in main plots (W ₁ = continuous flooding of 5 cm, W ₂ = irrigation after 2 days of water disappearance, and W ₃ = irrigation after 5 days of water disappearance) and five nitrogen levels in subplots (N ₁ = 0 kg N ha^?1, N ₂ = 60 kg N ha^?1, N ₃ = 90 kg N ha^?1, N ₄ = 120 kg N ha^?1, and N ₅ = 150 kg N ha^?1) on a rice cultivar, ‘Lalat’. Average maximum radiation utilization efficiency (RUE) in terms of above ground dry biomass of 2.09 (±0.05), 2.10 (±0.02), and 1.9 (±0.08) g MJ^?1 were computed under W ₁, W ₂, and W ₃, respectively. Nitrogen increased the RUE significantly, mean RUE values were computed as 1.60 (±0.07), 1.78 (±0.02), 2.060 (±0.08), 2.30 (±0.07), and 2.34 (±0.08) g MJ^?1 when the crop was grown with 0, 60, 90, 120, and 150 kg ha^?1 nitrogen, respectively. Midday average latent heat flux (on clear days) varied from 7.4 to 14.9 and 8 to 13.6 MJ m^?2 day^?1 under W ₂ and W ₃ treatments, respectively, at different growth stages of the crop in different seasons. The DSSAT 4.5 model was used to simulate phenology, growth, and yield which predicted fairly well under higher dose of nitrogen (90 kg and above), but the model performance was found to be poor under low-nitrogen dose.     

Aminopyralid Residue Impacts on Potatoes and Weeds

Aminopyralid is used in Alaska to control certain invasive weed species; however it appears to have an extended soil half-life in interior Alaska resulting in carry-over injury in potatoes. Field studies at three experiment stations in Delta Junction, Fairbanks, and Palmer, Alaska were established to determine the dose–response of weeds and above and below ground potato growth to soil-applied aminopyralid (0, 8, 15, 31, 62, and 123 g ae ha^?1) . Both prostrate knotweed and narrowleaf hawksbeard were susceptible to aminopyralid. At Delta Junction and Fairbanks, visual injury of potatoes greater than 25 % was observed at 15 g ae ha^?1 aminopyralid, whereas at Palmer visual injury was greater than 40 % at 8 g ae ha^?1, the lowest rate tested. Potato tuber production was reduced by aminopyralid at rates of 15 g ae ha^?1 and above at both Delta Junction and Palmer. Sub-samples of potato tubers from Delta Junction and Palmer were analyzed for aminopyralid content and grown out to determine if aminopyralid in tubers would reduce subsequent growth. The aminopyralid concentration in potato tubers increased with increasing field application rates, with 30 ppb extracted from tubers grown at the highest application rate (123 g ae ha^?1). All plants grown from daughter tubers except from control plots in Palmer exhibited injury symptoms. The number of emerged shoots, and shoot height decreased with increasing aminopyralid concentrations in the tuber, with injury rates greater than 70 % at 8 g ae ha^?1.     

The effect of floating vegetation on CH<Subscript>4</Subscript> and N<Subscript>2</Subscript>O emissions from subtropical paddy fields in China

Duckweed (Lemna minor), a floating macrophyte belonging to the Lemnaceae family, is commonly found in subtropical paddy fields. This plant rapidly takes up nutrients from water and forms dense floating mats over the water surface that may impact the biogeochemical processes and greenhouse gas production in paddy fields. In this study, we measured CH₄ and N₂O emissions from duckweed and non-duckweed plots in a subtropical paddy field in China during the period of rice growth using static chamber and gas chromatography methods. Our results showed that CH₄ emission rate ranged from 0.19 to 26.50 mg m^?2 h^?1 in the duckweed plots, and from 1.02 to 28.02 mg m^?2 h^?1 in the non-duckweed plots. The CH₄ emission peak occurred about 1 week earlier in the duckweed plots compared to the non-duckweed counterparts. The mean CH₄ emission rate in the duckweed plots (9.28 mg m^?2 h^?1) was significantly lower than that in non-duckweed plots (11.66 mg m^?2 h^?1) (p < 0.05), which might be attributed to the higher water and soil Eh in the former. N₂O emission rates varied between ?50.11 and 201.82 µg m^?2 h^?1, and between ?28.93 and 54.42 µg m^?2 h^?1 in the duckweed and non-duckweed plots, respectively. The average N₂O emission rate was significantly higher in the duckweed plots than in the non-duckweed plots (40.29 vs. 11.93 µg m^?2 h^?1) (p < 0.05). Our results suggest that the presence of duckweed will reduce CH₄ emission, but increase N₂O flux simultaneously. Taking into account the combined global warming potentials of CH₄ and N₂O, we found that growing duckweed could reduce the overall greenhouse effect of subtropical paddy fields by about 17 %.     

Effect of organic,inorganic and slow-release urea fertilisers on CH<Subscript>4</Subscript> and N<Subscript>2</Subscript>O emissions from rice paddy fields

Vietnam is one of the world’s top two rice exporting countries. However, rice cultivation is the primary source of agriculture’s greenhouse gas (GHG) emissions in Vietnam. In particular, strategies are required to reduce GHG emissions associated with the application of organic and inorganic fertilisers. The objective of this study was to assess the effects of various combinations of biochar (BIOC), compost (COMP) and slow-release urea (SRU) on methane (CH₄) and nitrous oxide (N₂O) emissions. In total, 1170 gas samples were collected from closed gas chambers in rice paddies at Thinh Long commune and Rang Dong farm in northern Vietnam between June and October 2014. The gas samples were analysed for CH₄-C and N₂O-N fluxes using gas chromatography. The application of BIOC alone resulted in the lowest CH₄ emissions (4.8–59 mg C m^?2 h^?1) and lowest N₂O emissions (0.15–0.26 µg N m^?2 h^?1). The combined application of nitrogen–phosphorus–potassium (NPK) + COMP emitted the highest CH₄ (14–72 mg C m^?2 h^?1), while ½NPK + BIOC emitted the highest N₂O (1.03 µg N m^?2 h^?1 in the TL commune), but it was the second lowest (0.495 µg N m^?2 h^?1) in the RD farm. Green urea and orange urea reduced N₂O emissions significantly (p < 0.05) compared to white urea, but no significant differences were observed with respect to CH₄ emissions. SRU fertilisers and BIOC alone measured the lowest greenhouse gas intensity, i.e. <2.5 and 3 kg CO₂ eq. kg^?1 rice grain, respectively. Based on these results, application of fertilisers in the form of BIOC and/or orange or green urea could be a viable option to reduce both CH₄ and N₂O emissions from rice paddy soils.     

Effects of poultry manure on soil solution electrical conductivity and early growth of Monochoria vaginalis

We investigated the effect of poultry manure (PM) on the occurrence and early growth of Monochoria vaginalis in relation to soil solution electrical conductivity (SSEC). PM was applied at rates corresponding to 0 g of nitrogen (N) m^?2 (PM-0), 1 g N m^?2 (PM-1), 3 g N m^?2 (PM-3), and 5 g N m^?2 (PM-5). At 7 d post-seeding, the soil solution was sampled to measure EC, and also the emergence and growth of M. vaginalis were evaluated. The emergence rate of M. vaginalis decreased with increasing application rate of PM and SSEC. SSEC was significantly negatively correlated with the emergence rate of M. vaginalis seedlings. The average leaf number and length of M. vaginalis did not differ between PM-0, PM-1, and PM-3, but were significantly lower in PM-5. In summary, PM would allow to better control the emergence and early growth of M. vaginalis.     

Qualitative response of roselle to planting methods,humic acid application,mycorrhizal inoculation and irrigation management

Crop management is an important factor affecting the quality of medicinal plants. Therefore, objectives of our investigation on roselle (Hibiscus sabdariffa L.) were: 1) To identify an appropriate planting method in semi-arid regions and 2) to study crop production under water-deficit conditions using eco-friendly techniques. We specifically investigated the effects of planting methods (direct sowing vs. transplanting) (experiment 1, in a randomized complete-block design), as well as effects of water regimes [irrigation after pan evaporation of 100 mm (normal irrigation) and 200 mm (deficit irrigation)], humic acid application (0 and 4 kg ha ^?1) and mycorrhizal inoculation (Glomus versiforme, Glomus intraradices, and control) (experiment 2, in a split-split-plot layout) on certain qualitative indices of roselle. The amounts of total soluble solids (TSS), anthocyanin content, and maturity index for direct seeding were, respectively, 17%, 15%, and 33% higher than those for transplanting, whereas vitamin C content and total acidity for transplanting treatment were, respectively, 17% and 20% more than those for direct sowing. According to data obtained from the average of the three mycorrhizal treatments, normal irrigation combined with humic acid application increased total acidity (0.88 mg.100 g^?1), anthocyanins (67.1 mg.l^?1), and vitamin C content (2177 mg.100 g^?1) over the control (deficit irrigation and no humic acid application, which had lower acidity (0.53 mg.100 g^?1), anthocyanins (38.8 mg.l^?1), and vitamin C content (1882 mg.100 g^?1). Total phenol and anthocyanins content under mycorrhizal inoculation were relatively higher than under control treatment at both levels of irrigation. G. intraradices produced the largest amount of vitamin C (2353 mg.100 g^?1) under deficit irrigation. On average, no-inoculation treatment had higher TSS, pH, and total acidity than any mycorrhizal inoculation treatment. Humic acid application and mycorrhizal inoculation, especially using G. intraradices, showed the highest values of anthocyanins (56.9 mg.l^?1) and vitamin C (2309 mg.100 g^?1) content. Overall, normal irrigation, combined with humic acid application and mycorrhizal inoculation, partially improved the quality indices of roselle.