Anna Mårtensson Pengarang

4. Characterisation of sweet stem sorghum genotypes for bio-ethanol production Precious Mangena, Hussein Shimelis and Mark Laing School of Agricultural, Earth & Environmental Sciences, University of KwaZulu-Natal, Pietermaritzburg, South Africa ABSTRACT In an effort to characterise and select promising sweet stem sorghum genotypes with enhanced biofuel productivity, the present study investigated phenotypic variability present among diverse sweet stem sorghum genotypes based on ethanol production and related agronomic traits. One hundred and ninety genotypes were evaluated. Data were subjected to variance, cluster, correlation, path coefficient and principal component analyses. Significant differences ( P < 0.01) were detected among tested genotypes for all measured traits. Days to flowering varied from 62 to 152 with a mean of 93. Plant height varied from 90 to 420 cm with a mean of 236 cm. Stem diameter ranged from 7 to 31 mm with a mean of 16 mm. Biomass yield varied from 6.668 to 111.2 t ha −1 with a mean of 30 t ha −1 . Stalk dry matter content ranged from 17.2% to 44.2% with a mean of 29.8%, while fibre content varied from 8.92% to 34.8% with a mean of 17.2%. The stalk brix yield varied from 3.3% to 18.9% with a mean of 12.1%. Ethanol productivity ranged from 240.9 to 5500 l ha −1 with a mean of 1886 l ha −1 . The best ethanol producing genotypes were AS203, AS391, AS205, AS251 and AS448. Days to flowering, plant height, stalk brix and stem diameter exerted the greatest indirect effects on ethanol production through higher biomass production. Biomass yield had the greatest direct effect on ethanol production. Therefore, the above traits should be considered during breeding sorghum for bio-ethanol production. Also, the traits had high heritability values, hence selection should provide for good genetic gains. Overall, the above sweet stem sorghum genotypes are useful genetic resources for breeding of sorghum with enhanced bio-ethanol production. KEYWORD S Correlation; genetic advance; genetic coefficient of variation; heritability; morphological diversity; path coefficient analysis; phenotypic coefficient of variation; principal component analysis Farm and operator characteristics affecting adoption of precision agriculture in Denmark and Germany Tseganesh Wubale Tamirat, Søren Marcus Pedersen and Kim Martin Lind Department of Food and Resource Economics, University of Copenhagen, Frederiksberg C., Denmark ABSTRACT Precision Agriculture (PA) has been advocated as a promising technology and management philosophy that provides multidimensional benefits for producers and consumers while being environmentally friendly. In Europe, private stakeholders (farm advisors, farm equipment producers, decision support providers, farmers) and research institutions have been trying to develop, test and demonstrate adoption of precision agriculture solutions with governments financing big projects in these areas. Despite these efforts, adoption is still lagging behind expectations. Whether farmers adopt PA or not is likely to be influenced by several factors. This study intends to identify the main socio-economic determinants of adoption of precision agriculture in Denmark and Germany employing a binary logit model on a cross-section survey data. The results show that farm size, farmer age and demonstration and networking events like attending workshops and exhibitions significantly influence farmers’ adoption decision. KEYWORD S Auto-guidance; GPS; logit; odds ratio; perception; precision technologies Heavy metal contamination in green space soils of Beijing, China Mao Lin, Suyan Li, Xiangyang Sun, Shaobin Yang and Jing Li College of Forestry, Beijing Forestry University, Beijing, People’ s Republic of China ABSTRACT Urban green space soil heavy metal pollution seriously affected the lives of residents, and soil environmental quality data is important for urban planning and functional construction. In this study, the concentrations of arsenic (As), cadmium (Cd), chromium (Cr),copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn) in 148 soil samples collected from green spaces in Beijing City, China were measured. The mean concentrations were 7.60, 0.29, 50.32, 31.61, 1.53, 23.89, 29.68, and 76.53 mg/kg, respectively. With the exception of Ni, the concentrations of the seven other heavy metals were greater than their background values. Additionally, the concentration of Hg was 3.06 times greater than the Grade 2 value (0.5 mg/kg) of Environmental quality standard for soils in China (GB 15618-1995), also exceeded the limit value (1 – 1.5 mg/kg) for Hg in soil of European Union (86/278/EEC). Soil pollution assessment was carried out using the geoaccumulation index (Igeo), the Igeo value of Cd and Hg were 0.70 and 4.11, respectively. It suggested that, the green space soil of Beijing was slightly polluted by Cd and seriously polluted by Hg, which posed great harm to public health. A positive correlation exists between Cu and Hg, Pb, and Zn, as well as between Hg and Pb, suggesting the metals in the green space soils originated from similar sources. Multivariate statistical analysis, such as principal component analysis (PCA) and cluster analysis (CA), were adopted to identify heavy metal sources. The results suggest that the sources of heavy metals in Beijing green space soils differ. Cd, Cu, Hg, and Zn derived from vehicular transport; Cd and Cr originated from industrial activities and phosphate fertilisers; As and Ni mainly contributed by parent materials. The spatial distribution characteristics of the eight heavy metals varied greatly, and the presence of these metals was strongly associated with anthropogenic activities. KEYWORD S Green space; heavy metal; contamination; geoaccumulation index; spatial distribution map Micronutrient availability in soils of Northwest Bosnia and Herzegovina in relation to silage maize production Djordje Grujcica, Milanka Drinicb, Iva Zivanovica, Ismail Cakmakc and Bal Ram Singha aFaculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Science, Ås, Norway; bFaculty of Agriculture, University of Banja Luka, Banja Luka, Bosnia and Herzegovina; cFaculty of Engineering and Natural Sciences, Sabanci University, Istanbul, Turkey ABSTRACT Maize (Zea mays L.) is the most widely grown crop in Bosnia and Herzegovina especially in Northwest part of the country. Considering that, the maize is extremely sensitive to micronutrient deficiency the main aim of this study was to asses: (1) micronutrient availability in soil, (2) micronutrient status in silage maize; and (3) the relationship between micronutrient soil availability and maize plant concentration. Soil samples for micronutrient availability (n = 112) were collected from 28 farms in 7 municipalities. Plant available micro- and macro- nutrients in soil were extracted using Mehlich-3, except plant available Se was extracted using 0.1M KH2PO4. Result showed that on average there was no significant difference between different soil types regarding their potential in plant available nutrients. P deficiency was present both, in soil and plants in whole region. Soil extractable P was ranging from 0.003–0.13 g kg −1 and total plant P was ranging from 0.79–4.95 g kg −1 . Zinc deficiency was observed in two locations both in soil (0.71 mg kg −1 ; 0.79 mg kg −1 ) and plant (11.5 mg kg −1 ; 15.8 mg kg −1 ). Potential Se soil deficiency was observed on some locations, while Se plant status is not high enough to meet daily requirements of farm animals. Extractable soil nutrients could be used as relatively good predictor of potential soil and plant deficiencies, but soil nutrient interactions and climate conditions are highly effecting the plant uptake potential. KEYWORD S Micronutrients; plant uptake; deficiency; maize; nutrient availability PGPRs of plum (Prunus domestica) rhizosphere enhance plant growth and antagonise fungal activity in vitro Izhar Alia, Tariq Sultanb, Fazli Subhana, Kashif Syed Haleema, Nighat Sultanac and Isfahan Tauseefa aDepartment of Microbiology, Hazara University, Mansehra, Pakistan; bLand Resource Research Institute, NARC, Islamabad, Pakistan; cDepartment of Biochemistry, Hazara University, Mansehra, Pakistan ABSTRACT Plant growth promoting rhizobacteria (PGPR) promote the plant growth by various direct and indirect mechanisms. The present study was undertaken to isolate and characterise the PGPRs of plum ( Prunus domestica) rhizosphere in Pakistan. A total of 95 rhizobacteria were isolated, out of which 40 strains were selected on the basis of morphological, biochemical and Gram staining characteristics. The selected isolates were screened for in vitro plant growth promoting potential and were subsequently evaluated for host plant growth promotion. The selected isolates demonstrated strong lytic enzymatic activities and were able to produce ammonia, siderophore, Hydrogen cyanide along with capability of phosphate solubilisation. Moreover, the results showed a significant growth suppression of pathogenic Fusarium oxysporum and Rhizoctonia solani in an in vitro assay. The plant microbe interaction study was carried out using 11 most efficient rhizobacterial strains inoculated to roots of plum plants. The inoculated PGPRs significantly augmented the leaves number per shoot, shoot diameter, shoot length and plant height. The inoculation also significantly increased the chlorophyll contents of leaves, concentration of micro and macro nutrients compared with control. The current study shows the importance of these selected PGPRs as bio-fertilizer to improve the health and productivity of plum species in Pakistan. KEYWORD S Bio-fertilizer; diversity; PGPR; plant growth; plum Physico – biochemical properties of tomato (Solanum lycopersicum) grown in heavy – metal contaminated soil H. A. Hashem a, A. I. Shoumanb and R. A. Hassaneina aDepartment of Botany, Faculty of Science, Ain Shams University, Cairo, Egypt; bDepartment of Basic Science, Institute of Environmental Studies and Research, Cairo, Egypt ABSTRACT The present study was undertaken to investigate the effect of soil contamination with heavy metals on physico-biochemical properties of tomato fruit. The deleterious effect of soil contamination on the quality and quantity of tomato plant yield was determined. Harvested tomato fruit characteristics including fruit length, diameter, volume and fresh and dry weights, total soluble solids, titratable acidity, lycopene and carbohydrates contents were measured in tomato fruits cultivated in soil contaminated with industrial effluents. In addition, some secondary metabolites (total phenols and flavonoids), micro- and macronutrients were also detected. Residual heavy metals (Cd, Co, Ni and Pb) were examined in the harvested fruits. The obtained results were compared with those of tomato fruits cultivated in non-contaminated soil. Results demonstrate that soil contamination with heavy metals have a negative effect on tomato fruits characteristics, titratable acidity, total soluble solids, lycopene, ascorbic acid, micro-elements and carbohydrates content. Moreover, fruits originated from plants grown in contaminated soil possess high phenols and flavonoids contents and higher heavy metals content compared to control fruits. It is recommended that fruits cultivated in that area not to be eaten by large quantities, to avoid excessive accumulation of heavy metals in the human body. Abbreviations: (AsA): Ascorbic acid; (DTPA): diethylenetriamine penta acetic acid; (TA): Titratable acidity; (TSS): Total soluble solids KEYWORD S Ascorbic acid; heavy metals; lycopene; reducing sugar; Solanum lycopersicum; yield Residual plant nutrients in crop residues – an important resource Stanislav Tormaa, Jozef Vilčeka,b, Tomáš Lošákc, Stanislav Kuželd and Anna Martenssone aNational Agriculture and Food Centre - Soil Science and Conservation Research Institute, Prešov, Slovakia; bDepartment of Geography and Applied Geoinformatics, Faculty of Humanities and Natural Sciences, University of Prešov, Prešov, Slovakia; cFaculty of Regional Development and International Studies, Department of Environmentalistics and Natural Resources, Mendel University in Brno, Brno, Czech Republic; d Department of Agroecosystems, Faculty of Agriculture, University of South Bohemia in České Budějovice, České Budějovice, Czech Republic; eDepartment of Soil and Environment, Swedish University of Agricultural Science, Uppsala, Sweden ABSTRACT With increasing demand for sustainable production, the need to effectively utilise site-based resources increases. One such resource is the remaining crop residues, both above and below ground, after harvest. In order to assess the magnitude of this resource, this study determined the plant nutrient contribution of residues from 17 different crops in seven different regions of Slovakia over a nine-year period. The soil profile 0.0–0.3 m was taken into account at belowground residues sampling. The results showed that winter rape, mustard, corn maize, triticale, winter rye with straw and sunflower left the most residues, exceeding 8 tons of dry biomass per hectare. Root crops (sugar beet, potatoes) and peas left less than 3 tons of residual dry biomass per hectare. Using these data, the nutrient potential coefficient, i.e. the amount of nutrients left by production of one ton of the main product was calculated by polynomial regression. With these coefficients and the known yield of a given crop, it was possible to calculate how much nitrogen, phosphorus and potassium each crop leaves in the soil after harvest. It was found that the amount of nitrogen left ranged from 20 to 132 kg, phosphorus from 2 to 24 kg and potassium from 13 to 218 kg per hectare. This has to be taken into account when calculating the fertiliser requirement of the subsequent crop in order to achieve better resource utilisation, thereby reducing the risk of eutrophication and improving farm profits by reducing expenditure on fertiliser. KEYWORD S Aboveground residues; belowground residues; fertiliser requirement; nutrient potential coefficient; resource efficiency Structure liming enhances aggregate stability and gives varying crop responses on clayey soils Jens Blomquist, Magnus Simonsson, Ararso Etana and Kerstin Berglund Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala, Sweden ABSTRACT It has been suggested that liming can improve soil structure and thereby decrease losses of particles and associated nutrients. In this study, two types of structure lime, slaked lime (Ca(OH)2) and a mixed product of calcium carbonate (CaCO3) and slaked lime (Ca(OH)2), were applied at three different rates in field trials on clayey soils (23%–40% clay). A combination of primary tillage and structure liming was also studied, in a split-plot trial on a clayey soil (25% clay). Aggregate (2–5 mm) stability, measured as reduction in turbidity (which is strongly correlated with losses of particulate phosphorus), was significantly increased with the highest application rates of both structure lime products. Aggregate size distribution was also improved with structure lime, creating a finer tilth in the seedbed. Yield response to structure lime was not consistent, with both negative and positive responses over the four-year study period. Positive yield responses can possibly be attributed to the finer tilth preventing evaporation in two dry growing seasons. Negative yield responses were probably an effect of impaired phosphorus availability associated with limited precipitation in May-July in 2011 and 2013. Two years after liming, soil pH levels were significantly elevated in plots with the highest application rate of structure lime, whereas no significant increases were found three years after liming. However, a lingering effect of liming was still detectable, as manganese concentration in barley grain was significantly lower in plots with the highest application rates of both structure lime products in the fourth study year. These results indicate that structure liming can be used as a measure to mitigate phosphorus losses from clayey soils, thereby preventing eutrophication of nearby waters. However, the yield response was varying and unpredictable and thus further investigations are needed to determine the circumstances in which field liming can act efficiently not only to prevent phosphorus losses, but also to ensure consistent yield increases. KEYWORD S Structure lime; aggregate stability; turbidity; phosphorus; aggregate size distribution; yield Two allelopathic substances from Paspalum commersonii Lam. Farhana Zamana,b, Arihiro Iwasakic, Kiyotake Suenagac and Hisashi Kato-Noguchia aDepartment of Applied Biological Science, Faculty of Agriculture, Kagawa University, Miki, Japan; bThe United Graduate School of Agricultural Sciences, Ehime University, Matsuyama, Japan; cDepartment of Chemistry, Faculty of Science and Technology, Keio University, Kohoku, Japan ABSTRACT Paspalum commersonii (Poaceae) is a herbaceous perennial weed distributed in the tropics and subtropics regions and grows mainly in the moist, or even flooded soil. It often appears in the rice field as a competitive weed and difficult to manage. Its strong competitive nature indicates possible allelopathic potential of P. commersonii. However, no studies have been found yet on the allelopathic activity of P. commersonii. Thus, we investigated the allelopathic potential of this weed and determined its allelopathic substances. Aqueous methanol extracts of P. Commersonii showed concentration-dependent inhibitory activity on the seedling growth of cress, alfalfa, rapeseed, lettuce, barnyard grass, foxtail fescue, Italian ryegrass, and timothy. Two substances were isolated through bioassay-guided fractionation and their structures were determined through spectral data as dehydrovomifoliol and loliolide. Dehydrovomifoliol and loliolide started inhibiting the shoot and root growth of cress at concentrations greater than 3 and 0.03 mM, respectively. The concentrations required for 50% inhibition (I50) of cress shoot and root growth were 3.34 and >3.50 mM for dehydrovomifoliol and 0.04 and 0.05 mM for loliolide, respectively. These results indicate that both substances may affect the inhibitory activity of P. commersonii. KEYWORD S Paspalum; allelopathy; growth inhibitor; dehydrovomifoliol; loliolide Water stress effects on biochemical traits and antioxidant activities of wheat ( Triticum aestivum L.) under In vitro conditions Abdul Qayyuma, Abdul Razzaqb, Yamin Bibic, Sami Ullah Khana, Kashif Sarfraz Abbasid, Ahmad Shere, Ayaz Mehmooda, Waseem Ahmeda, Imran Mahmoodb, Abdul Manafb, Ayub Khana, Abid Farida and Matthew A. Jenksf aDepartment of Agricultural Sciences, University of Haripur, Haripur, Pakistan; bDepartment of Agronomy, Pir Mehr Ali Shah, Arid Agriculture University Rawalpindi, Rawalpindi, Pakistan; cDepartment of Botany, Pir Mehr Ali Shah, Arid Agriculture University Rawalpindi, Rawalpindi, Pakistan; dDepartment of Food Technology, Pir Mehr Ali Shah, Arid Agriculture University Rawalpindi, Rawalpindi, Pakistan; eCollege of Agriculture, Bahauddin Zakariya University, Bahadur Campus Layyah, Multan, Pakistan; fDivision of Plant and Soil Sciences, West Virginia University, Morgantown, WV, USA ABSTRACT Water stress is one of the major environmental stresses that affect agricultural production worldwide, especially in arid and semi-arid regions. This research investigated the effect of water deficit, induced by PEG-6000 on wheat genotypes (GA-2002, Chakwal-97, Uqab-2000, Chakwal-50 and Wafaq-2001) grown in modified MS medium solution. Osmotic stress caused a more pronounced inhibition in leaf relative water content and leaf membrane stability more sensitive (index in Wafaq-2001 and Uqab-2000) genotypes compared with the tolerant (Chakwal-50, GA- 2002 and Chakwal-97) genotypes. Upon dehydration, an incline in proline, total soluble sugar, total soluble protein, superoxide dismutase, peroxidase, catalase and malondialdehyde activity content were evident in all genotypes, especially at osmotic stress of −8 bars. The observed data showed that status of biochemical attributes and antioxidant enzymes could provide a meaningful tool for depicting drought tolerance of wheat genotypes. The present study shows that genotypic differences in drought tolerance could be likely attributed to the ability of wheat plants to induce antioxidant defense under drought conditions. In order to develop genotypes with stable, higher yields in dry farming conditions, it is necessary to characterise genetic resources based on drought adaptation, determine suitable genotypes, and then use them in breeding programmes. KEYWORD S Wheat; osmotic stress; proline; membrane stability index; relative water content; antioxidant enzymes