Showing papers in "International Journal of Agriculture and Biology in 2013"

Application of allelopathy in crop production

Abstract: Increasing global population is a threat to food security and agricultural sustainability. Allelopathy has emerged as a pragmatic approach to solve multiple issues in modern agriculture. Multiple approaches including crop rotations, cover crops, intercropping, mulching, crop residue incorporation and water extracts application are being used to explore allelopathy for pest management, stress mitigation, and growth enhancement in crop production. Allelopathy offers natural control of weeds, insect-pests and diseases. Biosynthesis of secondary metabolites at higher rates and their role in stress signaling provides excellent defense against abiotic stresses. Allelochemicals exuded in plant rhizosphere improve nutrient acquisition through the processes of solublization, biological nitrification inhibition, chelation and selected retention. Allelochemicals promote growth at low concentration; however suppress the growth if applied at high concentration. Allelopathic water extracts of sorghum, brassica, sunflower, rice, wheat, maize and moringa improve crop growth when applied at low concentrations. In this manuscript, potential application of the allelopathic phenomenon in crop production is discussed. If wisely planned, use of this phenomenon is quite effective in managing agricultural pests and improving the productivity of agricultural systems.

Chemical composition and antimicrobial activity of essential oils of lavender (Lavendula angustifolia) and lavandin (Lavandula x intermedia) grown in western Romania

Abstract: The purpose of this study was to determine the chemical composition and antimicrobial properties of essential oils (EOs) isolated from lavender (L. angustifolia Miller) and lavandin (Lavandula x intermedia) harvested in 2011 in western Romania. The essential oils, isolated by steam distillation from inflorescences arrived at full flowering stage, were analyzed by gas chromatography coupled with mass spectrometry (GC-MS). The essential oil of L. angustifolia Miller analyzed contained as main components caryophyllene (24.1%), beta-phellandrene (16%) and eucalyptol (15.6%), while the essential oil of Lavandula x intermedia contains camphor (32.7%) and eucalyptol (26.9%). The antimicrobial activity was evaluated by the Kirby-Bauer method. Antimicrobial tests showed antimicrobial activity against Shigella flexneri, Staphylococcus aureus, E. coli and Salmonella typhimurium, while Streptococcus pyogenes is not sensitive to the action of the two essential oils. The study revealed that essential oils isolated and analyzed from lavender (L. angustifolia Miller) and lavandin (Lavandula x intermedia) display significant bactericidal effects against microorganisms such as Shigella flexneri, Staphylococcus aureus and E. coli even in the absence of active principles like linalool and linalyl acetate, considered responsible for the antibacterial and antifungal properties of essential oils obtained from different species of Lavandula. The results suggest once again that the antimicrobial activity of EOs is a resultant of the antibacterial properties of the major and minor components in their chemical composition. © 2013 Friends Science Publishers

White mulberry (Morus alba): A brief phytochemical and pharmacological evaluations account

Abstract: Different plants are rich source of medicines. Since old days, Ayurveda and other disciplines reported the various pharmacological properties of naturally occurring plants against certain specific diseases. Currently, increasing health concern urged the researchers to revitalize the natural products and to alleviate the diseases without harming the body. In spite of medicinal uses of natural products, health supplements from natural products and their use in diet are gaining importance. Several bioactive constituents in natural products have the ability to protect from degenerative diseases and free radical production. The objective of this review is to unveil the phytochemistry, nutritional profile and pharmacologically active constituents of Morus alba L. The bioactive constituents isolated from M. alba such as leachianone and kuwanon G showed antibacterial activities and 1-deoxynojirimycin (DNJ) showed αglycosidase inhibitors activity. Likewise, M. alba extract and its other compounds usually flavonoids have antioxidant properties by scavenging free radicals and protect many organs from oxidative stress. Anti HIV and chemo-protective activities have also been reported but further research may reveal their exact mode of actions. © 2013 Friends Science Publishers

Stay green character at grain filling ensures resistance against terminal drought in wheat.

Abstract: Water shortage is the main constraint limiting crop productivity across the globe especially when it occurs at reproductive and grain filling stages. This study was conducted to monitor the mechanisms of drought resistance, during reproductive stages (booting, heading anthesis and post-anthesis stages) by monitoring the stay green character, water use efficiency, grain filling rate, grain filling duration, grain yield and harvest index. Seeds of wheat cultivars C-591, Chakwal-50, Dharabi-2011, BARS2009, Uqab-2000, Sehr-2006, Shafaq-2006, Faisalabad-2008, Lasani-2008 and Mairaj-2008 were sown in 10 kg soil filled pots on November 25, 2011. The drought stress was applied at the respective reproductive stage, which continued till maturity. Controlled plants were well-watered throughout the crop ontogeny. Pots were maintained at 70% water holding capacity (WHC; well watered) till booting stage and then managed drought stress was induced as per treatment maintaining 35% WHC (drought stress). Drought stress at all the stages significantly influenced the crop performance in all the tested cultivars. Severity of drought was more when it was imposed at booting and heading stages while was less devastating when imposed at anthesis and grain filling stages. Cultivars Chakwal-50 and Mairaj-2008 showed more stay gray character and took longer duration for grain filling, which resulted in the maintenance of higher grain weight and grain number per spike, grain yield and water use efficiency under stress conditions. In drought sensitive cultivars (BARS-2009, Uqab-2000), the drought increased the grain filling rate, while grain filling duration was substantially decreased. To conclude, stay green character, grain filling rate and duration under drought stress may be used as selection criteria for developing and/or screening wheat cultivars for drought resistance at reproductive stages. © 2013 Friends Science Publishers

Differential response of wheat cultivars to terminal heat stress

Abstract: Heat stress negatively influences the chlorophyll and grain filling processes in plants. Genotypes showing stay green character and better grain filling under heat stress are better able to cope with the heat stress. This study was aimed at knowing the mechanisms of heat resistance, during reproductive stages (booting stage, heading stage, anthesis stage and post anthesis stage) by monitoring the stay green character, water use efficiency, grain filling rate, grain filling duration, grain yield and harvest index of different wheat cultivars. For this experiment, seeds of wheat cultivars Chakwal-50, C-591, BARS-2009, Dharabi-2011, Sehr-2006, Shafaq-2006, Uqab-2000, Lasani-2008, Faisalabad-2008 and Mairaj-2008 were sown in 10 kg soil filled pots on November 25, 2011. The heat stress was applied at each respective reproductive stage, which continued till maturity. The heat stress was imposed separately at booting, heading, anthesis and post anthesis stages by placing pots in glass canopies with temperature of 4-5°C above than the ambient until maturity. Controlled pots were maintained under well watered conditions at ambient temperature. Heat stress at all the stages drastically reduced the performance of all tested wheat cultivars; severity being higher at booting and heading stages than anthesis and grain filling stages. Cultivar Mairaj-2008 stayed green and took more duration for grain filling, which resulted in the maintenance of grain weight and grain number per spike under stress conditions thus showing more grain yield and water use efficiency. In heat sensitive cultivars (BARS-2009, Shafaq-2006), the imposition of heat increased the grain filling rate with a substantial decrease in grain filling duration. Thus, stay green character and grain filling rate and duration under heat stress may be considered as selection criteria for developing new wheat cultivars for heat resistance during reproductive stages. © 2013 Friends Science Publishers

Supplementary effects of Saccharomyces boulardii and Bacillus subtilis B10 on digestive enzyme activities, antioxidation capacity and blood homeostasis in broiler.

Abstract: The research was conducted to evaluate the feed supplementary effect of Saccharomyces boulardii and Bacillus subtilis on digestive enzyme activities, antioxidation capicity and blood homeostasis in broiler. A total of 300 day-old Sanhuang broilers (Chinese cross breed) were randomly divided into three groups with five replications in each group (n =20). The control group was fed basal diet contained antibiotic and experimental groups were supplemented with S. boulardii and B. subtilis in addition (1 × 10 8 cfu/kg) to basal diet for 72 days, respectively. The results revealed that activities of jejunal Na + -K + ATPase (ATP), lipase (LP) and Gamma glutamyl transpeptidase (γGT) concentration increased (P<0.05) in probiotic supplementary groups. Moreover, results from ileum showed high levels of γGT in B. subtilis supplemented group only. The serum glutathione peroxidase (GSH-PX), peroxidase (POD), glutathione (GSH), glutathione reductase (GR) and catalase (CAT) concentration were significantly higher, while there was a significant decrease (P <0.05) in malondialdehyde (MDA) content in supplementary groups. The blood biochemical analysis showed significant decrease in uric acid and triglycerides of S. boulardii and B. subtilis groups. Conversely, albumin and low-density lipoprotein concentration increased in S. boulardii and B. subtilis groups as compare to control. The present research revealed that, supplementation of S. boulardii and B. subtilis B10 could be applied to enhance digestive enzyme activities, antioxidation and blood profile of broilers. In addition it might be considered as a natural antioxidant feed additive for broiler. © 2013 Friends Science Publishers

Beneficial effects of mycorrhizal association for crop production in the tropics - a review.

Abstract: Mycorrhiza plays a significant role in sustainable agriculture and has mutualistic symbiotic association with plant roots. There are several species of mycorrhiza and among the species studied Glomus mosseae is well known to colonize several vegetables, fruits, cereals and industrial crops. This paper highlighted the symbioses and beneficial effects of arbuscular mycorrhiza fungi (AMF) with tomato (Solanum lycopersicum), brinjal (S. melongena), potato (S. tuberosum), lady's finger (Abelmoschus esculentus), cucumber (Cucumis sativus), bean (Phaseolus vulgaris), pepper (Capsicum annuum), wheat (Triticum aestivum), aerobic rice (Oryza sativa), corn (Zea mays), durian (Durio zibethinus), rambutan (Nephelium lappaceum), pineapple (Ananas comosus), citrus (Citrus sinensis), banana (Musa acuminata), oil palm (Elaeis guineensis) and kenaf (Hibiscus cannabinus). Application of AMF increased nutrient uptake, water relations and perform as bio-protectants against pathogens and toxic stresses. In order to further improve their benefits, it is necessary to ensure the management practices comprising low tillage, abridged use of chemical fertilizers, especially the phosphatic fertilizers.

Improving drought resistance in wheat (Triticum aestivum) by exogenous application of growth enhancers.

Abstract: Water stress due to its severity badly effects productivity in cereals, while the foliar application of growth-enhancing substances may be helpful in reducing the drought effects. This study evaluated the efficacy of foliar applied growth enhancers i.e. Moring oleifera leaf extract (MLE), benzyl amino purine (BAP, 50 mg L -1 ) and K (SOP, 2%) against water spray as control in wheat cv. Sehar-2006. Three irrigation levels were maintained at 100, 75 and 50% field capacity designated as well watered, moderate and severe drought stressed. Increasing drought stress significantly reduced plant growth and yield. The foliar applied MLE and BAP produced maximum leaf area, Chl a and b under well watered conditions and minimum in control under severe stress. Total leaf soluble proteins were also higher in well watered and drought stressed plants applied with BAP. Foliar applied MLE increased POD, catalase, ascorbic acid and leaf K + contents under moderate drought, while total phenolic contents under severe drought condition. BAP application exhibited enhanced SOD levels under severe drought. Highest grain yield per plant was also recorded for foliar applied MLE under well watered, moderate and severe water stress than other growth enhancers. Nonetheless, foliar applied growth enhancers particularly moringa leaf extracts ameliorated the adverse effects of drought by enhancing antioxidant levels and plant secondary metabolites. © 2013 Friends Science Publishers

Comparative effect of activated carbon, pressmud and poultry manure on immobilization and concentration of metals in maize (Zea mays) grown on contaminated soil

Abstract: Metal contamination of the soils is a widespread problem and immobilization of metals with organic amendments is one of the different remediation technologies. We investigated the effect of activated carbon, poultry manure and pressmud on immobilization of nickel, manganese, copper, zinc, iron and lead in the contaminated soil, plant growth and metal concentrations in maize shoots. The amendments were applied to the soil at the rate of 4% on dry weight basis. Amendments significantly (P < 0.001) affected shoot dry weight and concentrations of all metals in maize shoots as compared to the control. The maximum shoot dry weight (4.54 g pot-1) was recorded with pressmud, while it was minimum with the control (2.22 g pot-1). Maize shoots contained the minimum nickel (3.54 mg kg-1) with activated carbon and the minimum concentrations of manganese (11.02 mg kg-1), zinc (48.06 mg kg-1) and iron (104.66 mg kg-1) were recorded with pressmud. Maize shoots contained the minimum concentrations of copper (25.41 mg kg-1) and lead (53.40 mg kg-1) with poultry manure and control, respectively. Amendments significantly (P < 0.001) decreased ammonium bicarbonate-diethylene triamine penta acetic acid (AB-DTPA) extractable concentrations of metals except lead. Activated carbon treated pots had minimum AB-DTPA extractable concentrations of all the metals except iron and lead. Activated carbon was most effective in immobilization of Ni, Mn, Zn and Cu decreasing AB-DTPA extractable Ni in the soil, while Fe and Pb was increased due to application of other amendments.

Exogenous application of thiourea improves the performance of late sown wheat by inducing terminal heat resistance

Abstract: This study was conducted to evaluate the potential of thiourea in improving the terminal heat resistance in bread wheat. Four wheat genotypes PBW 550 and PBW 343 (heat sensitive) and C 306 and C 273 (heat resistant) were field sown at normal time (November) or late (December) to expose the crop to heat stress during grain-filling. Temperature during grain filling was ~25.6 o C in normal and 29.4 o C in late sown wheat crop. Prior to sowing, wheat seeds were soaked in 6.6 mM thiourea solution) for 6 h. Thiourea was also applied as foliar spray (6.6 mM) at anthesis. Heat stress, during grain filling, led to disruption of cellular membrane by increasing membrane injury index, lipid peroxide and H2O2 contents. Nonetheless, heat resistant (C 306 and C 273) genotypes had lower lipid peroxidation and membrane injury owing to better expression of antioxidants. However, thiourea application ameliorated the heat-induced damages by stimulating the total antioxidant activity through decrease in lipid peroxidation and membrane injury. Thiourea application also increased the total soluble proteins, amino acids and chlorophyll contents in all the tested genotypes. This all caused substantial increase in plant height, peduncle length, peduncle weight and grain weight. Genotypes PBW 550 and PBW 343 showed higher grain weight in spite of greater injury to membranes over genotypes C 306 and C 273. Combined application of thiourea as seed treatment and foliar spray was more effective in improving the wheat performance by enhancing membrane stability, antioxidant potential and yield components. © 2013 Friends Science Publishers

Production and Characterization of a Novel β-Glucosidase from Fusarium solani

Abstract: β-glucosidase was produced from Fusarium solani using different agricultural wastes under solid state fermentation (SSF). Optimum production of β-glucosidase was achieved with rice husk at pH 5, moisture level 60%, and fermentation period of 72 h. Higher yields of β-glucosidase (3206 U/gds) were obtained from F. solani when the medium was supplemented with lactose. The enzyme was partially purified with ammonium sulfate precipitation yielding a specific activity of 97.5 U/mg. βglucosidase was subjected to various kinetic and thermodynamic parameters to seek the nature of the enzyme. Optimum pH and temperature were found to be 4.5 and 65°C, respectively. The enzyme possessed Km 1 mM and Vmax 55.6 µmol min -1 . It was also observed that β-glucosidase was thermally stable up to 65°C. Mg 2+ ions enhanced the enzyme activity. These characteristics suggest that β-glucosidase isolated from F. solani could be used for hydrolysis of carbohydrates and cellulosic materials used in textile, paper, starch processing, animal feeds and fruits industries. © 2013 Friends Science Publishers

Screening of native bacillus strains to induce systemic resistance in tomato plants against fusarium wilt in split root system and its field applications.

Abstract: A study was carried out to screen some bacillus strains for their ability to induce systemic resistance against fusarium wilt of tomato under both split root system and field conditions. Fourteen bacillus strains were used for initial screening of resistance induction under split root design in green house evaluations. Increase in quantities of defense related biochemicals as total phenolics, PO, PPO and PAL enzymes were examined to document induced systemic resistance (ISR) phenomenon in tomato plants under influence of these bacterial inducers. Two Bacillus strains viz., B. fortis IAGS162 and B. subtilis IAGS174 provided maximum control over fusarium wilt under split root system. Calorimetric assays proved highly significant for defense related biochemicals in tomato plants under the influence of these two bacterial strains. Talc based formulations of these two strains were prepaired to check their efficacy under field conditions. These not only provided protection against fusarium wilt, but also markedly enhanced growth and fruit yield of plants under field conditions. Our study clearly indicated the importance of these microbial organisms for suppression of Fusarium wilt and growth promotion in our agriculture system. (C) 2013 Friends Science Publishers

Seed priming improves the performance of poor quality wheat seed

Abstract: Late sowing of wheat experiences terminal heat stress which affects the grain development process and the harvested grains are of poor quality if used as seed for next crop. This study investigated the role of sowing time and seed priming on seed vigor and crop performance in wheat. Seed harvested from the crop sown on November 10, 25, December 10 and 25 were primed with CaCl2 for 12 h, or not. The primed and non-primed seeds were sown under field conditions for two consecutive years. Seed harvested from late sown crop (December 10 and 25) caused poor stand establishment. However, seed priming improved stand establishment, allometric traits, yield contributing parameters, biological yield, grain yield and harvest index. Although, the grain yield was higher in seeds harvested from November 10 planted crop owing to more number of productive tillers per unit area, spike length, number of grains per spike, 1000-grain weight; seed priming also improved the grain yield of seeds harvested from late sown crop (December 10 and 25). These results suggest that seed priming can improve the field performance of poor quality wheat seeds. © 2013 Friends Science Publishers

Supplementing herbicides with manual weeding improves weed control efficiency, growth and yield of direct seeded rice

Abstract: Supplementing herbicide application with manual weeding in dry seeded rice fields can help control weeds more effectively. To test this assumption, pre and post-emergence herbicides applied either alone or supplemented with manual weeding were evaluated in a field study. Pendimethalin at 1137 g a.i. ha -1 as pre-emergence (0 DAS), bispyribac sodium, penoxsulam, pyrazosulfuron ethyl and ethoxysulfuron ethyl at 30, 15, 30 and 30 g a.i. ha -1 , respectively, as early post emergence (15 DAS) were applied alone and supplemented with manual weeding (hoeing/pulling, 30 DAS). A weedy check and manual weeding thrice (15, 30 and 45 DAS) were included for comparison. Data on weed dynamics and crop attributes were recorded following standard procedures. Weed density and biomass was significantly reduced under sole application of herbicides; nonetheless supplementing herbicides with manual weeding further reduced both of these attributes to a much larger extent. Bispyribac sodium recoded higher weed suppression when it was followed by manual weeding. Positive efficiency indices of different weed management treatments were also observed in the study. Significant improvement in rice growth and grain yield was recorded when herbicides were followed by manual weeding. Bispyribac sodium and ethoxysulfuron ethyl followed by manual weeding recorded similar grain yields. Rice growth and yield was negatively associated with weed density and biomass, and unrestricted weed growth incurred 75% yield loss in dry seed fine rice. Combination of bispyribac sodium and manual weeding was the best integrated weed management strategy to control weeds and enhance growth and yield of rice. © 2013 Friends Science Publishers

Efficacy of different neem (Azadirachta indica) products in comparison with imidacloprid against English grain aphid (Sitobion avenae) on wheat.

Abstract: Different neem (Azadirachta indica L.) extracts (leaf and seed) and seed oils were tested against English grain aphid (Sitobion avenae F.) with a neonicotinoid, imidacloprid on wheat. All neem oils and neem seed kernel extract proved comparatively more effective in laboratory bioassay studies, with LC50 values ranging from 0.34 to 1.10%. In field-cage experiment, neem seed oil-hexane was statistically similar with imidacloprid followed by neem seed oil-expeller and neem seed kernel extract, while neem seed oil-ethanol was at par with imidacloprid. On the basis of cumulative insect days in field trials, neem seed oilexpeller proved as effective as imidacloprid in controlling the aphids, while except neem seed cake extract, all other treatments were statistically at par with imidacloprid. Non-significant differences were found in the population of mummified aphids between control and neem seed kernel extract, neem leaf extract, neem seed oil-hexane, neem seed cake extract and neem seed oil-expeller. There existed non-significant differences in all treatments regarding aphid predators. Maximum increase in wheat yield (7.28 q/ha) was observed in neem seed kernel extract treated plots followed by those of imidacloprid (7.23 q/ha). Application of imidacloprid resulted in maximum cost-benefit ratio (1:1.34) followed by that of neem seek kernel extract 5% (1:1.31). If the additional cost of loss of beneficial organisms and environmental risks posed by the application of synthetic insecticides is considered, the cost-benefit ratio of neem seed kernel extract may be comparable to that of imidacloprid and may be used against wheat aphids. © 2013 Friends Science Publishers

Antifungal activity of different extracts of Chenopodium album against Fusarium oxysporum f. sp. cepae, the cause of onion basal rot.

Abstract: Antifungal potential of different parts of Chenopodium album L. was examined against Fusarium oxysporum Schlechtend. f. sp. cepae (Hans.) Snyder and Hansen, the cause of basal rot disease of onion (Allium cepa L.). In screening bioassays, the effect of different concentrations (0.5, 1.0, …3.0%) of methanolic leaf, stem, root and inflorescence extracts of C. album was investigated. Extracts of different parts of the test plant species showed variable antifungal activity. The highest antifungal activity was exhibited by inflorescence extract. Different concentrations of this extract suppressed fungal growth by 24–80%. Methanolic inflorescence extract was successively extracted with n-hexane, chloroform, ethyl acetate and n-butanol. The highest antifungal activity was shown by ethyl acetate fraction resulting in 68–100% reduction in fungal biomass. From ethyl acetate fraction, three unknown compounds viz. A, B and C were isolated through thin layer chromatography (TLC). TLC fraction A exhibited the highest antifungal activity with minimum inhibitory concentration (MIC) of 250 g mL -1 . Thus, antifungal constituents of ethyl acetate fraction of methanolic inflorescence extract of C. album can be used as natural fungicides for the management of basal plate rot of onion. © 2013 Friends Science Publishers

Effects of extreme heat stress on growth performance, lymphoid organ, IgG and cecum microflora of broiler chickens.

Abstract: In this study, the effect of extreme heat diet on growth performance, lymphoid organ, blood immunoglobulin and cecum microflora change in broilers exposed to continuous lighting and extreme heat stress (EHS) was studied. Broilers raised under normal environment temperature (25 degree C) or extreme heat stress temperature (33 plus minus 2 degree C), and consumed chow diet (CD) or extreme heat stress diet (EHSD). Five hundred Ross 308 days-old commercial broilers were arranged in a completely randomized block design of 5 treatment groups with 4 repetitions (25 heads per repetition pen). The broilers were divided into: T1 (normal environment + CD); T2 (EHS + CD); T3 (EHS + EHSD in which the tallow in CD was substituted by soy oil and contained 5% molasses); T4 (EHS + EHSD in which the tallow in CD was substituted by soy oil and contained 5% molasses, and 1.5 times more methionine and lysine than CD), and T5 (EHS + EHSD in which the tallow in CD was substituted by soy oil, contained 5% molasses, 1.5 times more methionine and lysine than CD, and 300ppm of vitamin C). The EHS significantly reduced the body weight gain and feed intake. The blood immunoglobulin, bursa of Fabricius, thymus, and spleen weight were significantly reduced when broilers were exposed to EHS. Compared to the normal environment temperature group, the cecum Lactobacillus sp. was low in the EHS treatment group, while Escherichia sp., Salmonella sp. and total aerobic bacteria in the EHS treatment group were high. A statistically significant difference was acknowledged between the treatment groups.

Effects of Carboxyl Methyl Cellulose and Edible Cow Gelatin on Physico-chemical, Textural and Sensory Properties of Yoghurt

Abstract: Effects of carboxyl methyl cellulose (CMC) and edible cow gelatin (ECG) on physico-chemical, textural, and sensory properties of yoghurt were investigated. Yoghurts were manufactured from full-fat cow milk with addition of CMC and ECG in combination or solely, at concentrations of 0.25 and 0.50% (w/w). Sole CMC addition at a concentration of 0.25% contributed to higher viscosity (7175 cP in comparison with the control being 4526 cP on day 1) and firmness (561 g compared to the control being 294 g on day 1), but caused lower water holding capacity and higher syneresis compared to the control. However, sole ECG addition at concentration of 0.50% resulted in higher water holding capacity (69.29% in comparison with the control being 48.41%) and lower syneresis (0.22 compared to the control being 2.64, in mL per 100 mL initial sample), while also contributing to viscosity (5551 cP on day 1) and firmness (369 g on day 1). The results suggest ECG is suitable for yoghurt compared to CMC, giving an improved gel network structure with lower syneresis and higher water holding capacity along with higher viscosity and firmness, while causing no significant harm on sensory perception. © 2013 Friends Science Publishers

Seed priming: a shotgun approach for alleviation of salt stress in wheat.

Abstract: Salinity is a major abiotic constraint to sustainable crop production. Seed priming is a useful tool to enhance the performance of crops on saline soils. A field study was carried out to explore the potential of priming to improve salt tolerance in wheat cultivars MH-97 and SARC-1. Seeds were primed in distilled water (hydropriming) and aqueous solutions containing 50 mg L -1 of salicylic acid (SA), kinetin (Kin), ascorbate and 50 mM calcium chloride (CaCl2) for 12 h. After priming, seeds were sown in normal (0.31 dS m -1 ) and saline (10 dS m -1 ) fields. Seed priming with ascorbate, SA and Kin effectively alleviated the salinity-induced damage in both wheat cultivars; however, ascorbate priming was the most effective. Seed priming with SA, Kin and ascorbate significantly decreased the uptake of Na + and Cl and enhanced the uptake of K + in leaves of both cultivars under salinity stress. These results suggest that priming with seed priming with ascorbate, SA and Kin are effective strategies to improve the wheat productivity under salinity stress. © 2013 Friends Science Publishers

Comparative efficacy of growth media in causing cadmium toxicity to wheat at seed germination stage.

Abstract: Cadmium (Cd) is toxic and negatively influences the crop growth. Growth medium may have central role in the expression of toxicity of heavy metals and these toxic effects may be less in soil as compared to other mediums. An experiment was conducted to determine the Cd toxicity on wheat in soil and filter paper media. Three levels of Cd (0, 5, 20 mg L -1 ) were evaluated in these mediums in thermophore plates. Results revealed the toxic effect of different levels of Cd on wheat growth indices. Wheat cultivated on soil had better germination and growth in comparison to filter paper. Maximum reduction in plumule and radicle length 32 and 37%, respectively was observed at 20 mg Cd L -1 on filter paper whereas 16 and 12%, respectively in soil medium as compared to control. Germination percentage and index was relatively less affected than plumule and radicle growth on both media. Cd concentration in wheat radicle and plumule increased with increasing its concentration in growth media. Filter paper medium accumulated higher concentration (10-49 mg Cd kg -1 ) in wheat tissues compared to soil medium (3-29 mg Cd kg -1 ). Bioaccumulation factor ratio (BAF-plumule/BAF-radicle) was less than 1 implied root as major sink of Cd. Pearson correlation demonstrated the negative regulation of Cd on various indices of wheat. It could be concluded that soil provides relief to wheat against Cd stress as it has natural ability to sorb Cd on the exchange sites. Further, plumule and radicle length was good indicator to determine Cd toxicity. © 2013 Friends Science Publishers

Phosphorus availability in different salt-affected soils as influenced by crop residue incorporation.

Abstract: An incubation study on phosphorus availability in two different naturally salt-affected soils (saline sodic; ECe = 6.59 dS m-1; pHs = 8.29; SAR = 17.39 (mmolc L-1)1/2; CaCO3 = 3.47%; Extractable P = 2.97 mg per kg; sandy loam and slightly salt-affected; ECe = 4.21 dS m-1; pHs = 8.18; SAR = 6.57 (mmolc L-1)1/2; CaCO3 = 3.21%; Extractable P = 2.76 mg per kg; sandy clay loam) with and without crop residues was conducted at National Agricultural Research Centre, Islamabad during 2011. Completely randomized design (factorial) with three replications was followed. Dried wheat straw (1 g per kg of soil) was incorporated uniformly in the respective pots. The phosphate fertilizer was added @ 20, 40 and 60 mg P2O5 per kg of soil as commercial TSP after the soils were transferred to the incubation pots of one kilogram capacity. Soil samples were collected periodically (0, 30, 60, 90 and 120 days after incubation) and analyzed for P availability. It was observed that greater P was available at the first day just after P application with and without crop residue (CR) that decreased gradually with the passage of time. After 60 days, the mean available P was 16.61 and 14.18 ppm in treatment T4 (60 mg P2O5 per kg soil) in saline-sodic soil with and without CR, respectively, while it was 13.21 and 11.75 ppm in marginally saline soil with and without CR, respectively in the same treatment. Although, initially there was no significant difference in P availability with CR incorporation as compared to without CR treatment however, after 60 days of incubation it increased significantly. The study indicated that after 60 days of incubation, both soils were able to maintain 41 and 39% P, respectively in available form when P2O5 was applied @ 60 mg per kg along with CR incorporation that was 11 and 9% higher as compared to the soils having no CR. Overall, the CR incorporation not only improved P availability but also lowered ECe (2% and 6%) and SAR (5% and 4%) of saline sodic and slightly salt-affected soils, respectively.