Biological profitability of maize inoculation with selected rhizosphere micro organisms (Pseudomonas fluorescens and Glomus intraradices) under Water Deficit Stress

This research focused on evaluating the usefulness of an arbuscular mycorrhizal fungus (Glomus intraradices) and a plant growth-promoting rhizobacterium (Pseudomonas fluorescens) to maize growth under water deficit stress. Field experiment was conducted at Soil and water research institute, Karaj Station, Iran, during 2006 growing season. Biological positive effects of the micro organisms on plant growth, nutrient uptake, grain yield and yield components in maize plants was recorded in the treatment receiving mixed inoculums of G. intraradices and P. fluorescens. Maize shoot P content, grain yield, yield components, harvest index, grain N and P, soil available P, root colonization percentage and water use efficiency increased significantly with the G. intraradices inoculation and P. fluorescens, alone or in combination under water deficit stress. The highest profitability was observed in the combined treatment of inoculation with G. intraradices and P. fluorescens, which synergistically increased plant growth compared with other treatments

Towards utilizing Asteraceae alternative oilseed species on marginal lands: Agronomic performance, fatty acid composition, oil biocompounds, and oil physicochemical properties of Asteraceae species

Including alternative and drought-resilient oilseeds in marginal lands, where conventional oilseed production is threatened, could be an effective measure to restore marginal lands and improve sustainable seed oil production. Based on this approach, the present study aimed to evaluate the potential of some new and neglected Asteraceae species as alternative oil seed crops in marginal lands. The agronomic performance, fatty acid profile, seed oil biocompounds, and physicochemical properties of blessed thistle (Cnicus benedictus), cardoon (Cynara cardunculus), milk thistle (Silybum marianum), niger seed (Guizotia abyssinica), pot marigold (Calendula officinalis) and safflower (Carthamus tinctorius) were studied under a marginal land condition (semi-dry poor soils) in two growing years. Niger seed possessed the highest oil content (39.45%), while the highest oil yield (470.21 kg ha−1) was noted in safflower. The GC and HLPC analysis indicated that all the species of seed oils were rich linoleic acid sources (51.65–73.45%). However, some species, such as safflower, also contained a high amount of oleic acid (25.41%) proportion. Pot marigold seed oils had high levels of calendic acid (more than 50% of total fatty acids). The tocopherol and phenol biocompounds as essential micronutrients for human health were abundant in the species studied, which the highest tocopherol contents recorded for blessed thistle (670.43 mg/kg) and safflower (655.75 mg/kg) oils, respectively. Accordingly, the antioxidant activity of the oilseeds followed the same trends, being the highest in blessed thistle and safflower oils. The high concentration of oleic acid in safflower oil was associated with decreasing oil density, saponification, peroxidase, and increasing viscosity indicating its high oil oxidative stability. According to agronomic and oilseed quality properties, most species, especially safflower and blessed thistle, can be considered promising alternative oilseed crops in marginal lands

Comparison among Different Integrated Nutrition Management for Soil Micro and Macro Elements after Winter Wheat Harvesting and Yield

A comparative field experiment has been conducted in order to study the effect of chemical, organic and integrated nitrogen suppliment on micro and macro nutrient residue after wheat harvesting, at Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran. The treatments consisted in three groups that are chemical, organically and integrated of them. Nitrogen was supplied in different proportion from chemical and organic sources. Also, zeolite was applied in two ways: mixed with soil and mixed with cattle manure during composting. Before sowing and after wheat harvesting, macro and micro nutrient availability in the soil were examined. The results showed that, among treatments supplying with 100% nitrogen required from composted cattle manure amended with 10% (w/w) zeolite had the best effect on nutrition residue after wheat production because zeolite decreased nitrogen leaching during the manure composting. Crop yield was not statistically different between fertilizer treatments but the highest seed yield was achieved from supplying 50% nitrogen required from cattle manure compost and 50% by urea amended with 10% (w/w) zeolite. This study demonstrated that composted cattle manure amended with zeolite improves soil fertility after wheat production compared with chemical fertilization

Modelling the population dynamic and management of Bromus diandrus in a non-tillage system

A cohort-based population model was developed to simulate the population dynamics and management of Bromus diandrus. Model parameters were derived from our experiments and from published sources. Individual and integrated management strategies were simulated. More than 85% of B. diandrus seeds emerged within the first cohort. In the absence of any control the seed-bank population grew until reaching an equilibrium at density of 17,324 seeds m -2. Results pointed to the difficulty in controlling this weed with individual control tactics. All integrated programmes simulated resulted in long-term reductions in the seed bank. Simulations showed that the combination of pre-emergence and post-emergence herbicides or combination of autumn shallow cultivation and post-emergence herbicides are the best techniques to employ in integrated weed management (IWM) programmes in cereal. A sensitivity analysis indicated that B. diandrus is particularly vulnerable to small changes in the fecundity of the first cohort. Consequently, it is important to find strategies which can reduce the effect of the first cohort, because this is a clue to the control of this weed. © 2012.This work was partially supported by FEDER funds and by the Spanish Ministerio de Ciencia e Innovacion (AGL2009-7883).Peer Reviewe

Phytochemical analysis and allelopathic potential of essential oil of yarrow (Achillea spp.) ecotypes against redroot pigweed (Amaranthus retroflexus L.)

This study will contribute to the knowledge of plant allelopathy and its application in weed management, as well as to the valuation of medicinal and neglected plant species. An allelopathy experiment was conducted to introduce Achillea spp. as an effective species on the red root pigweed (Amaranthus retroflexus L.). The allelopathic effect of dry material from the flower, leaf and stem of Tanacetum polycephalum L. and 9 Achillea spp. (Achillea santolina L., A. millefolium L., A. nobilis L., A. conferta DC., A. vermicularis Trin., A. beibersteinii Afan., A. talagonica Boiss., A. tenuifolia Lam., A. aleppica DC.) applied to the soil on the growth of redroot pigweed seedling was tested. Five different ratios of aerial dry material of different species as residues (at 0, 10, 20, 40, and 50 g kg−1 dry weight) were used in the pots. Achillea residual had a significant effect on the growth of redroot pigweed. Achillea vermicolaris and A. aleppica were the most effective species at stopping the growth of redroot pigweed, reducing its dry matter by 90% at 0.07 and 0.02 g kg−1 dry weight, respectively. Based on the results of GC/MS analyses, 152 different compounds were found in the essential oil of Achillea spp. The possible relationship between allelochemicals and seedling investigation by partial least squares regression between effective doses for controlling redroot pigweed and allelochemical compounds of Achillea species. Result showed that cis-Menth-2-en-1-ol, α-Terpinyl, propionate and Bornyl acetate had the most effect on inhibiting the growth of redroot pigweed. Our research revealed that the Achillea genus has a lot of potential as a bioherbicide. This means that its leftovers or mulch could be used as a good cover crop to control redroot pigweed

Exogenous 5-Aminolevulenic Acid Promotes Antioxidative Defence System, Photosynthesis and Growth in Soybean against Cold Stress

In the present study, the possibility of enhancing cold stress tolerance of young soybean plants (Glycine max [L.] Merr) by exogenous application of 5-aminolevulinic acid (ALA) was investigated. ALA was applied at various concentrations (0, 0.3, 0.6 and 0.9 mM) by seed priming and foliar application method. After ALA treatment, the plants were subjected to cold stress at 10 ± 0.5 °C for 72 h. Cold stress significantly decreased plant growth, relative water content, chlorophyll, photosynthesis and stomatal conductivity, while it increased electrolyte leakage and proline accumulation. ALA at low concentrations (0.3 mM) protected plants against cold stress, enhancing plant height, shoot fresh and dry weight, chlorophyll content, photosynthesis, stomatal conductivity as well as relative water content. Increase of electrolyte leakage was also prevented by 0.6 mM ALA. ALA also enhanced superoxide dismutase and catalase activities at 0.6 mM concentration especially under cold stress conditions. Proline increased with increasing in ALA concentration under both temperature conditions. In most cases, application of ALA by spraying method was better than seed priming method. Results showed that ALA, which is considered as an endogenous plant growth regulator, can be used effectively to protect soybean plants from the damaging effects of cold stress, by enhancing the activity of antioxidative enzymes, protecting cell membrane against reactive oxygen species and finally by promoting chlorophyll synthesis, leading to more intense photosynthesis and more carbon fixation, without any adverse effect on the plant growth

Exogenous 5-Aminolevulenic Acid Promotes Antioxidative Defence System, Photosynthesis and Growth in Soybean against Cold Stress

In the present study, the possibility of enhancing cold stress tolerance of young soybean plants (Glycine max [L.] Merr) by exogenous application of 5-aminolevulinic acid (ALA) was investigated. ALA was applied at various concentrations (0, 0.3, 0.6 and 0.9 mM) by seed priming and foliar application method. After ALA treatment, the plants were subjected to cold stress at 10 ± 0.5 °C for 72 h. Cold stress significantly decreased plant growth, relative water content, chlorophyll, photosynthesis and stomatal conductivity, while it increased electrolyte leakage and proline accumulation. ALA at low concentrations (0.3 mM) protected plants against cold stress, enhancing plant height, shoot fresh and dry weight, chlorophyll content, photosynthesis, stomatal conductivity as well as relative water content. Increase of electrolyte leakage was also prevented by 0.6 mM ALA. ALA also enhanced superoxide dismutase and catalase activities at 0.6 mM concentration especially under cold stress conditions. Proline increased with increasing in ALA concentration under both temperature conditions. In most cases, application of ALA by spraying method was better than seed priming method. Results showed that ALA, which is considered as an endogenous plant growth regulator, can be used effectively to protect soybean plants from the damaging effects of cold stress, by enhancing the activity of antioxidative enzymes, protecting cell membrane against reactive oxygen species and finally by promoting chlorophyll synthesis, leading to more intense photosynthesis and more carbon fixation, without any adverse effect on the plant growth.</p