1,720,965 research outputs found

    Can flaming be performed as selective weed control treatment in turfgrass?

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    Warm season species are the most suitable species for turfgrass in Mediterranean conditions but can suffer weed competition after transplanting. Flame tolerance of Cynodon dactylon and Paspalum vaginatum, during the first 5 weeks of development, was tested for selective flaming treatments. The plants were grown in a greenhouse and transplanted in 30 cm long 23.5 cm wide and 5 cm deep pots, containing peat based substrate. Four plants were hand transplanted in each pot. The thermal treatments were performed using a test bench equipped with a belt conveyor driven by an electric engine, a 25 cm wide prismatic burner and an LPG feeding group that allowed to operate with different values of pressures and speeds. Digital images were analysed with an automated procedure with the aim to assess crop canopy one week after treatments. Crop biomass was assessed at the end of the cycle. Cynodon dactylon was the most sensitive species showing on average a 50% reduction of the canopy using around 15 kg ha-1 of LPG, a maximum biomass loss of 75% with one treatment and 100% with two or more treatments. Paspalum vaginatum appeared more tolerant showing on average a 50% reduction of the canopy at about 30 kg ha-1 of LPG, a maximum biomass loss of 65% with one treatment and 100% with two or more treatments. However, selective flaming could represent a possible option to perform weed control in warm-season turfgrasses

    Tillage and cover crop effects on weed management and community changes in organic tomato cropping system

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    The adoption of no-till practices in organic horticultural production has been challenged by an ineffective cover crop management and absence of season-long weed control. The objectives of our research were to determine the effects of tillage, cover crop residues management and weed control approaches on weed abundance, season-long suppression, diversity and weed community changes in tomato cropping system. The trial was conducted during 2015-2016 season under Mediterranean conditions (Pisa, Italy). The results showed the success of the combination of roller/crimper and flaming in inhibiting the re-growth of the clover(Trifolium squarrosum L.) and preparing a dead mulch in no-till plots (NT).However, weeds were able to re-grow shortly after transplanting in these plots and no decrease in weed abundance, as total weed cover, by the dead mulch was registered further in the seasonal though the clover controlled initially 70% of weed abundance. Among the weed species present, the dead mulch enhanced selectively the emergence of Artemisia vulgaris L. and Daucus carota L. When used as green manure in conventionally tilled plots (CT), the clover had no residual effect on weeds. Compared with CT, the soil cover of weeds in NT was 40% higher. Likewise, weed biomass at harvest time in NT was much more than CT and the resulting competition was highly noticeable on tomato plant biomass. Regarding weed diversity, NT increased weed species richness and induced changes in the weed flora during the season. It was well shown that no-till practices are challenging in fields with high weed seed bank and perennial weed species. In some conditions, a dead mulch may offer also the ideal growth conditions mainly of nutrients and humidity for some weed species. Effective cover crop suppression strategies are possible in organic conservation systems while good stands of high biomass at the right sowing and killing time remain crucial for a longer weed management

    Developing technique and equipment for the management of organic and conservative horticultural systems.

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    The combination of low environmental impact farming techniques and conservation agriculture techniques is considered not feasible due to some limitations, mainly including is the strong dependence of conservation cropping systems by chemical control of weeds and the use of mineral fertilizers, which are considered essential for supporting to acceptable levels of crop productions. The SMOCA project (Smart Management Conservation of Organic Agriculture) aims to integrate organic cropping systems and conservation agriculture techniques in three different scenarios (arable open field, open field vegetables and orchards) thanks to development of machines and technical itineraries that allow to apply the reduced tillage techniques even in the absence of pesticides. Within this project, prototypes of machines for non-chemical cover-crop management, weed control and sodseeding/ planting were realized in order to implement conservation cropping systems in organic agriculture

    Rye (<em>Secale cereale</em> L.) and squarrose clover (<em>Trifolium squarrosum</em> L.) cover crops can increase their allelopathic potential for weed control when used mixed as dead mulch

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    Cover crops are essential tools in agroecosystems for reducing the reliance on synthetic inputs and associated environmental risks. Alongside their benefits to soil fertility, cover crops can control weeds by their competitive and allelopathic attributes. Laboratory and field experiments were conducted to assess the allelopathic potential of two cover crop species, rye (Secale cereale L.) and squarrose clover (Trifolium squarrosum L.), alone or in  mixture, on seed germination and growth of arable weeds. Aqueous extracts of the two cover crops and their mixture were tested in a bioassay on Conyza canadensis (L). Cronq., Amaranthus retroflexus L. and Digitaria sanguinalis (L.) Scop. In vitro effects of aqueous extracts varied in a dose-dependent manner, with cover crops and weed species. All three extracts were able to reduce the germination of A. retroflexus (-87%) considerably. Inhibitory effects by rye and mixture extracts on radicle growth of all weed species ranged between 51 and 82%.  Rye extract was the best at reducing shoot length of C. canadensis and D. sanguinalis (-39 to 44%), while squarrose clover was more effective on A. retroflexus (-79%). Plant extracts also delayed the germination time of weed species with substantial effect of the mixture on C. canadensisseeds. In the field experiment, no significant weed suppression was provided by cover crop residues incorporated as green manure compared to control plots, despite tillage being more effective in reducing weed density. Still, the cover crop mixture mulch controlled weed emergence significantly better than single cover crop mulches. The chemical characterization of cover crop residues, both shoots and roots, revealed a notable richness of allelopathic phenolic acids and flavonoids, that through slow decomposition may constitute potential natural herbicides. From the analysis of the aqueous extracts, other non-analyzed and/or unidentified water-soluble allelopathic compounds should underlie the phytotoxicity observed in vitro, at least for rye. For cover crop mixture, positive interactions among plant materials leading to a better release of allelochemicals and weeding effectiveness are discussed according to chemical profiles and field data. Our study demonstrated the allelopathic activity of the cover crops and their potential to be included in weed management strategies according to cropping system needs. Additional trials are needed to confirm the performance of cover crop residues under field conditions.   Highlights - Rye and squarrose clover are cover crops with potential allelopathic effects. - Aqueous extracts of residues of rye, squarrose clover and their mixture reduced and/or slowed weed germination of A. retroflexus and C. canadensis in in vitro bioassays. - The aqueous extracts, depending on the concentration of residues, had inhibitory effects on radicle and shoot growth of A. retroflexus, C. canadensis and D. sanguinalis. - Under field conditions, mulch of a mix of rye and squarrose clover suppressed weeds better than the single species

    Effects of flame weeding on organic garlic production

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    A lack of efficient machines and strategies for cropping practices are still problems on small farms and in difficult landscapes, especially in organic crop production. The aim of this study was to develop a new weed control strategy for a typical organic garlic (Allium sativum) grown in Liguria, Italy. Flaming was proposed as an additional tool for the physical weed control program. A field experiment was conducted to test the effects of different flaming doses and timing on weed control and garlic production. The treatments consisted of a broadcast flaming at 16, 22, 37, and 112 kghaL1 of liquefied petroleum gas (LPG) at three different crop growth stages—emergence (BBCH 9), three to four leaves (BBCH 13) and six to seven leaves (BBCH 16)—once (at each growth stage separately), twice (at BBCH 9 and BBCH 13, BBCH 9 and BBCH 16, and BBCH 13 and BBCH 16 stages) or three times (all stages combined). Treatments were compared with a weedy control and hand weeding. One flaming treatment was effective in controlling weeds during the growing season. Frequent flaming treatments did not further reduce the weed biomass measured at harvest. A higher production than the weedy control, in terms of the number of marketable bulbs and yield, was obtained for all the flaming interventions carried out at more than 16-kghaL1 LPG dose. Garlic flamed once at BBCH 13 at any LPG dose or three times at more than 16 kghaL1 led to a comparable number of bulbs as hand weeding. Three flamings at an LPG dose of 22 kghaL1 also gave a statistically similar yield to hand weeding. In general, garlic was shown to tolerate up to three flaming treatments without a decline in the production. The decline in yield compared with hand weeding could be offset by the economical savings of the mechanization process and by integrating flaming with other mechanical tools used for weed management

    Agronomic and Phytochemical Characterization of Chickpea Local Genetic Resources for the Agroecological Transition and Sustainable Food Systems

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    Legume crops play a key role in hastening both the agroecological and protein transition and improving the sustainability of cropping systems. Among legumes, chickpea (Cicer arietinum L.) is a valuable source of protein, fibers, and nutraceutical compounds, providing important agri-environmental effects. Nevertheless, few studies have explored the effect of genetic characteristics on production and quality traits in chickpea. Chickpea landraces seem particularly interesting for their positive agronomic and quality characteristics, opening the door for innovation in sustainable food systems. Thus, the present study aimed to characterize two chickpea Tuscan landraces (Rugoso della Maremma and Cappuccio della Valtiberina) in comparison with widely distributed commercial chickpea varieties (Ares, Maragi&agrave;, Pasci&agrave;, Principe, Reale, Sultano, and Vittoria). Our findings highlighted positive agronomic traits of landraces in terms of seed yield and yield components, demonstrating performance that is either superior or comparable to commercial varieties. Notably, Cappuccio della Valtiberina showed the highest 1000-seed weight (425.50 g), followed by Maragi&agrave; (432.92 g), Principe (392.32 g), and Reale (382.79 g), and the highest harvest index (0.55), similar to Reale (0.55). Overall, landraces achieved 18.75% higher yields than commercial varieties. Regarding chickpea quality, landraces exhibited profiles comparable to those of commercial genotypes in terms of protein and oil content, as well as nutraceuticals. Interestingly, the two landraces had the most favorable &omega;-6/&omega;-3 ratios (Cappuccio della Valtiberina, 12.45; Rugoso della Maremma, 13.71) among the genotypes except for Maragi&agrave; (11.78), indicating better nutritional quality compared to commercial varieties (&gt;14.00). These results demonstrated that landraces could offer promising prospects for future chickpea breeding programs, aiding in the selection of genotypes capable of adapting to changing growing conditions and supporting the development of sustainable food systems

    Genotype and Seasonal Variation Affect Yield and Oil Quality of Safflower (Carthamus tinctorius L.) under Mediterranean Conditions

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    The adoption of climate‐resilient and resource‐use efficient crop species and varieties is a key adaptation action for farmers in the face of climate change. Safflower, an emerging oilseed crop, has been recognized for its high oil quality and its favorable agronomic traits such as drought and cold tolerance, making it particularly suitable to Mediterranean conditions. A 2‐year field study was carried out to evaluate the effects of the genotype and growing season on the crop phenology, seed and oil production, macronutrient accumulation and partitioning, and fatty acid composition of spring‐sown safflower grown under rainfed conditions. The experiment was conducted during the 2012 and 2013 growing seasons on an alluvial deep loam soil (Typic Xerofluvent) at the Centre for Agri‐environmental Research “E. Avanzi” of the University of Pisa (Pisa, Central Italy). Higher seed yield and yield components (plant density, plant height, branching, number of capitula per plant and seeds per capitulum) were found in almost all genotypes when the seeds were sown in mid‐March 2012 compared to in late April 2013. More favorable conditions in 2012, i.e., early sowing date, higher precipitation, and quite mild temperatures, led to a better seed and oil yield and greater aboveground biomass and nitrogen uptake, with the highest amounts being removed by straw. Greater seed yield was found to be associated with a greater plant height and a higher number of capitula per plant. Oil content was negatively affected by the higher temperatures and the lower amounts of precipitation that occurred during the 2012 growing season. Seasonal variation in fatty acid composition depended on the genotype. Lower precipitation and higher temperatures during 2013 favored oleic acid content in high linoleic acid genotypes and linoleic acid in medium to high oleic acid genotypes. Among the genotypes, the linoleic‐type Sabina and the oleic‐type Montola 2000 performed the best in both seasons. The results, besides identifying promising safflower genotypes for spring sowing in the Mediterranean region and for future breeding programs, pointed out the importance of early sowing to contrast unfavorable environmental conditions during seed‐filling, thus ensuring higher yields

    Performance and Potentiality of Camelina (Camelina sativa L. Crantz) Genotypes in Response to Sowing Date under Mediterranean Environment

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    Given the growing interest for camelina, as a multipurpose oilseed crop, seven cultivars and two sowing times were compared to characterize camelina’s production potential in the rainfed agroecosystems of Central Italy. A split-plot design, with sowing date as main plot (autumn and spring) and cultivar (V1, V2, V3, V4, V5, V6, and CELINE) as subplot, was adopted over two growing seasons (2017–2019). Phenology, yield and yield components, protein and oil content, and fatty acid profile were evaluated. Going from autumn to spring sowing, a significant reduction was observed in the number of days (139 vs. 54 days) and GDD (642 vs. 466 C d) from emergence to beginning of flowering, with more consistent variations among cultivars. V1 and V2 were the earlier ones both in spring and autumn sowing. Autumn sowing increased seed yield (+18.0%), TSW (+4.1%), number of siliques per plant (+47.2%), contents of alfa-linolenic, eicosenoic, erucic and eicosadienoic acids, and polyunsaturated to saturated fatty acid ratio. Regarding genotype, V3 showed the best seed and oil yield in autumn, whereas V1 and CELINE were the best performing in spring. Finally, TSW and number of siliques per plant were the key yield components for camelina. Results identify, in relation to sowing date, the most suitable cultivars for the tested environment, in terms of earliness and quanti-qualitative traits
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