1,720,972 research outputs found
Can flaming be performed as selective weed control treatment in turfgrass?
Full text linkWarm 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
No full textThe 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
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Developing technique and equipment for the management of organic and conservative horticultural systems.
No full textThe 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
Full text linkCover 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
Full text linkA 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
Sodium content of plant-based meat and cheese analogues: comparison with benchmarks proposed by the World Health Organization
No full text: Although plant-based analogues of animal products have become increasingly common, their sodium content has not been adequately investigated. The main aims of this study were to: (i) compare sodium content of cheese analogues, meat analogues, and tofu and tempeh sold in Italy with the relative WHO benchmarks (720, 250 and 280 mg/100 g, respectively); and (ii) evaluate the effectiveness of Nutri-Score in identifying products exceeding these benchmarks. Food labels from 430 meat analogues, 49 cheese analogues and 42 tofu and tempeh products were collected and analysed. Meat analogues (93%) and tofu and tempeh (57%) had the highest percentage of products exceeding the benchmark while cheese analogues had the lowest (20%). All subcategories in the meat analogues category showed a higher median sodium content than the benchmark, with cured meats having the highest level. Among cheese analogues, the grated cheese subcategory showed the highest median sodium content with all products exceeding the benchmark, while tofu and tempeh had the lowest median sodium content. The Nutri-Score algorithm did not consistently identify products with sodium levels exceeding the established benchmarks. This study highlights the need to reduce sodium content of such products and emphasises the importance of improving consumers' nutritional awareness
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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