Effects of flame weeding on organic garlic production

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

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

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

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

Cover crops are essential tools in agro-ecosystems for reduc- ing the reliance on synthetic inputs and associated environmental risks. Alongside their benefits to soil fertility, cover crops can con- trol 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 a 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%) consider- ably. 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 a substantial effect of the mixture on C. canadensis seeds. In the field experiment, no signif- icant 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 than no-till. Still, the mulch of the mixture controlled weed emergence signif- icantly better than single cover crop mulches. The chemical char- acterization of cover crop residues, both shoots and roots, revealed a notable richness of allelopathic phenolic acids and flavonoids, which may constitute potential natural herbicides through slow decomposition. From the analysis of the aqueous extracts, other non-analysed and/or unidentified water-soluble allelopathic com- pounds 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 weed- ing 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 manage- ment strategies according to cropping system needs. Additional trials are needed to confirm the performance of cover crop residues under field conditions

Evaluation of the Agronomic Performance of Organic Processing Tomato as Affected by Different Cover Crop Residues Management

No‐till practices reduce soil erosion, conserve soil organic carbon, and enhance soil fertility. Yet, many factors could limit their adoption in organic farming. The present study investigated the effects of tillage and cover cropping on weed biomass, plant growth, yield, and fruit quality of an organic processing tomato (Solanum lycopersicon L. var. Elba F1) over two seasons (2015–2017). We compared systems where processing tomato was transplanted on i) tilled soil following or not a winter cover crop (Trifolium squarrosum L.) and with/without a biodegradable plastic mulch; and ii) no‐till where clover was used, after rolling and flaming, as dead mulch. Tomato in no‐till suffered from high weed competition and low soil nitrogen availability leading to lower plant growth, N uptake, and yield components with respect to tilled systems. The total yield in no‐till declined to 6.8 and 18.3 t ha−1 in 2016 and 2017, respectively, with at least a 65% decrease compared to tilled clover‐based systems. No evidence of growth‐limiting soil compaction was noticed but a slightly higher soil resistance was in the no‐till topsoil. Tillage and cover crop residues did not significantly change tomato quality (pH, total soluble solids, firmness). The incorporation of clover as green manure was generally more advantageous over no‐till. This was partly due to the low performance of the cover crop where improvement may limit the obstacles (i.e., N supply and weed infestation) and enable the implementation of no‐till in organic vegetable systems

PAIN DETECTION THRESHOLD AND PAIN TOLERANCE THRESHOLD IN SHISHA SMOKERS IN LEBANON - A HEALTH HAZARD

Shisha smoking is a common method of tobacco smoking in the Mediterranean Region with prevalence ranging between 20% and 70%. Actually, shisha smoking is becoming increasingly popular method of tobacco smoking worldwide. Pain is a subjective experience influenced by genetic, developmental, familial, psychological, social and cultural variables. An increase in pain tolerance threshold (Ptt) ,which is defined as the highest intensity of painful stimulation that a tested subject is able to tolerate, was noticed with cigarette smoking. However, the relation between shisha smoking and pain detection threshold (Pdt), defined as the lowest intensity of a painful stimulus at which the subject perceives pain and pain tolerance threshold (Ptt) has not been studied. The purpose of this study was to determine the association between Pdt and Ptt in shisha smokers in Lebanon. A total of 400 participants from different areas in Lebanon were recruited of which 216 were non-smokers and 184 were shisha-smokers. The sphygmomanometer cuff technique was used to detect Pdt and Ptt. As a result, the mean age of these participants was 27.46 years (standard deviation=11.79). Shisha-smoker male participants represented 53.7% while female shisha-smokers presented 40.8%. Pdt and Ptt were significantly greater in shisha smokers than in non-smokers with P = 0.001 and P \u3c 0.001 respectively. The mean number of heads of shisha smoked was 2.64 heads (standard deviation = 4.70). Both Pdt and Ptt are significantly increased in shisha smokers who smokes more heads of shisha per day with a p value of 0.031 and 0.002 respectively. However, in shisha smokers, the mean number of shisha smoking years was 2.68years (standard deviation = 5.22). Only Ptt significantly increased (P = 0.007) with more smoking years Moreover, Pdt and Ptt were both significantly higher (P \u3c 0.001) in males than in females. One may conclude that shisha smokers have higher tolerance thresholds for pain than non-smokers

Performance of field vegetable cropping systems under organic farming: effects of tillage and cover crop management

Conservation tillage in organic farming has been increasingly promoted to preserve soil fertility, decrease greenhouse gas emissions and improve the sustainability of agricultural systems. However, concerns regarding weed suppression, nutrients supply and soil compaction are limiting the expansion of these practices. For this, a two-year field experiment (2015-2017) implemented under Mediterranean conditions (Pisa, Italy) was conducted to evaluate the combined effects of tillage and cover crop management on weed suppression, plant growth, productivity, fruit quality and resource use efficiency in organic tomato production. We compared for this purpose systems consisting of i.) tomato transplanted on conventionally-tilled soil following or not a cover crop (Trifolium squarrosum L.) with/without a biodegradable plastic mulch; ii.) no-till where the cover crop was rolled as dead mulch and tomato directly transplanted. Initially, the living clover provided 20% reduction of weed biomass. In 2016, weeds were able to regrow shortly after transplanting and no weed control by the dead mulch was provided during the season. In contrast, the dead mulch of clover reduced weed abundance across the whole tomato growing season in 2017. However, no-till systems did not ensure the same weed control level of conventionally-tilled systems. During the growing season, residues of clover incorporated outperformed the dead mulch and the fallow conventionally-tilled system in weed control. Supplemental mechanical weeding on dead mulched plots reduced weed biomass and succeeded to improve plant performance. In both years, no effects were noticed on perennial weeds abundance. No-till systems had higher weed richness and different weed community structure compared to conventionally-tilled systems in 2017. N and P uptake were the highest in plastic mulch systems mainly when preceded by the clover and the lowest on the dead mulch. Conventionally-tilled systems without the legume green manure had the highest Nitrogen use efficiency. The best performance in terms of yield was obtained where the preceding clover was incorporated into the soil although it varied whether managed under plastic mulch or without it according to the site-year. The potential yield reduction in dead mulch systems accounted for at least 82% in 2016 and 65% in 2017. Greater soil nitrates availability was provided by the clover as green manure compared to dead mulch. No evidence of growth limiting soil compaction was seen in no-till systems although a slight soil resistance was seen in the first few cm up to fifteen cm of the topsoil. Soil visual quality (soil structure, aggregate dimension, rooting, residues decomposition) analysis did not reveal substantial differences between the management systems. The basic quality of red tomato (firmness, pH and TSS) was little influenced by tillage and cover cropping. Fruit vitamin C content however increased in tomato grown on clover dead mulch. Under cold storage, tomato fruits from the different agricultural practices behaved similarly. All results pointed out to the importance of N availability and weed control in reduced tillage systems. Based on that, the complete removal of tillage in a crop growing cycle may not be a successful solution in short term under some conditions, unless an effective weed management is provided both by highly performing cover crops i.e., high biomass and allelopathic action, and subsequent weeding and a good management of N supply during the season. Cover crops are an integral component of organic farming systems due to their benefits for soil fertility and their contribution to weed management. Allelopathic cover crops could be a tool in the multi-tactic approach used for weed management and could be potentially interesting for organic reduced tillage systems where cover crops are key for this purpose. In another study, we investigated two cover crop species, rye (Segale cereale L.) and squarrose clover (Trifolium squarrosum L.) used pure or in mixture for their allelopathic activity on some of common arable weeds. For this purpose, we prepared aqueous extracts with a series of dilutions from each cover crop type and we tested them through in-vitro tests i.e., seed germination and growth bioassay, on some selected weed species: Conyza canadensis (L.) Cronq., Amaranthus retroflexus L. and Digitaria sanguinalis (L.) Scop. The three aqueous extracts at different concentrations affected the germination and the early growth of almost all tested weed species although the magnitude of the effects was species-specific. An inhibition of Conyza canadensis radicle growth was obtained with all three extracts, reaching 75 to 80% with rye and mixture extract. Clover extract had the highest phytotoxic effect on Amaranthus retroflexus germination and growth whereas Digitaria sanguinalis growth was mostly affected by the mixture. Besides, the extracts had the potential of delaying germination onset of the dicot weeds. The phytotoxic effects of rye and mixture cover crops obtained in laboratory tests were also detected in field with a reduction in weed density almost forty days after their incorporation as green manure. Cover crops managed as green manure were more effective in reducing weed density than dead mulches. Our results showed all three cover crop types as potential cover crops for an ecological weed management, although additional studies should be done to test the effectiveness of squarrose clover in field conditions

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

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

Genotype and seasonal variation affect yield and oil quality of safflower under Mediterranean conditions

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

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

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.

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