1,721,028 research outputs found
Plant density and nitrogen fertilization affect agronomic performance of industrial hemp (Cannabis sativa L.) in Mediterranean environment
No full textThe renewed interest in industrial hemp (Cannabis sativa L.) is due to its large number of applications and for the wide range of agro-environmental conditions under which it can be cultivated. Two-year field experiments (2007 and 2008 growing seasons) were carried out in a Mediterranean environment of cen-tral Italy with the aim of assessing the impact of genotype, plant density and N fertilization on hemp yield,in terms of stems, inflorescences and seeds. The treatments consisted in:(a) seven genotypes (Epsilon68,Fedora17, Felina32, Ferimon, Futura75, Santhica27, and Uso31); three plant density (40, 80, and 120plants m−2); two N fertilization levels (50 and 100 kg of N ha−1). Physiological parameters, plant height,stem weight and diameter, inflorescence yield, seed yield and the characteristics of hemp and weed aboveground biomass were recorded. High plant density resulted in shorter plant height compared with low plant density (−41%) as the hemp plants tended to reach the reproductive stage early at high density. At full flowering, stem yield ranged from 3.4 to 8.0 t ha−1 of dry matter and was positively correlated with the duration of vegetative phase, which tended to be high in the intermediate flowering genotypes (Epsilon68, Futura75 and Santhica27). Stem diameter was inversely correlated with plant density (6.7,5.8 and 5.2 mm at 40, 80 and 120 plants m−2, respectively). Conversely to stem yield, inflorescence and seed production proved to be higher in the early flowering genotypes (Fedora17, Felina32, Ferimon andUso31) and increased as plant density increased. High N fertilization level had a positive impact on stems rather than inflorescence and seed yields (on average +28%, +17% and +4% in 100 kg of N ha−1 compared with 50 kg of N ha−1 fertilization level, respectively). Farmers should consider making a dual-purpose production of stems and inflorescences or stems and seeds, even if it is clear that yield is related to thechoice of genotype. Further research should be carried out to find various genotypes as well as flexibleagronomical practices that are able to improve both traditional (stems) and innovative (inflorescences and seeds) hemp yields under Mediterranean conditions
Efficacia di un nuovo erbicida di post-emergenza su grano duro
No full textIn varie condizioni malerbologiche tipiche del litorale e delle aree interne laziali con prevalente presenza di Lolium multifl orum e Phalaris
brachystachys è stata verifi cata l’effi cacia di Hussar Maxx, nuovo formulato a base di iodosulfuron + mesosulfuro
Influence of no-tillage and organic mulching on tomato (Solanum lycopersicum L.) production and nitrogen use in the Mediterranean environment of central Italy
No full textIn conservation tillage systems based on legume mulches it is important to optimize N management
strategies. The present study evaluated the effect of some winter legume cover crops converted into
mulches on the following no-tillage tomato (Solanum Lycopersicum L.) yield, tomato nitrogen uptake,
tomato use efficiency (NUE), soil nitrate and the apparent N remaining in the soil (ARNS) in a Mediterranean
environment. Field experiments were carried out from 2002 to 2004 in a tomato crop transplanted
into: four different types of mulches coming from winter cover crops [hairy vetch (Vicia villosa Roth.), subclover
(Trifolium subterranem L.), snail medic (Medicago scutellata L. Miller), and Italian ryegrass (Lolium
multiflorum Lam.)]; a conventional tilled soil (CT); and a no-tilled bare soil (NT). All treatments were
fertilized with three different levels of nitrogen (N) fertilizer (0, 75, and 150 kgNha−1). Cover crop aboveground
biomass at cover crop suppression ranged from 4.0 to 6.7 t ha−1 of DM and accumulated from 54
to 189 kgNha−1, hairy vetch showed the highest values followed by subclover, snail medic and ryegrass.
The marketable tomato yield was higher in no-tilled legume mulched soil compared to no-tilled ryegrass
mulched soil, CT, and NT (on average 84.8 vs 68.7 t ha−1 of FM, respectively) and it tended to rise with
the increase of the N fertilization level. A similar trend was observed on tomato N uptake. Hairy vetch
mulch released the highest amount of N during tomato cultivation followed by subclover, snail medic,
and ryegrass (on average 141, 96, 90 and 33 kgNha−1). The tomato NUE tended to decrease with the
increase of the N fertilization rates, it ranged from 39 to 60% in no-tilled legume mulched soil and from
−59 to 30% in no-tilled ryegrass mulched soil when compared to the CT. The soil NO3-N content and the
ARNS was always higher in the soil mulched with legumes compared to the soil mulched with ryegrass
and in NT and CT. This study shows that direct transplanting into mulches coming from winter legume
cover crops could be useful for improving the yield and the N-uptake in a no-tillage tomato crop. Furthermore,
considering the high N content in the upper soil layer and the remaining N content in the organic
mulch residues after tomato harvesting, there is a large amount of N potentially available which could
be immediately used by an autumn–winter cash crop
Frumento duro, lotta congiunta contro erbe infestanti e funghi
No full textUna sperimentazione biennale valuta la possibilità del doppio controllo di malerbe e patogeni nel Centro Italia
Combined effect of genotype and inter-row tillage on yield and weed control of chickpea (Cicer arietinum L.) in a rainfed Mediterranean environment
No full textChickpea is an important pulse crop in the rainfed Mediterranean area, but its competitiveness against
the weeds is very low. The combination of high competitive chickpea genotypes and inter-row cultivations
could be a feasible strategy for increasing weed control. A 2-year field experiment in a typical
rainfed Mediterranean environment of Central Italy was carried out to assess the competitive ability of
selected chickpea genotypes grown as pure stand and in mixture with natural weed infestation partially
suppressed by inter-row tillage. Experimental treatments consisted in six chickpea genotypes (Alto Lazio,
C1017, C133, C134, C6150 stable lines and cultivar Sultano) and four different weed managements [no
weed control (weedy); 1-hoeing performed at 25 DAE (days after chickpea emergence); 2-hoeings, one
performed at 25 and one at 50 DAE; weed-free]. Chickpea aboveground biomass at 25 and 50 DAE, chickpea
traits at harvesting, weeds, and competition parameters were recorded at final chickpea harvesting.
C6150, C1017, Sultano, and Alto Lazio gave the best seed yield in the absence of weeds (on average
2.30 t ha−1 of DM). In weedy field conditions, the natural weeds reduced seed yield from 56.1% to 75.1%,
while the1-hoeing and 2-hoeing treatments reduced the yield loss from 32.5% to 56.9% and from 5.3% to
54.9%, respectively depending on the chickpea genotypes. A good level of competitive ability combined
with an elevated yield potential allowed Alto Lazio to reach the highest grain yield production in weed
presence. The competitive balance index (Cb) was positively correlated with the chickpea aboveground
biomass and ground coverage especially in the early stage (25 DAE), and with the chickpea plant height.
2-hoeings were more effective in reducing weed infestation than 1-hoeing, even if at chickpea harvesting
the weed infestation was however high (on average 223 g m−2 of DM and 65 plants m−2 of weed
aboveground biomass and density, respectively). The weed aboveground biomass was mainly made up
of Polygonum aviculare L. and it was positively correlated with the number of chickpea fruitless pods
and negatively correlated with the chickpea seed yield. Our findings suggest that in the rainfed Mediterranean
environment of Central Italy, combining highly yielding competitive chickpea genotypes with 2
inter-row hoeings, applied at 25 and 50 DAE, is a feasible strategy in order to prevent consistent chickpea
seed yield reduction caused by the weeds
Influence of winter cover crop residue management on weeds and yield in pepper (Capsicum annuum L.) in a Mediterranean environment
No full textA cover crop/pepper sequence was adopted for two growing seasons (2009/2010 and 2010/2011) in Central Italy to evaluate the effect of different cover crop species and their residue managements on weed control and fruit yield of a pepper crop. The treatments consisted in: (a) three winter cover crops [hairy vetch (Vicia villosa Roth.), oat (Avena sativa L.), canola (Brassica napus L.)] and bare soil; (b) three cover crop residue managements [residues left in strips on soil surface in no-tillage (NT), green manure residues at 10 cm of soil depth in minimum tillage (MT), and green manure residues at 30 cm of soil depth in conventional tillage (CT)]; (c) three levels of weed management applied to the pepper crop [weed free (WF), inter-row mechanical control applied at 30 days after pepper transplanting (WH), and weedy (W)]. The mulch strips in NT covered 50% of the ground and were used as a transplanting bed for pepper seedlings. At cover crop suppression, hairy vetch showed a higher aboveground biomass compared to oat and canola (on average 792 vs. 526 g m−2 of DM, respectively), even if oat showed the lowest level of weed infestation. In pepper the lowest weed density was found in NT compared to MT and CT (on average 22, 33, 37 plants m−2). Oat residues always caused the lowest weed density and weed aboveground biomass, while hairy vetch showed an efficient weed suppression only inside the pepper rows in NT where the soil was mulched. An inter-row hoeing, carried out 30 days after pepper transplanting, determined a general reduction of weed density and weed aboveground biomass (on average −60 and −86%, respectively) and a higher pepper yield (on average + 84%) compared to weedy pepper. Hairy vetch showed the highest marketable pepper yield among the cover crop treatments, regardless of weed management treatment, and the yield in weedy treatments was higher in NT than MT and CT (on average 31.4 vs. 14.2 t ha−1 of FM, respectively). The pepper yield was positively related to the chlorophyll concentration of the pepper leaves (SPAD readings) which was higher and more constant throughout the pepper cropping period in hairy vetch residues. Therefore, the use of hairy vetch residues placed in mulch strips within row combined with an inter-row cultivation enabled us to obtain a satisfactory weed control and fruit yield in a pepper crop
Impact of managing cover crop residues on the floristic composition and species diversity of the weed community of pepper crop (Capsicum annuum L.)
No full textThe decline of farmland biodiversity is mainly attributed to the intensive use of chemical inputs in
agriculture. Cover crop residues may contribute to improve weed management while maintaining a high
level of weed diversity. A 2-year field experiment was carried out in central Italy to study the effect of
cover crop species and their residue management on weed community composition and weed species
diversity in a winter cover crop e pepper sequence. Hairy vetch (Vicia villosa Roth.), oat (Avena sativa L.)
and canola (Brassica napus L.) were sown in September 2009 and 2010 and grew undisturbed during the
winter season until spring when they were suppressed one week before pepper transplanting. Cover
crop residues were: (i) green manured at 30 cm depth (conventional tillage, CT), (ii) green manured at
10 cm depth (minimum tillage, MT), and (iii) left on the soil surface as mulch strips covering 50% of the
ground area in no-tilled soil (NT). A winter weedy fallow and a bare soil without cover crop in NT, MT and
CT were also included as controls. Weed plant density data in pepper were used for calculating weed
species richness. Compared to weedy fallow, oat, hairy vetch and canola consistently reduced the weed
density and weed aboveground biomass by the time of their suppression (on average 3.6, 21.5, and
41.3 plants m2 and 11.0, 49.2, and 161.8 g m2 of DM, respectively). In pepper, oat residues generally
determined a higher reduction of weed density and species richness compared to hairy vetch and canola
regardless the residue management treatments. Converting cover crop aboveground biomass into mulch
strips greatly reduced weed species density but did not always imply a reduction of weed species
diversity in pepper compared to MT and CT. The weed species richness was reduced inside the mulch
strips, while a richer and more diverse weed community was found outside the mulch strips in NT.Weed
community in pepper was mainly composed of annual dicot weeds such as Amaranthus retroflexus,
Chenopodium album, Solanum nigrum, Polygonum aviculare which were mostly associated with MT and CT
tillage systems, while in NT an increase of perennial species such as Rumex crispus was observed. These
results suggest that it is possible to manage cover crop residues in NT in order to obtain a lower weed
density and consequently a higher yield in pepper compared to MT and CT while maintaining a high level
of weed diversity
The competitive ability of different chickpea (Cicer arietinum) genotypes against Polygonum aviculare under fiald conditions
No full textPolygonum aviculare L. is a troublesome weed in chickpea cultivated in theMediterranean environment of
Central Italy. A 2-year field studywas carried out to evaluate the competitive ability and the yield response
of different chickpea genotypes against P. aviculare. Experimental treatments consisted in six chickpea
genotypes (Alto Lazio, C1017, C133, C134, C6150 stable lines and cultivar Sultano) cultivated in weed-free
conditions and with P. aviculare at four densities (4, 8, 16, 32 plants m2). The competitive ability of
chickpea against P. aviculare was assessed on the basis of (i) the relative biomass total (RBT); (ii) the
competitive balance index (Cb), and (iii) the competitive index (CI). The chickpea seed yield in weed-free
conditions ranged from 2.6 to 2.1 t ha1 of DM and was higher in C6150 and Sultano. P. aviculare caused an
average chickpea seed yield loss of 14, 46, 74 and 88% at the density of 4, 8, 16, 32 plants m2 compared to
the weed-free crop. The relationship between the P. aviculare density and the percentage of chickpea yield
losswas described by the rectangular hyperbola model with the asymptote constrained to 100% maximum
yield loss. The estimated coefficient I (yield loss per unit density as density approaches zero) was lower in
C133, Sultano, and C1017. RBT was higher than 1 in all chickpea genotypes at 4 plants m2 of P. aviculare,
while at higher P. aviculare densities it was similar to 1 suggesting that there is no resource use complementarity
between chickpea and the weed. Generally, at the density of 50 plantsm2 the chickpea cropwas
more competitive than P. aviculare at 4 plants m2 (Cb > 0), equally competitive at 8 plants m2 (Cb 1⁄4 0),
and less competitive at 16 and 32 plants m2 (Cb < 0). No chickpea genotype achieved the objective of
combining a high seed yield potential and a great competitive ability against P. aviculare. C6150 and Sultano
had a high seed yield production in weed-free conditions, but they were poorly competitive against
P. aviculare at intermediate and high weed infestation, while C1017 showed a satisfactory level of Cb and CI
at all P. aviculare densities although its seed yield was the lowest in weed-free conditions. However, the
results suggest that, from an agronomical point of view, P. aviculare plant density should be less than 4 plant
m2 in order to prevent severe chickpea seed yield loss in field conditions
Cover crops and mulches influence weed management and weed flora composition in strip-tilled tomato (Solanum lycopersicum)
No full textThis study was conducted in the Mediterranean environment of Central Italy from 2011 to 2013 with the aim of evaluating the effects of winter cover crops and their residues on weed composition in a cover crop-tomato sequence. Treatments consisted of five soil managements (three cover crop species - hairy vetch, phacelia, white mustard, winter fallow mulched
with barley straw before tomato transplanting and conventionally tilled soil), two nitrogen fertilisation levels (0 and 100 kg N ha-1) and two weed management levels (weed free and weedy) on tomato. Cover crop residues were arranged in strips on the soil surface and then used as beds for transplanting the tomato seedlings in paired rows. Rotary hoeing was performed in the bare strips between paired tomato
rows. At tomato harvesting, the weed aboveground biomass and density was higher in nitrogen-fertilised tomato than unfertilised tomato, except in hairy vetch and barley straw that showed similar values. Hairy vetch used as a cover crop and dead mulch was the most suppressive species with the highest production of residues, while phacelia and mustard were not suitable for controlling weeds. The tomato yield was high in nitrogen fertilised and weed-free treatments, except
in barley straw mulch, which showed similar values among the weed management treatments. The mulch strips caused variations in weed species composition that was mainly composed of perennial ruderal weeds, while in tilled soil, the weed flora was dominated by annual photoblastic weeds
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