scholarly journals Epidemiology of the Diseases of Wheat under Different Strategies of Supplementary Irrigation

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Roberto P. Marano ◽  
Roxana L. Maumary ◽  
Laura N. Fernandez ◽  
Luis M. Rista
Keyword(s):  
Yield Components ◽  
Disease Burden ◽  
Stem Elongation ◽  
Disease Incidence ◽  
Flag Leaf ◽  
Tan Spot ◽  
Santa Fe ◽  
Area Index ◽  
Septoria Leaf Blotch ◽  
Supplementary Irrigation

Wheat (Triticum aestivumL.) is one of the most important and highly productive crops grown under supplementary irrigation in the central region of Santa Fe. However, its production is limited by the presence of diseases in the main stages for yield definition. The objective of this work was to assess wheat health in response to different supplementary irrigation strategies under greenhouse and field conditions. The field experiment included three treatments: dry (D), controlled deficit irrigation (CDI), and total irrigation (TI) using the central pivot method. Disease incidence from stem elongation and severity in flag leaf and the leaf below the flag leaf were measured. Leaf area index (LAI), harvest index, air biomass, and yield components were determined. In greenhouse the treatments were TI and CDI, with evaluations similar to the field. The major leaf diseases observed were tan spot, leaf rust, and septoria leaf blotch. Significant differences in disease burden, LAI and yield components were observed in the different treatments. Under greenhouse conditions, only tan spot was observed. The results of this study indicated that the application of supplemental irrigation in wheat improved the yield, without increasing the incidence and severity of foliar diseases.

Juvenile lodging in barley: a yield-depressing phenomenon

1975 ◽  
Vol 26 (2) ◽  
pp. 231 ◽  
Author(s):  
CJ Gardener ◽  
AJ Rathjen
Keyword(s):  
Yield Components ◽  
Stem Elongation ◽  
South Australia ◽  
Leaf Length ◽  
High Fertility ◽  
Nitrogen Application ◽  
Area Index ◽  
Wire Grid ◽  
Plant Densities ◽  
The Relationship

A field experiment was conducted in South Australia to examine the relationship between juvenile lodging (lodging prior to stem elongation) and ear production in barley. Two levels of nitrogen application and six treatments were used either to prevent or increase juvenile lodging in two cultivars. Applications of 2-chloroethyltrimethylammonium chloride (CCC) at the fourth and sixth leaf stages shortened both pseudostems and leaves, prevented juvenile lodging, and increased the number of ears and the grain yield. CCC did not reduce the mature plant height, but did increase the incidence of Rhynchosporium secalis in one cultivar. Ear numbers were marginally increased by supporting the crop with a wire grid or by defoliating the crop to 20 cm at the fifth leaf stage, but this advantage was nullified by a compensating decrease in the other yield components. Removing up to 4 units of leaf area index at this stage did not reduce the yield. Deliberately lodging the crop before stem elongation had little effect since most of the controls lodged naturally. All treatments became erect during stem elongation, and the plants did not lodge again before maturity. It is concluded that short pseudostems, a maximum leaf length under 30 cm, fewer leaves per culm and a shorter period prior to stem elongation are characters which will reduce the juvenile lodging in barley which occurs when the crop is sown early at high plant densities or is grown at high fertility levels.

scholarly journals Relationship between Flag Leaf Characteristics and Main Yield Components in Oat (Avena sativa L.)

2019 ◽  
Vol 76 (1) ◽  
pp. 71
Author(s):  
Ionuṭ RACZ ◽  
Rozalia KADAR ◽  
Sorin VȂTCĂ ◽  
Ioana Virginia BERINDEAN ◽  
Adrian CECLAN ◽  
...  
Keyword(s):  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Avena Sativa ◽  
Yield Components ◽  
Flag Leaf ◽  
Chlorophyll Concentration ◽  
Area Index ◽  
Leaf Chlorophyll ◽  
Leaf Chlorophyll Concentration

The objective of this study was to investigate relationships between leaf area index, leaf chlorophyll concentration, yield components and grain yield in oat (Avena sativa L.). Ten oat varieties were analyzed in field conditions regarding those traits. Flag leaf chlorophyll concentration range between 451.51 and 747.79 units of μmol of chlorophyll per m2. Also, leaf area index range between 13.68 to 32.84 cm2. Significant correlation indices were highlighted between yield components and leaf area index, yield/yield components and chlorophyll concentration of flag leaf.

scholarly journals Influence of Take-All Epidemics on Winter Wheat Yield Formation and Yield Loss

2001 ◽  
Vol 91 (7) ◽  
pp. 694-701 ◽  
Author(s):  
Alexandra Schoeny ◽  
Marie-Hélène Jeuffroy ◽  
Philippe Lucas
Keyword(s):  
Winter Wheat ◽  
Yield Components ◽  
Stem Elongation ◽  
Disease Incidence ◽  
Wheat Yield ◽  
Economic Benefits ◽  
Winter Wheat Yield ◽  
Yield Formation ◽  
The Impact ◽  
Take All

The effects of take-all epidemics on winter wheat yield formation were determined, and disease-yield relationships were established to assess the agronomic efficacy and economic benefits of control methods. Epidemics were generated in naturally infested fields by varying cropping season, crop order in the rotation, and experimental fungicide seed treatment. Disease incidence and severity were assessed from tillering to flowering. Yield components were measured at harvest. Models simulating the formation of the yield components in the absence of limiting factors were used to estimate the losses caused by take-all. Losses were predicted by the disease level at a specific time or the area under the disease progress curve, reflecting accumulation during a specific period. Losses of grain number per square meter and 1,000-grain weight were linked to cumulative disease incidence between the beginning of stem elongation and flowering, and disease incidence at midstem elongation, respectively. Yield losses were accounted for by both cumulative disease incidence between sowing and flowering, and disease incidence at midstem elongation. Results confirm the importance of nitrogen fertilization in reducing the impact of take-all on wheat.

scholarly journals Effect of row spacing and plant density on grain yield and yield components of Crambe abyssinica Hochst

2018 ◽  
Vol 39 (1) ◽  
pp. 393
Author(s):  
Tiago Zoz ◽  
Fábio Steiner ◽  
André Zoz ◽  
Deise Dalazen Castagnara ◽  
Travis Wilson Witt ◽  
...  
Keyword(s):  
Grain Yield ◽  
Yield Components ◽  
Plant Density ◽  
Disease Incidence ◽  
Row Spacing ◽  
Crambe Abyssinica ◽  
Supplementary Irrigation ◽  
Yield And Yield Components ◽  
Rainfed Conditions ◽  
Plant Densities

Understanding the influence of row spacing and plant density on grain yield and yield components of crambe is critical in order to obtain higher grain yields. Therefore, the objective of this study was to evaluate the effects of row spacing and plant density on grain yield and its components in crambe in two distinct regions of Brazil (Marechal Candido Rondon-PR, MCR-PR, and Botucatu-SP, BTU-SP). Narrow and wide row spacing (0.20 and 0.40 m) combined with four plant densities (15, 25, 35, and 45 plants m-1) were evaluated in a randomized block layout with four replications in a 2 × 4 factorial design. The experiment at BTU-SP was run under rainfed conditions with supplementary irrigation, whereas the experiment at MCR-PR was run under rainfed conditions without supplementary irrigation. Both experiments were run in soils classified as Oxisols. There was no interaction between row spacing and plant density. Highest grain yield with supplementary irrigation was observed at 0.20 m row spacing. Without irrigation, row spacing did not affect grain yield owing to the plasticity of crop. The highest grain yield was observed with approximately 30 plants m-1 at both experimental locations. A strong negative correlation was observed between final plant population and number of grains per plant. There was high plant mortality, particularly at high plant densities cultivated under irrigation. Higher mortality occurred because of high intraspecific competition and a larger disease incidence due to the higher humidity in the irrigated experiment. A mechanism of self-adjustment by plant density was observed in crambe, with its intensity dependent on plant density and environmental conditions, such as water and nutrient availability and light incidence.

scholarly journals A retrospective database analysis of burden of IPD and pneumonia in children <15y in Veneto region

2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
E Barbieri ◽  
A Cantarutti ◽  
G Porcu ◽  
T Hu ◽  
T Petigara ◽  
...  
Keyword(s):  
Primary Care ◽  
Average Cost ◽  
Disease Burden ◽  
Disease Incidence ◽  
Population Data ◽  
Interrupted Time Series ◽  
Invasive Disease ◽  
Healthcare Resource Utilization ◽  
Incidence Rates ◽  
Regional Population

Abstract Background IPD and pneumonia are associated with high mortality and healthcare resource utilization (HCRU). This analysis assessed incidence, HCRU and costs of IPD and pneumonia following PCV13 introduction in 2010 in Veneto. Methods IPD, unspecified invasive disease episodes, outpatient pneumococcal and unspecified pneumonia episodes were identified in Pedianet, a pediatric primary care database from 2010-2017. HCRU includes primary care and specialist visits, antibiotic prescriptions, diagnostics, ER visits and hospitalizations. Incidence rates (IRs) were numbers of episodes/1,000 person-years. Standardized regional incidence rates (SRIRs) were calculated by standardizing IRs with regional population data by age and year. Regional expenditures (€/1,000 person-years) were calculated by multiplying SRIRs with average costs per episode. Interrupted time series (ITS) analyses assessed trends in annual IRs in the early and late PCV13 (2010-2013, 2014-2017) periods. Results During 2010-2017, IPD and unspecified invasive disease incidence decreased from 0.40 to 0.31/1,000 person-years. While incidence was numerically lower in 2017 than in 2010, ITS analysis did not detect a significant trend in the early (coef=1.97; p = 0.63) or late PCV13 (coef=0.50; p = 0.90) periods. Average cost per episode was €4206 and average regional expenditure was €171/1,000 person-year. SRIR for outpatient pneumonia decreased from 13.35 to 5.48/1,000 person-year during 2010 to 2017. Pneumonia episodes were associated with 0.29 ER visits and 0.15 short stay and 0.06 long stay hospitalization. Average cost per episode was €345, majority of which was associated with ER visits (€50.8) and hospitalizations (€243.9). Regional expenditures decreased from €12852.31 to €5351.98/1,000 person-year. Conclusions IPD and unspecified invasive disease burden did not change significantly following PCV13 introduction, while disease burden declined for outpatient pneumococcal and unspecified pneumonia. Key messages IPD and unspecified invasive disease burden did not change significantly following PCV13 introduction. Disease burden declined for outpatient pneumococcal and unspecified pneumonia following PCV13.

Is the flag leaf important in perennial ryegrass seed production?

2010 ◽  
Vol 14 ◽  
pp. 67-73
Author(s):  
J.A.K. Trethewey ◽  
M.P. Rolston
Keyword(s):  
Seed Yield ◽  
Perennial Ryegrass ◽  
Yield Components ◽  
Seed Weight ◽  
Photosynthetic Capacity ◽  
Flag Leaf ◽  
Active Radiation ◽  
Seed Yield Components ◽  
Seed Fill ◽  
Thousand Seed Weight

In cereals, the importance of the flag leaf for contributing carbohydrate during seed fill is well documented. However, in ryegrass this relationship is not so clear. This paper reports on an investigation of the effect on seed yield components of reduced photosynthetic capacity to the flag leaf, stem and head of perennial ryegrass (Lolium perenne). The hypothesis was that reduced photosynthetic capacity of the flag leaf does not affect seed yield components in perennial ryegrass. Following flowering, photosynthetic capacity was reduced by defoliation or shading the flag leaf, stem, or head of individual tillers. Seed yield components were measured at harvest. Reduced photosynthetically active radiation (PAR) to the flag leaf and stem did not affect thousand seed weight or seed yield when compared with control plants whereas reducing PAR to the head had a significant effect. The seed head itself may be more important than the flag leaf during seed fill, but when the seed head is shaded substantial re-mobilisation of stored carbohydrates can occur. Keywords: flag leaf, green leaf area, Lolium perenne, photosynthetically active radiation, seed fill, seed yield, thousand seed weight, water-soluble carbohydrates

scholarly journals Effect of nitrogen fertilization on camelina seed yield, yield components, and downy mildew infection

2016 ◽  
Vol 96 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Yunfei* Jiang ◽  
Claude D. Caldwell
Keyword(s):  
Downy Mildew ◽  
Seed Yield ◽  
Yield Components ◽  
Disease Incidence ◽  
Block Design ◽  
Interactive Effect ◽  
Yield Potential ◽  
Eastern Canada ◽  
Set Up ◽  
N Rates

Camelina [Camelina sativa (L.) Crantz] has potential in aquaculture, livestock feed production, and the biofuel industry. It is necessary to determine the appropriate production technology for the newly introduced crop under different environmental conditions. The objective of this 2-year study was to measure the response of five camelina genotypes in terms of seed yield, yield components, and disease incidence to applied nitrogen (N) at multiple sites in the Maritime provinces of eastern Canada. The factorial experiment was set up as a randomized complete block design. The two factors were six N rates (0, 25, 50, 100, 150, and 200 kg ha−1 N) and five genotypes of camelina (Calena, CDI002, CDI005, CDI007, and CDI008). The interactive effect of N rates and genotypes was considered. Results showed that camelina, which is usually considered a low-input crop, responded positively to increased applied N at rates up to 200 kg ha−1 N. Seed yield responded differently to applied N rates depending on genotype. Branch and pod development were decisive for seed yield. The advanced line CDI007 had the highest yield potential among the five genotypes. Downy mildew infection was positively correlated with applied N rates; however, seed yield was not significantly affected by downy mildew infection.

scholarly journals Major Genetic Changes in Wheat with Potential to Affect Disease Tolerance

2006 ◽  
Vol 96 (7) ◽  
pp. 680-688 ◽  
Author(s):  
M. J. Foulkes ◽  
N. D. Paveley ◽  
A. Worland ◽  
S. J. Welham ◽  
J. Thomas ◽  
...  
Keyword(s):  
Genetic Background ◽  
Field Experiments ◽  
Flag Leaf ◽  
Soluble Carbohydrate ◽  
Potential Yield ◽  
Genetic Changes ◽  
Septoria Leaf Blotch ◽  
Disease Tolerance ◽  
The United Kingdom ◽  
Canopy Area

Selection through plant breeding has resulted in most elite winter wheat germplasm in the United Kingdom containing the Rht-D1b semi-dwarfing allele, the 1BL.1RS chromosome arm translocation with rye, and an allele conferring suppression of awns. Near-isogenic lines (NILs) were used to test whether these major genetic changes have had any effect on disease tolerance. The ability of the NILs to tolerate epidemics of Septoria leaf blotch or stripe rust was measured in four field experiments over two seasons. Tolerance was quantified as yield loss per unit of green canopy area lost to disease. There was a trend for the presence of the 1BL.1RS translocation to decrease tolerance; however, this was not consistent across experiments and there was no effect of semi-dwarfing. The awned NIL exhibited decreased tolerance compared with the unawned NIL. There were significant differences in tolerance between the cultivar backgrounds in which the NILs were developed. Tolerance was lower in the modern genetic background of Weston, released in 1996, than in the genetic background of Maris Hunstman, released in 1972. The data suggest that certain physiological traits were associated with the tolerance differences among the backgrounds in these experiments. Potential yield, accumulation of stem soluble carbohydrate reserves, and grain sink capacity were negatively correlated with tolerance, whereas flag leaf area was positively correlated.

scholarly journals Optimizing irrigation and determining the most sensitive development stage to drought in barley (Hordeum vulgare L.) in a semi-arid environment

2020 ◽  
Vol 79 (1) ◽  
pp. 87-94
Author(s):  
Leila Romdhane ◽  
Nicola Dal Ferro ◽  
Amor Slama ◽  
Leila Radhouane
Keyword(s):  
Water Potential ◽  
Water Deficit ◽  
Leaf Water Potential ◽  
Yield Components ◽  
Stem Elongation ◽  
Leaf Water ◽  
Water Deficit Stress ◽  
Growth Stages ◽  
Development Stages ◽  
Three Stages

Rising temperatures and increasing water scarcity, which are already important issues, are expected to intensify in the near future due to global warming. Optimizing irrigation in agriculture is a challenge. Understanding the response of crop development stages to water deficit stress provides an opportunity for optimizing irrigation. Here we studied the response of two barley varieties (Rihane, Martin), to water deficit stress at three development stages (tillering, stem elongation, and heading) by measuring water status and grain yield components in a field experiment in Tunisia. The three stages were selected due to their importance in crop growth and grain development. Water deficit stress was initiated by withholding water for 21 days at the three stages with subsequent re-watering. Water deficit led to a progressive decrease in leaf water potential. In both varieties, heading was the stage most sensitive to water deficit. Leaf water potential measurements indicated that water deficit stress was more severe during heading, which to some extent may have influenced the comparison between growth stages. During heading, the number of ears per plant and weight of a thousand grains were reduced by more than 70% and 50%, respectively compared with stress at tillering. Comparison of yield components showed differences between the two barley varieties only when the water deficit was produced during the tillering stage.

scholarly journals Calibration and test of the cropgro-dry bean model for edaphoclimatic conditions in the savanas of Central Brazil

2002 ◽  
Vol 59 (4) ◽  
pp. 723-729 ◽  
Author(s):  
Elza Jacqueline Leite Meireles ◽  
Antonio Roberto Pereira ◽  
Paulo Cesar Sentelhas ◽  
Luis Fernando Stone ◽  
Francisco José Pfeilsticker Zimmermann
Keyword(s):  
Grain Yield ◽  
Yield Components ◽  
Simulation Models ◽  
Row Spacing ◽  
Dry Bean ◽  
Area Index ◽  
Central Brazil ◽  
Yield And Yield Components ◽  
Predicted Values ◽  
Bean Crop

Simulation models are important tools for the analysis of cultivated systems to estimate the performance of crops in different environments. The CROPGRO- model (DSSAT) was calibrated and validated using Carioca bean (Phaseolus vulgaris L.) to estimate yield and the development of the crop, sown in three row spacings (0.4, 0.5, and 0.6 m) and two fertilization rates (300 and 500 kg ha-1 of 4-30-16 N-P-K), in Santo Antônio de Goiás, GO, Brazil. To calibrate the model a combination of the genetic coefficients that characterize the phenology and morphology of the dry bean crop was used to obtain the best possible fit between predicted and observed anthesis and physiological maturity dates, leaf area index (LAI), total dry matter (TDM), yield components, and grain yield for the 0.6 m row spacing. To test the model the experimental records of the 0.4 and 0.5 m row spacings were used. In both, calibration and test, the performance of the model was evaluated plotting observed and predicted values of LAI and TDM versus time, using the r², and the agreement index (d) as statistical criteria. In relation to yield and yield components the percent difference between the observed and predicted data was calculated. The model appeared to be adequate to simulate phenology, grain yield and yield components for the Carioca bean cultivar, related to different levels of fertilization and row spacing, either during calibration or the testing phase. During the test, the grain yield was overestimated by less than 15.4%, indicating a potential use for the calibrated model in assessing climatic risks in this region.

Sign in / Sign up

Export Citation Format

Share Document