scholarly journals Effect of Solar Radiation on Severity of Soybean Rust

2012 ◽  
Vol 102 (8) ◽  
pp. 794-803 ◽  
Author(s):  
Heather M. Young ◽  
Sheeja George ◽  
Dario F. Narváez ◽  
Pratibha Srivastava ◽  
Andrew C. Schuerger ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Solar Radiation ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Epicuticular Wax ◽  
Soybean Rust ◽  
Disease Development ◽  
Area Index ◽  
Detached Leaf

Soybean rust (SBR), caused by Phakopsora pachyrhizi, is a damaging fungal disease of soybean (Glycine max). Although solar radiation can reduce SBR urediniospore survival, limited information is available on how solar radiation affects SBR progress within soybean canopies. Such information can aid in developing accurate SBR prediction models. To manipulate light penetration into soybean canopies, structures of shade cloth attenuating 30, 40, and 60% sunlight were constructed over soybean plots. In each plot, weekly evaluations of severity in lower, middle, and upper canopies, and daily temperature and relative humidity were recorded. Final plant height and leaf area index were also recorded for each plot. The correlation between amount of epicuticular wax and susceptibility of leaves in the lower, middle, and upper canopies was assessed with a detached leaf assay. Final disease severity was 46 to 150% greater in the lower canopy of all plots and in the middle canopy of 40 and 60% shaded plots. While daytime temperature within the canopy of nonshaded soybean was greater than shaded soybean by 2 to 3°C, temperatures recorded throughout typical evenings and mornings of the growing season in all treatments were within the range (10 to 28.5°C) for SBR development as was relative humidity. This indicates temperature and relative humidity were not limiting factors in this experiment. Epicuticular wax and disease severity in detached leaf assays from the upper canopy had significant negative correlation (P = 0.009, R = –0.84) regardless of shade treatment. In laboratory experiments, increasing simulated total solar radiation (UVA, UVB, and PAR) from 0.15 to 11.66 MJ m–2 increased mortality of urediniospores from 2 to 91%. Variability in disease development across canopy heights in early planted soybean may be attributed to the effects of solar radiation not only on urediniospore viability, but also on plant height, leaf area index, and epicuticular wax, which influence disease development of SBR. These results provide an understanding of the effect solar radiation has on the progression of SBR within the soybean canopy.

scholarly journals Genetic Variability, Correlation and Path Coefficient Studies in Elephant Foot Yam (Amorphophallus campanulatus Bl.)

2013 ◽  
Vol 5 (2) ◽  
pp. 371-381 ◽  
Author(s):  
K. K. Paul ◽  
M. A. B. Miah
Keyword(s):  
Genetic Variability ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Correlation Study ◽  
Path Coefficient ◽  
Area Index ◽  
Depth Study ◽  
Elephant Foot Yam ◽  
Positive Direct

An investigation has been made to characterize the local accessions of Elephant foot yam collected from thirteen aroid growing districts and in-depth study on genetic variability, correlation and path coefficient for plant height, petiole length, petiole breadth, leaf area index, corm length, corm breadth, corm weight, cormel number, cormel length, cormel breadth, cormel weight and yield per plant has also been carried out. Genotypic variances and coefficient of variation for most of the characters were remarkably higher than their corresponding environmental variances, which also indicate the existence of variation in genotypic origin. High heritability with high genetic advance in percentage of mean was also observed for all characters. In the correlation study plant height, leaf area index, corm length, corm breadth, corm weight, cormel number, cormel length, cormel breath showed positive correlation with yield per plant in genotypic and phenotypic level. Leaf area index, cormel number in phenotypically and cormel number in genotypic level showed relatively high positive direct effect on yield per plant.Keywords: Amorphophallus; Genetic variability; Correlation; Path coefficient.© 2013 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v5i2.13853        J. Sci. Res. 5 (2), 371-381 (2013)

scholarly journals Evaluations of In-Furrow Insecticides and Fungicides, 1995

1996 ◽  
Vol 21 (1) ◽  
pp. 241-241
Author(s):  
Gene Burris ◽  
Don Cook ◽  
B. R. Leonard ◽  
J. B. Graves ◽  
J. Pankey
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Pest Control ◽  
Cotton Seed ◽  
Stand Density ◽  
Research Station ◽  
Area Index ◽  
Seed Rate

Abstract The test was conducted at the Northeast Research Station in St. Joseph, LA. Plots were replicated 4 times in a RCB design and were four rows (40-inch spacing) X 65 ft. ‘Stoneville LA 887’ cotton seed was planted 2 and 3 May on a commerce silt soil which was fertilized sidedress with 90 lb N/acre. Cotton seed were planted with a John Deere model 7100 series planter which was equipped with 10 inch seed cones mounted to replace the seed hoppers. The seed rate was 4 seed/row ft. Granular in-furrow treatments were applied with 8 inch belt cone applicators mounted to replace the standard granular applicators. Control of thrips and aphids was evaluated on 5 randomly selected plants/plot. Evaluations were made on 18, 19, 24, 26, and 29 May and 8 Jun. Plant height counts were taken on 10 randomly selected plants/plot on 8 Jun. Stand density and leaf area was determined by counting the number of plants in a randomly selected meter on 29 May. Leaf area was recorded using a Li Cor leaf area machine. The data was recorded as cm2 and converted to a leaf area index (LAI). Major pests and/or secondary pest control was initiated in Jun and continued on an “as needed” basis through Aug.

scholarly journals Influence of Spiral Nematodes (Scutellonema spp.) on Maize Performance and Growth under Natural Field Infestation in Mwea, Kenya

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Samuel Maina ◽  
Rossa Nyoike Ng’endo
Keyword(s):  
Food Security ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Management Practices ◽  
Block Design ◽  
Negative Relationship ◽  
Stress Factors ◽  
Area Index ◽  
Number Of Leaves

Maize (Zea mays L.) is a significant food security crop in Kenya and it serves as the main source of nutrition and calories among the small-holder farmers. The overall maize yields per hectare have been fluctuating in the past few years posing a great risk to food security. Among the stress factors associated with maize yield loss include plant-feeding nematodes. In this regard, this study was conducted to evaluate the impacts of plant-parasitic nematodes specifically Scutellonema spp. under field conditions on maize performance in Mwea, Kenya. The field trials were laid out in a randomized complete block design with each treatment comprising of four replicates. The treatments included maize plots without nematicide (MPWN) and control plots treated with nematicide. The experiments were conducted in two trials. Soil samples were taken at a 0–20 cm depth at monthly intervals during 2018–2019. During the two trials, MPWN recorded significantly lower plant height and number of leaves per plant. Correlation analysis revealed a significant negative relationship between Scutellonema abundance with leaf area index, plant height, and number of functional leaves in MPWN during the 2019 trial. This implies that high population of Scutellonema perhaps has the potential to affect leaf area index, plant height, number of leaves per plant, which are aspects that in turn influence maize productivity. Therefore, holistic sustainable management practices to control Scutellonema spp. in maize fields such as use of organic amendments, resistant maize cultivars, and antagonistic organisms are crucial in order to alleviate negative impacts linked to Scutellonema infestation.

scholarly journals The effect of light availability on leaf area index, biomass production and plant species composition of park grasslands in Warsaw  

2013 ◽  
Vol 59 (No. 12) ◽  
pp. 543-548 ◽  
Author(s):  
P. Dąbrowski ◽  
B. Pawluśkiewicz ◽  
Kalaji HM ◽  
Baczewska AH
Keyword(s):  
Solar Radiation ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Light Availability ◽  
Vegetation Coverage ◽  
Light Conditions ◽  
Area Index ◽  
Sward Height ◽  
Poa Trivialis ◽  
Leaf Density

How light conditions affect development of park grasslands is a question that has not been satisfactory addressed. The aim of this study was therefore determination of the level to which unfavorable light conditions influence grassy parks area and relationships between parameters which determine state of turf grasses. Researches were conducted in two parks in Warsaw, in various light conditions and included measurement of: leaf density, sward height, leaf area index (LAI), and botanical composition of the communities. The leaf density of shaded areas did not exceed 70%. LAI value varied from 0.5 to 0.9-fold lower than in the areas in half-shade and in sun. The participation of basic lawn species at Skaryszewski Park was higher under shade, while at Łazienki Królewskie was higher in full-sunlight areas. The state of tested grassy areas in limited solar radiation does not satisfy the requirements of recreational and representational functions. The development processes of vegetation coverage were inhibited at the sites of lower solar radiation. LAI was influenced by both leaf coverage and sward height. Agrostis stolonifera and Poa trivialis may be recommended to create grass areas under limited solar radiation.

scholarly journals Effects of Extensive Green Roofs on Energy Performance of School Buildings in Four North American Climates

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 6 ◽  
Author(s):  
Milad Mahmoodzadeh ◽  
Phalguni Mukhopadhyaya ◽  
Caterina Valeo
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Green Roof ◽  
Green Roofs ◽  
Energy Performance ◽  
Design Parameters ◽  
Soil Thickness ◽  
Area Index ◽  
Roof Design

A comprehensive parametric analysis was conducted to evaluate the influence of the green roof design parameters on the thermal or energy performance of a secondary school building in four distinctively different climate zones in North America (i.e., Toronto, ON, Canada; Vancouver, BC, Canada; Las Vegas, NV, USA and Miami, FL, USA). Soil moisture content, soil thermal properties, leaf area index, plant height, leaf albedo, thermal insulation thickness and soil thickness were used as design variables. Optimal parameters of green roofs were found to be functionally related to meteorological conditions in each city. In terms of energy savings, the results showed that the light-weight substrate had better thermal performance for the uninsulated green roof. Additionally, the recommended soil thickness and leaf area index for all four cities were 15 cm and 5 respectively. The optimal plant height for the cooling dominated climates is 30 cm and for the heating dominated cities is 10 cm. The plant albedo had the least impact on the energy consumption while it was effective in mitigating the heat island effect. Finally, unlike the cooling load, which was largely influenced by the substrate and vegetation, the heating load was considerably affected by the thermal insulation instead of green roof design parameters.

scholarly journals Effect Of Planting Geometry On Growth Of Rice Varieties

2017 ◽  
Vol 5 (4) ◽  
pp. 423-429 ◽  
Author(s):  
Mohan Mahato ◽  
Bishnu Bilas Adhikari
Keyword(s):  
Growth Rate ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Dry Matter ◽  
Dry Matter Accumulation ◽  
Rice Varieties ◽  
Area Index ◽  
Crop Growth Rate ◽  
Planting Geometry

A field experiment was conducted under humid subtropical agro-climatic condition of Nepal during rainy season of 2014. The experiment was laid out in to two factor Randomized Complete Block Design with  three replications consisting three drought tolerant rice varieties (Sukhadhan-4, Sukhadhan-5 and Radha-4) and four planting geometry (15 cm × 10 cm, 15 cm × 15 cm, 20 cm × 15 cm and 20 cm × 20 cm). The results revealed that the highest plant height and maximum leaf area index was recorded in planting geometry 15 cm × 10 cm in all growth stages. Whereas, planting geometry 20 cm × 15 cm produced the maximum number of tiller m-2 in all growth stage.  While planting geometry 20 cm × 15 cm and 20 cm × 20 cm produced statistically similar crop growth rate and dry matter accumulation in all stage of growth. Regarding the varieties, Sukhadhan- 4 showed highest plant height up to 75 DAT and plant height was statistically similar to Radha - 4 in 60 and 75 DAT. But maximum number of tiller m-2, leaf area index, crop growth rate and dry matter accumulation were recorded in Sukhadhan – 5 varieties. Int. J. Appl. Sci. Biotechnol. Vol 5(4): 423-429

Influence of primed seed and varying seed rate on growth and productivity of soybean (Glycine max L.) under different planting techniques

2018 ◽  
Author(s):  
Rupinder Kaur Jassal ◽  
Harmeet Singh
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Seed Yield ◽  
Dry Matter ◽  
Seed Priming ◽  
Dry Matter Accumulation ◽  
Area Index ◽  
Active Radiation ◽  
Seed Rate

An experiment was conducted at Punjab Agricultural University, Ludhiana during 2015 and 2016 to study the effect of priming, different seed rate on growth and seed yield of soybean planted under bed and flat method. The study was planned in factorial split plot design, keeping two planting techniques (flat sowing and bed sowing) and two seed priming treatments ( non primed seeds and 100 ppm GA3 primed seeds) in main plot and three seed levels ( 50, 62.5 and 75 kg ha-1) in sub plot. The objective of the study was to evaluate the effect of seed priming on growth and productivity under different planting techniques with the use of varying seed rates. The results revealed that growth attributes viz. emergence count, plant height, dry matter accumulation, leaf area index and photosynthetic active radiation interception (%) was significantly higher under bed planting technique as compared to flat sowing method. The pooled seed yield was increased by 15.6 % in bed planted soybean crop as compared to flat planted crop. Soybean seeds primed with 100 ppm GA3 recorded significant results in all the growth parameters. Primed seed recorded increase in yield 15.3 % than non primed seeds. Seed rate of 62.5 kg ha-1 recorded significantly higher emergence count, plant height, dry matter accumulation, leaf area index and photosynthetic active radiation interception (%) which was statistically similar in results with 75 kg ha-1 seed rate in both the two years. Pooled seed yield of 62.5 kg ha-1seed rate was 4.61 % higher than 75 kg ha-1 and 12.6 % than 50 kg ha-1 seed rate.

scholarly journals Effect of Spacing and Nitrogen Level on Growth and Yield of Maize (Zea mays L.) in Mid hill of Nepal

2020 ◽  
Vol 3 (2) ◽  
pp. 50-55
Author(s):  
Ramhari Gaire ◽  
Chudamani Pant ◽  
Nischal Sapkota ◽  
Rajan Dhamaniya ◽  
Tej Narayan Bhusal
Keyword(s):  
Grain Yield ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Block Design ◽  
Organic Matter Content ◽  
Growth And Yield ◽  
Nitrogen Level ◽  
Area Index ◽  
Close Spacing

AbstractA field experiment was carried out to study the effect of spacing and nitrogen level on growth and yield of maize in Parbat from February to July, 2019. The experiment was laid out in two Factorial Randomized complete Block Design (RCBD) comprising of spacing: 60×15 cm and 60×25 cm and nitrogen: 30, 60, 90 and 120 kg/ha level as treatment with three replications. “Arun-2” variety of maize was planted on clay loam and acidic soil (pH 5.3) having medium in total nitrogen (0.15%), medium in soil available phosphorus (48.1 kg/ha), medium in soil available potassium (218.8 kg/ha) and medium in organic matter content (2.92%). Result shows that yield was significantly increased with increment in N-level up to 90 kg N/ha. The grain yield (5.18 mt/ha) was significantly higher at 90 kg N/ha than at 30 and 60 kg N/ha but at par with 120 kg N/ha. Significant effect on grain yield due to spacing was observed. The grain yield (4.11 mt/ha) obtained at spacing 60×15 cm. Moreover, the highest grain yield showed that highest grain yield (4.33 mt/ha) was obtained under 90 kg N/ha plus 60×15 cm spacing. The result revealed that different spacing and nitrogen level significantly affect the plant height and leaf area index. The plant height and leaf area index were significantly high at close spacing (60×15 cm) and at 120 kg N/ha. Likewise, yield attributing characteristics like cob length, cob diameter, number of kernel/rows, number of kernel row, thousand gran weight were the highest at 90 kg/ha but as par with 120 kg/ha at close spacing (60×15 cm). This study suggested that maize production can be maximized by cultivating “Arun-2” maize fertilizing with 90 kg N/ha and maintaining 60×15 cm spacing.

scholarly journals Correlation and path coefficient studies of Cocoyam (Xanthosoma sagittifolium L.)

2015 ◽  
Vol 50 (1) ◽  
pp. 47-52
Author(s):  
KK Paul ◽  
MA Bari
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Leaf Length ◽  
Leaf Number ◽  
Path Coefficient ◽  
Path Coefficient Analysis ◽  
Area Index ◽  
Xanthosoma Sagittifolium ◽  
Positive Direct

Plant height, leaf length, leaf breadth, leaf number, leaf area index, corm length, corm breadth, corm weight, sucker number exhibited positive correlation with yield per plant in both genotypic and phenotypic level in cocoyam (Xanthosoma sagittifolium). Path coefficient analysis revealed that leaf length, leaf number, corm length exhibited direct influences to yield per plant. In genotypic level yield per plant showed the highest positive direct effect with corm length followed by cormel breadth, sucker number.Bangladesh J. Sci. Ind. Res. 50(1), 47-52, 2015

scholarly journals Estimation of maize plant height and leaf area index dynamics using an unmanned aerial vehicle with oblique and nadir photography

2020 ◽  
Vol 126 (4) ◽  
pp. 765-773 ◽  
Author(s):  
Yingpu Che ◽  
Qing Wang ◽  
Ziwen Xie ◽  
Long Zhou ◽  
Shuangwei Li ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Plant Height ◽  
Large Scale ◽  
High Efficiency ◽  
Point Clouds ◽  
Phenotypic Traits ◽  
Area Index ◽  
Area Density ◽  
Leaf Area Density

Abstract Background and Aims High-throughput phenotyping is a limitation in plant genetics and breeding due to large-scale experiments in the field. Unmanned aerial vehicles (UAVs) can help to extract plant phenotypic traits rapidly and non-destructively with high efficiency. The general aim of this study is to estimate the dynamic plant height and leaf area index (LAI) by nadir and oblique photography with a UAV, and to compare the integrity of the established three-dimensional (3-D) canopy by these two methods. Methods Images were captured by a high-resolution digital RGB camera mounted on a UAV at five stages with nadir and oblique photography, and processed by Agisoft Metashape to generate point clouds, orthomosaic maps and digital surface models. Individual plots were segmented according to their positions in the experimental design layout. The plant height of each inbred line was calculated automatically by a reference ground method. The LAI was calculated by the 3-D voxel method. The reconstructed canopy was sliced into different layers to compare leaf area density obtained from oblique and nadir photography. Key Results Good agreements were found for plant height between nadir photography, oblique photography and manual measurement during the whole growing season. The estimated LAI by oblique photography correlated better with measured LAI (slope = 0.87, R2 = 0.67), compared with that of nadir photography (slope = 0.74, R2 = 0.56). The total number of point clouds obtained by oblique photography was about 2.7–3.1 times than those by nadir photography. Leaf area density calculated by nadir photography was much less than that obtained by oblique photography, especially near the plant base. Conclusions Plant height and LAI can be extracted automatically and efficiently by both photography methods. Oblique photography can provide intensive point clouds and relatively complete canopy information at low cost. The reconstructed 3-D profile of the plant canopy can be easily recognized by oblique photography.

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