scholarly journals Examination of the chlorophyll content of maize hybrids of different maturity groups at different N fertiliser doses

2013 ◽  
pp. 159-162
Author(s):  
Péter Ragán
Keyword(s):  
Regression Analysis ◽  
Chlorophyll Content ◽  
Leaf Growth ◽  
Maize Production ◽  
Maize Hybrids ◽  
Leaf Stage ◽  
Spad Value ◽  
Maize Leaves ◽  
Spad Readings ◽  
Relative Chlorophyll Content

Nitrogen fertilisation is a critical point of maize production. Five hybrids of different maturity dates were examined in a field experiment, three treatments (different application dates) and three basic fertiliser doses (0, 60, 120 kg ha-1 N) were used. At the 6-leaf-stage of maize, each fertilisation level of the 2nd and 3rd treatment was given 30 kg N ha-1 fertiliser active ingredient in addition to the basic fertiliser doses with the exception of the control plots and further 30 kg N ha-1 fertiliser was applied at the 12-leaf-stage. The final fertiliser doses were 0, 90 and 150 kg N ha-1 in the second treatment and 0, 120 and 180 kg N ha-1 in the 3rd treatment. The whole amount of the basic fertiliser (ammonium nitrate) was applied in the spring, one month before sowing. The relative chlorophyll content of the maize leaves was measured, with a Minolta SPAD-502 measurement device. The measurements were carried out at the 6-leaf growth stage (V6) of maize on the youngest fully developed leaf of the 6th, 7th and 8th plants from the second row of each plot. There were significant differences in the SPAD-readings measured at the V6 phenophase of maize between the hybrids (p<0.001) and the fertiliser treatments (p<0.05). The regression analysis did not show any correlation between the SPAD-values and fertilisation. The highest significant SPAD-reading and yield were obtained by applying 120 kg ha-1 N. As a result of the regression analysis performed on yield, it can be concluded that the correlation between fertilisation and yield in the 1st and 2nd treatment was moderately close (r=0.439, r=0.480) and it was close in the 3rd treatment (r=0.513). The correlation between the SPAD-readings and yield was the closes in the 2nd treatment (r=0.639), while the SPAD-value had a 40.9% influence on yield (p<0.001).

scholarly journals Maize hybrids contrasting for drought tolerance differ during the vegetative stage

2020 ◽  
Vol 41 (4) ◽  
pp. 1093
Author(s):  
Suerlani Aparecida Ferreira Moreira ◽  
Pablo Fernando Santos Alves ◽  
Carlos Eduardo Corsato ◽  
Alcinei Mistico Azevedo
Keyword(s):  
Water Stress ◽  
Drought Tolerance ◽  
Chlorophyll Content ◽  
Water Deficit ◽  
Leaf Temperature ◽  
Vegetative Stage ◽  
Maize Hybrids ◽  
Water Regimes ◽  
Dry Biomass ◽  
Relative Chlorophyll Content

Maize hybrids contrasting for drought tolerance differ during the vegetative stage. Drought is the main constraint on maize production in developing nations. Differences during development between genetic materials of maize grown under water restriction suggest that the plant can be improved with a view to its adaptation. In maize, sensitivity to water stress can occur at any stage of its phenological development. However, few studies report its effects on the vegetative phase of the cycle. On this basis, this study was conducted to examine how shoot and root-system indices are expressed in cultivation under water deficit as well as determine which indicators best explain the difference between hybrids in the evaluated water regimes. Commercial seeds of hybrids BR1055 and DKB-390 (drought-tolerant) and BRS1010 (drought-sensitive) were germinated in PVC tubes (1.0 m × 0.1 m) in a randomized complete block design, in a 3 × 2 factorial arrangement. The experiment was developed in a greenhouse where two water regimes were tested: no water stress and with water stress from the VE stage. The soil consisted of quartz sand mixed with a commercial fertilizer. Stem and root traits were evaluated up to the V5 growth stage. Relative chlorophyll content, leaf temperature, stem length, phenology, shoot dry biomass, root length, root dry biomass, root surface area, root volume and D95 were responsive to water deficit. The parameters that allowed the distinction between the hybrids in water the regimes were relative chlorophyll content, leaf temperature, phenology and average root diameter.

Evaluation of the level of N supply in maize hybrids at different nutritional levels

2010 ◽  
Vol 58 (Supplement 1) ◽  
pp. 89-94
Author(s):  
A. Ványiné Széles
Keyword(s):  
Active Ingredient ◽  
Growing Season ◽  
Vegetation Period ◽  
Maize Hybrids ◽  
Leaf Stage ◽  
Stochastic Correlation ◽  
Spad Value ◽  
N Supply ◽  
Average Precipitation ◽  
Average Rainfall

The aim of the research was to determine the effect of fertilisation and year on the SPAD value and on the dynamics of the SPAD value during the growing season.The results proved that the SPAD value steadily decreased over the growing season in a dry year, whereas it increased in a year with favourable precipitation. Fertilisation increased the SPAD values significantly (P<0.001). The significantly highest SPAD value, in both dry years and those with average rainfall, was achieved by applying 60 kg N ha −1 fertiliser active ingredient at the 6-leaf stage, and 120 kg N ha −1 at both the 12-leaf stage and the 50% silking stage.The correlation between fertilisation and SPAD values was greatly affected by the year, being closest in 2004 when there was an average precipitation supply, and weakest in 2007, the driest year. The correlation between the factors was weak at the 6-leaf stage, but became stronger as the vegetation period proceeded.As the growing season progressed, the SPAD values decreased in the dry year, but increased in the year with average precipitation supplies. Nutrient uptake was relatively intensive until the 12-leaf stage in the average year. In the dry year, the decrease in the SPAD value was the most intensive at the 50% silking stage.There was no stochastic correlation between the SPAD value measured at the 6-leaf stage and the yield, but the correlation between the two variables became stronger during the vegetation period.

scholarly journals Effects of External Coloured Shade Nets on Sweet Peppers Cultivated in Walk-in Plastic Tunnels

2015 ◽  
Vol 43 (2) ◽  
pp. 398-403 ◽  
Author(s):  
Attila OMBÓDI ◽  
Zoltán PÉK ◽  
Péter SZUVANDZSIEV ◽  
Zsuzsanna TÓTHNÉ TASKOVICS ◽  
Ambrus KOHÁZI-KIS ◽  
...  
Keyword(s):  
Chlorophyll Content ◽  
Air Temperature ◽  
Photosynthetically Active Radiation ◽  
Incident Radiation ◽  
Climatic Conditions ◽  
Active Radiation ◽  
Negative Relation ◽  
Spad Value ◽  
Positive Linear Relation ◽  
Relative Chlorophyll Content

Shading effect of external nets of different colours (white, green, yellow and red) on the yield of two “kapija” pepper (Capsicum anuum L.) cultivars was examined in walk-in plastic tunnels in Hungary under real cultivation circumstances. Shading nets decreased incoming radiation by 23-39% and reduced photosynthetically active radiation by 32-46%. The highest retention was obtained by yellow and green nets, in the range of 450-550 nm and 550-670 nm, respectively. Relation was reported between the degree of shading and the average air temperature of the tunnels, however, treatments did not decrease tunnel air temperature significantly, compared to that of unshaded and paint-shaded control tunnels. This can be explained by the applied proper ventilation and mist irrigation. A strong and negative relation was noted between the intensity of shading and the relative chlorophyll content (SPAD value) of leaves. Shading net treatments did not increase yields, yellow and green nets even decreased it. Instead of tunnel air temperature, yield was mainly affected by photosynthetically active radiation in the experiment. Strong positive linear relation was declared between the chlorophyll content of the leaves and the yield. Results of the current research led to the conclusions that under Hungarian climatic conditions the use of shading nets was less justified if proper cooling techniques (ventilation and mist irrigation) were applied; even under the relatively high incident radiation experienced during the trials. In greenhouses of less favourable climatic conditions, red or white shading nets are recommended instead of commonly used green ones in Hungary.

scholarly journals Leaf relative chlorophyll content as an indicator parameter to predict nitrogen fertilization in maize

2004 ◽  
Vol 34 (5) ◽  
pp. 1379-1387 ◽  
Author(s):  
Gilber Argenta ◽  
Paulo Regis Ferreira da Silva ◽  
Luis Sangoi
Keyword(s):  
Soil Surface ◽  
Growth Stages ◽  
Rio Grande Do Sul ◽  
Maize Hybrids ◽  
Chlorophyll Meter ◽  
Nitrogen Levels ◽  
N Source ◽  
Spad Readings ◽  
Made In ◽  
Relative Chlorophyll Content

The development of a portable chlorophyll meter (SPAD 502), that takes instantaneous measurements of greenness without leaf destruction, has emerged as a new tool to assess plant N status. This trial was carried out to determine the adequate SPAD readings to predict maize nitrogen needs in four growth stages. The experiment was conducted in the state of Rio Grande do Sul, southern Brazil, during the 1998/99 growing season. Treatments were two maize hybrids (Pioneer 32R21 and Cargill 901) and nine side-dressed nitrogen levels (0, 50, 100, 150, 200, 300, 400, 500 and 600kg ha-1). Nitrogen was side-dressed at the soil surface in four equal doses, according to the levels established on each treatment. The first, second, third and fourth applications were made in the stages of three to four, six to seven, 10 to 11 and 14 to 15 fully expanded leaves, respectively. Urea was used as the N source. Since there was no difference in the SPAD readings among maize hybrids, average values at each stage were used. Readings were carried out in the stages of three to four, six to seven, 10 to 11 fully expanded leaves and at silking. Chlorophyll evaluation samples were taken at two-thirds of the distance from the leaf tip towards the stem. The two upper leaves were sampled on each growth stage before maize flowering. The index leaf (first leaf below the ear) was evaluated during silking. Chlorophyll meter readings above 45.4, 52.1, 55.3, and 58.0 represented the adequate values for the stages of three to four, six to seven, 10 to 11 expanded leaves and at silking, respectively, to achieve high grain yield. The variation in SPAD readings were highest in the early stages of plant growth.

scholarly journals The impact of climatic factors on the relative chlorophyll content and yield of a maize hybrid in a long-term experiment

2019 ◽  
pp. 71-77
Author(s):  
Éva Horváth ◽  
Péter Fejér ◽  
Adrienn Széles
Keyword(s):  
Chlorophyll Content ◽  
Growth Stage ◽  
Climatic Factors ◽  
Control Treatment ◽  
Spad Value ◽  
Long Term Experiment ◽  
Small Plot ◽  
The Impact ◽  
Relative Chlorophyll Content

The impact of the climatic factors of crop year on the relative chlorophyll content of maize was examined for three years. The examinations were carried out on the Látókép Experiment Site of the University of Debrecen on calcareous chernozem soil in a small-plot, non-irrigated long-term field experiment with strip plot design. In addition to a non-fertilised (control) treatment, nitrogen (N) fertiliser doses were applied as base and top dressing. The 60 and 120 kg N ha-1 base dressing doses were followed by two top dressing doses at the V6 and V12 phenophases. Averaged over the different fertiliser treatments, SPAD readings increased in all three years as the growing season progressed. The highes SPAD value increase was observed in the average crop year (2017) at the V12 phenophase (11.8), which further increased at the R1 phenophas, by 3,7. No significant Spad value difference was observed between the average (2017) and the dry year (2018) at the V6 growth phase. However, in the wet crop year (2016), the V690 treatment provided the statistically highest relative chlorophyll content (46.8). At the V12 phenophase, the base dressing dose of 120 kg N ha-1+30 kg N ha-1 (V6150) showed to be successful in two years (2016 and 2018), while in 2017, the base dressing dose of A60 was successful. The impact of crop year on relative chlorophyll content can be clearly shown at the R1 growth stage. In all three years, the significantly highest relative chlorophyll content could be achieved at different nutrient levels: A60 in 2016, V6150 in 2017 and V690. In a wet year (2016), higher yield could be achieved as a result of the 60 kg N ha-1 base dressing and 30 kg N ha-1 at the V6 growth stage (V690) as top dressing in comparison with 2017 and 2018, when higher fertiliser dose (120 kg N ha-1 base dressing and 30 kg N ha-1top dressing at the V6 growth stage) was needed to achieve a significant yield surplus. Altogether, averaged over the different treatments, the highest yield (12.48 t ha-1) was observed in the wet year, when the relative chlorophyll content was also the highest (50.6).

scholarly journals Evaluation of the correlation between SPAD readings and absolute chlorophyll content of maize under different nitrogen supply conditions

2019 ◽  
pp. 121-126
Author(s):  
Attila Simkó ◽  
Szilvia Veres
Keyword(s):  
Chlorophyll Content ◽  
Nitrogen Fertilization ◽  
Zea Mays L ◽  
Development Stage ◽  
Nitrogen Supply ◽  
Experimental Plant ◽  
Agricultural Crops ◽  
Total Chlorophyll Content ◽  
Spad Readings ◽  
Relative Chlorophyll Content

Currently, one of the most important objectives of agriculture is to maintain the principles of the sustainability. The use of precision technologies in agriculture belongs to this topic. The use of precision technologies is increasingly widespread in the cultivation of various agricultural crops, including maize. Sensing is an important part of these techniques. In our experiment we compared two methods: measuring relative chlorophyll content and the method of determine the extractable chlorophylls. The experimental plant was maize (Zea mays L.) and the measurements were performed at an early development stage (V8) of three genotypes. Three levels of nitrogen (0; 80; 160 kg ha-1) were applied during the experiment. The relative chlorophyll content was measured by SPAD-502 (Minolta, Japan) and a handheld GreenSeeker (Trimble, USA) device. The extractable total chlorophyll content decreased in parallel with the increased nitrogen level. The obtained SPAD values were diversified furthermore the NDVI values have not been changed for the effect of different nitrogen fertilization. In the early stages of development of maize, these parameters need to be complemented with other measurements to provide reliable information about the crops nitrogen status.

scholarly journals Sensitivity and Recovery of Grain Sorghum to Simulated Drift Rates of Glyphosate, Glufosinate, and Paraquat

Agriculture ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 70 ◽  
Author(s):  
Ralph Hale ◽  
Taghi Bararpour ◽  
Gurpreet Kaur ◽  
John Seale ◽  
Bhupinder Singh ◽  
...  
Keyword(s):  
Growth Stage ◽  
Leaf Growth ◽  
Flag Leaf ◽  
Grain Sorghum ◽  
Yield Reduction ◽  
Leaf Stage ◽  
Herbicide Treatments ◽  
Significant Yield ◽  
Glyphosate Drift ◽  
Herbicide Drift

A field experiment was conducted in 2017 and 2018 to evaluate the sensitivity and recovery of grain sorghum to the simulated drift of glufosinate, glyphosate, and paraquat at two application timings (V6 and flag leaf growth stage). Paraquat drift caused maximum injury to sorghum plants in both years, whereas the lowest injury was caused by glyphosate in 2017. Averaged over all herbicide treatments, injury to grain sorghum from the simulated herbicide drift was 5% greater when herbicides were applied at flag leaf stage, as compared to herbicide applications at the six-leaf stage in 2017. In 2018, injury from glyphosate drift was higher when applied at the six-leaf stage than at the flag leaf stage. Paraquat and glufosinate drift caused more injury when applied at flag leaf stage than at six-leaf stage at 14 days after application in 2018. About 21% to 29% of injury from the simulated drift of paraquat led to a 31% reduction in grain sorghum yield, as compared to a nontreated check in 2017. The simulated drift of glyphosate and glufosinate did not result in any significant yield reduction compared to the nontreated check in 2017, possibly due to the recovery of sorghum plants after herbicides’ drift application.

A novel spectral index for estimation of relative chlorophyll content of sugar beet

2021 ◽  
Vol 184 ◽  
pp. 106088
Author(s):  
Jing Zhang ◽  
Haiqing Tian ◽  
Di Wang ◽  
Haijun Li ◽  
Abdul Mounem Mouazen
Keyword(s):  
Sugar Beet ◽  
Chlorophyll Content ◽  
Spectral Index ◽  
Relative Chlorophyll Content

scholarly journals The Preferences of Different Cultivars of Lettuce Seedlings (Lactuca sativa L.) for the Spectral Composition of Light

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1211
Author(s):  
Barbara Frąszczak ◽  
Monika Kula-Maximenko
Keyword(s):  
Chlorophyll Content ◽  
Blue Light ◽  
White Light ◽  
Leaf Shape ◽  
Red Light ◽  
Spectral Composition ◽  
Fresh Weight ◽  
Light Spectrum ◽  
Dark Green ◽  
Relative Chlorophyll Content

The spectrum of light significantly influences the growth of plants cultivated in closed systems. Five lettuce cultivars with different leaf colours were grown under white light (W, 170 μmol m−2 s−1) and under white light with the addition of red (W + R) or blue light (W + B) (230 μmol m−2 s−1). The plants were grown until they reached the seedling phase (30 days). Each cultivar reacted differently to the light spectrum applied. The red-leaved cultivar exhibited the strongest plasticity in response to the spectrum. The blue light stimulated the growth of the leaf surface in all the plants. The red light negatively influenced the length of leaves in the cultivars, but it positively affected their number in red and dark-green lettuce. It also increased the relative chlorophyll content and fresh weight gain in the cultivars containing anthocyanins. When the cultivars were grown under white light, they had longer leaves and higher value of the leaf shape index. The light-green cultivars had a greater fresh weight. Both the addition of blue and red light significantly increased the relative chlorophyll content in the dark-green cultivar. The spectrum enhanced with blue light had positive influence on most of the parameters under analysis in butter lettuce cultivars. These cultivars were also characterised by the highest absorbance of blue light.

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