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Changes of relative chlorophyll content at maize smut inoculated hybrids
55-58Views:285The leaf chlorophyll content analysis is important for several reasons. The natural or anthropogenic stressors directly effect on the chlorophyll content. Through the measurement of the chlorophyll content it is possible to obtain data concerning the physiological status of the plant, moreover the chlorophyll content is closely related to the nitrogen content, so it is linked to photosynthesis and the photosynthetic activity which determine biomass production.
One of the most common symptoms of plant diseases is the larger and smaller interveinal chlorotic areas. These might be local, or expand to the whole plant. There are multiply reasons of chlorosis such as reduction of chlorophyll content, unfavorable effects on the chlorophyll content,disorders regarding function of chloroplasts or ultimately destruction of the chloroplasts. Although such a chlorotic deviancy can contribute to significant losses in photosynthesis; however the underperformance photosynthesis of the sick plants is a more complex process.
As we unambiguously experienced during our investigations on common smut that the infected maize plants most common accompanying symptom was chlorosis on the leaves, so it is especially important to examine how the infection influenced on the chlorophyll content of different hybrids. -
The impact of climatic factors on the relative chlorophyll content and yield of a maize hybrid in a long-term experiment
71-77Views:234The 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).
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Seasonal changes of photosynthetical parameters as a results of forest gap model
133-136Views:174Photosynthetic parameters of English oak (Quercus robur L.) as a member of Querco robori-Carpinetum were investigated in two different habitat in terms of gap forest management: in the gap and in the host forest. The artifical opening process of the forest resulted in more light for growing saplings and need for acclimatization. Photosynthesis is one of the most important way for plant life and plant production. In the centre of photosynthetic efficiency the quality and quantity traits of photosynthetic pigments are standing. During our work some photosynthetic parameters of plants (in the gap and in the forest as well) were measured: relative chlorophyll content as SPAD index, chlorophyll a and b content, total chlorophyll content and ratio of chlorophyll a and b. Based on our results no significant differences among our data in early spring. Although, during the summer significant differences occurred between the measured values in the gap and in the forest area. Lower total chlorophyll content was experienced in the gap, than in the forest area due to the lower chlorophyll-b content. Because of the high light intensity higher chla/chlb ratio was measured in the gap. The lower chlorophyll contents of gap habitat may have a part of the acclimatization process of photosynthetic apparatus against high light stress, which can determinate the survival chance of individual.
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Evaluation of the correlation between SPAD readings and absolute chlorophyll content of maize under different nitrogen supply conditions
121-126Views:422Currently, 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.
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Preliminary studies to evaluate the use of spectral data in monitoring of apple orchard parameters
37-41Views:134The introduction/application of precision agricultural technologies has more important role in various fruit growing sectors among others apple growing. Remote sensing methods can detect electromagnetic waves where the green colour of the leaf is responsible for the chlorophyll content. The absorption of chlorophyll is in the wavelength range of 450–670 nm. Samples of apple tree leaves were taken on a weekly basis from the apple orchard at Horticultural Unit of Pallag on University of Debrecen in 2019 summer. Our studies were performed on 2 cultivars (Early Gold, Golden Reinders) and the samples were processed using 2 methodologies: a non-destructive spectral method and spectrophotometric method chlorophyll and carotenoid contents were calculated, which were created into some groups and compared with the spectral values. When the plant begins to lose strong green colour and turns yellow spectral measurements show that chlorophyll content decreases as the proportion of chlorophyll-carotenoid in the plant changes. In case of grouping into intervals, it can be observed that as the chlorophyll content increases the reflectance value decreases continuously due to the strong absorption. Based on the results, close relationship between the pigments can be detected.
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Effect of plant growth promoting Rhizobacteria (PGPRS) on yield and quality of processing tomato under water deficiency
19-22Views:233Chlorophyll fluorescence was measured of H1015 tomato hybrid with different bacterial treatments (B0–B1–B2–B3) and three irrigation treatments: regular irrigated (RI), deficit irrigated (DI) and non-irrigated conditions (I0). The aim of the experiments was to show the effects of plant growth promoting rhizobacteria on the yield, dry matter and vitamin C content of processing tomato during different irrigation treatments, and measuring the chlorophyll fluorescence during the ripening and development stages. According to the results, none of the bacterial treatments had a statistical effect on the quantity and quality of the tomato and on the chlorophyll fluorescence, only the irrigation. Further studies are needed.
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The impact of environmental factors on the measurement of the normalized difference vegetation index
141-147Views:171The level of nitrogen supply of a plant population can be quickly measured with non-destructive optical measurement devices and the differentiated determination of nitrogen shortage and the replenishment of nitrogen can also be carried out. The level of nitrogen supply is based on the fact that the chlorophyll content of crops is in close correlation with nitrogen content and that the amount of chlorophyll can be easily measured on the basis of the light absorption of chlorophyll molecules. The successfulness of optical measurements can be influenced by the change of weather parameters; therefore, it is important to know the correlations between measurement results and weather parameters when it comes to practical use.
The GreenSeeker Model 505 measurement device determines the relative chlorophyll content in the form of the Normalized Difference
Vegetation Index (NDVI) calculated on the basis of the intensity of the reflected red and infrared rays of light from the crop population. The measurements were performed in alfalfa population with 10 replications at five measurement heights and four measurement times. The weather parameters were measured by a weather station located in the middle of the alfalfa population and the correlations between the meteorological data and the NDVI values were examined. During the statistical evaluation of the results, it was established that the NDVI measurement is primarily influenced by the relative humidity of the air, secondly by air temperature and thirdly by wind speed. Relative humidity was in strong correlation with the NDVI values which were also influenced by the measurement height and time. Regression was not significant in the case of 20 cm measurement height, but the measurements above 40 cm height showed significant correlations. The correlation was shown to be strong at each measurement time, but the influence of humidity was the lowest at 11:00 and 14:00. -
Correlation analysis of relative chlorophyll content and yield of maize hybrids of different genotypes
211-214Views:153In 2021, correlation between relative chlorophyll content and yield in three maize hybrids of different genotypes was examined. The data were collected at the Látókép Experimental Station of the University of Debrecen located on the Hajdúság loess ridge in Hungary. The soil of the small plot field strip plot trial, which was set up in 2011, was calcareous chernozem. Apart from the control treatment (without fertilisation), N fertiliser is applied in the form of base and top dressing. The base fertiliser containing 60 and 120 kg ha-1 N of nutrient applied in spring was followed by top dressing containing +30–30 kg ha-1 N in V6 and V12 phenophases. SPAD values measured at different phenological stages of the growing season increased by an average of about 28% up to 10 leaf stage for all three hybrids. In the pre-silking period (Vn), the relative chlorophyll content decreased by 8% on average. After an average increase of 14% in the tasselling and silking period, SPAD decreased by an average of about 29% at full maturity (R6).
For the different fertiliser treatments, higher N doses resulted in higher yields. In the basal fertiliser treatment, the A 60 N dose resulted in an average 34% increase in yield, and the A 120 N dose resulted in an average 94% increase in yield compared to the control. The 60 kg ha-1 N basal fertiliser (A60) increased in the V6 phenophase with an additional 30 kg ha-1 N resulted in an average yield increase of 26%. When 120 kg ha-1 N of basal fertiliser (A120) was increased by an additional 30 kg ha-1 N in the V6 phenophase, only the Merida hybrid showed a significant yield increase (7%). No further yield increase was observed when V690 and V6150 treatments were increased by an additional 30 kg ha-1 N in the V12 phenophase. The yield of the Armagnac hybrid decreased by almost 20%, the yield of Fornad by 3% and the yield of Merida by 1%.
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Biostimulant induce growth, chlorophyll content and fresh herbage yield of alfalfa (Medicago sativa L.) and variegated alfalfa (Medicago × varia Martyn) plant
19-25Views:109The use of biostimulants is associated with promoting plant growth by stimulating cell division and improving nutrient availability and uptake. A study was conducted at the University of Debrecen, Hungary, to examine the effect of biostimulants on alfalfa growth, chlorophyll content and fresh herbage yield. The experiment was arranged in a randomised complete block design with three biostimulant treatments plus control replicated three times. Data collected were subjected to analyses of variance using Genstat, where significantly different means were separated at a probability of 5% using the least significant difference. The findings show no different variation in plant height or chlorophyll content (SPAD) throughout the early stages of growth. Nonetheless, a notable impact was noted in the latter stages (28 days after biostimulant treatment application) on the growth of the alfalfa plant. Biostimulant treatments did not had effect on fresh yield for second through fourth cuts, but the fifth cut showed a significant effect, with T1 treatment recording the highest herbage yield of 19745 kg ha-1 followed by T2 (Tricho Immun plus Ino Green) and T3 (Tricho Immun), with yields of 19528 kg ha-1 and 17273 kg ha-1, respectively, while the T0 (control) recorded the lowest herbage yield of 12060 kg ha-1. However, the average mean yield indicated the application of biostimulants significantly increased fresh yield herbage by 20.5%. Correlation coefficient values suggested plant height at both 14 and 28 DAH (days after harvest) strongly correlated with fresh herbage yield (r = 0.7756 and 0.7455) which reflected in the increase in fresh herbage yield. Therefore, our results suggest that the use of biostimulants in alfalfa cultivation holds promise for improving growth and yield potential through their positive effects on chlorophyll content and the growth of alfalfa plant.
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Variability examination of photosynthetic pigment content and specific leaf area in individual maize (Zea mays L.) plants
153-157Views:251Currently, maize is one of the most important crops (Zea mays L.) both globally and in Hungary. We compared physiological parameters of a maize genotype – p9903 – at two different experimental sites in a field experiment. Furthermore, we examined these parameters’ variability in individual plants on the leaves with different ages. Absolute chlorophyll content of the leaves were analysed, separately that of chlorophyll a and chlorophyll b. We also measured the absolute carotenoid contents of leaves. Furthermore, we calculated these photosynthetic pigments’ content ratio. Specific leaf area (SLA) and dry matter weight were also measured in order to characterise plant production. The results obviously reflect the decreasing in the efficiency of photosynthetic apparatus on the low yield site. Otherwise, we identify significant differences only in certain cases of leaves.
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Effect of ethephon levels and amino acids on the growth characteristics of oat crop
57-61Views:117A field experiment was conducted during the 2021-2022 season in an agricultural field in Basra Governorate. The aim was to study the effect of spraying ethephon and amino acids on the growth characteristics of oats (Avena sativa L.) Shifa cultivar. The experiment involved three levels of ethephon (0, 0.240, and 0.600 kg ha-1), represented by the symbols E0, E1, and E2 respectively, and two spray levels of amino acids (0 and 5 ml L-1), represented by the symbols A0 and A1. A factorial experiment was applied using the R.C.B.D (randomized complete block design) in a split plots arrangement with three replications. The results revealed significant differences in the levels of ethephon for most of the studied characteristics. The level of 0.240 kg ha-1 (E1) was superior in terms of chlorophyll content, crop growth rate, and the number of tillers, with increases of 39.07%, 39.26%, and 16.36%, respectively, compared to the control treatment (E0). Regarding the amino acids treatments, spraying at a concentration of 5 ml L-1 (A1) demonstrated significant superiority, resulting in the highest plant height, flag leaf area, chlorophyll content, and crop growth rate. This study concludes that amino acids play a crucial role in plant growth, and the combination of 5 ml L-1 amino acids with 0.240 kg ha-1 of ethephon significantly increased chlorophyll content and crop growth rate.
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Study of plant physiological parameters in winter oilseed rape (Brassica napus var. napus f. biennis L.) production on chernozem soil
111-115Views:259We made plant physiology examinations in Arkaso winter oilseed rape hybrid substance: relative chlorophyll content (SPAD) and leaf area index (LAI) measurements. The experiment was set in University of Debrecen Agricultural Sciences Center at Látóképi Experimental Station in four replications, in two different sowing times (I. sowing date on 08/22/2014 and II. sowing date on 09/09/2014 sowing againhappened because of the incomplete germination in the second subtance 01/10/2014) Three different plant density 200, 350 and 500 thousand ha-1, under the same nutrient supply, 45 cm row spacing. The experiment was green crop of winter wheat. The relative chlorophyll content (SPAD) and leaf area index (LAI) measurements were made in seven different times. We measured the maximum value of chlorophyll content in the first sowing time at 500, and the second sowing time at 350 thousand ha-1 plant density. The measurement results proved that there was a linear relationship between the number of plants and the LAI. The maximum leaf area index values we measured in both the sowing time at 500 thousand ha-1 reached.
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Investigation of the impacts of the by-product of sewage treatment on some characteristics of maize in the early growth stage
77-82Views:74The use of sewage sludge on arable land has been widespread for many years. This by-product, treated as waste, can provide valuable nutrients to the soil, but the applied amount of sewage sludge to arable land is limited. The possibility of application of sewage sludge is essentially determined by the composition of the sludge. The goal of the experiment was to demonstrate that the physiological, morphological, and biochemical parameters of maize (Zea mays L. cv. Armagnac) linearly change with increasing concentrations of sewage sludge (25%, 50%, and 75% as m/m%). The experiment was set up in a glasshouse. The following parameters were investigated: plant height, relative chlorophyll content, photosynthetic pigments (chlorophyll-a, chlorophyll-b, carotenoids), and leaf proline and malondialdehyde (MDA) content, and PS II quantum efficiency in the 3-leaf stages of the plants. Sewage sludge applied in lower doses had a beneficial effect on the initial growth of maize. The relative chlorophyll content was significantly higher in all treatments compared to the control. There was no significant difference in the maximum quantum efficiency of PS II reaction centers among the treatments. In this experiment, different concentrations of sewage sludge treatments had different impacts on the MDA and proline content of maize leaves. The proline content was significantly higher in all treatments, while the MDA content did not change significantly compared to the control.
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The effects of water supply on the physiological traits and yield of tomato
25-30Views:185The SPAD value, the chlorophyll fluorescence and the canopy temperature of the leaves and fruits of tomato hybrid “H1015” were investigated under non-irrigated (I0), deficit irrigated (I50) and well-irrigated (I100) conditions. The aim of the experiments was to show which treatment effect on the examined traits affected photosynthesis, leaf temperature and yield quantity, as well as quality under water scarcity. In the control treatment (I0), the canopy temperature increased, but the SPAD decreased compared to the other two treatments (I50 and I100). Chlorophyll fluorescence produced a fluctuating result. In the end, the number of the fruits was high, but the number of the sick and green berries was increased.
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Results of the sensory analysis of precision maize production
59-62Views:231This research was carried out in 2018, at the Látókép Experimental Station of the University of Debrecen in a moderately warm and dry production area, on deep humus layered medium-hard calcareous chernozem soil. In the scope of the research, the chlorophyll content of maize (Zea mays L.) was examined under field circumstances by means of local sensory measurements and we were looking for correlation between the obtained values and the amount of yield. Our measurements were carried out with Minolta SPAD-502 and GreenSeeker devices at 3 measurement times (4 leaf stage, 10 leaf stage and silking). It was found that phenological phases had an effect on the obtained SPAD and NDVI values and were in a slightly significant correlation with the yield. The most significant correlation was found between the results obtained during silking and the amount of yield. This may be because the least time has passed between the measurement time and harvest. Results obtained during the 10-leaf stage show excessive values in each case, which can be due to a measurement error. It was found that the phenological phase had an effect on the correlation of SPAD and NDVI values and the amount of yield. As the phenological phase progressed, the correlation between the measured results and yield has increased.
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Examination of the chlorophyll content of maize hybrids of different maturity groups at different N fertiliser doses
159-162Views:131Nitrogen 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).
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Physiological traits and yield of three soybean (Glycine max (L.) Merr.) genotypes as affected by water deficiency
11-15Views:217Soybean is a very important legume; it has the highest protein content, and it is a very important source of vegetable oil. Soybean is droughtsusceptible, and drought is one of the major abiotic stresses that has been increasing over the past decades as a result of the global climatic changes. To evaluate the influence of drought stress, three soybean genotypes were grown under rainfed conditions, and compared to irrigated controls. The obtained results showed that the chlorophyll content, leaf area index and plant height decreased under drought stress conditions, which led to noticeable and sometimes significant yield reduction. Our results suggest more specific studies on the physiological changes of the local soybean genotypes under drought stress to better select the adopted ones.
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The impact of cultivar and irrigation on yield, leaf surface temperature and SPAD readings of chili pepper
103-108Views:238Paprika is an extremely popular and widespread plant species in Hungary. Chili peppers belongs to paprika and it can be consumed fresh or processed. The production of peppers began with the cultivation and control of some parameters for good results of paprika production. The aim of this article is to compare the water supply of four chili pepper hybrids ("Habanero", "Hetényi Parázs", "Unikal" and "Unijol") by means of investigation on open field and to examine how different temperatures and water stress factors influence the yield of chili peppers. The experiment area consisted of four different hybrids in three different irrigation treatments (control, deficit- and regular irrigation). The chlorophyll content was estimated with SPAD and the leaf surface temperature with Raytek MX4 TD. Our research concluded that deficit irrigation produced the highest yields for all cultivars and the lowest yields for the highest water supply.
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Effect of arginine, putrescine and spermidine on the polyamine, proline and chlorophyll content of tobacco (Nicotiana tabacum L.)
39-43Views:154Polyamines, such as spermidine (Spd) spermine (Spm) and their direct precursor, the diamine putrescine (Put) are vital and essential aliphatic amines which are also present in plants. Although ethylene and polyamines are also involved in fruit ripening, the genes coding them must also take part in other biosynthetic pathways. In the ethylene and polyamines play an important role in development of salt stress tolerance, and in responses for biotic and abiotic stresses. Exogenous application of all three main polyamines (Put, Spd, Spm) increase salt tolerance of plants, but, accordingly to previous experiments, spermidine has the main effect on the enhancement of salt tolerance. Nicotiana tabacum L. plants were grown in vitro on MS medium, the treatments were as follows: arginine (150 mg l-1), putrescine (10 mg l-1), spermidine (10
mg l-1). Proline, chlorophyll a, b and polyamine contents were measured. The obtained results show that the arginine decarboxylase and the spermidine synthase genes involved in polyamine metabolism, cannot be enhanced by exogenous addition of their precursor molecules. On the contrary, the spermine synthase gene has a positive effect to the lower-class forms of polyamines. -
Effect of net shading technology on the yield quality and quantity of chilli pepper under greenhouse cultivation
5-9Views:317This study was undertaken to identify the effect of net shading technology on the total capsaicinoids, vitamin C and relative chlorophyll content expressed as SPAD (Soil Plant Analysis Development) values and total marketable fruit yield of ‘Star Flame’ chilli pepper (Capsicum annuum) for two harvesting times cultivated under modified atmosphere. ‘Star Flame’ pepper was grown under three (3) different net shading colours (white, red and green). Samples without net shading were used as control. Samples were subjected to chromatographic analyses using HPLC for the determination of total capsaicinoids and vitamin C. Interaction in shading technology and harvest times (p=0.010) had significant effect on total capsaicinoids as a result of green and white shading technologies showing higher differences when compared to control samples. Vitamin C content was observed to have increased in white and red shadings (p=0.001) after the first harvest and gradually decreased after the second harvesting time (p=0.002). Relative leaf chlorophyll content was significantly higher in white shading in the first and second harvest. Samples used as control had significantly higher marketable values when compared to white and green shadings with red recording low marketability of ‘Star Flame’ chilli peppers.
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The effect of different shading net on the Quantum Efficiency of PS II in chilli pepper cultivar ‘Star Flame’
21-23Views:385The study was undertaken to identify the effect of different shading net on the quantum efficiency of PS II on ‘Star Flame’ chilli pepper (Capsicum annuum) over a period of time cultivated under plastic house environment. ‘Star Flame’ pepper was grown under red shading net and samples without shading were used as control. Analysis of photosynthetic activity revealed a significant difference (p<0.05) between Fv/Fm values in control and red shading at the end of July (p = 0.031) after the first harvest. Chlorophyll fluorescence parameter Fv/Fm reflects the maximum quantum efficiency of photosystem II (PS II) used in the detection of early stress in plants.
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Examination of Zn deficiency on some physiological parameters in case of maize and cucumber seedlings
5-9Views:111Zinc (Zn) is an essential micronutrient needed not only for people, but also crops. Almost half of the world’s cereal crops are deficient in
Zn, leading to poor crop yields. In fact, one-third (33%) of the world's population is at risk of Zn deficiency in rates, ranging from 4% to
73% depending on the given country. Zn deficiency in agricultural soils is also a major global problem affecting both crop yield and quality.
The Zn contents of soils in Hungary are medium or rather small. Generally, the rate of Zn deficiency is higher on sand, sandy loam or soil
types of large organic matter contents. High pH and calcium carbonate contents are the main reasons for the low availability of Zn for
plants (Karimian and Moafpouryan, 1999). It has been reported that the high-concentration application of phosphate fertilisers reduces Zn
availability (Khosgoftarmanesh et al., 2006). Areas with Zn deficiency are particularly extensive in Békés, Fejér and Tolna County in
Hungary, yet these areas feature topsoils of high organic matter contents. Usually, Zn is absorbed strongly in the upper part the soil, and it
has been observed that the uptakeable Zn contents of soil are lower than 1.4 mg kg-1.
Maize is one of the most important crops in Hungary, grown in the largest areas, and belongs to the most sensitive cultures to Zn
deficiency. Zn deficiency can causes serious damage in yield (as large as 80 %), especially in case of maize. On the other hand, Zn
deficiency can also cause serious reduction in the yields of dicots. One of the most important vegetables of canning industry is cucumber,
which is grown all over the world.
In this study, the effects of Zn deficiency have investigated on the growth of shoots and roots, relative and absolute chlorophyll contents,
fresh and dry matter accumulation, total root and shoot lengths, the leaf number and leaf area of test plants in laboratory. Experimental
plants used have been maize (Zea mays L. cv. Reseda sc.) and cucumber (Cucumis sativus L. cv. Delicatess). A monocot and dicot plant have
chosen a to investigate the effects of Zn deficiency, because they have different nutrient uptake mechanism.
It has been observed that the unfavourable effects of Zn deficiency have caused damage in some physiological parameters, and
significantly reduced the growth, chlorophyll contents of monocots and dicots alike. -
Using sensors in precision crop production
267-270Views:158Proper plant nutrition that takes into consideration both the requirements of plants and ecological conditions is one of the most important precondition of successful plant production. An important element of the N-fertilization of wheat is that the optimum zone of nitrogen supply is significantly narrower than that of other plant species, therefore it can easily happen that we apply higher or lower nitrogen doses than the optimal one. A possible solution to this problem can be precision agriculture. Applying the methods of precision agriculture we can take into consideration the heterogeneity of fields. By applying precision methods either online or offline we can intervene faster than if we would rely only on regular soil and plant analysis procedures. The determination of the doses of nitrogen and the timing of application are influenced also environmental and
economic aspects. The chlorophyll content of the leaves indicates the nitrogen status of plants, since there is a relationship between the nitrogen content and the amount of chlorophyll in the leaves. According to plant analysis results there was a strong and significant relationship between the values of the NDVI (Normalized Difference Vegetation Index)and the total nitrogen content measured in the leaves. -
The Effect of Smut Gall Tumour Infection on Iron and Zinc Uptake and Distribution in Maize Seedlings
27-32Views:99The amounts of Fe, and Zn were measured in maize seedlings infected by smut gall tumour (Ustilago maydis Dc. Cda.) and in healthy seedlings five days after infection. The amount of elements was also measured under different stress intensities. Due to the infection, as a biotic stress, the amount and distribution of examined elements have been changed. On the bases of the differences in the Fe distribution between the symptoms less and tumorial leaf parts, we have come to the conclusion that the infection also effects the mobilisation of Fe and Zn inside the plants. The Fe uptake was much higher in the infected plants and the tumour development also had an effect on the uptake and distribution of the examined elements. The experiments of infecting maize seedlings by monosporidial strain of crown gall tumour showed no tumour development. We found that the monosporidial strain also acts as a biotic stress and has an effect of iron and zinc distribution. We observed a slight difference in the iron and zinc contents in the roots of corn seedlings infected by different monosporidial sporidium concentrations, while the iron and zinc contents in the shoots were increased by the intensity of the infection. The roots do not form tumours. There is no difference between the roots of the infected and healthy corn seedlings. Since the Fe and Zn contents of the shoots of infected plants depend on the intensity of the infection, we have come to the conclusion that there must exist a „special” communication system regulating the transportation of the examined elements.
In the experiments with infected maize seedlings, it became necessary to get the iron chlorosis before the disease reaches the lethal phase. Although most of the iron reserves are located in the embryo, to accelerate the chlorosis, the endosperm was removed, and it was observed, that the iron chlorosis appears later in maize seedlings when the endosperm is removed. The relative chlorophyll content of the first and second leaves was measured in iron efficient and iron deficient maize seedlings at different times.
The higher IAA content of tumorial plant tissues is already known. The treatment with IAA decreases the iron concentration in the shoots and in the roots of +Fe precultured plants and increases at -Fe precultured ones. The TIBA retards the shoot-to-root transport of IAA. When the seedlings were treated simultaneously with IAA and TIBA, higher iron concentrations were observed in the shoots and in the roots of corn seedlings.
We found extremely high iron concentrations in the roots of infected seedlings and, in line with this, serious damage to the roots was observed that this can be caused by the high iron content generated free radicals. The results demonstrate that IAA has a role in the shoot to root communication. -
The effect of washing for the shelf-life parameters of spinach (Spinacia oleracea L.)
131-135Views:123Spinach is a very popular green leafy vegetable because of its versatile usage and beneficial for the health. However, spinach may contain several pathogen bacteria: Escherichia coli, Klebsiella spp., Salmonella spp., Enterobacter spp., Citrobacter spp., Shigella spp. and Listeria monocytogenes, which can cause several serious health problems. This study investigates the effects of washing with citric acid for the shelf-life parameters of spinach in comparison to the effect of washing with water and control. Washing of spinach with 0.5% citric acid solution decreased the elasticity of the spinach leaves, as well as the chlorophyll content. On the other hand, the total plate count, as well as the yeast and mold count could be decreased with this treatment, but difference was not detectable at the forth storage day. The fecal indicator E. coli did not change, indicating washing was not effective in this case. Further optimisation of treatment and storage conditions may decrease microbial risk of fresh spinach consumption without decreasing its sensory quality.