Diff erent Levels of Nitrogen Fertilizer in Nursery Stage Positively Aff ect the Activity of Defense-related Enzymes and Resistance of Tobacco Plant to Phytophthora nicotianae

This study aimed to determine the effects of different levels of nitrogen (N) fertilizer on the growth, production, and nutrient content of Cichorium intybus. The study was carried out at the Faculty of Animal Science, Universitas Gadjah Mada. Cichorium intybus were cultivated on a 1x1.5 m plot. Treatments on this study were different levels of nitrogen fertilizer: 0 kg/ha (N0); 25 kg/ha (N1); and 50 kg/ha (N2), with 3 replications on each treatment. Fertilizing was performed once, on day-5 of the growing phase. The height and length of the plants were recorded once a week for 21 days. The Cichorium intybus were defoliated on day-21. For the harvesting, the plants were cut 7.5 cm above the soil. Variables observed in this study include vegetative growth parameters (height and length of the plant, length of the leaf, the width of the leaf, and several leaves) and biomass production (fresh, dry matter (DM) and organic matter (OM) productions). All data were analyzed using one-way variance analysis, followed by Duncan Multiple Range Test for significantly different results. According to this study, the different levels of nitrogen fertilizer significantly affected (P-value <0.05) plant height and length, length and width of leaf, and biomass production. The highest production was obtained on the group receiving 50 kg/ha of nitrogen fertilizer, which produced 16.74 ton/ha fresh production, 1.36 ton/ha DM, and 1.10 ton/ha OM. Hence, it can be concluded that 50 kg/ha of nitrogen fertilizer treatment yields the highest production.

Molecular detection and quantification of nifH gene sequences in the rhizosphere of sorghum ( Sorghum bicolor) sown with two levels of nitrogen fertilizer

Aims Our objective was to explore the effects of different levels of nitrogen (N) fertilization on soil respiration and its temperature sensitivity during growing season in winter wheat (Triticum aestivum) in East China. Methods Three levels of N fertilization, N1 (15 g·m·a), N2 (30 g·m·a), and N3 (45 g·m·a), and the control group (CK) were set up in winter wheat fields. The LI-8100 Automated Soil CO2 Flux System was used to measure soil respiration rate during the growing season (December 2013 to May 2014) of winter wheat. Important findings During the growing season of winter wheat, mean soil respiration rates of N1, N2 and N3 treatments were 5.29, 6.17 and 6.75 μmol·m·s, respectively, which were 7.8%, 23.6% and 37.8% greater than that of the CK (4.90 μmol·m·s). Compared to CK, the N1, N2, and N3 treatments increased the aboveground biomass by 39.9%, 104.4%, and 200.2%, respectively, and the increases were significantly correlated with total soil respiration during the growing season. Soil respiration increased exponentially with soil temperature at the depth of 5 cm, which explained 65%–75% of the variation (p < 0.05). The temperature sensitivity of soil respiration (Q10) calculated based an exponential equation was between 2.09 and 2.32. These results suggested that nitrogen fertilization promoted plant growth, significantly increased biomass of winter wheat, and stimulated the soil respiration.

The use of nitrogen fertilizers in the appropriate dosage can modify the bromatological compositions of the plant. The objective of this study was to evaluate the chemical composition of the fractions of the corn plant submitted to different levels of fertilization. The experiment was carried out in the municipality of Bocaiúva, located in the interior of Minas Gerais. In the execution of the experiment, the transgenic corn VT PRO 3 from Agroceres was used. The experiment was arranged in a randomized block design with five replications. The treatments consisted of four N doses: 100, 200, 300 and 400 kg N/ha/cut). A single source of N, urea, was used. The data obtained were submitted to analysis of variance and regression analysis. The increase in nitrogen doses influenced the crude protein content of the corn plant. The maximum point for CP content was observed at a dose of 173 N (Kg/ha), and 20.01% of CP was observed. The neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents of the stem were influenced by the increase of N rates (p &lt; 0.05). It is concluded that in the results obtained there was an influence of nitrogen fertilization on the chemical composition of corn.

Management of chemical fertilizers application is very important in their effect on environment and plant yield especially in arid and semi-arid region. In order to determine the effect of different sowing date and levels of nitrogen fertilizer on yield, morphological characteristics and essence of Calendula officinalis a field experiment was conducted using split plot on the basis of randomized complete block design with three replications at Agriculture Research Center of Sistan, Iran during 2008-2009. Main plots were consisted of sowing date in 3 levels, 1th, 15th and 30th of April and sub plots included levels of nitrogen fertilizer in 2 levels (50 and 100 kg/ha) (to be consistent with the rest of the work). The evaluating factors were weight of stem, the number of flower in 5 plants, weight of fresh flower, weight of dry flower and essence content. The results of main effects of compound variance analysis including sowing date and nitrogen fertilizer showed that sowing date on April 1st and 50 kg/ha of nitrogen fertilizer had the most effect in increasing these factors. Also, interaction effects of sowing date nitrogen fertilizer was significant at 5% probability level on all factors. In general, the results of this research demonstrated that using of suitable sowing date along with consumption of 50 kg/ha nitrogen increase yield and essence of C. officinalis. Key words: Calendula officinalis, sowing date, nitrogen fertilizer, yield, essence.

Study the response of the corn crop / Bohooth 106 cultivar, at different levels of nitrogen fertilizer (NF) and cultivation distances (CD). were tested under three levels of nitrogen fertilizer NF of 200, 250 and 300 kgN.ha-1, and two levels CD of 15 and CD of 20 cm The split -split plot arrangement in RCBD with three replications was used. The results showed that the NF of 300 kgN.ha-1 was significantly superior to the other two levels of NF of 200 and 250 kgN.ha-1 in all studied conditions. Soil characteristics(SBD and TSP), plant and root parameters (RL, RDFW and PDFW) and yield and plant growth parameters (PVI, PH, LA and GY). The CD of 20 cm was meaningfully best than of CD of 15 cm in all studied conditions.

Application of the AquaCrop model in decision support for optimization of nitrogen fertilizer and water productivity of soybeans

With growing demands for ethanol, many researchers are turning to Panicum virgatum (switchgrass) as a feedstock of cellulosic ethanol. This study was conducted to examine the germination, biomass, nitrogen, survival, and chlorophyll absorbance of two cultivars of switchgrass grown in competition with Bromus inermis (smooth brome) and with two different levels of nitrogen fertilizer. I predicted that these factors would affect the aforementioned variables, as nitrogen promotes plant growth, competition from other plant species detracts from nutrient availability, and these cultivars are physiologically different. The experiment was conducted in a greenhouse as 12 treatments replicated 20 times. Results indicated that the Liberty cultivar had lower germination, but higher survivorship than the Cave-in-Rock cultivar and that treatments with higher levels of competition resulted in lower biomass. Additionally, control treatments of both switchgrass cultivars grown in the absence of smooth brome had the highest levels of chlorophyll absorbance, and competition treatments had overall lower levels of nitrogen than control treatments. Both levels of nitrogen fertilizer decreased chlorophyll absorbance. Furthermore, switchgrass cultivars grown in competition with smooth brome had lower levels of nitrogen compared to control treatments. My results also indicate that during establishment, competition from other species has a greater effect than nitrogen fertilizer. Replicating this experiment for a multi-year randomized block setup would be ideal for extending this study.

Precision agriculture has always been the research hotspot around the world. And the optimization of nitrogen fertilization for crops is the core concerns. It is not only to improve the productivity of crops but also to avoid the environmental risks caused by over-fertilization. Therefore, accurate estimation of nitrogen status is crucial for determining an nitrogen recommendation. Remote sensing techniques have been widely used to monitor crops for years, and they could offer estimations for stress status diagnosis through obtaining vertical structure parameters and spectral reflectance properties of crops. As an active remote sensing technology, lidar is particularly attractive for 3-dimensional information at a high point density. It has unique edges in obtaining vertical structure parameters of crops. However, capability of spectral reflectance properties is what the current lidar technology lacks because of single wavelength detection. To solve this problem, the concept of novel hyperspectral lidar (HSL), which combines the advantages of hyperspectal reflectance with high 3-dimensional capability of lidar, was proposed in our study. The design of instrument was described in detail. A broadband laser pulse was emitted and reflectance spectrum with 32 channels could be detected. Furthermore, the experiment was carried out by the novel HSL system to testify the potential application for monitoring nitrogen stress. Rice under different levels of nitrogen fertilization in central China were selected as the object of study, and four levels of nitrogen fertilization (N1-N4) were divided. With the detection of novel lidar system, high precision structure parameters of crops could be provided. Meanwhile, spectral reflectance properties in 32 wavebands were also obtained. The high precision structure parameters could be used to evaluate the stress status of crops. And abundant spectral information in 32 wavebands could improve the capacity of lidar system significantly. The results demonstrate that it is more effective for HSL system to distinguish different levels of nitrogen fertilization. Overall, HSL allows for probing not only high precision structure parameters but also spectral reflectance properties of crops. Compared with other approaches, the novel HSL has the potential to provide more comprehensive information of crops which can be assessed remotely in the application of precision agriculture.

Abstract. Precision agriculture has always been the research hotspot around the world. And the optimization of nitrogen fertilization for crops is the core concerns. It is not only to improve the productivity of crops but also to avoid the environmental risks caused by over-fertilization. Therefore, accurate estimation of nitrogen status is crucial for determining an nitrogen recommendation. Remote sensing techniques have been widely used to monitor crops for years, and they could offer estimations for stress status diagnosis through obtaining vertical structure parameters and spectral reflectance properties of crops. As an active remote sensing technology, lidar is particularly attractive for 3-dimensional information at a high point density. It has unique edges in obtaining vertical structure parameters of crops. However, capability of spectral reflectance properties is what the current lidar technology lacks because of single wavelength detection. To solve this problem, the concept of novel hyperspectral lidar (HSL), which combines the advantages of hyperspectal reflectance with high 3-dimensional capability of lidar, was proposed in our study. The design of instrument was described in detail. A broadband laser pulse was emitted and reflectance spectrum with 32 channels could be detected. Furthermore, the experiment was carried out by the novel HSL system to testify the potential application for monitoring nitrogen stress. Rice under different levels of nitrogen fertilization in central China were selected as the object of study, and four levels of nitrogen fertilization (N1-N4) were divided. With the detection of novel lidar system, high precision structure parameters of crops could be provided. Meanwhile, spectral reflectance properties in 32 wavebands were also obtained. The high precision structure parameters could be used to evaluate the stress status of crops. And abundant spectral information in 32 wavebands could improve the capacity of lidar system significantly. The results demonstrate that it is more effective for HSL system to distinguish different levels of nitrogen fertilization. Overall, HSL allows for probing not only high precision structure parameters but also spectral reflectance properties of crops. Compared with other approaches, the novel HSL has the potential to provide more comprehensive information of crops which can be assessed remotely in the application of precision agriculture.

Ten genotypes of bread wheat were crossed in a line x tester mating design. The twenty-one F1's and their parents (seven lines and three testers) were estimated under three levels of nitrogen fertilizer; low (25 kg N/fed), mid (50 kg N/fed) and normal (75 kg N/fed) in three experiments. Each experiments in a randomized complete block design with three replications at the Experimental Farm, Faculty of Agriculture, Menoufia University, Shebin El-Kom, Egypt during 2019/2020. The results cleared that nitrogen fertilizer levels mean squares were significant for all studied traits. A significant difference was found among lines, testers, line x testers and their interaction with nitrogen levels for all studied traits. Analysis of genetic revealed that GCA and SCA variances were significant for all studied traits under different levels of nitrogen fertilizer, indicating the importance of both additive and non-additive components in the inheritance of these traits. However, the hybrids L1 x T1, L2 x T1, L2 x T3, L3 x T2, L4 x T2, L5 x T2, L6 x T2, L7 x T1and L7 x T3were excellent harmonious combiners for specific combining ability effects for grain yield per plant and most of its components under different nitrogen fertilizer levels. The parental lines 1, 4, 6 and 7 proved to have better general combiners for grain yield per plant and most of its components under different levels of nitrogen. Therefore, these genotypes must be taken care of when breeding to tolerate low levels of nitrogen fertilization.

Nitrogen (N) is an essential nutrient for plants. Increase in crop production is associated with increase in N fertilizers. Excessive use of N fertilizers and the low nitrogen utilization efficiency by crop plants is a major cause for environmental damage. Therefore, to reduce the N-fertilizer pollution, there is an urgent need to improve nitrogen use efficiency. Identification and/or development of genotypes which can grow and yield well at low nitrogen levels may provide a solution. Understanding the molecular mechanism of differential nitrogen use efficiency of the genotypes may provide some clues. Keeping the above facts in mind, in this study we have identified the high N-responsive and low N-responsive contrasting rice genotypes, out of 20 genotypes that were grown at low (1 mM), moderate (10 mM), and high (25 mM) levels of N (KNO(3)). Proteome analysis of leaves revealed that the proteins involved in the energy production/regulation and metabolism in plant leaf tissues are differentially expressed under N treatments. Moreover, some disease-resistant and stress-induced proteins were found to be overexpressed at high levels of N. The present study could be useful in identifying proteins responding to different levels of nitrogen fertilization, which may open new avenues for a better understanding of N use efficiency, and for developing new strategies to enhance N efficiency in cereal crops.

BackgroundBlack shank disease caused by Phytophthora nicotianae is a serious threat to flue-cured tobacco production. Whole-plant resistance is characterized by the expression of a number of pathogenesis-related proteins, genes, and the activity of different defense-related enzymes. In this study, we investigated the activity of defense-related enzymes and expression of differentially expressed proteins through the iTRAQ technique across two flue-cured tobacco cultivars, i.e., K326 and Hongda, in response to the black shank pathogen.ResultsResults showed that the highest disease incidence was recorded in flue-cured tobacco cultivar Hongda compared with K326, which shows that Hongda is more susceptible to P. nicotianae than K326. A total of 4274 differentially expressed proteins were detected at 0 h and after 24 h, 72 h of post-inoculation with P. nicotianae. We found that 17 proteins induced after inoculation with P. nicotianae, including pathogenesis (5), photosynthesis (3), oxidative phosphorylation (6), tricarboxylic acid cycle (1), heat shock (1), and 14–3-3 (1) and were involved in the resistance of flue-cured tobacco against black shank disease. The expression of 5 pathogenesis-related proteins and the activities of defense-related enzymes (PPO, POD, SOD, and MDA) were significantly higher in the leaves of K326 than Hongda after inoculation with P. nicotianae.ConclusionThese results provide new molecular insights into flue-cured tobacco responses to P. nicotianae. It is concluded that differences in protein expressions and defense-related enzymes play an important role in developing resistance in flue-cured tobacco cultivars against black shank disease.

A pot experiment was carried out at the Experimental Farm, Faculty of Agriculture, South Valley University, Qena, Egypt during the 2015-2016 and 2016-2017 seasons to study the effect of nitrogen fertilizer levels and types of irrigation water (W1; Tap water only, W2; manipulated wastewater with sandy filter, W3; manipulated wastewater with nano-titanium dioxide + sandy filter and W4; a mixture of treated wastewater with nano-titanium dioxide and sandy filter + tap water) on growth, yield and its attributes of barley cv. Giza 2000. A randomized complete block design (RCBD) using a split-plot arrangement with four replications was used. The main plot was four different levels of nitrogen fertilizer and the sub-plot were four different types of irrigation water. The seeds of above mentioned variety were used in the pot experiments. The highest mean values of plant height, number of tillers plant-1, spike length, number of grains spike-1, spike weight, biological yield plant-1 and grain yield plant-1 were obtained from high level of nitrogen (60 kg N fed-1). Also, the highest values of above traits were obtained from irrigation with treated wastewater with nano-titanium dioxide and sandy filter + tap water (W4). It could be concluded that under the conditions of the experiment, application of high levels of nitrogen (N60) under irrigation with treated wastewater with nano-titanium dioxide and sandy filter+ tap water (W4) is recommended.

Unmanned aerial vehicles-collected (UAVs) digital red–green–blue (RGB) images provided a cost-effective method for precision agriculture applications regarding yield prediction. This study aims to fully explore the potential of UAV-collected RGB images in yield prediction of winter wheat by comparing it to multi-source observations, including thermal, structure, volumetric metrics, and ground-observed leaf area index (LAI) and chlorophyll content under the same level or across different levels of nitrogen fertilization. Color indices are vegetation indices calculated by the vegetation reflectance at visible bands (i.e., red, green, and blue) derived from RGB images. The results showed that some of the color indices collected at the jointing, flowering, and early maturity stages had high correlation (R2 = 0.76–0.93) with wheat grain yield. They gave the highest prediction power (R2 = 0.92–0.93) under four levels of nitrogen fertilization at the flowering stage. In contrast, the other measurements including canopy temperature, volumetric metrics, and ground-observed chlorophyll content showed lower correlation (R2 = 0.52–0.85) to grain yield. In addition, thermal information as well as volumetric metrics generally had little contribution to the improvement of grain yield prediction when combining them with color indices derived from digital images. Especially, LAI had inferior performance to color indices in grain yield prediction within the same level of nitrogen fertilization at the flowering stage (R2 = 0.00–0.40 and R2 = 0.55–0.68), and color indices provided slightly better prediction of yield than LAI at the flowering stage (R2 = 0.93, RMSE = 32.18 g/m2 and R2 = 0.89, RMSE = 39.82 g/m2) under all levels of nitrogen fertilization. This study highlights the capabilities of color indices in wheat yield prediction across genotypes, which also indicates the potential of precision agriculture application using many other flexible, affordable, and easy-to-handle devices such as mobile phones and near surface digital cameras in the future.