تـأثير هرمون البراسينولايد على بعض الصفات المظهرية والكيميائية والمركبات الفعالة لنبات الجرجير Eruca sativa Mill.

A field experiment was conducted during the rabi season of 2020 at All India Coordinated Research Project (AICRP) on Wheat, Jawaharlal Nehru Krishi Vishwa Vidyalaya, Jabalpur (M.P.) to evaluate nutrient balance under the optimization of fertilizer levels with plant growth regulators. The experiment was laid out in a randomized block design comprising nine treatment of different dose of fertilizer along with plant growth regulators namely chlormequat chloride and tebuconazole applied at the rates of 0.2% and 0.1%, respectively and replicated three times. The recommended dose of fertilizer, 120:60:40 kg NPK ha-1 was applied as per treatment. The result showed that using 150% recommended doses of NPK, recorded higher value of available nitrogen (297.320 kg ha-1), phosphorus (18.970 kg ha-1) and potassium (311.630 kg ha-1) content in soil after the harvest of wheat was significantly influenced by the application of different doses of fertilizer, while lowest available content of all the three major nutrients was recorded from control. Growth regulators had no significant influence on the available nitrogen, phosphorus and potassium content in soil. The highest nitrogen content in both grain and straw were observed with the application of 150% recommended doses of NPK with growth regulators (1.99%) and (0.567%), respectively. Phosphorus content and potassium content both in grain and straw were significantly influenced by fertilizer doses, highest value recorded with 150% recommended doses of NPK and the lowest phosphorus and potassium content in both grain and straw were recorded in control while all the other treatments receiving fertilizers with or without being at par with each other. Uptake of all the major nutrients viz., nitrogen, phosphorus and potassium showed the similar trend with significantly highest uptake recorded with the application of 150% recommended doses of NPK with growth regulator and optimal NPK application demonstrated a positive nutrient balance in the soil. It concluded that nutrient management with growth regulator in wheat, economically viable and ecologically sound option to extend these benefits of balanced nutrition in enhancing both crop production and soil heath.

به منظور بررسی تأثیر قارچ آربسکولار میکوریز بر وزن خشک و غلظت عناصر نیتروژن، فسفر و پتاسیم شبدر برسیم در یک خاک آلوده یه کادمیم، یک آزمایش به‌صورت فاکتوریل در قالب طرح کاملا تصادفی با سه تکرار اجرا گردید. فاکتورهای مورد بررسی شامل سطوح مختلف آلودگی خاک به کادمیم (0، 5، 10، 20، 40 و 80 میلی گرم کادمیم در کیلو گرم خاک) و سطوح تلقیح با قارچ آربسکولار میکوریز گونه گلوموس موسیه (با و بدون تلقیح با میکوریز) بود. نتایج نشان داد که تأثیر قارچ آربسکولار میکوریز بر تمامی صفت‌های اندازه‌گیری شده در سطح آماری یک درصد معنی‌دار گردید. با افزایش غلظت کادمیم در خاک، وزن خشک 37 درصد و 39 درصد غلظت نیتروژن 35 درصد و 28 درصد، غلظت پتاسیم 9/27 درصد و 37 درصد و غلظت فسفر 37 درصد و 39 درصد به ترتیب در ریشه و اندام‌های هوایی کاهش یافت. همچنین نتایج نشان داد که قارچ آربسکولار میکوریز، وزن خشک، غلظت نیتروژن، غلظت پتاسیم و غلظت فسفر را در ریشه و اندام‌های هوایی به ترتیب 42 درصد و 26 درصد، 3/40 درصد و 30 درصد، 6 درصد و 4/15 درصد، 54 درصد و 2/91 درصد افزایش داد. اثر متقابل سطوح کادمیم و میکوریز بر وزن خشک اندام‌های هوایی، غلظت نیتروژن اندام های هوایی و ریشه و غلظت پتاسیم ریشه گیاه در سطح یک درصد معنی دار گردید.

Subsurface drip irrigation can improve crop water and fertilizer use efficiency, but it can cause soil hypoxia. We report on experiments performed in Aksu Prefecture, Xinjiang (41°17′ N latitude, 80°17′ E longitude), from April 2023 to October 2024 using oxygenated drip irrigation from the surface to 50 cm depth in an apple (Malus pumila Mill.) orchard, to examine the effects of drip irrigation on inter-root hypoxia, tree growth, fruit quality, and yield. Compared with surface oxygenated drip irrigation (CK), irrigating at 10 and 30 cm increased soil water content in the root system, elevated gibberellin, zeatin ribosides, and indoleacetic acid contents and reduced abscisic acid contents in new shoot tips. Compared with CK, branch and leaf nitrogen, phosphorus, and potassium contents were increased with irrigation at depths of 10 and 30 cm. The leaf nitrogen (N), phosphorus (P), and potassium (K) contents were increased by 18.03%, 22.42%, and 16.63%, respectively, in the treatment with a burial depth of 30 cm. Among treatments, irrigation at 30 cm produced the highest average daily plant water potential, and irrigation at 50 cm was the lowest. Maximum leaf soil–plant analysis development (SPAD) values occurred when irrigated at 30 cm, and minimum values occurred at 50 cm. For both years, the largest range of light flux utilization occurred when irrigated at 30 cm and the lowest when irrigated at 50 cm. Significant correlations between indoleacetic acid (IAA), total gibberellin (GA), zeatin riboside (ZRs), leaf N content, leaf K content, plant water potential (PWP), net photosynthetic rate (Pn), SPAD, and apple yield were determined by partial mantel analysis. A significant correlation was found between abscisic acid (ABA), IAA, GA, leaf P and K content, and apple quality. Principal component analysis revealed a burial depth of 30 cm had the highest principal component composite score, indicating that this burial depth, and oxygenation and fertilization regime most favored apple growth, yield, and quality.

Development of a low-cost portable device for pixel-wise leaf SPAD estimation and blade-level SPAD distribution visualization using color sensing

Chroococcum and A. brasilense bacteria were isolated and identified from the root and the surrounding area of Arundo donax andCladium marisas plants growing in different areas in Ramadi city in order to be used in pollinating the seeds of zucchini squash plant. A pot experiment was carried out in the spring season on 16 ⁄ 3 ⁄ 2019 in one of the fields of the College of Agriculture - University of Anbar, by following the design of complete randomized sectors RCBD. It included two factors of salinity of irrigation water and four levels of S0, S1, S2 and S3 (1.3, 3, 5 and 7 dSm-1) and the factor of adding the bacterial isolates of Azotobacter L1 and Azospirillum L2 and their two mixtures L3, and without adding the L0 inoculum in order to study the effect of bacterial pollination on some growth characteristics of squash plants irrigated with different salinity water levels. The results showed a decrease in plant height, number of leaves and dry weight of the shoots from 53.48 cm, 33.00 leaf-1, 25.97 gm-1 at the S0 level, to 26.95 cm, 14.08 g-leaf-1, and 12.41 g-leaf-1 at the S3 level. The treatment of the two isolates mixture L3 achieved a significant increase in plant height, number of leaves and dry weight, and it was 55.53 cm, 44.00 leaf-1 and 28.33 g-leaf-1 compared with the comparison treatment at the S0 level. The salinity of irrigation water caused an increase in the nitrogen concentration in the vegetative parts of the plant from 1.77% to 2.07%, and caused a decrease in the concentration of phosphorus and potassium from 0.63 and 2.37% to 0.21 and 0.56%. The concentration of nitrogen, phosphorus and potassium significantly increased in the vegetative parts of the plant when the bacterial inoculation treatments were obtained, and the treatment L3 recorded the highest values and reached 2.75% N at the level of salinity of S3 and gave the highest value for the concentration of phosphorus and potassium, which were 0.75 and 2.87%, respectively, at the S0 level.

Nitrogen (N) is an important component of proteins and chlorophyll, and has been correlated with optical sensors as a means to determine N status during crop production. In this experiment, chrysanthemum ‘Amico Bronze’ and ‘Jacqueline Yellow’ had initial controlled-release fertilizer rates of 0, 5, 10, 15, or 20 g. Normalized Difference Vegetation Index (NDVI), Soil Plant Analytical Development (SPAD), and atLEAF sensor readings were taken at 10, 17, 24, 31, 38, and 45 days after adding initial fertilizer treatments (DAT). NDVI was correlated with leaf N concentration at all sampling dates except 17 DAT. Values for NDVI increased linearly up to 31 DAT for all treatments then plateaued at 45 DAT. Values for SPAD were only correlated with leaf N at 24 DAT, whereas, NDVI was correlated as early as 10 DAT. The atLEAF sensor was not correlated with leaf N at any sampling date. With weeks combined, correlation analysis showed correlations among leaf N and fertilizer rates, fertilizer rates and SPAD, and SPAD with NDVI and atLEAF. Thirty-one days after initial fertilizer treatment, 10 pots per treatment per cultivar were supplemented as following: 15 g supplemented to the 0 g treatment, 10 g to the 5 g treatment, and 5 g to the 10 g treatment at 31 DAT. With supplemented fertilizer treatments (SFTs), NDVI increased weekly until 45 DAT for ‘Amico Bronze’, while SPAD values did not increase in any treatments. The greatest atLEAF values occurred with 10 (+5) g and 0 (+15) g N in both cultivars. All sensor readings were only taken on leaves without any flowers. The greatest number of flowers, plant height, and shoot dry weight occurred with 10 (+5) g of additional N, but no differences occurred between 5 (+10) g and 0 (+15) g for height and shoot dry weight. No correlations existed between fertilizer rates, SPAD, NDVI, and leaf N for SFT in either cultivar. In summary, results indicated that NDVI values correlated greater ( P ≤ 0.05 and P ≤ 0.01) with leaf N than SPAD and atLEAF chlorophyll sensors. Supplemental fertilizer application improved plant quality in terms of number of flowers, plant height, and shoot dry weight for all treatments, indicating that SFT could be used to correct N deficiency during crop production; however, not in combination with nondestructive sensor readings because of inconsistencies in the ability of all three sensors to separate among fertilizer treatments during a short production schedule.

The purpose of this work was to determine the impact of weather conditions during the spring and summer growth of winter triticale on the yield and content of nutrients in its grain. The research results were achieved from a controlled field experiment carried out at the Experimental Station of the University of Warmia and Mazury in Olsztyn, located in Tomaszkowo near Olsztyn (53o42′ N; 20o26′ E). The impact of weather factors during the spring and summer growth of winter triticale on the yield and content of nutrients in its grain was explained by correlation and multiple regression analyses. The duration of the spring and summer growing season (b′ = 0.929**) and the average daily temperatures during the plant growth (b′ = 0.409*) had the strongest, significantly positive impact on winter triticale yield. A significant linear correlation was found only between the content of nitrogen and potassium in winter triticale grain and the selected weather parameters. The nitrogen content depended on the number of plant growing days and average minimum daily temperature, while the potassium content was affected by the number of spring and summer growing days, average daily temperature, total precipitation volume and the number of days with precipitation. Considering the cumulative impact of the examined weather parameters on the content of macroelements in triticale grain, a significant effect was found for phosphorus and potassium, whose levels depended, to the largest extent, on the precipitation volume and number of days without precipitation ≥10 days, respectively. The content of phosphorus and nitrogen in grain was significantly negatively correlated with the yields of winter triticale.

The effect of soil nutrient gradients on Collembola communities inhabiting typical urban green spaces

Abstract. The aim of the study was to assess the influence of different fertilizer doses on the content of macroelements (nitrogen, phosphorus and potassium) in dry biomass and grain of maize during the 2016 – 2018 period. A field experiment with fertilization of maize was carried out on Alluvial-meadow soil (Fluvisol) in the region of Tsalapitsa village, near Plovdiv. Three variants of mineral fertilization were studied V2 (N15P10K0), V3 (N20P15K0) and V4 (N25P20K0), and a control variant V1 (N0P0K0) – without fertilization. It was established that N% content in maize dry biomass was affected significantly by the variants of fertilization (18% of the variance). Significant differences (P≤0.05) between the control variant and all the variants of fertilization were established. Increasing the fertilizer dose, nitrogen content in dry biomass increased, too. The highest was the average content of nitrogen in maize leaves (0.94%), followed by the cobs (0.71%) and the lowest was the content in the stems (0.58%). Phosphorus and potassium content of dry biomass were affected significantly by the year of the study (10% and 9% of the variance, respectively). At the 7-8th leaf growth stage of maize, the highest nutrients content (N, P, K) in dry biomass were reported. With aging of plants the nutrient content in their biomass decreased. Nitrogen, phosphorus and potassium content in maize grain was significantly affected by the year of the experiment. Mineral fertilization had impact mostly on the nitrogen content of the grain, which was the highest in V3 variant, accepted as optimal – 0.66% on average.

Chlorophyll and nitrogen (N) content in rice at critical crop growth stages are important input parameters for crop growth and nutrient uptake models used to optimize N application. Hence, the study was conducted to predict chlorophyll and N content in rice using multiple regression-based models involving normalized difference vegetation index (NDVI), Soil Plant Analysis Development (SPAD), Customized leaf color chart (CLCC), chlorophyll and N content. An experiment was conducted with six varieties i.e. CR Dhan 312, CR Dhan 310, Lalat, Shatabdi, Swarna Shreya, CR Dhan 206 with four N levels (i.e. 0, 80, 100 and 120 kg N ha−1) in split plot design and replicated thrice. The NDVI, SPAD and CLCC readings were taken at 45, 49 and 54 days after transplanting (DAT). Plant sampling was done for estimating the chlorophyll and nitrogen content in laboratory following standard methodology. Multiple linear regressions were performed between NDVI, SPAD and CLCC readings and chlorophyll & N content in rice in different variables combinations. Multiple linear regression (MLR) models with two variables i.e. NDVI and SPAD predicted the chlorophyll and N content of rice varieties. The predicted values for nitrogen and chlorophyll were comparable to those obtained using models from individual varieties when combined data from six different varieties were used to create MLR models. The study concludes that variations in chlorophyll and N concentrations in rice can be estimated using data from optical sensors with notable accuracies.

A pot experiment was done in a greenhouse to investigate the effect of low phosphorus (P) and moisture content on growth and yield components of four spring wheat (Triticum aestivum L.) varieties. Days to emergence of seedlings were shortened, plant height, tiller number, and SPAD (Soil-Plant Analyses Development) index of the leaves were significantly (p < 0.01) reduced by low P. Root and shoot biomass, nitrogen and P uptake decreased significantly with low moisture and P content in the potting mix. Moisture and P interactions had a significant (p < 0.01) effect on shoot and root biomass and P uptake and these variables were closely related to each other with regression (Coefficient of determination R2) values ranging from 0.72 to 0.90. The study underlines the strong relationship between moisture, P availability and uptake and provides more information on P nutrition during the vegetative stage of wheat in moisture and P deficient soils.

Rapid and accurate crop chlorophyll content estimation and the leaf area index (LAI) are both crucial for guiding field management and improving crop yields. This paper proposes an accurate monitoring method for LAI and soil plant analytical development (SPAD) values (which are closely related to leaf chlorophyll content; we use the SPAD instead of chlorophyll relative content) based on the fusion of ground–air multi-source data. Firstly, in 2020 and 2021, we collected unmanned aerial vehicle (UAV) multispectral data, ground hyperspectral data, UAV visible-light data, and environmental cumulative temperature data for multiple growth stages of summer maize, respectively. Secondly, the effective plant height (canopy height model (CHM)), effective accumulation temperature (growing degree days (GDD)), canopy vegetation index (mainly spectral vegetation index) and canopy hyperspectral features of maize were extracted, and sensitive features were screened by correlation analysis. Then, based on single-source and multi-source data, multiple linear regression (MLR), partial least-squares regression (PLSR) and random forest (RF) regression were used to construct LAI and SPAD inversion models. Finally, the distribution of LAI and SPAD prescription plots was generated and the trend for the two was analyzed. The results were as follows: (1) The correlations between the position of the hyperspectral red edge and the first-order differential value in the red edge with LAI and SPAD were all greater than 0.5. The correlation between the vegetation index, including a red and near-infrared band, with LAI and SPAD was above 0.75. The correlation between crop height and effective accumulated temperature with LAI and SPAD was above 0.7. (2) The inversion models based on multi-source data were more effective than the models made with single-source data. The RF model with multi-source data fusion achieved the highest accuracy of all models. In the testing set, the LAI and SPAD models’ R2 was 0.9315 and 0.7767; the RMSE was 0.4895 and 2.8387. (3) The absolute error between the extraction result of each model prescription map and the measured value was small. The error between the predicted value and the measured value of the LAI prescription map generated by the RF model was less than 0.4895. The difference between the predicted value and the measured value of the SPAD prescription map was less than 2.8387. The LAI and SPAD of summer maize first increased and then decreased with the advancement of the growth period, which was in line with the actual growth conditions. The research results indicate that the proposed method could effectively monitor maize growth parameters and provide a scientific basis for summer maize field management.

The Soil Plant Analysis Development (SPAD) value obtained from the SPAD meter is directly related to leaf chlorophyll content. The chlorophyll content is related to nitrogen content means the amount of fertilizer of a crop. Therefore, determining SPAD value is directly involved with crop health. Minolta SPAD meter can directly measure this value, and this is a well-established method in the research field for measuring chlorophyll content. Still, this instrument is too costly, which is beyond a farmers’ reach in the perspective of Bangladesh. The purpose of this study is to predict the SPAD value for paddy leaves using the smartphone-based direct contact imaging method to estimate the chlorophyll content of a paddy leaf. Numerous features were extracted from each image to predict the SPAD values. The features were then used as parameters in the multiple linear regression model. The models' performance was evaluated using images captured from a paddy field using a Minolta SPAD-502 Chlorophyll Meter. The multiple linear regression model's R2 and root mean square error (RMSE) values were 0.71 and 3.6512, respectively. Therefore, this result confirms that the direct digital contact imaging method has the potential to quantify the SPAD value of paddy leaves accurately. However, these results could be more accurate if the image acquisition was made from the seedling to mature stage of the paddy. In the future, an android app will be developed using this value which can directly measure the chlorophyll content of paddy leaves.

This study aimed to evaluate the effects of different salinity levels on the morphological and genetic traits of Lepidium sativum L. (garden cress). Three treatments using well water with varying salinity levels (5.30, 19.17, and 23.35 mg/L) were compared to a control irrigated with Tigris River water (0.80 mg/L). Parameters measured included germination time, plant height, number of leaves and branches, and chlorophyll content. Germination occurred first in M1 (18 hours), followed by M2 (24 hours), and M3 (72 hours), indicating an inverse relationship between salinity and germination speed. M1 plants reached the greatest height (30.67 cm), followed by M2 (30.02 cm), and M3 (16.28 cm). Leaf count was highest in M1 (23), then M2 (22), and lowest in M3 (10). Branch count peaked in M2 (7.1), followed by M1 (6.7), with M3 lowest (5.5). Chlorophyll content was highest in M2 (38.14 Soil Plant Analysis Development (SPAD)), then M1 (37.76 SPAD), and lowest in M3 (33.62 SPAD). Randomly Amplified Polymorphic DNA- Polymerase Chain Reaction (RAPD-PCR) analysis was conducted to assess genetic variation. A total of 135 bands were observed: 83 were absent and 52 unique. M2 showed the highest number of unique bands (20), followed by M3 (18), and M1 (14). For absent bands, M2 had 32, M1 had 29, and M3 had 22. The results demonstrate that increased salinity negatively affects germination, plant growth, and genetic diversity, with moderate salinity inducing more genetic variation than high or low levels.

The pot experiment was conducted in a greenhouse to study the effect of nitrogen nutrition of 0, 200, 400, 600 and 800 mg N.kg-1 soil on the concentration of nitrogen, phosphorus and potassium in sorghum plants. The plants were analyzed in 4-5 leaves growth stage by dividing the leaves, stems and roots. It was established that the sorghum plants formed the largest amount of dry biomass when grown at N600 level. Higher levels (N600 and N800) increased the nitrogen content of stems and roots and phosphorus in all plant parts, but they significantly reduced the nitrogen concentration in the leaves. The concentration of potassium in the leaves and stems increased in parallel with the levels of nitrogen from 3.64% K2O and 4.02% K2O at N0 to 4.42% K2O and 5.03% K2O at N800, respectively. The nitrogen level very strongly positively correlated with the nitrogen concentration of roots (r = 0.927**) and the potassium concentration of leaves (r = 0.993**) and stems (r = 0.985**). The relationship between nitrogen fertilization and the nitrogen concentration of leaves was negative (r = - 0.535*). The positive and proven relationship was established between the nitrogen level and the phosphorus concentration of plant organs.