Effects of Pruning and Nitrogen Fertilization for The Rejuvenation and Physicochemical Characteristics Of Fruits of Declining Apricot Trees (Prunus Armeniaca L. CV. New Castle)

Effects of pruning and nitrogen fertilization for the rejuvenation and physicochemical quality of fruits, bearing on declining apricot trees (Prunus armeniaca L. cv. New Castle) were assessed. Studies were conducted from 2011 to 2015 on the 25 years old senile and declining apricot trees. Ten treatments comprised of a factorial combination of three pruning levels/severity (heading back of main scaffolds at 20, 40 and 60%) with three levels of nitrogen doses (500, 625 and 750g N/tree). For the first time in the year 2011, the experimental trees received the treatments during its dormant period (winter). In the successive years, all the treatments were followed by corrective pruning facilitate rapid restoration of growth and production of the orchard. The factorial treatment combination of heavy pruning (60%) with the lowest doses of nitrogen level (500g/tree) increased the qualities of fruits in terms of weight, volume, firmness, total soluble solids, sugars and acidity content. Whereas, the ascorbic acid content was facilitated by heavy pruning (60%) with the highest doses of nitrogen level (750g/tree) in all the following years. Bangladesh J. Bot. 50(4): 1119-1126, 2021 (December)

Simulation modeling of rice genotypes of yield and yield attributes at different nitrogen levels and different dates of transplanting using CERES 3.5 v for eastern Uttar Pradesh

The present investigation was carried out at Agrometeorological Instructional Farm of Narendra Deva University of Agriculture & Technology, Kumarganj, Faizabad (U.P.) during Kharif season of 2005-06 to investigate the CERES v 3.5 model validations for rice at different dates of transplanting and different genotypes. Treatment consisted of three genotypes, viz., Sarjoo-52, NDR-359 and Pant Dhan-4, two dates of transplanting, viz., July 5, 2005 and July 25, 2005 & three nitrogen levels, viz., 80 kg/ha, 120 kg/ha and 160 kg/ha. The experiment was laid out in Randomized Block Design (RBD). From the response of simulation model it is observed that accuracy of simulated value decrease with late sowing in all the genotypes. Among the varieties the Pant Dhan-4 was found to have maximum closeness to observed value followed by Sarjoo-52 and NDR-359 at all nitrogen level for Biomass (gm/m2). Grain yield predication at 120 kg N level was found closest in Pant Dhan-4 and Sarjoo-52, while in NDR­-359 shows the better closeness at 160 kg N in both dates of transplanting. In the weight/grain (gm) 120 kg nitrogen level was found to have highest accuracy of (100%), i.e., no difference between observed and predicted value in both transplanting dates and nitrogen level.

Metabolomics Analysis Reveals Potential Mechanisms in Bupleurum L. (Apiaceae) Induced by Three Levels of Nitrogen Fertilization

Bupleurum (Apiaceae) is widely used in traditional Chinese medicine to treat inflammatory and infectious diseases. Although roots are the only used parts in China, other countries use the whole plant. The yield and quality of Bupleurum depend mainly on fertilizers, especially nitrogen. The current study aimed to assess the relationship between the nitrogen fertilization level and the quality and metabolomic response of different parts (flowers, main shoots, lateral shoots and roots) of Bupleurum to three nitrogen fertilization levels (control group: 0 kg·ha−1; low-nitrogen group: 55 kg·ha−1; high-nitrogen group: 110 kg·ha−1). The results showed that a high nitrogen level increases Bupleurum yield and quality parameters only in aerial parts, especially flowers, but has no significant effect on roots. The HPLC method was exploited for simultaneous quantification of three saikosaponins (A, C and D), which are the main bioactive components in the plant. It was found that the total content of saikosaponins decreased with high nitrogen fertilization in roots but significantly increased in flowers. Moreover, nitrogen fertilizer promoted the content of saikosaponin A but inhibited saikosaponins C and saikosaponins D in most parts of the plant. To study the response of primary metabolites, we adopted gas chromatography–mass spectrometry (GC−MS) analysis; 84 metabolites were identified that were mostly up-regulated with a high nitrogen level in flowers but down-regulated in roots. Four differential metabolites—D-fructose, lactose, ether and glycerol—were recognized as key metabolites in Bupleurum under nitrogen fertilization. Meanwhile, The Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment results explained that the impact of nitrogen fertilization on Bupleurum was attributed to the C-metabolism, N-metabolism, and lipids metabolism. This research put forward new insights into potential mechanisms and the relationship between the quality and yield of Bupleurum and nitrogen fertilization.

Phenology, Agrometeorological Indices and Yield of Pusa Basmati-1509 as Influenced by Sowing Dates and Nitrogen Levels under Temperate Conditions

The purpose of the study was to optimize the sowing date and nitrogen level in early maturing rice (Pusa basmati 1509) under temperate climate for realizing higher yield. The experiment was conducted on silty clay loam soil, neutral in reaction, low in available nitrogen, medium in available phosphorus, potassium and organic carbon. Treatments included three sowing dates viz 20th April, 30th April, and 10thMay and five nitrogen levels viz 0, 30, 60, 90 and 120 kg N ha-1 laid out in split plot design with three replications. Among the sowing dates, 20th April took maximum no. days to reach different phenological stages and maturity. The GDD (1431) and HTU (15161 oC d-1 hr-1) requirement to reach maturity was maximum for 20th of April sowing. Significantly higher grain yield, higher HUE (2.90 kg ha-1 oC-1 d-1) and HTUE (0.273 kg ha-1 oC-1 hr-1) was realized form 1st date of sowing i.e., 20th of April. Higher doses of 120 kg N ha-1resulted in slightly more number of days to reach different phenological stages and maturity that was also reflected in higher accumulation of more GDD 1403° and HTU (14987 °C d-1 hr-1) at maturity. Highest HUE (1.42 kg ha-1 oC-1 d-1) and HTUE (0.133 kg ha-1 °C-1 hr-1) was realized at 120 kg N ha-1. Further among the sowing dates, 20th April and 30th April had significantly higher growth parameters viz. plant height, leaf area index, tillers m-2, dry matter accumulation, leaf area index and SPAD reading as compared to 10th May. Most of the growth and yield parameters were found significantly higher at nitrogen level of 120 kg ha-1. However, most of them were at par with followed by nitrogen level of 90 kg ha-1.

Morphological and physiological plasticity response to low nitrogen stress in black cottonwood (Populus deltoides Marsh.)

It is important to evaluate nitrogen use efficiency and nitrogen tolerance of trees in order to improve their productivity. In this study, both were evaluated for 338 Populus deltoides genotypes from six provenances. The plants were cultured under normal nitrogen (750 μM NH4NO3) and low nitrogen (5 μM NH4NO3) conditions for 3 months. Growth, chlorophyll content and glutamine synthetase activity of each genotype were measured. Under low nitrogen, heights, ground diameter, leaf area, leaf and root biomass, and chlorophyll contents were significantly lower than those under normal nitrogen level. Correlation analysis showed that nutrient distribution changed under different nitrogen treatments. There was a negative correlation between leaf traits and root biomass under normal nitrogen level, however, the correlation became positive in low nitrogen treatment. Moreover, with the decrease of nitrogen level, the negative correlation between leaf morphology and chlorophyll levels became weakened. The growth of the genotypes under the two treatments was evaluated by combining principal component analysis with a fuzzy mathematical membership function; the results showed that leaf traits accounted for a large proportion of the variation in the evaluation model. According to the results of comprehensive evaluation of plants under the two treatments, the 338 P. deltoides genotypes could be divided into nine categories, with wide genotypic diversity in nitrogen use efficiency and low nitrogen tolerance. As a result, 26 N-efficient genotypes and 24 N-inefficient genotypes were selected. By comparative analysis of their morphological and physiological traits under the two treatments, leaf traits could be significant indicators for nitrogen use efficiency and nitrogen tolerance, which is of considerable significance for breeding poplar varieties with high nitrogen use efficiencies.