Effect of spraying with zinc nanoparticles, Humic acid, and adding the mineral fertilizer on the growth of pear seedlings (Hollywood cultivar)

Tulip (Tulipa gesneriana L.) is an important and highly valuable flower of the cut flower industry. The most critical step in its cultivation is to break dormancy in order to initiate the growth, especially in tropical and sub-tropical areas of the world. Therefore, the current research was conducted to break bulb dormancy and foster the growth of tulip in Potohar region with the help of different primers. The objective of this study was the selection of best primer at appropriate concentration level to enhance growth, yield and vase life of the flower. Tulip bulbs were treated with different primers: T0 (distilled water), T1 (chitosan @ 5 g/L), T2 (gibberellic acid @ 0.15 g/L), T3 (humic acid 160 g/L), T4 (imidacloprid 19 g/L) and T5 (salicylic acid 0.1 g/L) for 24 hours, respectively. The experiment was laid out using Complete Randomized Design (CRD) with three replications. Statistical results revealed that characteristics including early germination, plant height, number of leaves, stalk length, fresh and dry weight of flower, weight of bulbs, diameter of bulbs and number of daughter bulbs were significantly increased in T2. Whereas, leaf area, diameter of stem and flower was maximum in T0. Plants under T3 showed an increase in chlorophyll content of leaves. While floral characteristics like early formation and opening of flower bud, more number of flowers and vase life were improved in T1. Thus, statistical results showed that priming can effectively help to improve morpho-physiological attributes of tulip.

The research was carried out at the Plant canopy of the Department of Horticulture and Landscape, College of Agriculture, University of Kerbala during the growing season of 2016. A factorial experiment with two factors designed. In accordance of randomized completely block design R.C.B.D. to study the effect of spraying with three levels of humic acid (0, 5 and 10 cm3.l−1)and three levels of Alga seaweed extract (0, 1 and 1.5 cm3.l−1)on some vegetative, root growth characteristics and leaf content of mineral elements N, P, K for local apricot seedlings. Treatments with three replicates. Each containing 45 seedlings with five seedlings per experimental unit were adopted. The results showed that a significant increase in plant height, stem diameter, number of leaves, leaf area, leaf content of chlorophyll, nitrogen, phosphorus and potassium, dry weight of shoot, root length, and dry weight of root was noticed when treated with humic acid or seaweed extract (ALGA) alone or jointly compared with control treatment. The interaction between treatments measured at a concentration of 10 cm3.l−1 humic acid and 1.5 cm3.l−1. Alga the highest significant increase in the vegetative, root and leaf content of N.P.K for apricot seedlings was observed.

In sustainable agriculture, protection of the ecosystem and reduce chemical fertilizers are the main goals. Nowadays, sweet basil, one of the best general fragrant foliage, is considered as an industrial plant. In present study to compare different levels of cow manure biochar (CMB) and humic acid (HA) on vegetative traits and mineral absorption rate of green basil plants, an experiment was conducted based on a completely randomized block design with four replications in 2015. The treatments included different levels of CMB (0, 1%, 2%, and 3%) and HA (2.5, 5 and 7.5 g/L) in the culture medium. The traits that were analyzed were included: plant height, leaf number, leaf area, stem diameter, leaf chlorophyll concentration (LCC), fresh and dry weights of aerial part and root, concentration of potassium, nitrogen, calcium and phosphorus. Results showed that fresh and dry weights of shoot and root were increased by application of 3% CMB and 7.5 g/L HA in the culture medium. Theuse of CMB and HA significantly affected most of the studied traits except LCC, stem diameter, and leaf area. Concentration of N, P, K and Ca was considerably increased by application of 3% CMB and 7.5 g/L HA in the culture medium. The highest concentration of nutrients was detected in the plants treated with 3% CMB. In conclusion, the use of 3% CMB and HA at 7.5 g/L in the culture medium can be recommended to improve the qualitative and quantitative traits of basil plants.

Understanding the physiological responses of apricot (Prunus armenica L.) seedlings to treatments involving Humic Acid (HA), Silicon (Si), and their combination (HA + Si) is crucial for advancing sustainable agricultural practices. Focused on growth parameters, physiological attributes, and leaf mineral concentrations, this study addressed critical knowledge gaps in the influence of these treatments on apricot seedlings. The study highlighted a significant increase in stomatal conductance (SC), with the combined HA + Si treatment displaying the highest SC value at 303.98 mmol.m-2s-1. In contrast, control seedlings of the Alyanak apricot cultivar showed the lowest SC, registering at 122.52 mmol.m-2s-1. Regarding chlorophyll concentrations, the Şekerpare apricot cultivar treated with HA + Si achieved the highest value of 43.74, while in the Alyanak apricot cultivar, the Si treatment alone marked the second highest concentration at 43.02. The combined treatment (HA + Si) also reduced leaf temperatures (32.28 °C), notably in apricot cultivar Hacıhaliloğlu. Visual evaluation analyses underscored significant increases in Leaf Area (LA), Total Leaf Number (TLN), Shoot Length (SL), and other parameters, with the combined HA + Si treatment consistently outperforming individual ones. Mineral analysis revealed elevated Nitrogen (N) and Phosphorus (P) with HA, increased Magnesium (Mg) with Si and HA + Si, and significant effects on Potassium (K) and Calcium (Ca). Principal Component Analysis (PCA) confirmed the positive impacts on overall plant performance, corresponding to a cumulative explanation of 53.82%. This study provided crucial insights for tailoring agricultural practices to optimize apricot seedlings growth, emphasizing the effectiveness of HA and Si treatments, particularly in combination, for enhanced physiological responses.

Silvicultural treatments were applied in forest nursery to produce high quality and quantity seedlings. Fertilizer application is one of the most important treatments that were used to improve seedling morphological and physiological traits. The study investigated the influence of NPK fertilizer levels viz. 0, 0.5, 1, and 1.5 g pot-1, Humic acid levels viz. 0, 5, 10 and 15 g pot-1 and their interactions on growth and physiological properties of Paulownia tomentosa. Morphological growth parameters (the increment in the stem height, stem diameter and leaf number) and physiological parameters (leaf area, chlorophyll content and protein percent, and N, P, K content) were measured. The results indicate that the highest values of stem height and stem diameter increment were (52.70 cm and 10.69mm) at (1.5g) of NPK fertilizers. The maximum values of both traits were (51.40 cm and 10.33mm) recorded at (15g) of Humic acid. The highest mean value of nitrogen (2.90 and 2.53 %) reported from application of (1.5 g NPK and15g Humic acid), respectively. Among physiological parameters chlorophyll content recorded the highest value which were (56.97 and 56.04) at (1.5g NPK and 10g Humic acid,) respectively. From interaction between (1g NPK x 15g Humic acid) recorded the highest value of potassium which was (3.74%). The results will help will improve nursery practices to produce healthy and a high quality of P. tomentosa seedlings to meet the plantation programs.

This study was conducted in the field of vegetable crops, Department of Horticulture and Landscape Design, College of Agriculture and Forestry, University of Mosul, Mosul, Iraq, during the spring growth season of 2024.The study aimed to investigate the effect of two factors on growth and anatomical traits of two tomato. The first factor consisted of11 treatments (Nano and conventional calcium) using different concentrations and combinations: Results of the study can be summarized as follows: Queen cultivar plants significantly outperformed GS-12 cultivar plants in plant height, leaf chlorophyll content, leaf area, percentage of dry matter in leaves. The values ​​of these traits reached 81.181 cm plant-1, 58.367 SPAD, and 28248.8 cm2 plant-1, 18.2818%, respectively, for each trait. Plants treated with (conventional calcium 200 mg L-1) and (Nano calcium 50 mg L-1 + conventional calcium 150 mg L-1) gave the highest significant value for leaf chlorophyll content, reaching 54.967 SPAD. While the treatment (Nano calcium 150 mg L-1 + conventional calcium 50 mg L-1) achieved the highest significant value in plant height, reaching 79,000 cm2 plant-1, and all fertilizer treatments were significantly superior compared to the no-spray treatment (comparison treatment) in the number of branches and stem diameter. The plants treated with (Nano calcium 400 mg L-1) gave the best significant value in leaf area, reaching 30,727 cm2 plant-1, with significant superiority over most other treatments. As for the treatment (Nano calcium 100 mg L-1 + conventional calcium 100 mg L-1), it gave the best significant value for the percentage of dry matter, reaching 18.9667%. In general, significant increases were achieved in the case of binary interaction in the vegetative growth traits, and they were as follows: In the trait of plant height, the best significant value was obtained when treated with (Nano calcium 150 mg L-1 + conventional calcium 50 mg L-1) interacted with the Queen variety, reaching 85.333 cm plant-1. In the chlorophyll content of leaves, the treatment (conventional calcium 200 mg L-1) interacted with the Queen variety gave the best significant value, reaching 65.667 SPAD. In the trait of the number of branches and leaf area, they were obtained when treated with (Nano calcium 400 mg L-1) interacted with the Queen variety, reaching 6.9000 branches plant-1 and 41685 cm2 leaves-1. In the percentage of dry matter in leaves, the treatment (conventional calcium 400 mg L-1) interacted with the Queen variety reached 19.8667%, and the treatment (Nano calcium 50 mg L-1 + conventional calcium 150 mg L-1) intercropped with the Queen variety gave the highest significant value in stem diameter, reaching 14.4667 mm stem-1. The treatment of plants with (Nano calcium 150 mg L-1 + conventional calcium 50 mg L-1) was characterized by the highest significant values ​​in each of the percentage of total acidity that can be adjusted, reaching 0.136533%. No significant differences were recorded between the GS-12 variety and the Queen variety in the stomatal density and stomatal area. The use of the two treatments (Nano calcium 200 mg L-1) and (conventional calcium 200 mg L-1) led to a significant increase in stomatal density, reaching 200.00 stomatal and significantly superior to the control treatment, while no significant differences were found in the control treatment. Significant differences in the gap area according to the fertilizer type compared to the comparison treatment.

Zinc release by humic and fulvic acid as influenced by pH, complexation and DOC sorption

Humic acid (HA) is widely used in agriculture as a biostimulant to enhance plant growth and nutrient uptake. Studies on the early growth promotion of agarwood seedlings using plant biostimulants have not been explored. Therefore, the objective of this study was to extract and characterize peat-derived HA and to determine the optimum rate that would exert biostimulant action on the early growth of agarwood seedlings at the nursery stage. HA was extracted from peat soil using a modified rapid alkaline hydrolysis method. Produced peat humic acid (PHA) was compared with commercial humic acid (CHA) for its chemical and spectroscopic characteristics. One-month-old agarwood seedlings were treated with PHA at different rates (0, 20, 40, 80, 160 and 320 mg kg−1) before the commencement of the experiment. The study was conducted for four months. The C/N ratio of both PHA and CHA were 25.85 and 26.93, respectively. Scanning electron microscope (SEM) and fourier-transform infrared spectroscopy (FTIR) spectra observation reveals that PHA and CHA have similar surface morphology and functional groups respectively. Results revealed that agarwood seedlings treated with 80 mg kg−1 of PHA significantly increased the plant height, stem diameter, the number of leaves, leaf area, dry matter weight, N and P concentrations in plant tissues, and N, P and K uptakes. Based on the findings, incorporation of PHA at the rate of 80 mg kg−1 with planting medium could be used as an optimum rate to enhance the growth of agarwood seedlings in the nursery stage.

The experiment was conducted in 2022 at the Department of Horticulture and Landscape Engineering, College of Agriculture, Tikrit University, to determine the impact of organic fertilizer and stimulants on the vegetative growth of pomegranate seedlings in their first year of permanent cultivation. The study treated seedlings with auxins IBA and NAA at 100 and 200 mg L-1, glucose sugar at 5000 mg L-1, and Commercial stimulation Taravert Evo at 6 and 12 ml seedling-1. The experiment used a Randomized Complete Block Design (R.C.B.D) with two factorial elements. The experimental unit comprised one seedling, and Duncan’s multiple test at 5% was used to compare the averages. The treatment with organic fertilizer at 40% increased vegetative growth characteristics like leaf area, total leaf area, seedling height and diameter, and leaf chlorophyll content, while the stimuli increased them. It caused substantial changes in vegetative development (leaf area, total leaf area, and plant height). Stimuli treatment significantly altered vegetative development (leaf area, total leaf area, plant height, and chlorophyll content). The analyzed parameters’ interactions significantly affected vegetative features as leaf area, total leaf area, seedling diameter, and leaf chlorophyll content.

The research was carried out in the Al-Bidaa area/Al-Mahaweel district during the autumn season of 2023-2024. The objective was to investigate the impact of agricultural sulfur and the application of humic acids on various growth parameters of potato plants in a private field. The experiment included two factors, the first of which is agricultural sulfur (S) at three levels (0,750,1500) kg ha−1, agricultural sulfur was added to the soil 30 days before cultivation, and the second factor was humic acids (A) at three concentrations (0, 25, 50) gm fertilizer/100 liters of water. Spraying was done 2 times during the agricultural season. It was coundected. The experiment used a totally randomized block design with three replicates, and Genstat was used to compare treatment arithmetic means by least significant difference (L.S.D.) at 5%. The potato crop’s vegetative growth traits were significantly improved by the addition of agricultural sulfur, humic acid spraying, and their bi-interaction. Specifically, the addition of agricultural sulfur at a level of (S2) 1500 kg ha−1 resulted in the highest rates of plant height, leaf area, shoot dry weight, chlorophyll content, and number of main stems, amounting to (53.91 cm) 6166 cm2 plant−1, 5.11 tons ha−1, 53.66 spad, and 3.98 plant stem−1, respectively. Adding humic acids at the level (A2) of 50 g fertilizer/100 liters of water achieved the highest rate of the studied traits, which reached (53.79 cm2). 5914 cm2 plant−1, 4.28 tons ha−1, 49.34 spad, 3.63 plant stem−1) respectively, and bi-interaction between agricultural sulfur and humic acids achieved the highest significantly excelled in treatment S2A2 for the traits studied above, amounting to (58.00 cm2, 7043 cm2 plant −1, 5.30 tons ha−1, 57.60 spad, 4.59 plant stem−1) respectively.

A field experiment was carried out in one of the agricultural fields belonging to Al-Khalis district / Diyala governorate, which is located 14 km north of Baquba district, during the autumn season of 2022, in soil with clay loam texture in order to study the effect of organic fertilization with humic and fulvic acid and spraying the amino acid proline on vegetative groswth. for sunflower plants (Helianthus annuus L.) A factorial experiment was carried out with two factors according to the randomized complete block design (RCBD) and with three replications. The first factor was sprayed with humic acid and fulvic acid at concentrations of 6 gm.L.-1 For each of them as well as the control treatment, the second agent was sprayed with proline acid at four levels: 0, 10, 20, and 30 mg.L-1 The results showed that there was a significant superiority when adding humic acid + fulvic acid at a concentration of 6g.L-1 In the average characteristic of plant height, stem diameter, plant dry weight, chlorophyll index, leaf area of the plant, and the number of leaves per plant, which were 160.60 cm, 21.57 mm, 174.25 g, and 57.43 SPAD and 687.31 cm2 and 38,81 leaves. Plant-1, respectively. The results showed that there was a significant superiority when spraying with proline at a concentration of 30 mg.L-1 In the mean of plant height, stem diameter, plant dry weight, chlorophyll index, plant leaf area, and number of leaves per plant, which were 166.95 cm, 21.10 mm, 180.00 g, 54.07 SPAD, and 704.01 cm.2 and 40,05 leaves. Plant-1 respectively, the results showed that the interaction between the levels of foliar fertilization with humic and fulvic acids and foliar fertilization with proline acid had a significant effect on all traits, as the overlap treatment gave 6 ml.L-1 Humic + Fulvic X30 mg.L-1 Proline has the highest mean of plant height, stem diameter, plant dryness, chlorophyll index, leaf area of the plant, and number of leaves per plant, which were 171.80 cm, 23.76 mm, 197.00 g, 64.23 SPAD, and 802.82 cm.2 And 41,80 leaves-1 respectively. Keywords: Humic acid, fulvic acid, proline acid, organic acids, foliar nutrition, sunflower.

The time of formation of mangosteen seedlings propagated by seeds can be considered as the biggest difficulty in the seedling production system of this species. Considering that the use of humic acids as a growth promoter has been well documented in some species, the objective of this work was to evaluate the growth of mangosteen seedlings in response to the application of humic acid (HA) doses extracted from vermicompost (0; 2; 20; 40; 200 mg C L-1). Growth rate was determined using the following variables: stem diameter, plant height, number of leaves, leaf area, stem dry matter, leaf dry matter, shoot dry matter, root dry matter, total dry matter and Dickson quality index . The dose 150 mg C L-1 was the one that approached the maximum values and therefore should be recommended for the production of seedlings. The results at 240 days after planting (DAP) showed that the HA increased the growth of mangosteen seedlings, helping to reduce the time of seedling formation under conditions for permanent planting.

Background and Objective: Poor soil fertility is a great limitation to crop production. The adverse effects of chemical fertilizer and the unavailability of organic fertilizer in large quantities are another challenge. The research was conducted at the Research Farm of Ekiti State University, Ado-Ekiti, Nigeria to examine the effects of appropriate doses of humic acid (HA) fertilizers for maximum performance of okra.
 Materials and Methods: The experiment was laid out in Randomized Complete Block Design (RCBD) with three replicates. The two factorial experiments comprise four levels of humic acid fertilizer (0, 5.0, 10.0, and 15.0 g HA plant-1) and NPK 15-15-15 (150 kg hac-1), and two okra varieties. The two okra varieties were allocated to main plots while the fertilizer levels were allocated to sub-plots. The collected data on final plant height (cm), the number of leaves per plant, the number of fruits per plant, the weight of fresh fruit per plant (g), the fruit length (cm), the leaf area (cm3), the fruit diameter (cm), and the stem diameter (cm) and analyzed with the IRRI STAR Software.
 Results: The result showed that the traits measured were significantly different for (HA) levels and NPK fertilizers. The varieties were significantly different for the measured traits except for leaf area, fruit diameter, and fruit length while the varieties x amendment levels were significant for plant height, leaf area, fruit diameter, and stem diameter while others are not significant. The measured traits increases as the humic acid levels increase. It was observed that the plants that received 15.0 g HA plant-1 performed better, followed by 10.0g HA plant-1 and NPK 15-15-15 respectively. However, the differences in the plants that received 5.0g HA plant-1 and 7.5g HA plant-1 were minute.
 Conclusion: It is therefore concluded that 5.0g HA plant-1 should be applied for optimal okra yield.

The research team had conducted this work at a private orchard in Saqlawiya – Falluja district in 2019 toinvestigate the influence of foliar application of liquorice (glycyrrhizin) extract (GLE) and humic acid (HA)on some vegetative growth traits and yield of Al-Ibrahimi apple cultivar. The factorial experiment consistedof 2 factors; the first one was GLE which consisted of 3 levels (L0, L1, L2) of (0, 3, and 6 g.L-1) respectively;while the second one was HA with 4 levels (0, 2, 4, and 6 g.L-1) had symbols of (H0, H1, H2, and H3)successively. Thus, the total number of treatments was 12 of 3 replications. Every apple tree considered as anexperimental unit. The HA treatments were applied 7 times to soil every 20 days starting from 20th February2019 while the foliar applications of GLE were 5 times starting from the 1st April in the same year.A significant improvement in vegetative growth, quantity, and quality of yield due to GLE and HAapplications has been shown in increasing individual leaf area (LA), length of branches (LOB), number ofleaves (NOL), total chlorophyll content in leaves (TCL) , and total carbohydrates content in leaves (TCCL),average weight of fruits (AWF), and number of fruits per tree (NFT) that reflected positively on increasingyield per individual tree (YPT), total percentage of soluble solids (PSS), vitamin C content in fruits (CC) ,and decreasing acidity of fruits (TPA). The interaction between factors had significant influence in most ofstudied traits. Thus the L1H3, L2H2, and L2H3 treatment had the best results.

Sustainability in natural ecosystems is dependent on chemical and biological balance in the soil which is mainly governed by the cross-interaction of microbial communities with organic matter and plant roots. The development of efficient tools to manage these key factors could offer to modern agriculture a way to improve productivity and reduce the reliance on chemical fertilizers. The research described in this thesis is focused on the increase of efficiency of the most promising bio-effectors (i.e. plant growth promoting microorganisms PGPMs) and active natural compounds derived from recycled products with the final goal to contribute to the ecological intensification of agriculture, by developing a viable alternative to mineral fertilisers. Firstly, we started with a series of laboratory extractions of organic matter from recycled products and evaluated their bioactivity on maize seeds germination and seedlings growth in preliminary hydroponic experiments. Investigation on the chemical and molecular characteristics of water-extractable organic matter (WEOMs) and humic acids (HAs) from different on-farm composts were carried out with a primary focus on illuminating the relationship with plant growth promoting activity. A greenhouse pot experiment was carried out using maize plants treated with different phosphate solubilising microorganisms (Trichoderma harzianum and Bacillus amyloliquefaciens) in a phosphorus deficient soils, when different type of P-fertilizers were used ( mineral fertilizers: triple super phosphate and rock phosphate vs organic amendments: composted cow/buffalo manure and composted horse manure). Here we investigated the ability of each bio-effectors to promote maize plant growth and nutrient uptake and evaluated the effects on the microbial community through PLFA and NLFA analysis. Mineral fertilizers produced the best performances but evidence is provided that the addition of composted manure and microorganisms positively affected indigenous mycorrhizal fungi population and plant fitness when compared to control. However, None of the known PGPM per se has the potential to fulfill the requirements of providing a feasible alternative to mineral fertilizers. Therefore, relying on previously promising results, we decided to perform a greenhouse experiment in which different combination of bio-effectors were tested to verify the potential synergistic effect towards the increasing efficiency of plant nutrient uptake. Two phosphate solubilizing bacteria, Pseudomonas proradix and Bacillus amyloliquefaciens, a mixture of two arbuscular mycorrhizal fungi (AMF), Glomus mosseae and Rhizophagus irregularis, and a humic acid (HA) extracted from compost were combined in order to study the best combination when composted cow/buffalo manure were used as a P-source. Best results were obtained with the combination of phosphate solubilizing microorganisms, AMF and humic acids, evidencing a clear synergistic effects. Furthermore, the analysis of PLFA biomarkers and DGGE molecular fingerprint provided an insight into microbial communities changes and composition, revealing the increased development of AMF and the simultaneous depletion of saprophytic fungi when plants were co-inoculated with B. amyloliquefaciens and HA. The outcomes achieved by this dissertation provide valuable information on the dynamics of the multi-partite interactions involved in the rhizosphere and highlight the role of humic substances in sustaining microbial activity and possibly driving plant microbes cross-communication. The combination of different bio-effectors is thus confirmed as a potential biotechnological tool to overcome mineral fertilization systems.