This study sought to estimate the heavy elements, lead, iron, zinc, manganese, cadmium, and copper in cultivated and uncultivated soils of Basrah, Iraq. Results showed that the concentration of elements in all locations was within permissible limits on surface layers, which were higher in concentration than in deep layers due to the elements’ internal transport, natural, some physical and chemical properties, i.e., pH, electrical conductivity (EC), and organic matter (OM). The soil acidity ranged between 7.70–7.25 and 7.88–7.25 for cultivated and uncultivated soils, respectively. As for the electrical conductivity, it has a range between 2.70–10.16 and 3.13–23 dS.m^-1 Organic matter extended between 0.269–1.500 and 0.349–0.816. The elements in cultivated soils were lesser than in the uncultivated grounds. The analysis of variance (ANOVA) results at the 5% significance level showed no remarkable differences in the concentration of the studied elements, while significant variations appeared in the copper content.

Keywords: Pollution agricultural soil, trace elements, organic matter

Key findings: All element values studied in the agricultural soil were within natural limits due to a concentration increase in some elements, especially iron, compared with uncultivated soils, while lead showed no effect. The unit concentration in the cultivated soils in Basra City was lower than in international soils. The elements’ concentration in soil is as follows: Iron > manganese > copper > cadmium > zinc > lead.

A field experiment materialized during the winter of 2022 at the College of Agriculture, University of Kerbala, to determine the effect of foliar spraying of several concentrations of NPK and amino acids on growth characteristics and yield of broccoli plants (Brassica oleracea var. Italica). The study implemented a randomized complete block design (RCBD) with two factorial experiments and three replications. The first factor included three concentrations of NPK (0, 1.5, and 2.5 g L^-1), and the second with three concentrations of amino acids (0, 1, and 2 ml L^-1). The findings demonstrated notable disparities, with the third concentration of NPK (2.5 g L^-1) exhibiting superior performance, giving a plant height of 63.78 cm, leaves per plant (18.076 leaves plant^-1), stem diameter (3.326 mm), flower disc weight per plant (510.84 g plant^-1), and the flower holder diameter (18.671 mm). Regarding the impact of amino acid, the concentration at 2 ml L-1 appeared with maximum values across traits, i.e., plant height (62.50 cm), number of leaves (17.477 leaf plant^-1), stem diameter (3.241 mm), flower disc weight (485.49 g), and the diameter of the flower container (15.972 mm). The interaction between the two factors displayed significant effects, with the highest interaction between the third concentration of NPK (2.5 g L^-1) and the concentration of amino acid (2 ml L^-1) arising in most traits.

Keywords: Broccoli (Brassica oleracea), NPK doses, amino acid, growth and yield traits

Key findings: In broccoli (Brassica oleracea), NPK at 2.5 g L^-1 provided better results than other doses for plant height, leaf count, stem diameter, floral disc weight, and flower stand diameter. Similarly, the highest averages for plant height, leaf count, stem diameter, floral disc weight, and flower stand diameter emerged with the amino acid at 2 ml L^-1.

This study investigated the effects of dry yeast and licorice on the growth and morphology of Stevia rebaudiana. The field experiment on Stevia rebaudiana Bertoni under the wooden cover commenced in 2023 at the Department of Horticulture and Gardening Engineering, University of Tikrit, Iraq. Using three different amounts of ground licorice (0, 5, and 10 g) and three varied quantities of dry yeast (0, 2.5, and 5 g) became factors to assess the response of S. rebaudiana Bertoni to them. The highest ratios of plant height, number of leaves per plant, and leaf thickness had ratings at 55.20 cm, 729 leaves, and 0.370 mm, respectively. The results demonstrated that the treatments involving ground addition with licorice (10 g) were considerably superior. However, when adding the dry yeast to the ground up, the optimal ratios of the previously mentioned qualities rose to 87.04 cm, 737 leaves, and 0.620 mm, respectively. The results showed that the treatments significantly improved plant height, number of leaves, and a leaf’s thickness. The interaction between the dry yeast and licorice had the highest impact, resulting in a 97.50 cm plant height, 789 leaves, and 0.740 mm leaf thickness. These findings suggest that dry yeast and licorice combined can be eco-friendly fertilizers to promote Stevia growth.

Keywords: Stevia (Stevia rebaudiana Bertoni), nano bio-enriched, licorice and dry yeast, response, growth traits, leaf chlorophyll content, potassium

Key findings: By adding ground licorice (10 g) and dry yeast (5 g) to stevia plants, the highest plant height, number of leaves, and leaf thickness occurred with the interaction of these two factors, reaching maximum ratios of 97.50 cm, 789 leaves, and 0.740 mm, respectively.

Chamomile (Matricaria chamomilla L.) is one of the most renowned medicinal plants and a winter annual herbaceous long-day crop. The presented research on the chamomile (M. chamomilla L.) scrutinized the effects of using biostimulants (Bio health), mineral fertilizers (NPK), and phytoregulator (Kinetin) on the growth and active ingredients of chamomile plants and select the best combination of fertilizers and growth regulator for best results. The experiment commenced in a randomized complete block design (RCBD) with three replications. The experimental treatments included three factors; the first factor was the biofertilizer with two levels (0 and 10 g L^-1), the second was NPK fertilizer addition with three levels (0, 300, and 500 kg ha^-1), and the third was the foliar spray of kinetin with three concentrations (0, 50, and 100 mg L^-1). The hydro-distilled essential oil of Matricaria chamomilla L. underwent analysis by GC. The highest floral inflorescence (384.33 floral inflorescence plant^-1), inflorescence dry weight (0.11 g plant^-1), volatile oil (1.54%), and turpentine (13.33%) were distinct with the combination and interaction of the three factors, biofertilizer (10 g L^-1), NPK (300 kg ha^-1), and kinetin (50 mg L^-1).

Keywords: Biofertilizer, chamomile, NPK fertilizer, phytoregulator, turpentine, volatile oil

Key findings: The interaction and combined application of biological and mineral fertilizers along with kinetin provided fruitful and productive to meet the nutritional needs of the growth indicators and inflorescences, which boosted the medicinal importance of the chamomile plant.

The latest experiment on mung bean (Vigna radiata L.) materialized during the spring of 2023 in the laboratories of the Department of Horticulture and Landscape Gardening, College of Agriculture, University of Kufa, Iraq. The study aimed to improve mung bean seed germination under water-stress conditions. It employed a completely randomized design (CRD) by organizing two factors with three replications. The first factor included water-stress treatments by adding Polyethylene glycol solution (PEG 6000) to the mung bean seeds, with three levels (0, -8, and -12 bar). The second factor included seed soaking for 24 h in three different concentrations of gibberellin acid (0, 125, and 250 mg L^-1). The results revealed that water stress significantly affected the properties of mung bean seedlings. The -8 bar water stress reduced the average seed germination ratio of mung bean (85.89%), root and plumule lengths (2.84 and 3.50 cm), seedling dry weight (0.010 mg), and strength (551.96). The gibberellin concentration of 250 mg L^-1 showed superiority in all traits. The interaction of stress treatments significantly affected the studied traits. The mung bean seed achieved a germination percentage of 100% when exposed to G3 treatment (250 ppm) compared with the treatment PEG-0, giving the lowest mean (93.67%). Therefore, the study concluded that gibberellin could better help in mung bean seed germination under drought conditions and increase the number of seedlings.

Keywords: Mung bean (Vigna radiata L.), PEG 6000, water-stress conditions, gibberellin levels, seed germination, growth traits

Key findings: Water stress significantly affected the seedlings of mung beans (V. radiata L.). The PEG 6000 (-8 Bar) created the water-stress condition considerably, lowering the mung bean seed germination and seedling ratio, root and plumule lengths, seedling dry weight, and strength. However, gibberellin (250 mg L^-1) showed a significant superiority for all the above germination and growth traits in mung beans.

A field experiment transpired during the autumn of 2022 to study the effects of mineral fertilizer combinations and seaweed extract on maize growth and yield traits in Al-Hussainiya, Kerbala, Iraq. The research had a randomized completely block design (RCBD) arranged in split plots with three replications, where the main plots included seaweed extract (Algazone Mx30) with two concentrations (2 and 4 ml L^-1). The subplots included mineral fertilizer formulations of nitrogen (0, 150, and 300 kg ha^-1) and phosphorus fertilizers (0, 50, and 100 kg ha^-1). The maize cultivar ‘Maha’ was the sample used for the experiment. The results showed excellence in treatments, which represents seaweed extract with a concentration of 4 ml L^-1 combined with 150 N + 50 P giving better performance in plant height (188.82 cm), leaves plant^-1 (15.65), leaf area plant^-1 (5548.3 cm²), rows per ear (16.46), grains row^-1 (39.41), grain yield (10.74 t ha^-1), and protein concentration (13.81%) in grains. With the interaction of two study factors, the mineral fertilizer use had a 50% reduction because there was no significant difference between the two doses of NP, i.e., 150 N + 50 P and 300 N + 100 P kg ha^-1, and the seaweed extract (4 ml L^-1).

Keywords: Maize (Zea mays L.), seaweed extract, fertilizer combination, growth and yield-related traits, quality attributes

Key findings: A significant improvement in growth, yield, and quality traits of maize was evident due to the combined use of nitrogen and phosphorus fertilizers with the foliar application of seaweed extract (4 ml L^-1).

The presented study transpired in 2015–2016 in the Wasit Province, Iraq, to investigate the allelopathic impact of two sunflower (Helianthus annuus L.) cultivars, namely, Asgaro and Flamme, on weed suppression. The study found that sunflower cultivars significantly reduced the number and biomass of companion weeds in sunflower fields, with a varying reduction depending on the cultivar genotype. The cultivar Asgaro exhibited the most pronounced allelopathic effects, resulting in a 68.6% reduction in total weed numbers and a 61.0% reduction in weed biomass compared with the control (no sunflower). However, the genotype Flamme had the minimum allelopathic effects. Specifically, genotype Flamme reduced weed population by 24% and weed biomass by 35.4% compared with the control. More analysis revealed that the root exudates of the Asgaro genotype were more efficient in suppressing weeds than the Flamme genotype. Substance analysis demonstrated that the Asgaro genotype had a significantly higher amount (0.403 mg/g) than the Flamme genotype (0.220 mg/g) of specific compounds and phenols. The study found that aggregate phenolic levels increased after 28 days, then declined by the end of the season, with chromogenic tests revealing several allelochemicals in the root exudates.

Keywords: Sunflower (Helianthus annuus L.), cultivars, allelopathic effect, phenolic compounds, weed flora and biomass

Key findings: Sunflower cultivars with allelopathic potential have significantly reduced the total population and biomass of companion weeds in the sunflower fields. However, the extent of reduction varied, depending on the genotype of the sunflower cultivar. This action refers to having different allelochemical compounds affecting weeds.

This study proceeded in the spring of 2022 to assess the efficiency of Metribuzin herbicide alone and combined with some agricultural methods, such as mulching and hoeing, to control potato weeds. The effect of Metribuzin at a rate of 400 g ha^-1 with mulching reduced the total weed density to 19.0 plants m^-2, similar to Metribuzin at a rate of 800 g ha^-1 (16.0 plants m^-2). The efficiency of Metribuzin herbicide at 400 g ha^-1 combined with one or two hoeings reduced the number of weed densities by 19.3 and 10.6 plants m^-2 for one hoeing and two hoeings, respectively. The effect positively manifested in plant heights, the number of leaves, the foliage dry weight, and its reflection on the potato yield weight.

Keywords: Potato (Solanum tuberosum L.), Solanaceae, weed management, Metribuzin, mulching, hoeing, weed population

Key findings: Metribuzin herbicide treatment at a rate of 800 g ha^-1 alone or in combination with mulching or hoeing was effective in controlling weeds. It manifested in the yield and chemical properties of the potato. Integration between mulching or hoeing with 400 g ha^-1 of Metribuzin significantly controlled the weeds and the studied potato traits.

The presented study sought to investigate the response of roselle (Hibiscus sabdariffa L.) plants on the influence of micronutrients nano fertilizer (silicon and zinc), carried out in June 2021 on private orchard fields in the Wasit Province, Iraq. The treatment construction was a perfectly randomized factorial experiment (5 × 5 × 3) in a completely randomized design, done with three replications. The roselle plant received micronutrients spraying with nano fertilizer silicon at concentrations of 0, 3, 6, 9, and 12 ppm and nano zinc with concentrations of 0, 500, 1000, 1500, and 2000 ppm, studying their effects on the plant height (cm), fresh and dry weights (g plant−1), anthocyanin content, total soluble sugars, acidity citric acid, and TFAA of roselle rhizome in yield in single and two-way interactions. The discovery revealed a single application of the previously indicated factors had a considerable influence on the roselle’s development and productivity features, especially at high concentrations. Different outcomes resulted using two-way interactions. The most crucial effect observed was on the total soluble sugars. Based on the results, adding nano silicon and nano zinc to the roselle plant significantly increased all traits, regardless of the vegetable characteristics or chemical content achieved with the highest concentrations using the highest effects, whether alone or with two interactions.

Keywords: Roselle, micronutrients, nano fertilizer, silicon, zinc, total free amino acids

Key findings: In the roselle plants, adding nano silicon and nano zinc and their interactions highly improved all the vegetative and biochemical traits.

The conduct of a field trial on oat (Avena sativa L.) transpired during the crop season of 2020–2021 at the District Seddat Al-Hindiyya, Al-Mahnawiyah region, Babylon Governorate, Iraq. The latest study aimed to evaluate oat cultivars’ response based on their growth and yield under water stress conditions and identify the drought-tolerant genotypes. The experiment in a randomized complete block design (RCBD) had a split-plot arrangement, two factors, and three replications. The main plots included three levels of water stress, i.e., depletion of available water by 50% (D1), 60% (D2), and 70% (D3), while the sub-plots included four oat cultivars, namely, Shefa’a, Oats-11, Gouda, and Carlop. The results showed the control treatment (with 50% depleted available water) proved superior in oat growth and related traits, i.e., plant height, flag leaf area, chlorophyll content, relative water content, panicles m², seeds per panicle, 1000-seed weight, and grain yield with averages, reaching 98.76 cm, 43.78 cm², 48.58 SPAD, 77.24%, 631.5 panicles m^-2, 61.17 grains panicle^-1, 42.94 g, and 16.11 t ha^-1, respectively, compared with the D3 irrigation treatment, with values for above traits showed a significant decline: 93.97 cm, 30.05 cm², 34.47 SPAD, 65.75%, 340.3 panicles m^-2, 46.42 grains panicle^-1, 31.51 g, and 4.54 t ha^-1, respectively. The oat cultivar Shefa’a was considerably superior, leading the majority of growth and yield traits compared with other cultivars. The results confirmed and recommended growing the oat cultivar Shefa’a under dry and semi-arid environments.

Keywords: Oat (Avena sativa L.), cultivars, water stress conditions, drought tolerance, growth and yield traits, physiological parameters

Key findings: The depletion of 50% of available water excelled other water regimes (available water depletion of 60% and 70%) in oat growth and yield-related traits. The oat cultivar Shefa’a also leads in grain yield compared with other cultivars under all the water regimes.