Cotton is one of the world’s most important natural fiber and cash crops. The research carried out studies of plants F₁-F₄ considering the importance of cytogenetic analysis of interspecific hybrids for identifying structural differences between homologous chromosomes of crossed forms and substitution of individual chromosomes or chromosome segments because of introgression of interspecific hybrids in cotton breeding. The article comprised a cytogenetic analysis of introgressive lines obtained through the participation of intergenomic crosses and F₁-F₄ cotton hybrids. The results revealed that in crossed variants of F₁-F₄ hybrid plants, the presence of open bivalents and univalents in PMC (pollen mother cell) showed the absence of complete conjugation in the chromosomes. It could be due to the structural differences between the homologous chromosomes in the crossed forms caused by exchanging chromosomes with alien ones. According to the tetrad analysis, the average value ranged from 95.65% F₁L-158/16 × Sultan to 99.61% F₁L-4747-48/16 × Sultan in F₁ hybrids. Based on the tetrad analysis in 16 combinations, the meiotic index ranged from 96.76 ± 0.34 to 99.54 ± 0.19 in F₂ hybrids and 96.51 ± 0.56 to 99.34 ± 0.30 in F₃ hybrids, and in 17 combinations, the range was from 97.14 ± 0.29 to 98.92 ± 0.12 in F₄ hybrids. It also confirmed that meiosis is preceding naturally in the remaining hybrid variants, with a decrease observed in the meiotic index. The results also increased the number of other types of gametes (Monod, dyad, triad, pentad, hexad, and polyad), negatively affecting normal gametes formation.

Keywords: Upland cotton, G. barbadense L., G. hirsutum L., hybrids, introgressive lines, meiosis, tetrad, sporadic, bivalent, degree of fecundity

Key findings: The cytological analyses of introgressive cotton lines and hybrids confirmed their donor ability to enrich the cotton genome. Results established the stabilization of the meiotic division that raised the meiotic index and pollen fertility. The structural differences between homeologous chromosomes confirm the introgressed fragments of wild forms and valuable traits in the cultivated cotton genomes.

The study aimed to determine the role of workers’ comprehension level in agricultural extension centers through their knowledge of administrative processes when providing agricultural extension services in some central governorates of Iraq, as well as, some of the respondents’ characteristics and the relationship between the studied independent variables. The research area has 220 employees, with a sample of 50% selected in four governorates (Babylon, Anbar, Baghdad, and Salah al-Din) using simple random sampling. A number of agricultural extension workers selected from each of the studied governorates came from outside the research sample as a pretest to express the opinion of the sample members regarding the provision of agricultural extension services to these centers. Their number reached 25 agricultural extension workers. The reliability coefficient was 0.89 degrees, and the respondents provided data in October 2022. The arithmetic mean, standard deviation, percentage, simple and multiple correlation coefficients, and frequency distribution tables helped analyze and interpret the research results. The findings indicated that 44.55% of respondents had no knowledge about extension centers’ instructional, planning, and promotional roles in agricultural extension services. It also appears from the results that there is a weakness in the role of the respondents in the processes studied, namely, planning, coordination, communication, training, and education. The research suggests holding extension meetings to inform extension workers of their role in understanding the administrative processes of agricultural extension centers while providing extension services and the importance of that to them, as well as, training workers in their roles and using their knowledge to understand the administration.

Keywords: Role of workers, agricultural extension centers, administrative operations, extension service

Key findings: In light of the results, 44.79% of the workers surveyed had low knowledge of the role of extension centers. Outcomes revealed the sample members’ low educational role (50%), planning role (46.36%), and a direct and significant association between agricultural extension centers’ extension services and their staff’s unique traits. The results indicated that 49.09% of the sample members do not know the counseling extension center’s coordination role, while 44.80% do not know its training role.

Coniferous woods of uneven age have a natural distribution in Atrush, Iraq, and this study selected 10 random samples from diverse places and densities to understand their stand dynamics, using a 17.9 m radius circular sample. The tree and stand variables and global tree coordinates measurements occurred for each sample. Using different diameters to measure total height determined the phases of tree seedlings. When the diameter was over 10 cm, the trees were over 1.3 m tall. Through analysis, it revealed that the densities of these trees spread in the study site and reached 28181.89 trees that varied widely. The number of tree members at the lower diameter was the highest, fluctuating from sample to sample, indicating variances in natural renewal between study sites. The site is rich in natural regeneration. Samples 2, 8, and 10 showed balance for the quantity of seedlings, juveniles, and trees, indicating stability in tree movement. The obtained results relied on mechanisms of community aggregation using tree spatial distribution data.

Keywords: Turkish pine (Pinus brutia Ten.), stand dynamic, pattern analysis, stand characteristics, diameter and height

Key findings: The study samples also showed diverse clear distribution patterns, mostly declining regularly and randomly while appearing minimally clustered. It was evident that most trees, whether of varieties, diameters, or heights, are in the first or second class, except the eighth, second, and tenth samples, indicating the strength of natural regeneration in the study area.

The recent maize experiment commenced in the 2022 fall crop season at the District Al-Hussainiya, Kerbala, Iraq. The experiment comprised two factors, with the first factor a combination of different levels of nitrogen (0, 150, and 300 kg N ha^-1) with corresponding labels, N₀, N₁, and N₂, respectively, and three levels of potassium (0, 80, and 160 kg K ha^-1) symbolized as K₀, K₁, and K₂, respectively. The second factor was a foliar application of organic nutrients (potassium humate) with two concentrations (1 and 2 g L^-1). The organic nutrient application occupied the main plots, while the inorganic fertilizer combinations were in the subplots. The experiment used the maize cultivar ‘Sumer,’ planted in clay mixed soil in a randomized complete block design (RCBD) with a split-plot arrangement and three replications. The results showed a significant effect of adding fertilizer combinations of nitrogen and potassium and foliar application of the organic nutrient potassium humate (2 g L^-1) individually and in combinations in most growth, yield, and quality-related traits. The combination of inorganic and organic fertilizers also revealed a significant superiority in enhancing the plant height, number of leaves, ear length, grain rows per ear, grains per row, grain yield, and the percent oil and protein in the maize grains. The interaction between the two study factors contributed to reducing the used amount of mineral fertilizer to 50%, as there was no significant difference between the fertilizer combinations of nitrogen and potassium 150 N + 80 K and 300 N + 160 K kg ha^-1 in addition with organic nutrient application at the rate of 2 g L^-1.

Keywords: maize (Zea mays L.), fertilizer combination, nitrogen and potassium, organic nutrient, potassium humate, growth and yield traits

Key findings: A significant improvement in growth, yield, and quality traits of maize resulted from fertilizer combinations of nitrogen and potassium (N₁K₁ and N₂K₂) combined with foliar application of organic nutrients (potassium humate) at the rate of 2 g L^-1.

The experiment transpired during the crop season 2021 using a clay mixture soil. The aim was to study the effects of different concentrations of nitrogen fertilizer and the date of its application on some growth and yield characteristics of peanut (Arachis hypogaea L.) in the College of Sciences, University of Al-Qadisiyah, Al-Diwaniyah, Al-Qādisiyyah, Iraq. Using the randomized complete block design (RCBD) in the arrangement of split plots had three replications. The first factor was on three additional dates: addition at the beginning of the vegetative growth stage, the start of the flowering stage, and when flowering is complete. The second factor included three nitrogen fertilizer concentrations (50, 100, and 150 kg N ha^-0.1). The results showed the following: The concentration of nitrogen fertilizer (50 kg N ha^-0.1) was significantly superior in some vegetative growth characteristics, i.e., the highest plant height (35.51 cm), maximum number of branches (8.31 branches plant^-1), and heaviest dry weight (104.60 g plant^-1). For yield characteristics: The concentration of 50 kg N ha^-0.1 recorded a significant increase in the yield characteristics—the highest average number of pods was 39.21 pods plant^-1, and the 100-seed weight was 50.91 g plant^-1. The 100 and 150 kg N ha^-0.1 treatments gave higher plant height (39.8 and 41.02 cm) and dry weight (120.40 and 124.50 g plant^-1), respectively. On the effect of time of adding, the addition at the beginning of flowering was significantly superior for plant height (37.41 cm), dry weight (114.30 g plant^-1), number of pods per plant (36.40 pods plant^-1), and 100-seed weight (46.61 g), compared with adding during the vegetative growth stage, which showed the lowest values for the studied characteristics. The interactions between nitrogen concentrations and the adding time resulted in a significant effect from the concentration of 50 kg added as the flowering starts on the number of pods and seeds compared with the control treatment.

Keywords: Peanut (A. hypogaea L.), nitrogen fertilizer, fertilizer application timings, growth and yield-related traits

Key findings: Peanut (A. hypogaea L.) is an oil crop containing essential fatty acids, such as, linoleic and oleic acids. Nitrogen fertilizer and the time to add fertilizer are resources to improve plant production and increase the oil percentage. This review presents these resources and ways to apply them to increase growth and productivity of A. hypogaea.

In two different locations — the Badush Dam area and the College of Agriculture and Forestry-University of Mosul, Iraq — a field experiment commenced in the winter of 2021–2022 to investigate how planting distances between lines at 30, 45, and 60 cm affect the growth and productivity characteristics of safflower cultivars (Gilla, Almais, and Urdine). The experiment with a randomized complete block design used two parameters. The outcomes showed significant differences between planting distances in most read-up attributes for both regions. A planting distance of 30 cm gave the most essential impetus for the height of a plant in the Badush Dam region. Moreover, both regions recorded the highest rate for seeds/capitula from a planting distance of 45 cm and the maximum rate for branches/plant, leaf area, 1000-seed weight, seed yield, oil content (%), and oil yield, and capitula/plant only in the college region. In both experimental sites, the varieties substantially impacted every trait under study. The highest values emerged for the Gilla variety for the 1000-seed weight at both sites. The utmost rates showed for the plant height, branches/plant, leaf area, capitula/plant, seeds/capitula, seed yield, and percentage of oil for the Almais variety. Moreover, the oil yield regarding branches/plants in the kidney site, leaf area in the dam site, and seed yield in both sites revealed a significant interaction between the Almais variety and the planting distance of 60 cm.

Keywords: Safflower, planting distances, cultivars

Key findings: Broad distances fared better for the qualities under study due to the influence of planting distances. The study determined that safflower should have a planting distance of 60 cm due to its increased yield productivity, and the Almais variety also showed superiority over the other two kinds.

The existing study held in the Plant Tissue Culture Laboratory, University of Tikrit, Iraq, sought to increase the production of some secondary metabolite compounds in tissue cultures of Chrysanthemum hortorum Hort. cv. ‘Dwarf White.’ Inducing callus by culturing the bases of young leaf explants on the MS medium received supplementation of different concentrations of Benzyl adenine (BA) (0, 1.5, and 2 mg L^-1) and Indole-3-acetic acid (IAA) (0.0, 0.5, and 1.5 mg L^-1). Tyrosine addition at different concentrations (0, 30, 60, and 80 mg L^-1) and sucrose at 30, 60, 80, and 100 g L^-1 concentrations ensued. In addition, fructose and glucose applications at 90.0, 60.0, 30.0, and 120.0 g L^-1 transpired for the callus growth. The combination of 2.0 mg L^-1 BA + 1.5 mg L^-1 IAA gave the highest average fresh and dry weights of callus, reaching 1.8 and 5.72 mg, respectively. The best treatment was 60 g L^-1, which recorded the maximum pyrethrin concentration, amounting to 2.134 μg/ml DW. The treatment of 90 g L^-1 fructose + 60 mg L^-1 tyrosine was more effective in increasing pyrethrin production in the callus, reaching 3.175 μg/ml DW. The treatment of 90 g L^-1 glucose + 60 mg L^-1 tyrosine was recorded with the utmost pyrethrin concentration, reaching 3.346 μg/ml DW. The treatment of 90 g L^-1 glucose + 80 mg L^-1 tyrosine provided 2.826 μg/ml DW of pyrethrin.

Keywords: Chrysanthemum hortorum, secondary metabolites, explants, carbon sources, pyrethrins, tyrosine, callus, in vitro

Key findings: Callus induction by culturing the base of young leaf explants on the MS medium had BA at 0, 1.5, and 2 mg L^-1 and IAA at 0.0, 0.5, and 1.5 mg L^-1 supplementations. The results showed that the combination of BA at a concentration of 2.0 and 1.5 mg L^-1 of IAA gave the highest average fresh and dry weights and the maximum percentage of callus. The above combination served to maintain induced callus. Secondary metabolite compounds gained estimation by the HPLC device.

The presented experiment on faba bean (Vicia faba L.) began in the winter of 2022–2023 at the College of Agriculture, University of Anbar, Anbar, Iraq. The study aimed to determine the effects of foliar application of zinc on the growth and physiological traits of the faba bean genotypes. The experiment had a randomized complete block design (RCBD) with a split-plot arrangement and three replications. The prime plots included three concentrations of zinc, i.e., 0, 30, and 60 mg Zn L^-1, while the subplots comprised three different genotypes (American, Dutch, and Spanish) of faba beans. The results revealed that the faba genotypes significantly displayed their latent potential in growth and physiological parameters. The American faba bean genotype proved superior in plant height (37.52 cm), leaf area (1413 cm² plant^-1), and zinc concentration in leaves (113.30 mg kg^-1 dry matter). However, the Spanish faba bean genotype led to an average leaf chlorophyll content (56.59 SPAD). The zinc foliar application with the highest concentration (60 mg L^-1) provided the least number of days to flowering (60.89 days) and also excelled in obtaining the tallest plants (41.13 cm), branches per plant (3.85), leaf area (1337.6 cm² plant^-1), the chlorophyll content (52.23 SPAD), and the zinc concentration in leaves (116.58 mg kg^-1 dry matter). The interaction of the American faba bean genotype and the highest zinc foliar application (60 mg L^-1) significantly affected the plant height, leaf area, and zinc concentration in leaves. The interaction between the Spanish genotype and zinc concentration (60 mg L^-1) gave the highest average for leaf chlorophyll content, and the interaction of the Dutch genotype with the highest zinc concentration exhibited a shorter period from planting to flowering.

Keywords: Vicia faba L., exotic genotypes, vegetative growth traits, micro-nutrients

Key findings: Zinc foliar application significantly impacted faba bean genotypes for growth and physiological traits. The superiority of the high concentration of zinc (60 mg L^-1) in maturation and physiological features might be due to its positive role in stimulating various physiological processes and improving plant performance. In addition to delaying the leaf senescence by preserving the chlorophyll content, it positively affected the increase in photosynthesis process efficiency.