The effect of spraying with gibberellin and the amino acid tecamine max on the growth of grafted Christi thorn seedlings

Abstract:

In this research the effect of the addition of both seaweed extract and GA3 to the vegetative growth characteristics and chemical constituents of grafted Sidr seedlings was studied from 1st October 2024 until 5th December 2025 at the wooden canopy of Samarra University - the Department of Horticulture and Landscape Design/ College of Agriculture. The experiment had two factors with three levels, the first factor was the concentration of seaweed extract with three levels; 0, 4 and 8 ml Lt-1, and the second factor was the concentration of growth regulator GA3 with three levels; 0, 50, and 100 mg Lt-1 were used as foliar sprays to investigate the effects on total vegetative growth. The research utilized the Randomized Complete Block Design (RCBD) with two factors and three replications (3 replications per experimental unit) for a total of 6 replications (2 seedlings/experimental unit). The data was analyzed for differences between mean values using Duncan’s Multiple Range Test at the 5% significance level. The major findings are summarized as follows: Seaweed applications to the foliage at the 8 ml/l level resulted in leaf count, main branch count and secondary branch count of 85.33 cm, 3.82 mm and 84.44 cm respectively (when calculated as average per seedling) and 5.33 main branches per seedling and 9.0 secondary branches per seedling, compared to the control treatment, which exhibited the lowest average values for these variables. The results indicate that using algae extract as a foliar spray creates a substantial variation in the level of chlorophyll, nitrogen, phosphorus, potassium and carbohydrates at T₂, which is the highest level at 8mg/L, with increments of 1.31 for chlorophyll, 0.24 for nitrogen, 1.10 for phosphorous and potassium; the lowest levels of T₀ where 1.18 for chlorophyll, 0.18 nitrogen, and 1.01 phosphorus and potassium were observed. Furthermore, GA3 is a plant growth hormone that has an affirmative affect on growth (e.g., plant height, stem diameter, number of leaves, number of main branches and number of secondary branches), particularly at a concentration of 100 mg/L(s); 91.0 cm, 3.75 mm, 82.0 leaves, 5.0 main branches, and an excess of 2.0 branches are noted as the results of GA3 application. The treatment with seedling-no. 1 recorded the lowest moral quantity of these characteristics compared to treatment 2, which had the highest moral quantity of those characteristics (plant height and stem diameter). Both treatments showed a significant increase in nitrogen levels when gibberellic acid was added to their respective treatments. Maximum levels of nitrogen were observed at the addition of GA2 at 100 mg/liter of GA3. Statistically significant differences existed between treatments when marine algae extract was used in conjunction with gibberellic acid on all the characteristics examined. Both treatments produced significant differences from each other, the treatment with T₂GA100 provided the greatest level of the above characteristics, while T₀ (GA0) provided the lowest level. Statistically significant increases were noted as a result of the combinations between marine algae powder and gibberellic acid on the chemical content of sidr tree leaves. T₂GA2 recorded the greatest amount of total chlorophyll, nitrogen, phosphorus, potassium, and total carbohydrate content. The findings indicated that these values were more ethical than the other coefficients, which demonstrates the efficacy of using combined marine algae and gibberellins for enhancing photosynthesis and metabolic functions of plants through leaf spraying.