تأثير الرش بالنتروجين والبوتاسيوم النانوي في تحسين بعض الصفات الفسلجية والكيموحيوية وتحمل نبات الاقحوان (Calendula officinalis L . ) تحت ظروف الاجهاد المائي

Rp-Effect of Foliar Application of Nano-Nitrogen and Potassium in Improving Some Physiological , Biochemical Traits and the Tolerance of .pdf

In order to study the effect of spraying with nano nitrogen and potassium on some physiological and biochemical characteristics of (Calendula officinalis L.) under water stress conditions, a factorial experiment was conducted according to a Completely Randomized Design (CRD) with three replicates in plastic pots at the College of Agriculture/University of Kerbala during the winter agricultural season on (10/1/2023) and the experiment continued until the end of the winter season (4/15/2024). The experiment included three factors (two factors with three concentrations each and one factor with two levels) and three replicates. The first factor was represented by two levels of irrigation water by adding 50% and 100% of the field capacity value, which is symbolized by S1 and S2, respectively. The second factor was represented by foliar spraying with three different concentrations of liquid nano nitrogen fertilizer, namely 0, 2 and 4 ml L-1, symbolized by N0, N1 and N2, respectively. The third factor was represented by foliar spraying with three different concentrations of nano potassium fertilizer, namely 0, 2 and 4 g L-1, symbolized by K0, K1 and K2, respectively. The treatments were randomly distributed to all experimental units, and the experiment included 54 experimental units. The data were statistically analyzed according to the adopted design, and the averages were compared at the probability level (0.05). The experiment included studying some morphological, physiological and biochemical characteristics of the plant leaves, in addition to studying the nature of the active substances of the oil extract in C. officinalis flowers.
The study results showed the following:
1. The level of water stress by adding irrigation water at 50% of the field capacity value significantly decreased most of the phenotypic, physiological and biochemical characteristics of C. officinalis plants, including plant height, number of leaves and flowers, stem and flower diameter, total leaf area, dry weight of the root system, relative water content, chlorophyll, nitrogen, phosphorus and potassium, except for root length, proline, abscisic acid and the activity of catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD) enzymes in leaves, whose average values increased at the level of adding irrigation water at 50% of the field capacity value, while the level of added irrigation water at 100% of the field capacity value gave the highest values, except for root length, proline concentration, abscisic acid and the activity of catalase (CAT), superoxide dismutase (SOD) and peroxidase (POD) enzymes in leaves.
2. A response was obtained in the individual effect of foliar spraying of liquid nano nitrogen fertilizer and nano potassium fertilizer, and the best concentration was 4 ml N L-1 and 4 g K L-1, as this concentration of nano nitrogen and potassium had a significant effect in increasing plant height, number of leaves and flowers, stem and flower diameter, total leaf area, root length, dry weight of the root system, relative water content, chlorophyll, nitrogen, phosphorus and potassium. The values of proline, abscisic acid, and the activity of catalase enzymes (CAT), superoxide dismutase (SOD) and peroxidase (POD) in the leaves decreased at a concentration of (4 ml L-1 and 4 g L-1) compared to the control treatment (0 ml L-1 and 0 g L-1).
3. The bilateral interactions between the three experimental factors (water stress, nano nitrogen and potassium) showed a significant effect on all studied traits of the C. officinalis plant.
4. The triple interaction treatment between water stress and nano nitrogen and potassium achieved significant differences in all studied traits of C. officinalis plants.
5. The study showed that C. officinalis plants that were foliar sprayed with liquid nano nitrogen fertilizer and nano potassium fertilizer at a concentration of (4 ml L-1 and 4 g L-1) respectively and irrigated with irrigation water at a rate of 100% of the field capacity value were the best treatment in increasing most of the studied traits such as plant height, number of leaves and flowers, diameter of stem and flowers, total leaf area, dry weight of the root system, its chlorophyll content, relative water content, and percentage of nitrogen, phosphorus, and potassium.
6. Spraying with nitrogen and potassium nano-fertilizers at a concentration of 4 ml L-1 and 4 g L-1, respectively, improved plant tolerance to water stress.
7. The study showed the presence of some active substances (volatile oils) in flower petals that regulate the plant’s response to water stress (act as antioxidants to resist stress conditions), such as (tau.-Cadinol and Naphthalene, 1,2,3,5,6,8a-hexahydro-4,7- dimethyl-1-(1-methylethyl)-, (1S-cis) and α-Muurolene and γ-Muurolene).