Investigating the adaptive behavior of the wild almond (Prunus scoparia Schneider) in the humid climate of the Hyrcanian forests, Iran

Background and objectives: Different plants from different climates are collected according to the objectives of botanical gardens. Climate is one of the important ecological factors that has the greatest impact on the longevity of plants. Changing the location of the plant from a dry to a humid climate may cause stress and change in vegetative behavior. Therefore, the selection of plants for each region should be based on climate knowledge. The objectives of this research included investigating the effect of climate and nutritional treatments on the growth of wild almond (Prunus scoparia Schneider).
Methodology: This research was conducted by two related experimental methods. One of which included investigating the effect of climate on the growth of wild almond in Nowshahr Botanical Garden in Nowshahr county in north of Iran and the other one was the nutritional treatments on the seedlings of the wild almond in the Garden. The investigated factors in the climate effect test included the species of wild almond, environmental indicators and soil. The nutritional treatments were carried out as a completely randomized factorial design in three replications in the nursery section that the test factors were three levels of calcium nitrate as foliar spraying with a concentration of zero (control), 5 and 7.5 mM and two levels of potassium sulfate as foliar spraying with a concentration of zero (control) and 6 mM. The time of conducting this research was from 2017 to 2022. The seeds of the wild almond species were collected from the heights of Ghatour valley from Rahal village to Ghatour district located in Khoy county, Iran with an altitude range of 1492 to 1873 meters above sea level. Some parameters related to soil, plant and climate were evaluated at the same time as the experiment started in Nowshahr and Khoy counties. After the seeds germinated and the seedlings emerged from the soil, nutrition treatments were carried out by spraying potassium sulfate and calcium nitrite.
Results: The results of the experiments showed that Nowshahr's climate had a significant effect on the growth indicators of almond species from temperature, humidity, evaporation, sunny hours and ice days. The highest photosynthesis rate of 2.45 mg/fresh weight and the highest plant transpiration rate of 1.35 mmol/square meter per second were observed in Khoy climate. The lowest root length in Nowshahr Botanical Garden was 63.32 cm with the highest share of leafless branches at 60.98%. Correlation relationships of root length in the soil and the intensity of leaf fall (leafless branches) show a significant positive correlation at the 1% level with the amount of plant transpiration. The results of the test data showed that the use of potassium sulfate compared to the control seedlings, led to an increase in the amount of plant growth and, as a result, expanded the canopy width. In this research, the relationship between calcium absorption and transport in the plant showed that the reduction of calcium in the leaf tissues in the control seedlings decreased the resistance of the plant to maintain the leaves. Calcium foliar application increased the amount of calcium in leaf tissue in almonds. One of the effects of this phenomenon is the increase in the durability of almond seedlings to about 30%.
Conclusion: Foliar treatments of potassium and calcium nutrients, although to some extent increased the durability of almond seedlings during the experiment, but the growth disorders caused by the effect of climatic factors prevailed over the nutritional treatment. Therefore, the seedlings could not successfully adapt to the new environment even with the help of nutritional behavior.