Exploring the Impact of Foliar Application of Potassium Nitrate and Forchlorfenuron on Saffron Flower and Corm Yield

Saffron, a cherished native plant of Iran, holds immense value, and its optimal growth and development hinge on the precise administration of nutrients and growth regulators. However, scant information exists concerning the nutritional attributes and the impacts of external application of growth regulators on its overall performance. This study intends to scrutinize the influence of varying concentrations of forchlorfenuron and potassium nitrate on the attributes of daughter corms as well as the ultimate saffron yield. Through this investigation, a deeper understanding of the relationship between growth regulators, nutrients, and saffron production can be attained, shedding light on the potential avenues for enhancing its cultivation and yield. This experiment was conducted as a factorial based on a randomized complete block design in the research farm of Zanjan University. According to the results, the interaction effect of forchlorfenoren 2.5 and 5 mg.liter-1 and potassium nitrate 500 mg.liter-1 decreased the number of daughter corms. Characteristics such as the weight of daughter corms of more than 7 grams per square meter, corm diameter, number of flowers per square meter, and the amount of safranal, crocin, and picrocrocin showed a significant increase due to the interaction of forchlorfenoren 5 mg.liter-1 and potassium nitrate 1000 mg.liter-1. The highest wet and dry weight of the stigma was 11.49 and 1.15 grams per square meter, respectively, with the treatment of furchlorfenoren at the level of 5 mg.liter-1. Also, the use of potassium nitrate at the level of 1000 mg.liter-1 increased the fresh and dry weight of the stigma by 10.22 and 1.01 grams per square meter, respectively. The maximum stigma length was obtained in treating furchlorfenoren 10 mg.liter-1 and potassium nitrate 250 mg.liter-1. Based on the outcomes derived from foliar application experiments, it is advisable to consider utilizing a concentration of 5 mg.liter-1 for forchlorfenuron and 1000 mg.liter-1 for potassium nitrate during the period extending from March to April. This recommendation holds under the premise that environmental conditions are conducive, encompassing factors such as favorable temperatures for foliar spraying. This practice is particularly relevant to the climatic conditions prevalent in the Zanjan region.