Evaluation of growth-promoting agents on saffron yield and quality

Abstract

Saffron is an important plant whether in the food or medical industry. So, improving stigma quality and quantity is of special importance. To evaluate the effects of chemical/hormone treatment on saffron yield and stigma quality, its corms were treated with Gibberellic acid, 6-Benzylaminopurine, Salicylic acid, and Potassium nitrate. Some floral traits such as flower fresh weight, stigma length, stigma weight, and some quality traits (crocin, picrocrocin, and safranal) and corms’ total sugar and starch content were measured. The results showed significant differences between control and treatments, in a way that in all floral traits, picrocrocin, and safranal, an improvement was observed in treated corms. Also, corm total sugar and starch content were affected by treatments. Correlation analysis showed a positive relationship in some studied traits such as stigma dry weight and stigma length, stigma dry weight and flower fresh weight (r = 0.410) as well as in picrocrocin and safranal. While, a negative correlation was detected in day-to-flowering and flower fresh weight, day-to-flowering, and safranal. Almost all floral traits had a positive correlation with corms’ starch content and a negative correlation with corms' total sugar. Generally, it could be pointed out that earlier flowering was in a positive relationship with quality and quantity traits in this plant. Consequently, exogenous chemical/hormone treatments in appropriate dosage would lead to earlier flowering and improve saffron yield and quality.