Foliar Application of Nutrients Improves Saffron (Crocus sativus L.) Flowering

چکیده مقاله

Saffron, a member of Iridaceae, has many medicinal applications and it is well known as preciouses food ingredient. Its oil has more than 150 volatile and aromatic compounds. Saffron yield and quality is influenced by agronomic practice like fertilization. So far the effects of soil application of chemical and organic fertilizers have been studied on saffron growth and flowering, and it has been concluded that saffron responses positively to nutrients availability. However, the influence of foliar nutrition has not been fully investigated and, moreover, the results of previous studies are different or sometimes even contradictory. Therefore, this experiment aimed to evaluate the impact of foliar spraying of nutrients on saffron flowering criteria. The study was carried out during 2016-18 based on a randomized complete block design, with three replications in a two-years-old field, in Sarayan faculty of agriculture, (University of Birjand), Iran. For plant foliar nutrition was used chemical fertilizer, containing 12% N, 8% P2O5, 4% K2O, 2000 ppm Fe, 1000 ppm Zn, 1000 ppm Mn and 500 ppm Cu, provided by ©Dalfard Company. Corm planting was done in October 2016 and nutritional spraying was done two times during March 2018, when field was two-years-old, in order to evaluate its effects on flower yield of the next foreseen fall harvesting time (November 2018). Effects of foliar application of nutrients were significant and positive on reproductive growth parameters of saffron. Nutrient spraying increased number of flower and flower weight by 17 and 8%, respectively, compared to the control. Flower yield (130 and 105 kg ha-1) and dry style one (1.50 vs 1.27 kg ha-1) in plants nutrited foliarly also was higher than non-treated ones. These results are similar to those reported previously by Rezvani- Moghaddam et al. Accordingly to the latter Authors we ascertained the foliar nutrient application is considered as an appropriate strategy for restoring corm growth before the spring dormancy and for increasing its reserves for the next flowering time. Improving replacement corms growth will result in better flowering in the coming flowering season.