How irrigation rounds and mother corm size control saffron yield,quality, daughter corms behavior and phosphorus uptake

Abstract

tIn saffron (Crocus sativus L.) production, whether corms or stigma, irrigation management and mothercorms size play a key role in nutrients uptake, daughter corms formation and stigma yield. Herein theeffects of irrigation rounds and mother corm size on daughter corms behavior, phosphorus uptake, stigmayield and quality were evaluated as a two-year field experiment based on a randomized complete blocksdesign arranged in factorial-split with three replicates. In this study, 15 main plots [irrigation rounds atfive levels (no irrigation during growing season, summer irrigation in August, summer irrigation + Octoberirrigation, summer irrigation + October irrigation + November irrigation and summer irrigation + Octoberirrigation + November irrigation + April irrigation) × mother corms’ size at three levels (≤5 g or small-sized, 5.1–10 g or middle-sized and >10 g or large-sized)] and two sub-plots (the first and second year)were considered. From the results, the maximum flower number (101.9 flowers per m2) and dried stigmayield (373.8 mg m−2) were obtained when large-sized (>10 g) mother corms were planted. Irrespectiveof mother corm size, the maximum flower number and dried stigma yield were observed when fourirrigation rounds were performed. Nevertheless, the maximum crocin and picrocrocin content wereobtained under no irrigation conditions. In both years, large-sized daughter corms weight and phosphorusacquisition efficiency increased with increasing mother corms size. Moreover, phosphorus content insaffron parts and phosphorus acquisition efficiency significantly increased with increasing irrigationrounds. Overall, although four irrigation rounds are highly recommended, applying at least two rounds(in summer and before flowering in October) under limited water conditions is unavoidable.