Field Age and Adsorbent Type Effects on Saffron Allelopathy Mitigation and Crop Performance under Replanting Conditions

Alipour, Mahdi; Azizi, Majid; Kaveh, Hamed

doi:10.22034/jmpb.2025.368174.1857

Field Age and Adsorbent Type Effects on Saffron Allelopathy Mitigation and Crop Performance under Replanting Conditions

Articles in Press

Document Type : Research Paper

Authors

¹ Department of Horticultural Sciences, Ferdowsi University of Mashhad, Mashhad, Iran

² Department of Horticultural Sciences, Faculty of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran

³ Department of Plant Production, Faculty of Agriculture and Natural Resources, University of Torbat Heydarieh, Torbat Heydarieh, Iran

10.22034/jmpb.2025.368174.1857

Abstract

Declining saffron yields after 6-7 years of continuous cultivation due to allelopathic effects present a major challenge in saffron production. This study examined how allelochemical adsorbents could mitigate these effects in established saffron fields. The research was conducted during the 2021-2022 growing season in Torbat Heydarieh, Iran, using a split-plot design arranged in randomized complete blocks with three replications. The main plot factor was field age (3 and 7 years), while the subplot factor consisted of two adsorbent materials: activated carbon (at 1% and 3%) and zeolite (at 2% and 4%), each applied using two methods (mixed with soil below corms or throughout soil around corms), plus an untreated control. Results showed distinct treatment responses between field ages. Compared to controls, the 2% zeolite treatment mixed throughout the soil produced the best results in 3-year fields, improving leaf area by 99.9%, while 1% activated carbon under corms worked best in 7-year fields, increasing leaf area by 49.1%. The most striking improvement came from using 3% activated carbon in 7-year fields, which increased flower production by 250% relative to control plots. Biochemical analysis revealed that 3% activated carbon below corms in 3-year fields enhanced crocin content by 29.8% while reducing safranal by 12.7% compared to control treatments. Corm production also improved substantially, with 1% activated carbon in 3-year fields yielding 214.6 corms/m², representing a 62.2% increase over control plots. Principal Component Analysis revealed that vegetative traits and yield parameters explained 82.8% of the variation through the first three components. Our findings demonstrate that strategic adsorbent application effectively counteracts allelopathic effects, offering a practical solution for maintaining saffron productivity in aging fields. This approach could help extend field longevity and support small-scale farmers facing replanting challenges.

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