Pelleting with superabsorbent, chitosan, and phosphorus fertilizer as a new method to improve growth, yield, and physiological attributes of potato mini-tuber

Abstract

Seed pelleting is a technique of covering seeds with adhesive agents to improve seed performance and plant establishment while reducing production costs. To evaluate the responses of potato superelite minitubers to different pelleting treatments both qualitatively and quantitatively, a 2-year experiment was conducted based on randomized complete block design with three replications in Mohaghegh Ardabili University, Ardabil, Iran during 2018 and 2019. Experimental treatments included 17 different combinations of zeolite (ZE) or cocopeat (CO) fillers, coating (SC) or soil application (SS) of triple superphosphate, superabsorbent polymer (SP), and chitosan (CH). The results showed a significant effect of pelleting on yield, physiological, and qualitative traits. The highest fresh and dry tuber weight belonged to SS + ZE treatment, which showed 50.6 and 49.0% increase compared to the control treatment (without pelleting), respectively. Pelleting minitubers by ZE + SS had the highest fresh tuber and biological yield (23.6 and 28.0 ton.ha-1, respectively), which showed an increase of 61.0 and 59.2%, compared to the no pelleting treatment. Most pelleting treatments increased the leaf proline content and activity of the antioxidant enzymes. The highest peroxidase activity and lowest catalase activity (16.1 and 29.6 U.mg protein-1.min, respectively) were observed in the CO+SC+CH treatment. Co-application of ZE, SC, and SP resulted in the highest protein, nitrate, and starch content. In addition, minituber pelleting with ZE+SS+SP increased methionine content significantly by 31.51% compared to the control. In general, the co-application of triple superphosphate, SP, and ZE increased the tuber yield and quality traits. Finally, the use of CH with these compounds resulted in improving physiological characteristics.