Genetic Parameters of Flax Varieties under Concentrations of Potassium Fertilizer

Abstract A factorial field experiment was implemented in the 2023-2024 winter season in the Research Station of Field Crops Department, College of Agriculture, University of Anbar, to detect the influences of three potassium fertilization rates (0, 75, and 150 kg K₂O ha⁻¹) on the growth and yield of four flax cultivars: Sakha 3, Sakha 5, Sakha 6, and Geza. A randomized complete block design (RCBD) with three replications was utilized. The results indicated that Sakha 3 outperformed the other cultivars in the more of the evaluated parameters, while Sakha 5 recorded the highest mean of plant height (100.42 cm). On the other hand, Geza exhibited the highest 1000-seed weight (7.91 g). Applying of potassium at a level of 150 kg ha −¹ was significantly excelled in the plant height (101.32 cm), fruiting branches number (14.65 fruiting branch plant −1 ), and seeds number (9.02 seed capsule −1 ). While the applying of potassium at a level of 75 kg K 2 O ha − ¹ resulted in the highest capsules number (37.72 capsule plant −1 ), weight of one thousand seeds (9.05 g), and yield (1.282 t ha − ¹). Genetic and environmental variances were calculated, along with the genetic and phenotypic variation coefficients, and broad-sense heritability (H²). The 1000-seed weight trait demonstrated the highest genetic variation (GCV = 32.55%), phenotypic variation (PCV = 39.21%), and heritability estimate (H² = 90.11%), suggesting that it is a reliable selection criterion for enhancing flax productivity and yield potential.