Introduction

Allium ampeloprasum ssp. persicum (Shadegan leek) is an endemic and economically valuable plant in Iran, particularly adapted to the arid and semi-arid conditions of Khuzestan province. Traditional cultivation methods in northern Khuzestan, characterized by wide ridge planting, often result in suboptimal productivity due to low plant density, inefficient water use, and high weed competition. Recent advances in planting patterns and harvest management strategies offer potential for improving yield and resource efficiency (Ojong et al., 2024). However, the interaction between planting patterns and cutting frequency and their combined effects on both vegetative and reproductive production in Shadegan leek remain inadequately studied. This research aimed to investigate these interactions to optimize dual-purpose cultivation strategies for enhanced leaf and seed yield.

Materials and Methods

A two-year field experiment was conducted during the 2019–2021 growing seasons at a research station in northern Khuzestan to evaluate the effects of planting pattern and cutting frequency on crop performance. The study utilized a split-plot design arranged within a randomized complete block framework with three replications. The main plot factor consisted of three distinct planting patterns: irregular manual planting, which served as the conventional control method; two-row ridge cultivation; and four-row ridge cultivation on 75-cm wide ridges. Assigned to the sub-plots were three cutting frequency regimes: 3, 5, and 7 harvests, all applied uniformly until the initial flowering stage. Each experimental unit included four ridges, each four meters long. To ensure data accuracy and minimize edge effects, all measurements were consistently taken from the two central ridges within each plot. Throughout both growing seasons, standardized agronomic practices—including irrigation, weeding, and fertilization—were meticulously maintained across all treatments to isolate the effects of the experimental variables.

A comprehensive set of agronomic and qualitative parameters was measured. These included plant density and height, the flowering rate at key phenological stages, and yield components such as the cumulative fresh leaf yield from all cuttings and the final seed yield at maturity. Seed quality was further assessed by measuring the 1000-seed weight and conducting standardized germination tests to determine seed viability. All collected data were statistically analyzed using SAS software (version 9.4). A combined analysis of variance (ANOVA) for the two-year period was performed after verifying the underlying statistical assumptions. For treatment means where the F-test indicated significant differences, a comparison was conducted using Duncan’s Multiple Range Test at the 5% probability level. This robust experimental and analytical approach was designed to provide reliable insights into the interactions between planting geometry and harvest management for optimizing production.

Results and Discussion

Plant density and survival were significantly influenced by cutting frequency and planting pattern, with four-row cultivation maintaining higher plant stands under frequent harvesting. Plant height remained stable across treatments, suggesting genetic control over this trait. The three-way interaction (year × cutting frequency × planting pattern) significantly influenced cumulative fresh leaf yield. The highest leaf yield (86.83 t ha⁻¹) was achieved in the second year under the combination of 7 cuts and two-row ridge cultivation, while the lowest yield (18.83 t ha⁻¹) was recorded in the first year with 3 cuts and irregular manual planting. The superior performance in the second year underscores the role of perennial adaptation and soil improvement over time (Wekgari et al., 2024). Flowering rate was highest (82.67%) under 5 cuts with four-row cultivation, while 7 cuts suppressed flowering due to resource depletion.

These results highlight a clear trade-off between leaf and seed production (Saini et al., 2022). Frequent cutting (7 cuts) combined with two-row ridge cultivation maximized leaf yield but compromised seed yield and quality. In contrast, moderate cutting (3 cuts) with high-density planting (four-row ridges) optimized seed production and quality.The highest seed yield (224.83 kg ha⁻¹) was obtained with 3 cuts and four-row ridge cultivation, whereas the lowest (44.16 kg ha⁻¹) occurred with 5 cuts and irregular manual planting. Frequent cutting adversely affected seed quality: the 1000-seed weight declined from 2.72 g (3 cuts) to 2.37 g (7 cuts), and the seed viability decreased from 83.5% (3 cuts with two-row cultivation) to 58.8% (7 cuts with four-row cultivation).

Conclusion

The study demonstrates that integrated management of planting patterns and cutting frequency is essential for optimizing Shadegan leek production. For maximal leaf yield, 7 cuts with two-row ridge cultivation is recommended. For high-quality seed production, 3 cuts with four-row ridge cultivation is ideal. These findings provide a scientific basis for developing sustainable cultivation protocols tailored to specific production objectives, thereby enhancing the productivity and economic viability of Shadegan leek farming in the region.