اثر نوع تیغه کولتیواتور بر جا به‌جایی خاک و عملکرد پنبه بر اساس اولویت بندی انفرادی و گروهی صفات

Background and Objectives:
In addition to weed control, cultivators play an important role in soil disturbance, furrow reshaping, and inter-row cultivation, all of which can influence weed suppression and cotton yield. Selection of an appropriate cultivator blade for cotton protection operations requires simultaneous consideration of its effects on soil physical properties, weed control efficiency, and crop performance. This study aimed to evaluate the effects of three types of cultivator blades on soil movement and weed control and to identify the most suitable blade combination and application timing for cotton production.
Materials and Methods:
A field experiment was conducted using a randomized complete block design (RCBD) with 11 treatments and three replications. The treatments consisted of three cultivator blade types—crescent, sweep, and rolling—applied at two timings (six and eight weeks after planting). Treatments included: crescent cultivator applied once at six weeks (T1); rolling cultivator applied once at six weeks (T2); sweep cultivator applied once at six weeks (T3); crescent at six weeks followed by rolling at eight weeks (T4); crescent at six weeks followed by sweep at eight weeks (T5); rolling at six weeks followed by sweep at eight weeks (T6); crescent applied twice at six and eight weeks (T7); rolling applied twice at six and eight weeks (T8); sweep applied twice at six and eight weeks (T9); full-season weed control (T10); and no weed control (T11).
Within each plot, soil volume disturbed, furrow depth, soil throw toward plants, weed control index, cotton yield, and economic returns were measured. An integrated evaluation of all measured attributes and their relative priorities was performed to identify the optimal treatment using Design-Expert version 7.0 software.
Results:
Among the evaluated cultivator blades, the sweep blade applied at six weeks after planting (T3) resulted in the greatest soil disturbance (1,026 m³ h⁻¹), whereas the rolling blade produced the lowest soil disturbance (630 m³ h⁻¹), likely due to its tooth configuration and soil-scraping mechanism. The highest weed control index (89.64%) was achieved with two applications of the crescent cultivator (T7), which was not significantly different from the crescent–sweep combination applied at six and eight weeks, respectively (T5; 80.79%). The highest cotton yield (1,934 kg ha⁻¹) was also obtained under T7. In contrast, excessive soil disturbance and reduced soil moisture associated with two applications of the sweep cultivator (T9) led to a reduction in cotton yield to 1,478 kg ha⁻¹.
Conclusion:
Effective use of cultivator blades in cotton production requires consideration of their combined effects on soil physical conditions, weed control efficiency, and crop yield. Different blade types modify soil structure and control weeds through distinct mechanical mechanisms. Based on the integrated prioritization of agronomic, technical, and economic indicators, the application of the crescent cultivator at six weeks followed by the sweep cultivator at eight weeks after planting (T5) is recommended as the most suitable cultivation strategy for cotton fields.