Effects of Irrigation Intervals on the Growth and Yield of Flax under Kabul Climate Conditions

Flax (Linum usitatissimum L.) is an important oilseed and fiber crop with significant economic value. Efficient irrigation management is essential for improving crop productivity under the semi-arid conditions of Kabul, where water resources are limited. However, information on the optimum irrigation interval for flax production in this region is scarce.

This field experiment was conducted at the Agricultural Research Farm of the Faculty of Agriculture, Kabul University, during the spring season of 2025.The objective of this study was to evaluate the effect of different irrigation intervals (4, 8, 12, 16, and 20 days) on the growth and yield of flax, Badakhshee variety. The experiment was arranged in a Randomized Complete Block Design (RCBD) with five treatments and three replications across two sites.

Data were recorded on plant height, number of branches per plant, number of pods per plant, number of grains per pod, 1000-grain weight (g) and total yield per hectare. The results showed that irrigation intervals significantly (P ≤ 0.05) affected all measured parameters. The highest plant height (68.67 cm), number of pods per plant (189), and grain yield (1856.67Kg ha⁻¹) were obtained under the 12-day irrigation interval, which increased yield by approximately (27.87%) compared to the 20-day interval. In contrast, the lowest values for most traits were recorded under the 20-day irrigation interval.

These findings indicate that irrigation every 12 days provides optimal moisture conditions for flax growth under Kabul agro-climatic conditions. Therefore, this interval is recommended for maximizing yield while ensuring efficient water use.