Impacts of water availability and plant density on morpho-physiological characteristics of fenugreek (Trigonella foenum-graecum)

Saabunud / Received 01.05.2022 ; Aktsepteeritud / Accepted 17.07.2022 ; Avaldatud veebis / Published online 17.07.2022 ; Vastutav autor / Corresponding author: Mojtaba Hassanzadehdelouei ; hassanzadehdluie@gmail.comPlant density and water availability are the most important factors determining the yield of crops and medicinal plants. To investigate the effect of these two factors and their interaction on the yield and morpho-physiological characteristics of fenugreek, an experiment was conducted in the form of split plots based on a randomized complete block design (RCBD) with three replications in 2020. Water availability (favourable conditions, mild stress and severe stress) were placed in main plots and plant densities (22, 44 and 66 plants m2 –1 ) were placed in subplots. The results showed a three-fold increase in plant density under optimal moisture conditions increased grain yield from 998 to 1 380 kg ha–1 and biological yield from 2 600 to 3 259 kg ha–1 , respectively, while in mild and severe water stress, did not affect grain yield and biological yield. In all three moisture conditions, a 3-fold increase in plant density reduced the number of seeds per pod and a 2-fold increase in plant density reduced the number of pods per plant. Although in some crops, the increase in density under water stress conditions can compensate for the decrease in yield, in fenugreek, the increase in density under water stress conditions was not beneficial for the plant. Increasing the density to medium (44 plants m2 –1 ) reduces the source strength and applying high density through sink restriction causes a decrease in yield. On the other hand, moisture limitation by reducing the number of pods per plant, the number of seeds per pod and the number of seeds per plant reduced the size of the sink and the mass of 1 000 seeds, which indicates the strength of the source, was not affected