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Wild mustard is one of the common and troublesome winter weeds of chickpea fields and a great competitor to reduce the chickpea productivity. Plant species (chickpeas cv. Saral and wild mustard) were compared at freezing temperatures (+4 as a control, 0, À4, À8, À12, À16, and À20 C) based on the morphophysiological traits and their recovery ability. Chickpea chlorophyll fluorescence was more sensitive to low temperatures than wild mustard. Chickpea and wild mustard F v 0 /F m 0 (light-adapted maximum efficiency of photosystem II [PSII] photochemistry) decrease 33% and 11% exposed to À16 C, respectively, compared with +4 C. Particularly at lower temperatures, wild mustard electrolyte leakage was smaller than that of chickpea; the temperature drop had a greater impact on the stems than the leaves. Per temperature degree drop from À12 to À20 C, the survival probability decreased by 12.5%.Wild mustard had a greater root dry matter (RDM) compared with chickpea plants.50% dry matter depression temperature (RDMT 50 ) could better distinguish among the species freezing response; wild mustard RDMT 50 was $1 C higher than chickpea.Plant survival and F v 0 /F m 0 correlation suggested the reliability of chlorophyll fluorescence measurements to assay plants freezing tolerance. The important contribution of a more powerful root system to wild mustard survival under adverse circumstances may be suggested by the positive association between plant survival and RDM. Higher tolerance of wild mustard to freezing stress ultimately leads to greater survival, regeneration, continued growth, and geographical distribution. Therefore, the wild mustard invasion will be possible in chickpea fields after freezing stress, especially in the cold climates and high-altitude regions.

Photosynthesis is one of the parameters first affected by freezing stress. So studying the efficiency of photosynthetic parameters could be an effective strategy in screening freezing‐tolerant genotypes. An experiment was conducted to assess freezing temperature effects (0°C, −4°C, −8°C, −12°C, −16°C, −20°C, and −24°C) on two faba bean landraces (Borujerd and Neyshabur). Leaf chlorophyll and carotenoid content were decreased as the temperature declined below 0°C. Net photosynthetic and transpiration rate declined earlier in Neyshabur, whereas a relatively constant trend was observed in Borujerd at temperatures between 0°C and −12°C. A 43% greater Np was recorded in Borujerd than Neyshabur at −12°C. Np recovered by 30% and 36% in Borujerd and Neyshabur, respectively, on Day 14 compared with the second day of the recovery period. Except for Ci, which showed a relatively constant trend, the other parameters showed a decreasing trend till 7 days after freezing stress (DAF). WUEi increased more significantly in Neyshabur than in Borujerd after the seventh day of the recovery period. With a subtle evaluation of the landraces' freezing tolerance, both landraces LT50su and RDMT50 remained up to −10°C and −12.5°C, respectively, indicating faba bean plants (the landraces here) can tolerate freezing stress up to −10°C (by enduring minor damages). The positive relationship between the survival percentage and Np indicated that Np could be a reliable criterion to screen freezing‐tolerant faba beans at early growth stages.

Spray water quality parameters such as hardness, pH, alkalinity, turbidity, and total dissolved solids (TDS) can influence the performance of herbicides. Polyvalent cations found in hard water can reduce the efficacy of post‐emergence herbicides that are weak acids. Various approaches have been proposed to mitigate the negative effects of spray water properties on herbicide performance. Water conditioning adjuvants are designed for overcoming the adverse effects of hard water. One group of adjuvants are nitrogen containing compounds such as ammonium sulfate (AMS). The ability of AMS to overcome hard water antagonism is well‐documented but the positive effect of other ammonium compounds are variable and depend on herbicides and weed species. Other adjuvant groups that can overcome effects of poor spray quality are ethoxylated amine surfactants, organic acids and ethylenediaminetetraacetic acid (EDTA). Water quality is poor in many parts of the world, and accordingly, the study of water property effects on herbicide performance is needed to optimize use, and prevent overuse, of herbicides.