Which crop among the following is relatively most tolerant to salinity:
Show Hint
Barley is often used as a reclamation crop in salt-affected areas because of its high salinity tolerance and ability to produce grain under saline conditions.
Step 1: Understanding the Concept:
Salinity tolerance is the ability of a crop to grow and yield in soils with high concentrations of soluble salts.
Saline soils restrict water uptake due to high osmotic pressure and can cause toxic accumulations of sodium and chloride ions inside plant tissues. Step 2: Detailed Explanation:
Crops are classified into sensitive, moderately tolerant, and highly tolerant groups based on their threshold electrical conductivity (\( \text{EC}_e \)) values:
1.Green gram (A): This is a highly salt-sensitive pulse crop.
Its growth and yield are severely restricted even at low salinity levels (\( \text{EC}_e > 2\text{ dS/m} \)).
2.Rice (B): Rice is moderately sensitive to salinity.
While it can tolerate some salinity under flooded conditions due to dilution effects, it is highly sensitive during the seedling and flowering stages.
3.Maize (C): Maize is moderately sensitive to salt stress, with yields declining rapidly when \( \text{EC}_e \) exceeds 4 to 5 dS/m.
4.Barley (*Hordeum vulgare*) (D): Barley is recognized as one of the most salt-tolerant cereal crops.
It can tolerate electrical conductivity levels up to 8 dS/m with minimal yield loss, and can produce reasonable yields even at salinity levels as high as 12 to 16 dS/m.
This high tolerance is due to physiological mechanisms like efficient ion exclusion and vacuolar compartmentalization of sodium. Step 2: Final Answer:
Among the given options, the crop that is most tolerant to salinity is Barley.
