Physiology of growth and differentiation of Humaidh (Rumex vesicarius L.)‎

الملخص EN

Humaidh (Rumex vesicarius L.) was grown in three sea- sons (autumn, winter and spring) in Riyadh, Saudi Arabia and growth and differentiation characteristics were studied.

Humaidh showed four developmental stages: juvenile, mature, flowering and fruiting stages.

The plant life span was longest during autumn followed by winter and then spring.

Growth parameters i.e.

leaf area, fresh and dry weight of different plant organs increased significantly with age of the plant to a maxi- mum level during the flowering stage and then decreased with further development during the fruiting stage in the three studied seasons.

Al- though fresh and dry weights of whole plants followed similar trends, they kept their momentum during the fruiting stage.

The above growth parameters showed highest levels during autumn followed by spring and then winter.

Leaf area ratio (LAR) varied with age of plants, but lowest values were recorded in fruiting stages and winter showed highest LAR values as compared to autumn and spring.

Mois- ture content of the plant and its different organs varied with age of the plant and season, lowest values were observed during flowering and fruiting stages.

Relative growth rate (RGR) and net assimilation rate (NAR) values fluctuated with age of plants and season.

Highest RGR and NAR values were observed in juvenile stage and lowest in fruit- ing stage in all the studied seasons.