Effect of drought and salicylic acid on vegitive growth and prolin accumulation of two cowpea (vigna unguiculata l.)‎ plants

الملخص EN

Current study was conducted during one growing season from March to July, 2021 in local farm under field conditions via plastic pots, in biology department / faculty of science/ university of Zakho-Kurdistan region of Iraq.

the experiment comprises studying soaking two local cowpea seeds, Iraqi and American cultivar in both 250 ppm of salicylic acid and distal water for four hours separately before planting.

in addition to utilizing foliar spraying of 250 ppm of salicylic acid at three stages, vegetative (4th true leaf stage), starting flowering stage and without spraying as a control treatment.

and the effects of drought in three levels, control with continuous irrigation, three and five days of water deficit at flowering stage, followed by continuous daily irrigation (75% from field capacity) till the harvest date of the experiment.

the results showed that immersion the seeds will promote seed germination percentage, plant length, number of flowers, shoot fresh weight, roots fresh weight, roots length, shoots dry weight, roots dry weight and Proline accumulation.

moreover, the growth reduced as a result of water shortage due to water stress except roots length which were increased.

Proline concentrations increased by rising the period of water withholding from 3 to 5 days compared to continuous irrigated treatment (control).

meanwhile, salicylic acid stimulates the accumulation amount of Proline in stressed plant leaves.

the Iraqi cultivar exceed the American cultivar in: seed germination percentage, plant length, number of flowers, root fresh weight, root length and roots dry weight, while the American cultivar surpasses the Iraqi cultivar in: number of branches, number of leaves, leaves area, shoot fresh weight, shoot dry weight and Proline concentration.