Effects of zinc fertilizers on growth and quality of petunia plant under drought stress condition

Drought stress is one of the major abiotic stresses which adversely affect crop productivity and plant growth. A good nutritional status of the  plant could alleviate the adverse effects of drought stress. Zinc dificiency is one one the most predominant mineral dificiency especially in dry and semi-dry regions. Zinc has a critical role in protein metabolism, gene experssion, cell-wall integrity, other micro-nutrient content and carbon metabolism.Hybrid Petunias are garden standbys developed from several South American Petunia species. These sun and heat-loving annuals or tender perennials were among the first ornamentals to be bred for the bedding plant market in the 1950s. Petunia is cultivated in flower beds and pots and requires full sunlight to produce plants and flowers with bright attractive colors. Petunias are as easy to grow as they are pretty. They require ample sun and grow best in rich soil with good drainage. They bloom best with regular fertilization and will continue to flower all seasons.

seedlings grown on media containing 70: 30 garden soil: sand were spraed with diefferent concentrations (0, 5, 25 and 50 MgL-1) of  Nanoparticles and zinc- sulfate. Spraying repeated in two weeks interval on plants after drought stress implementation (50 and 100 percent of field capacity). Morphological and physiological traits were evaluated during the growing period and after final harvest.

results showed that drought stress affected all of the studied traits significantly. Spraying with zinc nanoparticle had significant and positive effects on all morphological and physiological trait except stomatal conductance. Spraying with zinc-sulfate enhanced plant growth, proline accumulation, flower and leaf number. In case of flower number, no significant difference were observed among treatments under drought strss condition, while, under normal condition, plants treated with 25 mg/l of each  compound produced 7 more flowers than control.
 

spraying with zinc nanoparticles was more effective than zinc- sulfate on alleviation of drought stress and consequently on growth and flowering of petunia plants.