The Study of the Effect of some Bio-Fertilizers and Municipal Solid Waste Compost Application as Growing Media on some Growth Indices of Zinnia (Zinnia elegans)

Due to the excessive use of chemical fertilizers and also the lack of adequate information on the growth responses of ornamental plants to bio-fertilizers and municipal solid waste compost، this investigation was carried out on Zinnia. Therefore، a field experiment was conducted in complete randomized block design with three replications. Fertilizers included municipal solid waste compost، phosphate biofertilizer Barvar-2، nitroxin biofertilizer (containing Azotobacter spp. and Azospirillum sp.)، municipal solid waste compost+ nitroxin + phosphate Barvar-2، municipal solid waste compost + nitroxin، nitroxin + phosphate Barvar-2، municipal solid waste compost + phosphate Barvar-2 and control (without using any fertilizer). The results showed that the highest content of potassium، phosphorus and sodium ions، and greatest flower diameter and plant height were associated with municipal solid waste compost + phosphate Barvar-2 treatment. The interaction of different fertilizer treatments at different growth stages showed that municipal solid waste compost + phosphate Barvar-2 treatment had the highest and nitroxin + phosphate Barvar-2 treatment the lowest effects on fresh and dry leaf weight، chlorophyll a، b، total chlorophyll and carotenoid contents. Moreover، fertilizers had no significant effects on relative water content (RWC) compared to the control. Overall، it was found that municipal solid waste compost + phosphate Barvar-2 treatment is a suitable growing substrate for Zinnia.