Effect of Foliar application of K , Fe, Zn and CO2 Enrichment on Growth of sweet orange (Citrus sinensis) Transplants.

Abstract

Influence of different foliar fertilizers and CO2 enrichment on growth characteristics of sweet orange transplants grown under nursery condition was investigated from Septemper 2009 to June 2011 .Three foliar fertilizers namely KNO3 ,Fe-EDDHA and ZnSO4 were used in three concentrations: 0(distilled water was used for spraying the control transplants), 5000 mg K L-1 + 20 mg Fe L-1 +15 mg Zn L-1 and 10000 mg K L-1 + 40 mg Fe L-1 + 30 mg Zn L-1. The transplants also exposed to three CO2 levels , near those of ambient air ( 0.0385 % ) ,( 0.0685 % )and( 0.0985 %.The results demonstrated that the number of leaves, leaf area , number of shoots per transplants, stem diameter,dry weight of shoots and roots, relative chlorophyll content , leaf N content and percentage of carbohydrate in shoots were increased in transplants foliar sprayed with 10000 mg K L-1 + 40 mg Fe L-1 + 30 mg Zn L-1. Elevated CO2 level to(0.0985 %) increased number of leaves and leaf area, number of shoots/ transplants , stem diameter , shoots and roots dry weight and carbohydrate percentage in shoots .Whereas transplants grown under ambient air( 0.0385 % ) contained the highest relative chlorophyll content and N leaf content.