Response of Three Citrus Rootstocks to Organic and Biological Fertilizers

Abstract

This study was conducted in a lath house, Dept of Hort. and Landscape, College of Agricultural Engineering Sciences, Univ. During the 2021 growing season, Baghdad will investigate the influence of organic and Biological fertilizers on three Citrus rootstocks' growth and leaf mineral content. The first factor is the addition of liquid organic fertilizers Vit-Org (O) at three levels without addition (O0), soil addition at 10 ml.L-1 (O10) and soil addition at 20 ml.L-1 (O20). The second factor is the addition of nitrogen-fixing bacteria without addition (N1), add 30 ml.Transplant-1 of Azotobacter chroococcum (N2) and add 30 ml.Transplant-1 of Azospirillum brasilemse (N3). The third factor is three citrus rootstocks: sour orange (R1), Rangpur (R2), and C-35 Citrange (R3). Treatments were replicated three times (three transplants in the experimental unit) at split blocks design in an R.C.B.D. The number of transplants used was 243 transplants. The experimental results showed that the addition of Vit-Org liquid organic fertilizer had a significant effect in increasing vegetative growth characteristics and leaves mineral content, as treatment with a concentration of 20 ml.L-1 (O20) was superior to increase in stem diameter of 2.99 mm and increase in leaves nitrogen content of 1.49%, phosphorous was 0.35%. Treatment with a concentration of 10 ml.L-1 (O10) was superior in increased leaves number of 66.27 leaves: transplants-1 and leaf area of 17.70 cm2 . The addition of nitrogen-fixing bacteria, especially the addition of Azospirillum brasilemse (N3), showed significant superiority in most vegetative growth traits; it gave the highest increase in leaves, the number of 65.28 leaves.transplant-1 , highest leaves nitrogen content of 1.56%, phosphorous 0.32%. The addition of these bacteria did not significantly affect the increase in stem diameter and leaf area. Rootstocks varied among themselves in vegetative growth characteristics and leaf minerals content, as Rangpur rootstocks (R2) excelled in increasing the stem diameter of 2.32 mm and the leaves number of 83.90 leaves.transplant-1 . In contrast, sour orange rootstock (R1) was superior in increased leaf area of 21.49 cm2 and leaves phosphors content of 0.30%. In contrast, C-35 rootstock (R3) outperformed in leaves nitrogen content by 1.44%. Twice and triple interactions between the study factors significantly affected all studied vegetative growth traits and leaf mineral content. Keywords: Citrus Rootstocks, Organic, Biological Fertilizers