Influence of seeds inoculation with PGPR, Gibberellic acid and Seaweed extract on seeds germination and seedling growth of Acacia farnesiana L

Abstract

A factorial experiment was carried out in a randomized complete block design, RCBD, in Sarchnar Nursery of the Directorate of Agriculture in Sulaimani in the Kurdistan Region - Iraq. The experiment was conducted for the period between 4.4.2021 and 4.10.2021 which included three factors that were PGPR, (pseudomonas putida and Bacillus Subtilis) (P0) without inoculating seeds in PGPR, (P1) inoculating seeds in PGPR, GA3 at three concentration (G0) 0 ppm, (G1) 75 ppm and (G3) 150 ppm and foliar application with seaweed extract (Alga 600) (L0) 0 mgL-1, (L1) 1.5 mgL-1, and their interactions. The results showed the superiority of the PGPR (P1) in the traits (germination percentage, plant height, stem diameter, N,P,K percentage, relative chlorophyll in the leaves, fresh and dry weight of the shoot system, dry weight of the root system and Root dry matter) which recorded(68.00%, 177.00cm, 8.05mm, 1.80%, 0.33%, 2.43%, 33.42 SPAD, 164.04gm, 66.84gm, 13.40gm, and19.94) respectively, treatment with GA3 at the concentrate 75ppm (G1) showed its superiority in the characteristics of the (germination percentage, plant height, stem diameter, N,P,K percentage, relative chlorophyll in the leaves, fresh and dry weight of the root system and Root dry matter) were recorded (78.67%, 170.00cm, 13.10mm, 2.32%, 0.38%, 2.67%, 68.84gm, 13.40gm, 19.84) respectively. Whereas, foliar application with seaweed treatment (Alga 600) (L1) excelled in the traits (Germination percentage, plant height, stem diameter, N,P,K percentage, relative chlorophyll in the leaves, fresh and dry weight of the root system and Root dry matter) which were recorded (70.11%, 170.00cm, 9.19mm, 1.34%, 0.35%, 2,45%, 33.99 SPAD, 63.52gm, 12.67gm,19.73)respectively . The triple interaction treatment between PGPR inoculation, 150ppm of GA3 and foliar application with seaweed extract, P1G2L1 was superior in the traits (germination percentage, plant height, stem diameter, N,P,K percentage, relative chlorophyll in the leaves, root dry weight and root dry matter) and the values were recorded ( 96.33%, 204.33 cm, 15.67mm, 2.76%, 0.48%, 2.76%, 52.27 SPAD, 17.81 gm and 28.86) respectively. Whereas, the inoculation with PGPR, Gibberellic acid at 75ppm and without using seaweed extract P1G1LO treatment recorded significant superiority in the traits shoot fresh and dry weight, and it was recorded (233.24 gm and 47.41 gm) respectively.