Effect of some plant extracts on hardwood cuttings of Bottlebrush (Callistemon viminalis)

TL;DR

This study evaluates the effects of various plant extracts on rooting and growth of Callistemon viminalis hardwood cuttings, finding licorice extract at 6 g/L as effective as IBA in promoting rooting.

Contribution

It introduces the use of specific plant extracts, especially licorice, as natural rooting agents for Callistemon viminalis cuttings, comparing their effectiveness to traditional IBA.

Findings

Licorice extract at 6 g/L achieved 86.66% rooting.

Licorice extract's effectiveness was comparable to 3000 ppm IBA.

Certain extracts like cinnamon and fenugreek had low rooting success.

Abstract

The study was conducted at the Collage of Agricultural Engineering Sciences, University of Sulaimani, Kurdistan Region-Iraq so as to investigate response hardwood cuttings of Callistemon viminalis to some plant extracts. The hardwood cuttings were taken on 11 March 2021 and soaked separately in 3 and 6 g/L aqueous extracts of moringa leaf, licorice root, willow shoot, fenugreek seed and cinnamon bark for 1 hour. They were compared to the cuttings dipped in 3000 ppm IBA for 10s and control cuttings which were soaked in distilled water for 1 hour. The experiment laid out in CRD with three replications in a greenhouse, and each replication included six cuttings which planted in a mixture of sand and rice husk medium. The results showed that the highest (86.66%) rooting was achieved in the cuttings treated with 6 g/L licorice extract and they were significantly different with control cuttings (53.33%), but they were not significantly different with 3000 ppm IBA (66.66%). Cinnamon 3g/L and fenugreek 3g/L extracts gave the lowest (6.66% and 33.33%, respectively) rooting and other studied parameters. The cuttings dipped in 3000 ppm IBA gave the highest (18.91) root number and the highest (66.66%) survival cuttings after transplanting. The longest root (15.54 cm) was found in cuttings were treated with 6 g/L moringa extract. The longest (5.83 cm) shoot was observed in treated cuttings with 3 g/L willow extract. The highest chlorophyll a and b (10.08 and 4.62 mg/L, respectively) were observed in cuttings treated with 6 g/L willow extract. Moreover, 3000 ppm IBA gave the highest (20.23%) total carbohydrate and (1.77 mg/g) IAA content along with 6 g/L licorice, moringa and fenugreek extracts, after 30 days from planting of the cuttings. Licorice root extract at 6 g/L fairly improved the measurements similar to 3000 ppm IBA throughout the study.