Allelopathic Effect of Neem (Azadirachta indica) Leaf Extracts on Germination and Seedling Growth...

During January-July 2019, at the research laboratory of Agricultural Chemistry, Hajee Mohammad Danesh Science and Technology University, Dinajpur, Bangladesh, aqueous leaves extract of different concentrations of Azadirachta indica or Neem was used to study the impact of their allelopathic effects on the germination and growth of some vegetable crops namely cucumber, chilli, and brinjal. T0=control, T1=3 percent aqueous extracts, T2=6 percent aqueous extracts, T3=9 percent aqueous extracts, and T4=12 percent aqueous extracts of neem were the four treatments. When compared to other concentrations, 12 percent aqueous leaf extracts significantly inhibited the germination of the tested crops. With growing concentrations of leaf extracts, the germination percentage decreased. Cucumber, chilli, and brinjal seed germination percentages were 82.22 percent, 91.11 percent, and 71.11 percent in the control treatment, respectively, while cucumber, chilli, and brinjal seed germination percentages were 55.55 percent, 66.67 percent, and 40 percent in the 12 percent aqueous leaf extract treatment, respectively. Other germination parameters affected by the leaf extracts included germination speed, mean daily germination, peak value, and germination value. At 3%, the longest root and shoot lengths were discovered. Leaf extract concentrations of 6% and 9% were found to be superior to the monitor. Biomass allocation, such as root and shoot dry weight, yielded similar results. The existence of secondary metabolites (allelochemicals) in Azadirachta indica aqueous leaf extract can explain the stimulatory and inhibitory effects, with the inhibitory effect being more pronounced at higher concentrations.

Please see the link - https://www.journalajrib.com/index.php/AJRIB/article/view/30131