Leucaena leucocephala and Prosopis juliflora: A comparative study of their seedlings with better drought adapted features in the time of rainfall pattern shifting L. leucocephala vs. P. juliflora under rainfall shift conditions

Abstract

Leucaena leucocephala (Lam.) de wit, and Prosopis juliflora (Sw) DC, were introduced across the country due to their wide importance and
they are posing threat to native trees and ecosystem because of their wild and invasive nature. Therefore, study of their invasive features
becomes important during the current rainfall shift as India is witnessing a decrease in average rainfall and rainy events but an increase
in downpour events. Our study throws light upon these plants’ invasiveness and rainfall-adapted characteristics. We performed the study
in the Botanical Garden, Banaras Hindu University, Uttar Pradesh, India. The study included two experiments (1) Seed germination under
different treatments- 48% H2SO4 for 40 minutes (T1), Water at 100°C for 10 minutes (T2), one-day water-soaked seed (T3); (2) Seedlings
survival percentage and growth-indices under different watering conditions i.e., 50 mL water per seedling every day (W1), 50 mL water
once in four days (W2), 50 mL water once in ten days (W3). Result of this study revealed that P. juliflora exhibited better germination
speed and percentage in all three treatments (T1, T2, T3) in comparison to the L. leucocephala, while under T1 treatment, both exhibited
best germination. On the 60th day of experiment maximum survival percentage was recorded under W2 water condition but maximum
root length was observed under W3 treatment for L. leucocephala and P. juliflora while maximum stem height was found under W1 and
W2 treatments for L. leucocephala and P. juliflora respectively. These finding would conclude that P. juliflora is more potential invader
in comparison to L. leucocephala as this gave the best result under the drought stress condition W2 and W3 for all the parameters and
study performed. Study also highlight the need of mitigation measures to curb the unlimited growth of P. juliflora under the present
scenario of rainfall shift favouring the invasion of drought tolerating plants.