Levée des graines et croissance des plantules de néré sous différents régimes d’irrigations en pépinière au Bénin

Alimi Tassiki a, b, c, ?, Salami Arouna b, c, Alidou Bakara b, c, Raoul Gaba Yarou a, b, c, Abdou-Azimou Chabi Goura b, c, Michel Batamoussi Hermann a, b, c

Abstract

Commonly  known  as the  African locust  bean,  Parkia  biglobosa (Jack,  R. BR.) is a food species  whose  importance is well recogni zed both  regionally and  internationally. This study, conducted in 2022, evaluates the effects of irrigation regimes and growing  media  aims to determine the optimal conditions for seed germination and the growth of young  Parkia  biglobosa seedlings  in a nursery setting. The  experimental design  used  is a Complete  Randomized Block (CRB) w ith  four  replications. Each  of them consisting of six treatments. Statistical analyses  were  performed using SPSS version  21, and  Tukey's test  was applied with  a significance le vel of 5%. The results  showed that  bi-daily  watering (morning and evening) every other  day under  shade  significantly (P < 0.05)  improved seed germination and seedl ing growth. Under the shade,  the first  seed  germination occurred approximately three  weeks  (20.97  days  ±3.81)  after  sowing,  with  a germination speed  of 29.04  days  ±3.1 and  a germination rate  of

36.81%  ±11.36. The bi-daily  irrigation regime  promoted the  germination of 42.50%  ±6.46 of the  seeds.  Additionally, watering every  two  days  slightly  outperf ormed daily watering across all germination variables studied (latency time,  speed,  duration, and germination rate).  Regarding the  growth  of young  seedlings,  bi-daily  watering every  other  day resulted in better diameter (0.33  cm) and  height  (16.17  cm) growth, while  the  shaded  environment only favored  height  growth  (14.6  cm). Finally,  this experiment showed  that,  unlike  the growth  of young seedlings,  Parkia  biglobosa seeds are less demanding of light for their  germination. Therefore, it is essential to water the pots every morning and evening,  spaced  at least one day apart.