Effects of increasing rainfall gradient on sorghum Leaf Area Index (LAI) at juvenile stage in agroforestry parklands systems in Burkina Faso (West Africa)

Abstract

LAI is defining key factor for sorghum productivity. However, few research investigated how it is affected under different rainfall conditions in agroforestry parklands. This research investigated the effect of an increasing rainfall gradient on sorghum LAI at juvenile stage for recommendations to maintain and/or improve sorghum productivity under climate change. Field experiments were conducted at three climatic zones in parkland systems consisted of an association of Sorghum bicolor (L.) Moench (sorghum) with Vitellaria Paradoxa C. F Gaertn (karité) and Parkia biglobosa (Jacq.) Benth (néré). The LAI was measured using the planimetric method with the ImageJ software. Sorghum LAI was higher in agroforestry parklands under low rainfall. The rainfall level affected differently sorghum LAI according to the associated tree species in agroforestry parklands. Promoting agroforestry with karité and néré trees in association with sorghum under reduced rainfall could contribute to maintain and/or improve sorghum productivity with climate change. Trees pruning could improve sorghum LAI and productivity associated with karité and néré trees in agroforestry parklands under increased rainfall with climate change.