Flooding period influence early growth of Grevillea robusta nursery seedlings

Flooding has become a common occurrence due to climate change leading to prolonged water-logging which suffocates plant rooting, thus reduced growth, yield or total loss. Limited research has been conducted on the same. This study is aimed at investigating the effect of flooding period on the early growth of Grevillea robusta nursery seedlings in Njoro, Kenya. An experiment was set up for 2 months in Egerton University Agroforestry tree nursery using a six months old Grevillea seedlings. Completely randomized block design (RCBD) with 4 treatments replicated 3 times was used. The treatments were: Non-flooding, 2 days flooding, 4 days flooding and 6 days flooding. Data was collected for shoot, foliage and root variables and analyzed using SAS statistical package while means were separated using least significance difference (LSD). Non-flooding recorded the highest performance for all the shoot and foliage variables while the least was 2 days flooding. On the other hand, 6 days flooding was the second in performance for most of the variables especially 3rd internode length (20.2 mm) and fresh shoot biomass (56.4 g) were significantly (P=0.002 and 0.05) higher respectively compared with 2 days flooding (13.5 mm and 46.7 g) respectively. In conclusion, flooding affects the growth of Grevillea seedlings negatively by reducing their growth and this was more pronounced in 2 days flooding. However, for 6 days flooding, the seedlings seem to adjust through development of adaptive strategies in the roots. Further research needs to be conducted on other species and also prolonged flooding period.