Tendai P Chibarabada1 and Gaylord T Murahwa2
1Agronomy Department, Zimbabwe Sugar Association Experiment Station, P. Bag 7006, Chiredzi, Zimbabwe; tchibarabada@zsaes.org.zw
2Midlands State University, Private Bag 9055, Gweru, Zimbabwe
Biostimulants enhance nutrition efficiency, abiotic stress tolerance, and crop quality. The study evaluated biostimulants under saline-sodic conditions to improve yields and help plants tolerate stress. Two saline-sodic study sites in Zimbabwe with pH ranging from 7.14 – 8.34, and sodium adsorption ratio (SAR) ranging from 8 – 15.1 were selected. Varying rates of biostimulants (Cosmocel® product mix and Soilex®) were applied as a foliar spray and soil drench, respectively as per supplier recommendations. Data collected included periodic leaf gas exchange measurements [stomatal conductance (gs), assimilation (A)], growth parameters (tillers and plant height) and yield and ERC% at maturity. Biostimulants improved A and gs by 18-40% relative to the control at one site that had highest SAR. Soilex® significantly increased plant height and plant population at both sites (P<0.05). Despite positive results of A, gs, height and tiller counts, yield was not significantly improved. ERC% was significantly improved (12.98% – 13.66%) by Cosmocel® tank mix (P>0.05). The study is ongoing and will evaluate biostimulants over several crop cycles and different environments. Effects on soil quality parameters over time will also be evaluated.