Morphological and Physiological Responses of Three Corn Hybrids to Saturated Soil

Abstract

To evaluate the morphological and physiological responses of three corn hybrids to saturated soil conditions, the experiment was conducted at the National Corn and Sorghum Research Center, Pak Chong district, Nakhon Ratchasima province. A split plot in RCBD was used with 3 replications. There were 3 main plots: normal irrigation (7-day interval), saturated soil (SS) at V2 stage (7 days) and SS at V6 (7 days) and 3 sub plots: SW4452, NS3 and CP888new corn hybrids. The experiment was carried out in the dry season 2014 (31 Jan to 5 June), dry season 2015 (11 Feb to 31 May) and late rainy season 2016 (19 Aug to 2 Dec). The results showed that grain yield (GY) did not significantly different between SS. GY of corn under SS at V2 and V6 decreased 17 and 18%, respectively, from control (C, normal irrigation). Corn applied SS at V2 and V6 had greater root number (RN) and percentage of aerenchyma development (%AD) than control. SS treated at V2 stimulated ethylene production significantly greater than control. No adventitious root formed in corn under control plots as was observed in corn under SS at V2 and V6. Corn treated with SS at V2 reduced photosynthesis rate (Pn), LAI, total dry weight (dw) and 100-seed weight (SW). SS at V2 and V6 treatments also reduced ear girth, ear length and seed numbers per ear. For hybrids, NS3 was well-adapted, morphologically and physiologically, to SS conditions. Adjustment was observed since SS was treated at V2 and exhibiting greater RN, %AD, Pn, LAI, green leaf (%), root dw, root partitioning, ear number per plant and 100-SW. NS3 can be a model for SS tolerant varieties development.