Soil salinity and constantly varying waterlogging stress especially during spring add serious burden to corn production and profitability across North Dakota. Seed germination, seedling emergence and seedling establishments are most critical period when these abiotic stresses have most detrimental effects on corn. Therefore, finding new tools for growers to counter soil salinity and waterlogging stress induced damages specifically at the early developmental stages is essential to improve overall production and profitability. To address this serious abiotic stress induced production challenges of corn, new seed treatment based innovation was advanced in this project.
To improve salinity and waterlogging stress resilience in corn, two different natural bioprocessed elicitors; Gro-Pro-fermented marine peptide extracts from seaweed and fish byproduct (1 mL/L concentration), and bioprocessed soluble chitosan oligosaccharide (COS- 1 g/L concentration) were targeted and compared with control (no seed treatment). Both soil salinity and waterlogging stress experiment were conducted in the greenhouse with 10 commercial corn cultivars Proseed 1689, Proseed 1480 VTZP, Proseed 1382 VTZP, Proseed 1392, Proseed 1280, Legacy L-2937, Dairyland DS-7294, HeftySeed H4402, REA1B820, Renegade Rt-1592. For soil salinity experiment corn plants were grown under three different levels (0-1 ds/M no salinity, 3-4 ds/M medium salinity, 7-8 ds/M Electrical Conductivity high salinity) of soil salinity from one week after germination until harvest. For waterlogging experiment corn plants were exposed to three different soil moisture levels from (1 cm water above the soil level, full saturation, and field capacity) seed germination to maximum 15 days after germination. Several agronomic, physiological and biochemical parameters of corn plants were determined from both salinity and waterlogging stress experiment.
Most corn cultivars investigated in this project were moderately tolerant to soil salinity and waterlogging stress. All corn cultivars were survived under soil salinity level up to 7 ds/M electrical conductivity, however their growth, photosynthetic activity, and cob formations were significantly affected by moderate to high salinity levels (from 3-4 to 7 ds/M EC). For waterlogging experiment, most corn cultivars did not survive and recover after constant exposure to 1 cm water above the soil level for 15 days. Overall, root growth and photosynthetic activity of corn was significantly affected by waterlogging stress (full saturation and 1 cm water above the soil level). Among corn cultivars, Legacy L-2937 and Rea1b820 were found to be more tolerant to soil salinity when compared to Proseed, while Dairlyland DS-7294 and Legacy L-2937 performed better under higher waterlogging stress. Seed treatment with Gro-Pro @1% (amino acid enriched marine peptide) improved fitness and growth of corn plants both under salinity and waterlogging stress. The findings of this study indicated that Gro-Pro @1% can be targeted as seed elicitor treatment to improve soil salinity and waterlogging stress resilience in corn. We are continuing this study and comparing other potential natural bioprocessed elicitors to improve salinity and waterlogging stress resilience in corn and for further wider applications to improve seed vigor, seedling emergence and seedling establishment of corn under constantly varying abiotic stresses.