Foliar application of molybdenum reduces yield loss and pre-harvest sprouting in japonica rice seed subjected to simulated flooding during seed development and maturation

Tejakhod, S., Hammond, J. P. ORCID: https://orcid.org/0000-0002-6241-3551 and Ellis, R. H. ORCID: https://orcid.org/0000-0002-3695-6894 (2018) Foliar application of molybdenum reduces yield loss and pre-harvest sprouting in japonica rice seed subjected to simulated flooding during seed development and maturation. Seed Science and Technology, 46 (1). pp. 175-189. ISSN 0251-0952 doi: 10.15258/sst.2018.46.1.17

Abstract/Summary

Flooding damages rice crops and its incidence is increasing. Foliar spray applications of molybdenum (100, 600 or 3000 mg Mo L-1), abscisic acid (ABA, 50 μM), or deionised water (control) were made to pot-grown plants of the Japonica rice cv. Gleva at flag leaf appearance to determine their effects on seed yield and pre-harvest sprouting after flooding. Plants were submerged , to simulate flooding, for four days from 20 or 30 days after anthesis (DAA). Seed yield per plant, seed weight, and pre-harvest sprouting were determined after harvest at 37 DAA. Seed yield and weight were substantially reduced and pre-harvest sprouting promoted by submergence, with greater sprouting after the later treatment. Prior treatment with molybdenum or ABA reduced pre-harvest sprouting (P < 0.05), and possibly reduced damage to seed yield (0.10 > P > 0.05), compared with deionised water. The molybdenum concentration in both sprouted and non-sprouted seeds harvested at 37 DAA responded positively to molybdenum application rate. Molybdenum application rate had no consistent effect on seed ABA concentration. Foliar application of 100 mg Mo L-1 at 200 L ha-1 provided the most promising mitigation of flood damage, but benefits were minor in the context of seed damage from submergence.