Hydrochory dispersal of weed diaspores from grain crops (Echinochloa crus-galli, Echinochloa colona y Oryza sativa f. spontanea)

VALVERDE, ARIEL; RAMPOLDI, A. ; RODRIGUEZ, H. ; STRIKER GS; MOLLARD, F. P. O.

Mar del Plata

Congreso; IV Congreso Argentino de Malezas; 2023

ASACIM

In this study, we investigated water dispersal (hydrochory) of weed seeds and the traits contributingto their buoyancy. Diaspores of Echinochloa crus-galli, Echinochloa colona, and Oryza sativa f.spontanea (weedy rice) were collected from agricultural areas in Argentina. Various treatments wereconducted to evaluate diaspore buoyancy, including the removal of appendages, trichomes, andsurface tension. These treatments showed a significant time x treatment interaction (P<0.05). Aftersix days, a decrease in the buoyancy capacity of the studied diaspores was observed. Approximately30-40% of the diaspores with appendages from weedy rice and E. crus-galli still floated after 14 days,while 100% of the appendage-free diaspores sank within just six days. Accessions of E. colonaexhibited variability, with a range of 10% to 60% of diaspores remaining afloat after 14 days. Theresults highlight the importance of surface tension and trichomes in diaspore buoyancy. Thesefindings are relevant for the development of effective weed control strategies, such as adjustingflooding periods and intensity in rice fields and establishing sedimentation basins in drainagechannels, which would help mitigate the spread of unwanted weeds and promote agriculturalproduction.