Fungicide seed treatments increase growth of perennial ryegrass

Abstract

Field, laboratory and glasshouse experiments were carried out to measure effects of seed treatments with captan or thiram on growth of perennial ryegrass (Lolium perenne L.). Field-sown captan-or thiram-treated seed gave twice as many seedlings as untreated seed. Spaced plants growing from fungicide-treated seed produced almost 6 times more dry matter 16 weeks after sowing than those from untreated seed. This effect, though diminishing with time, was still apparent more than a year after sowing. Fungicides in sterile agar growth medium were phytotoxic to seedlings at concentrations of 10/~g/ml and greater. Seedlings grown from treated seeds sown from 5 to 15 mm away from developing colonies of the virulent seedling pathogen Fusarium oxysporum Schlecht. were more than 4 times larger than those grown from untreated seeds. Captan-treated seed sown into pots containing field soil produced more and larger seedlings than untreated seed. Methyl bromide fumigation of the same soil also increased both number and size of seedlings. Fungicidal, rather than direct chemical effects, at early stages of seedling growth, account for increased growth of plants from fungicide-treated seed.

Productivity of prairie grass (Bromus willdenowii Kunth) affected by sowing date and the head smut fungus (Ustilago bullata Berk.)

“…These results parallel those obtained from ryegrasses (Falloon, 1980;1987), and reinforce the suggestion of CuIIeton and McCarthy (1983) that prairie grass seedlings growing in cool soils may be more susceptible to soil-borne pathogens than those growing in warmer conditions.…”

“…This study has demonstrated that fungicide seed treatment with thiram can increase numbers of seedlings that establish from prairie grass sowings in autumn. These results parallel those obtained from ryegrasses (Falloon, 1980;1987), and reinforce the suggestion of CuIIeton and McCarthy (1983) that prairie grass seedlings growing in cool soils may be more susceptible to soil-borne pathogens than those growing in warmer conditions. The beneficial effects of thiram seed treatment on prairie grass seedling establishment gave only short-term advantages in herbage production.…”

Seed size and capitulum position drive germination and dormancy responses to projected warming for the threatened dune endemic Cirsium pitcheri (Asteraceae)

“…However, despite surface sterilization with bleach and the use of sterile equipment, fungal growth was a significant problem in our experiment, particularly for seeds from WFD. To control the spread of fungus, we treated Petri dishes with a dilute solution of captan fungicide (3.5 g/L), a tissue culture and seed sterilization treatment (Falloon, 1987; Payamnour et al., 2014).…”