|Pederson G A,|
|Pratt R G,|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 9, 1995
Publication Date: N/A
Interpretive Summary: White clover plants survive summer droughts by survival of stolons. Stolons are stems that grow and root along the ground. These stolons often mold during hot, humid summers in the Southeastern US and die. These molds may be due to disease organisms called fungi. Brown Loam Syn. No. 2 (BLSyn) white clover is able to survive through the summer better than other white clovers. This study looked at how fungi affected white clover stolon survival through the summer drought by comparing white clover treated with a fungicide (chemical that kills fungi) or not treated with a fungicide. The experiment also looked at how Brown Loam Syn. No. 2 stolons survive the summer drought. The results of this study suggest that fungi do reduce white clover stolon survival during summer droughts, and that resistance to these fungi could be one way in which BLSyn stolons survive through the summer better than other white clovers.
Technical Abstract: White clover stands in the Southeastern US survive during summer drought predominantly through stolon persistence. The decay and death of stolons during the hot, humid summer may be partially due to fungal diseases. This study determined the effect of summer fungicide applications on stolon survival of `Regal' and `Louisiana S-1' white clover compared with drought-tolerant Brown Loam Syn. No. 2 germplasm (BLSyn). The three white clover entries were grown at Mississippi State, MS, in three separate 1-yr studies. During summer stolon dormancy, plots of each entry were either sprayed biweekly or not sprayed with benomyl. In two of three years, BLSyn had greater ground cover, stolon density, and relative live stolon length following the summer drought than Louisiana S-1. In all three years, BLSyn had greater relative live stolon length following the summer drought than Regal. Plots treated with benomyl had greater stolon density (in two of three years) stolon growing point density, and relative live stolon length than untreated plots. Benomyl treatment gave less of an increase in relative live stolon length of BLSyn than in the two cultivars. These results suggest that fungal pathogenesis may reduce white clover stolon survival during summer dormancy, and that greater fungal disease resistance could be part of the mechanism of improved summer survival in BLSyn white clover.