マレイン酸ヒドラジド (コリン塩) による芝生の多年生雑草防除に関する研究

1. We screened out C-MH (MH choline salt) for practical use from four salts of Maleic hydrazide, because it had the highest physiological activities in our many experiments and its herbicidal effctiveness was stable in various conditions.<BR>2. We tested C-MH at 0.5-1.0% for perennial weed control in spring, summer and autumn in the fields.<BR>Many perennials could not sprout next spring from reproductive organ of the underground portion by autumn application of C-MH.<BR>Philadelphia fleabane, Kentucky bluegrass and dandelion etc. were severely damaged by early spring application. Many perennials recieved only a temporary setback by summer application and were recovered gradually. But cutting off or chemical killing of the overground portion of the perennials 1 week after summer application could inhibit the regeneration.<BR>3. In the turfgrass tested, Manilagrass was damaged a little by C-MH application, but its elongation was inhibited for a long term by cutting off after its application. In this case, howtver, a very fine and green turf was formed with an increase in the number of tillers and leaves.Japanese lawngrass was sensitive to C-MH and was moderately damaged by its application. Bentgrass was more sensitive to C-MH and sometimes killed.<BR>4. C-MH reached 0-3 cm of surface soil by rainfall or water supply. C-MH was easily inactivated in soil by soil micro-organism for about 1 week. The decomposition pathways nvolved : MH-N → NH₄⁺-N → NO₃^--N.<BR>5. In autumn, MH was translocated from overground portion to underground portion of perennials in large quantities in about 1 week by C-MH spray application and was not decomposed till next spring, and then inhibited the sprouting.<BR>As above-mentioned, in summer C-MH could not control the perennials, but inhibited the regrowth of the underground portion by cutting off the overground portion after MH application. For this reason, we first assume that in summer MH is considerably decomposed in leaves and stems, and we secondly estimate that MH inhibits cell division in the meristematic regions, but not cell enlargement, as similar phenomena are observed in the inhibition of sucker of tobacco plant.