Effects of polyethylene mulching on buried seeds of Ipomoea coccinea

• Published in: Journal of Weed Science and Technology Vol. 69; no. 4; pp. 127 - 137
• Main Authors: Asami, Hidenori, Ishioka, Gen
• Format: Journal Article
• Language: English; Japanese
• Published: The Weed Science Society of Japan 2024
• Subjects: buried seed; Ipomoea coccinea; polyethylene mulching; soybean
• ISSN: 0372-798X; 1882-4757
• DOI: 10.3719/weed.69.127

In Japan, the uncontrolled growth of morning glory (Ipomoea spp.) in soybean fields has become a severe issue, necessitating an effective control method for buried seeds. We investigated the effects of using a polyethylene mulch sheet cover to reduce buried seeds by heating the soil. Field experiments were conducted in a soybean field in the Hiroshima Prefecture between 2017 and 2019. The mean soil temperature was noted to be higher near the field surface. The average soil temperature (April–October) at 15 cm below the soil surface was the highest on plots covered with clear mulching sheets (24.8–26.2°C), while the plots covered with black mulching sheets were slightly cooler (23.6–23.9°C), followed by uncovered plots (21.4–21.9°C). The relative humidity of the soil surface in the plots covered with mulch sheets was maintained at approximately 30% higher than that of the uncovered plots. Although the cumulative number of seedlings of I. coccinea during the soybean cultivation period was lower in the plots covered with mulch sheets before soybean sowing than in the uncovered plots (72–77% of the uncovered plots), the effect of reducing buried seeds was limited. The heating effect of the mulch sheets was higher in the plots from spring to fall, and the percentage of buried seeds after one soybean cultivation period ranged from 26 to 44%, lower than that of the uncovered plots. Therefore, covering the ground with a mulch sheet effectively reduced the number of buried seeds of I. coccinea and was considered a highly effective treatment, even in a single year.