Effects of flooding on rooting and sprouting of isolated stem segments and on plant growth of Paspalum distichum L.

Abstract

Summary. Bud sprouting, shoot height, and fresh and dry weights of plants arising from single‐node stem segments of Paspalum distichum L. decreased as the depth of burial in the soil increased. Sprouting, rooting and shoot growth of single‐node segments submerged in 5–15 cm of water were reduced significantly in the dark. Light alleviated this water‐induced reduction in 1‐, 3‐ and 7‐node segments. Submergence actually promoted sprouting of the proximal bud and shoot growth from the distal bud in 3‐node segments, and shoot growth of the first two buds from the distal end in 7‐node segments, Flooding the roots of 3‐week ‐old plants for one month had no effect, but markedly reduced tiller production and dry weights after 2 and 3 months. Treatment at 100% relative humidity promoted new shoot production in 4‐month old plants only if all shoots were decapitated (clipped) but not in plants with 6 shoots left intact. Submergence of the whole plant in water drastically reduced new shoot production regardless of clipping treatment. Effects of flooding varied with its duration. It is concluded that though P. distichum, a wetland perennial weed, survives root flooding and submergence conditions, these conditions do not support maximum growth of the plants.