IMPACT OF SOIL MOISTURE AND SOIL DEPTHS ON RESPROUTING ABILITY OF JOHNSON GRASS (Sorghum halepense L.) RHIZOMES

An experiment was conducted in the department of Weed Science during September-December 2013, to study the effect of different levels of soil moisture and soil depths on the resprouting ability of Sorghum halepense L. rhizome fragmentations. The experiment was carried out in pots filled with a mixture of sand, silt and clay. Fresh rhizomes were collected from New Developmental Research Farm, The University of Agriculture Peshawar, cut into pieces each having 3-4 buds/eyes or about the pieces that usually a rotavator cuts during seed bed preparation for the next crop. These pieces were buried in pots (with a diameter 10 inches) into various depths i.e 2, 4 and 6 inches from soil surface. The pots were irrigated with low, medium and high levels of irrigation according to the mentioned plan of work. The basic experiment was replicated three times. Data were collected on days to sprouting, number of sprouts pot^-1, plant height (cm), rhizome weight (g) and number of other weed species. The analysis of the data showed that different moisture level had no significant effect on the resprouting of rhizomes and plant height of Sorghum halepense L. However, various soil depths had a significant effect on the resprouting ability of rhizome and plant developed from that rhizome. Maximum sprouting pot^-1 occurred in 6 inches depth as compared to 2 (0.55) and 4 inches depths (0.66). Days to sprouting in various treatments were different and were less affected by both factors (soil depth and moisture levels). Plant height was significantly affected by various soil depths but different soil moisture did not affect the plant height. Maximum plant height was noted in 6 inches soil depth (31.22 cm) as compared to 4 inches soil depth (8.44 cm), however it was statistically at par with the 2 inches soil depth (13.27 cm). Similarly rhizome weight and germination of other weeds species were neither affected significantly by various moisture levels nor soil depths. The number of broad leaf weeds was significantly affected by soil depth and various moisture levels as compared to grassy weeds. Maximum broad leaf weeds germinated in optimum soil moisture level (1.55) as compared to low (0.88) and high moisture level (1.33). Similarly maximum broad leaf weeds occurred in 2 inches soil depth (1.77) as compared to 4 (0.88) and 6 inches soil depth (1.11). Ten different weed species were recorded from the pots during the experiment. Among them Poa annua, L. Digitaria sangunalis L. Eragrostis sp. Leptochloa were the grassy while Oxallis corniculata L. Portulaca oleracea. L. Trianthema portulacastrum L. Euphorbia hirta L. Medicago denticulata and Ammi visnaga L. were broad leaf weeds.