Florida beggarweed germination in laboratory experiments was highest between 21 and 38 C and at osmotic potentials above −0.2 MPa, with complete germination inhibition below −0.8 MPa. Patterns of seedling emergence in the field corresponded to timing and size of rainfall events in relation to the time of soil disturbance. Smaller percentage total seasonal emergence was observed following large rainfall events where soil had not been disturbed compared with plots recently disturbed, and soil disturbance not followed by rainfall did not promote major weed flushes.

Peanuts [Arachis hypogaea (L.) ‘Florunner’], infested with sicklepod (Cassia obtusifolia L.) and Florida beggarweed [Desmodium tortuosum (Sw.) DC.] were grown in 20.3-, 40.6-, and 81.2-cm rows on Dothan sandy loam at Headland, Alabama, and on Greenville sandy clay loam at Plains, Georgia. In-row seeding rates were equal, regardless of row width. Peanuts were maintained free of sicklepod and Florida beggarweed for 0, 2, and 5 weeks after emergence or throughout the season. In either the absence or presence of weeds, peanut yields generally increased with decreasing row width. Quality of peanuts was not adversely affected; in fact, desirable attributes such as percent sound mature kernels (SMK's) were sometimes increased as the row width decreased. Weed growth with close rows was much less than with standard 81.2-cm rows. Although yields of peanuts were lower with increasing time of weed competition, the influence of row spacing on competitiveness of the peanut canopy remained relatively constant on both soil types. Generally, weeds from either seeded or natural stands produced equivalent competitive results.

Experiments were conducted during 2000 and 2001 at a total of 13 locations throughout Alabama, Georgia, Florida, North Carolina, and Texas to evaluate efficacy of herbicides at or below the manufacturer's suggested use rate. Herbicide applications included diclosulam and flumioxazin applied PRE alone or followed by imazapic applied early postemergence (EPOST). All possible combinations of diclosulam at 0, 13.5, or 27 g ai/ha and flumioxazin at 0, 53, or 105 g ai/ha applied PRE were included. Imazapic was applied at 35 g ai/ha. Ivyleaf morningglory was controlled more than 87% when imazapic was applied EPOST regardless of PRE herbicide. Pitted morningglory control > 67% was observed with applications of diclosulam (27 g/ha) followed by imazapic, diclosulam (13.5 g/ha) plus flumioxazin (53 g/ha), diclosulam (13.5 g/ha) plus flumioxazin (105 g/ha), and diclosulam (27 g/ha) plus flumioxazin (105 g/ha). Sicklepod was controlled more than 74% with flumioxazin (53 g/ha) followed by imazapic and diclosulam (27 g/ha) plus flumioxazin (105 g/ha) followed by imazapic. Florida beggarweed was controlled more than 84% by all PRE herbicide combinations except flumioxazin (53 g/ha) alone or diclosulam (27 g/ha) alone or with imazapic. Yellow nutsedge was controlled at least 90% with diclosulam at either rate followed by imazapic and by diclosulam plus flumioxazin followed by imazapic regardless of rate. Pod yield was generally higher when herbicides were applied regardless of herbicide combination or rate. Peanut yield was maximized with the lowest rates of flumioxazin or diclosulam PRE followed by imazapic EPOST.