High costs of labor, fuel, and machinery; need to conserve moisture; loss of soil from erosion; and desire to double crop are some of the factors considered in the trend towards no‐tillage methods of planting crops. No‐tillage planting of corn in Pensacola bahiagrass (Paspalum notatum Flugge) sod and small grains such as rye (Secale cereale L.) was compared to conventional planting “rotavating, disking, and planting” for 3 years on Lakeland fine sand (Typic Quartzipsamment). When Pensacola bahiagrass was treated with paraquat + residual herbicide before planting corn by the notillage method, it recovered quickly and competed with the corn for water and nutrients. Corn (Zea mays L.) planted no‐tillage had lower yields than when conventionally planted, but after corn harvest the bahiagrass growth was adequate for grazing. Adding extra N to the no‐tillage corn increased yields of both corn and grass. Corn under no‐tillage in rye treated with paraquat + residual herbicides generally yielded about the same as conventionally planted corn. Pensacola bahiagrass when treated with glyphosate in combination with other herbicide was almost all killed and offered little competition to the corn. Forage yield in the fall was only 37% of yield after paraquat‐residual herbicide application. The effectiveness in controlling broadleaf weeds with atrazine, cyanazine, alachor, linuron, and combinations of these herbicides varied seasonally, but had no significant effect on corn yields. Weed growth at corn harvest was considerably less on the no‐tillage plots; however, after 3 years of continuous no‐tillage corn perennial weeds were beginning to appear while few perennial weeds were observed in the conventionally planted corn.

Various chemical and cultural treatments were evaluated for smutgrass [Sporobolus poiretii (R.&S.) Hitchc], control and their effects on pangolagrass (Digitaria decumbens Stent.) and bahiagrass (Paspalum notatum Flügge). Herbicide treatments were dalapon (2,2-dichloropropionic acid) at 1.7, 3.3, and 5.0 kg/ha with Sunoco HE spraying oil at 0, 9.4, 19.0 and 37.0 L/ha. Five weeks after herbicide treatment plots were clipped (clipped vs. nonclipped) and fertilized (0 vs. 112 kg/ha N). Increasing dalapon from 1.7 to 5.0 kg/ha increased smutgrass control and decreased the number of smutgrass plants/plot. Pangolagrass ground cover generally increased with fertilization, as the rate of dalapon increased up to 3.9 kg/ha. Bahiagrass ground cover decreased with rates of dalapon above 1.7 kg/ha. Increasing the rate of oil increased bahiagrass ground cover after 90 days. Nitrogen applied 5 weeks after dalapon treatment and semi-annually for 5 yr generally decreased ground cover of smutgrass and bahiagrass, but increased pangolagrass. Clipping treated smutgrass plants increased pangolagrass and bahiagrass ground cover while decreasing the ground cover of smutgrass.

A survey of Florida highway rights-of-way was conducted during 1984–85 to determine the occurrence and severity of cogongrass infestation. Florida Department of Transportation district maintenance engineers surveyed 8,200 km of limited-access and other major highways (22% of highway system). Cogongrass was distributed widely from the north central region southward through the central Florida ridge north of Lake Okeechobee. Highest frequencies were in counties where cogongrass was used for forage and soil stabilization during the 1950s. The large, widely scattered cogongrass infestations probably were established during extensive roadway construction and routine maintenance which used rhizome-contaminated fill soil.

Ethalfluralin [N-ethyl-n-(2-methyl-2-propenyl)-2,6-dinitro-4-(trifluoromethyl)benzenamine], a recently introduced dinitroaniline herbicide, was tested at two locations in Florida for weed control in peanuts (Arachis hypogaea L.). When applied alone as a preplant incorporated (PPI) treatment at 0.8 and 1.7 kg/ha, and as a preemergence or ground cracking (GC) treatment at 1.1 and 2.2 kg/ha, ethalfluralin provided 85 to 100% control of goosegrass (Eleucine indica (L.) Guerin.), crabgrass (Digitaria ciliaris (Retz.) Koel), and Florida pusley (Richardia scabra L.) without peanut injury. Excellent control of Florida beggarweed (Desmodium tortuosum (SW.) DC.) and smallflower momingglory (Jacquemontia tamnifolia (L.) Griseb.) (100 and 97% respectively) was observed at one location when ehalfluralin was applied at 1.7 kg/ha PPI. Consistent control of both grass and broad-leaf weeds required a combination of ethalfluralin with naptalam (N-1-naphthylphthalamic acid) plus dinoseb (2-sec-butyl-4,6-dinitrophenol) applied at GC. This herbicide program provided weed control comparable to that obtained with the standard GC treatment of alachlor (2-chloro-2′,6′-diethyl-N-(methoxymethyl) acetanilide) plus naptalam + dinoseb.

Field studies were initiated in 1985 and 1986 to evaluate the effects of dalapon, glyphosate, imazapyr, and sulfometuron applications to established cogongrass alone or in combination with either mowing or discing. Mowing and discing treatments were performed 4 mo before and 8 months after the herbicide treatments in the 1985 experiments and 2 months before and 7 months after the herbicide treatment in the 1986 experiments. When applied alone, glyphosate at 3.4 kg ai/ha and imazapyr at 0.8 kg ai/ha caused the greatest reduction in shoot and rhizome biomass about 2 yr after application. However, the rhizome infestation was reduced only 43% by glyphosate and 51% by imazapyr, as compared to the nontreated control. With no herbicide, two mowing or discing were generally more effective than a single mowing or discing treatment. The reduction in shoot and rhizome biomass for two mowing without herbicide was 65 and 38% and for two discing, 73 and 66%, respectively. Acceptable (> 80%) levels of cogongrass control, based on reductions in rhizome biomass occurred only when applications of dalapon, glyphosate, or imazapyr were made in combination with two discing despite the fact that mowing before and after treatment reduced shoot biomass by at least 89%.