Control and Ecology of Weeds in Continuous Corn Grown Without Tillage

Abstract

Corn (Zea mays L.) was grown continuously without tillage (no-tillage) and with conventional tillage for 7 years to evaluate several herbicides for use in both crop culture systems. The only consistently satisfactory herbicide combinations for the no-tillage corn were 2-chloro-4,6-bis(ethylamino)-s-triazine (simazine) and 1,1′-dimethyl-4,4′bipyridinium ion (paraquat) or 2-chloro-4-(ethylamino)-6-(isopropylamino)-s-triazine (atrazine), simazine, and paraquat. Annual weed population shifted rapidly with different herbicide systems; fall panicum (Panicum dichotomiflorum Michx.) was the major annual weed where triazines were used as the residual herbicide. After several years of corn grown with no-tillage, hempdogbane (Apocynum cannabinum L.) became a significant problem in some plots. Corn yields with no-tillage were equal to yields in tilled areas provided weed control was satisfactory.

A long‐term study of weed flora shifts in different tillage systems

“…As a consequence, non‐tillage cropping systems including only summer crops in fields infested with high densities of D. sanguinalis present a difficult challenge, even with herbicides. The inconsistent behaviour of perennial weeds in this rotation agrees with other findings (Triplett & Lyttle, 1972; Derksen et al ., 1994).…”

“…The weed spectrum could shift rapidly in non‐tillage systems, depending on the weed species present and the herbicides selected (Triplett & Lyttle, 1972). In our study, except for glyphosate applied only in NT plots, herbicide usage was identical in the tillage systems considered and weed shifts can be attributed mainly to the degree of soil disturbance.…”

Evolution of Resistance to Auxinic Herbicides: Historical Perspectives, Mechanisms of Resistance, and Implications for Broadleaf Weed Management in Agronomic Crops

“…The introduction of the triazine herbicides in the 1950s led to the rapid evolution of triazine-resistant weeds and a shift in weed populations to redroot pigweed (Amaranthus retroflexus L.) and fall panicum (Panicum dichotomiflorum Michx. ), which germinate relatively late in the growing season (Triplett and Lytle 1972). Today there are 69 weed biotypes resistant to triazine herbicides (Heap 2011).…”

Potential changes in weed floras associated with reduced‐cultivation Systems for cereal production in temperate regions

“…There are also observations in several countries that perennial species, both monocotyledons and dicotyledons, increase in the absence of cultivation (Peters, 1972;Triplett & Little, 1972;Baeumer & Bakermans, 1973;Bachthaler, 1974;Cussans, 1975;Pollard & Cussans, 1976), Many of these reports refer to an increased incidence of Agropyron repens (L.) Beauv, (Bachthaler, 1974;Cussans, 1975), but other species may also be locally important eg, Arrhenatherum elatius (L.) Beauv, (Ayres, 1977), Cirsium arvense (L.) Scop,, Rumex spp, and Convolvulus spp, (Peters, 1972), Perennial grasses might have provided the greatest threat to the adoption of minimal cultivation systems (Cussans, 1975) but for the timely introduction of the herbicide glyphosate, which appears to have alleviated many of the problems of perennial species (Baird et al, 1971;Tiedau, Nuyker & Baeumer, 1974), While rhizomatous species and other perennials may not be discouraged by the absence of soil disturbance they may remain localised (Cussans, 1966), However, the number of perennating organs such as rhizomes, may increase in an undisturbed situation.…”