Influence of Small Grain Crops on Weeds and Ecofallow Corn (Zea mays)

Weed Science ◽  
1995 ◽  
Vol 43 (1) ◽  
pp. 128-133 ◽  
Author(s):  
Gail A. Wicks ◽  
Garold W. Mahnken ◽  
Gordon E. Hanson

Spring small grains were not as competitive with barnyardgrass and witchgrass as winter wheat. Winter wheat grain yields were greater than spring barley or spring wheat in 1986, 1987, and 1988 and oat in 1986 and 1988. Barnyardgrass, stinkgrass, and witchgrass control with glyphosate plus 2,4-D plus atrazine at 0.6 plus 0.8 plus 1.7 kg ha−1was usually less when the herbicides were applied to stubble of spring small grain versus winter wheat due to the advanced weed growth at treatment Barnyardgrass and witchgrass were more difficult to control than stinkgrass, redroot pigweed, tumble pigweed, kochia, and tumble thistle. No-till corn planted into winter wheat stubble had fewer barnyardgrass and witchgrass than corn planted into spring wheat stubble. The addition of metolachlor plus atrazine at 1.7 plus 0.6 kg ha−1eliminated differences among small grain cultivars in weed control in corn. Corn grain yields from winter wheat plots were greater than other small grains in 1989 because of better weed control and more crop residue.

1997 ◽  
Vol 11 (4) ◽  
pp. 748-754
Author(s):  
Gail A. Wicks ◽  
Garold W. Mahnken ◽  
Gordon E. Hanson

Imidazolinone-resistant and -tolerant corn hybrids give growers a new weed control option. Field experiments were conducted in 1993 and 1994 to evaluate imazethapyr for controlling weeds in no-till corn planted into winter wheat stubble in a winter wheat–ecofallow corn rotation. Imidazolinone-tolerant (IT) and imidazolinone-resistant (IR) corn were protected genetically from injury by imazethapyr that was applied preplant, preemergence, or postemergence to ‘Pioneer Brand 3417,’ ‘Pioneer Brand 3417 IR,’ ‘ICI Seeds 8532,’ and ‘ICI Seeds 8532 IT’ hybrids. No difference in corn injury occurred between IR and IT corn. Imazethapyr applied to resistant or tolerant corn hybrids could be used to control weeds in ecofallow corn. Imazethapyr at 35 or 70 g ai/ha controlled triazine-resistant kochia better than the standard herbicide treatment of metolachlor plus cyanazine.


1968 ◽  
Vol 70 (3) ◽  
pp. 323-329 ◽  
Author(s):  
J. K. R. Gasser

SUMMARYSoil samples taken in the autumn after ploughing ryegrass, clover, and ryegrass/clover leys were used to measure the mineral-N (ammonium-N + nitrate-N) in the fresh soil (mineral-Nfresh), the increase in mineral-N on incubating the fresh soils (Δmineral-Nfresh), and the increase in mineral-N on incubating the re-wetted air-dry soils (Δmineral -Nair-dry). Mineral-Nfresh and Δ mineral-Nair-dry were measured on further soil samples taken the following spring. Values of Δmineral-Nair-dry, not only correlated best with grain yields and N uptakes by wheat without fertilizer-N, but also with yield responses and fertilizer-N recovered from fertilizer-N applied to the winter wheat.Treatment of the ley altered measurements on samples taken in the autumn but not those taken the following spring.Soil samples taken in the autumn 1960 from under three-year grass leys were used to measure mineral-Nfresh, Δ mineral-Nfresh and Δ mineral-Nair-dry Spring wheat was grown in 1961 followed by spring barley in 1962. Further soil samples were taken in spring 1962 after cultivations were complete and before the barley was sown or fertilizers applied.A mineral-Nair-dry was the best measurement to use on soils from under grass leys. Values depended on grass species, and were increased by N applied to the ley. Differences had largely disappeared 18 months later. A mineral-Nalr.dry was positively correlated with grain yields of spring wheat grown both with and without fertilizer-N, and with the yield response or the nitrogen recovered from, a dressing of 56 lb N/acre.With fertilizer-N yields of winter wheat after the mixed leys tended to the same maximum value independently ofmineralizable-N in the soil. After grass leys maximum yields of spring wheat given fertilizer-N increased with increasing mineralizable-N in the soil.


Weed Science ◽  
1986 ◽  
Vol 34 (1) ◽  
pp. 110-114 ◽  
Author(s):  
Donald A. Crutchfield ◽  
Gail A. Wicks ◽  
Orvin C. Burnside

Research was conducted to determine the effect of winter wheat (Triticum aestivumL.) straw mulch level on weed control in a winter wheat-ecofallow corn (Zea maysL.)-fallow rotation at North Platte and Sidney, NE, in 1981 and 1982. Wheat straw mulch was established at 0, 1.7, 3.4, 5.1, and 6.8 Mg/ha in stubble fields. After application of 1.5 times the recommended rate at corn planting, metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide] concentration remained higher in unmulched soil than in mulched soil for more than 4 months, due to interception of metolachlor by the mulch. Even though the amount of metolachlor in the soil was reduced by mulch, weed control was not reduced and increased with increasing mulch level. Thus, increasing metolachlor rate was not necessary to maintain adequate weed control in no-till winter wheat stubble since mulch itself provided some measure of weed control.


Weed Science ◽  
1968 ◽  
Vol 16 (2) ◽  
pp. 232-234 ◽  
Author(s):  
K. P. Buchholtz ◽  
R. E. Doersch

Corn (Zea mays L.) plots receiving broadcast spray applications of triazine herbicides without cultivation yielded as much as plots receiving the standard two cultivations for weed control. One cultivation resulted in an average 6% increase in corn grain yield on herbicide treated plots. This yield increase probably was due to improved weed control. Weed growth reduced grain yields an average of 1.23 bu/A for each 100 lb/A of dry weeds. In some experiments, increases in corn yield due to improved weed control by cultivation on plots treated with herbicides were less than increases expected based on weed growth reductions. This disparity may have been due to injury to the corn by cultivation.


1990 ◽  
Vol 4 (3) ◽  
pp. 606-611 ◽  
Author(s):  
Randy L. Anderson

Clomazone is used in the Central Great Plains for weed control during fallow in a winter wheat-fallow rotation. Improved precipitation storage during non-crop periods has stimulated new crop rotations such as winter wheat-corn or proso millet-fallow. The objective of this study was to determine if clomazone applied in the fall after winter wheat harvest would injure succeeding spring-planted crops. Greenhouse studies indicated crop tolerance to clomazone was in the order of safflower > corn > proso millet > barley > winter wheat. Clomazone did not affect grain yields of safflower, corn, or proso millet grown at two field sites with different soil textures (silt loam and sandy loam), nor germination of seed from treated plants of these crops. A no-till production system with clomazone increased grain yields for all crops compared to the conventional system where tillage replaced clomazone for fallow weed control.


1980 ◽  
Vol 95 (3) ◽  
pp. 583-595 ◽  
Author(s):  
A. Penny ◽  
F. V. Widdowson

SUMMARYAn experiment at Rothamsted during 1958–67 measured effects on yield, on K uptake and on soil K of applying all combinations of 38, 75 and 113 kg N and 0, 31 and 62 kg K/ha per cut to grass leys, which were cut and removed. Soil K was depleted most where most N and least K were given. Annual applications of 0, 33 and 66 kg P/ha were also tested; soil P was not depleted. The grass was then ploughed.In 1968, residual effects were measured by spring wheat. In 1969 and in 1970 104 kg/ha of fresh K was applied on half of each plot; potatoes (1969) and spring wheat (1970) valued residual and fresh effects of K.In 1971 potatoes tested 0, 104 and 208 kg/ha of fresh K, cumulatively with the three amounts given to the grass and also extra K (104 kg/ha) on half-plots, cumulatively with that given in 1969 and 1970. In 1972 winter wheat, and in 1974 and 1975 spring barley, measured residues of all treatments previously applied (the site was fallowed in 1973).Finally, in 1976, potatoes tested 0, 156 and 312 kg/ha of fresh K on whole plots, cumulatively with the previous dressings of K, and also 156 kg/ha of extra K on half-plots, again cumulatively. All these test crops were given basal N.Yields and K contents of wheat at ear emergence and yields of wheat grain were largest after grass given 38 kg N and 62 kg K/ha per cut, because here soil K depletion was least. Wheat grain yields benefited consistently from fresh K. K content of the wheat at ear emergence was a good indicator of the need for K, but K content of grain was not, because it was unaltered by K fertilizer. Barley was a poor test crop for K, because yields of grain were little affected by previous treatments.Percentage K in potato leaves (in July in 1969 and 1971, in August in 1976) and yield of tubers were well correlated. Largest yields in 1969, 1971 and 1976 came where the leaves contained 3·43, 3·76 and 2·82% K, respectively, i.e. from soil containing most exchangeable K, plus most fresh K. There was no indication that maximum yields had been obtained, so the largest amounts (kg/ha) of fresh K tested (104 in 1969, 312 in 1971 and 468 in 1976) were insufficient to counteract depletion of soil K by the grass. Because the grass did not deplete soil P, the test crops benefited only little from either residual or fresh P.


2019 ◽  
pp. 25-30
Author(s):  
Valentina Aleksandrovna Fedorova ◽  
Nina Alekseevna Naumova ◽  
Ekaterina Vasylyevna Yachmeneva ◽  
Yulia Pavlovna Tarasenkova

Objects of research were: spring wheat Saratovskaya 70-st, Cardinal, 3 Curenta, Madam, Nil avocet yr7's, Angarida; spring barley Ratnik-st, Medium 135, grace, Vakula, Brassa; spring oats Showjumping-st, Leo, Bulan, Kuranin. As a result of the study of these varieties of spring crops, the most adapted to local soil and climatic conditions samples were identified. The selected samples were distinguished by high biological plasticity, growth and development rates, maximum use of moisture, as well as the ability to form high grain yields.


Plant Disease ◽  
2003 ◽  
Vol 87 (1) ◽  
pp. 51-55 ◽  
Author(s):  
T. C. Paulitz ◽  
J. D. Smith ◽  
K. K. Kidwell

Rhizoctonia oryzae (teleomorph = Waitea circinata) causes sheath spot of rice and root rot of wheat and barley. R. oryzae commonly is isolated from barley, wheat, and pea plants in eastern Washington and Idaho. Eight representative isolates were tested for virulence on spring barley (Hordeum vulgare cv. Baronesse), soft white winter wheat (Triticum aestivum cv. Madsen), and hard red spring wheat (cv. Scarlet) planted in natural soil in the greenhouse and maintained at 16°C. All isolates caused significant reduction of emergence in barley, but only seven of the eight isolates and one of the eight isolates reduced emergence of winter wheat and spring wheat, respectively. All isolates caused significant stunting and reduction in the number of seminal roots, root length, and number of root tips on wheat and barley. Some isolates also reduced the frequency of fine secondary roots, resulting in a reduction of the average root diameter. Spring barley was more susceptible to R. oryzae than winter or spring wheat. The main effects of both cultivar and isolate were significant, and there was a significant isolate-cultivar interaction. R. oryzae isolate 80042 was the most virulent on barley, whereas R. oryzae isolate 801387 was the most virulent on wheat. The two isolates from pea were intermediate in virulence on wheat and barley. When screening germ plasm for potential resistance, isolates exhibiting the maximum virulence for each host should be used.


1991 ◽  
Vol 5 (2) ◽  
pp. 369-375 ◽  
Author(s):  
Gail A. Wicks ◽  
Robert N. Klein

We conducted research to determine if soybeans can be grown successfully in a no-till environment, in the semi-arid areas of the central Great Plains near North Platte, NE. Soybeans planted no-till into winter wheat stubble that was sprayed with glyphosate yielded more than when planted into soil that was rototilled in a winter wheat-soybean-fallow rotation. However, grain yield averaged only 420 kg ha-1during 1975, 1976, and 1977. No-till soybean grown in a winter wheat-grain sorghum-soybean rotation during 1982 through 1985 yielded an average of 1370 kg ha-1. Low yields were associated with lack of precipitation during the fallow period after winter wheat harvest or grain sorghum harvest and during the soybean pod elongation and filling period. Several herbicides gave excellent weed control in soybeans when applied either after wheat harvest, early preplant, or at planting time. None of the herbicides persisted long enough to reduce grain yields of winter wheat planted into the soybean residue. With present production costs these nonirrigated rotations are not economical in the semi-arid region of the central Great Plains of the United States.


1982 ◽  
Vol 74 (3) ◽  
pp. 521-526 ◽  
Author(s):  
Orvin C. Burnside ◽  
Gail A. Wicks

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