Volunteer Wheat Research Articles

Biology of Hessian Fly (Diptera: Cecidomyiidae) in the Southeastern United States: Geographic Variation and Temperature-Dependent Phenology

Population dynamics of the Hessian fly, Mayetiola destructor (Say), were studied in volunteer and sown fields of soft red winter wheat, Triticum aestivum L. em Theil, in the Piedmont region of Georgia and the Coastal Plain regions of Georgia and South Carolina. The Hessian fly estivated during the summer at all locations with the initial emergence occurring about 1September. Eggs, larvae, and puparia, however, were collected in August in some years indicating that limited activity is possible during the summer. The primary difference in Hessian fly phenology between the two regions was the occurrence of a winter brood and second spring brood in the Coastal Plain. Typically, two fall and one spring brood occurred in the Piedmont region, and two fall, one winter, and one to two spring broods occurred in the Coastal Plain region. The 1985-1986 season was substantially warmer than 1986-1987 and 1987-1988, and a third fall brood was observed in both regions with a seasonal total of four and six broods occurring in the Piedmont and Coastal Plain regions, respectively. The first fall brood at all locations and the second fall brood in the Coastal Plain occurred before normal wheat plantings; consequently, these broods developed primarily in volunteer wheat. An average (±SD) of 638 ± 110 centigrade degree-days (DD) accumulated between most broods, but some broods required substantially more degree-days to complete development. The variability in degree-day accumulations indicated that further refinement will be needed before specific management activities can be timed using degree-day calculations. This research demonstrated that volunteer wheat is the primary interim host before wheat is normally planted, and indicated that delayed planting of wheat is of limited utility for controlling the Hessian fly in the southeastern United States.

大豆晩播栽培における収獲ロス麦の雑草化による被害とその防除法

大豆晩播栽培における収獲ロス麦の雑草化による被害とその防除法

CANOLA YIELD AND PROFITABILITY AS INFLUENCED BY VOLUNTEER WHEAT INFESTATIONS

The effects of different densities of volunteer wheat (Triticum aestivum L. ’Neepawa’) on the yield of canola (Brassica campestris L. ’Tobin’ and B. napus L. ’Westar’), and the seed yield of the volunteer wheat were determined in field experiments conducted at Vegreville, Alberta and Scott, Saskatchewan. Hyperbolic models provided a good fit to the data in most instances and indicated that volunteer wheat can severely reduce canola yield. A model pooled over locations and years indicated that volunteer wheat populations as low as one plant m−2 reduced canola yield by approximately 1%. Yield loss predictions from the models were used to determine the economics of volunteer wheat control with herbicides. In some cases, revenue losses due to reduced canola yield could be alleviated when the value of the volunteer wheat was considered.Key words: Volunteer wheat, canola, rectangular hyperbola, multiple regression, economic threshold, volunteer cereals

Survey of Winter Wheat (Triticum aestivum) Stubble Fields Sprayed with Herbicides After Harvest in 1986

A survey of 146 fields was conducted to investigate herbicide performance in winter wheat-producing areas of southwestern Nebraska during August and September of 1986. Only 55% of the fields received an excellent rating for weed control and stubble quality; one third rated as unacceptable. Weed control after wheat harvest was improved by planting ‘Bounty 310’, ‘Siouxland’, ‘Vona’, and ‘Centura’ winter wheat cultivars rather than ‘Mustang’, ‘Hawk’, ‘Pioneer 2656’, and ‘Wings'. Fertilizing winter wheat in the fall, planting wheat at the optimum date, high wheat stem density, using a winter wheat-corn-fallow rotation, not spraying herbicides after wheat harvest on days that it rained or air temperature exceeded 35 C, and spraying weeds when they were small also improved weed control in wheat stubble. Nine months after wheat harvest, fields treated with atrazine before July 16 had more volunteer wheat than fields treated later.

Identification, Distribution and Vector Population Dynamics of Barley Yellow Dwarf Virus in Three Cereal‐Producing Areas of Spain

AbstractELISA‐based surveys during 1985–87 in three major cereal‐growing areas of Spain confirmed the presence of barley yellow dwarf virus (BYDV). Samples of small grain cereals and grasses with and without BYDV‐like symptoms were collected in the central, southwestern, and northeastern Spain. Infections were found in all cereal species sampled and in some grasses. About 37 % of the samples collected in 1985 were infacted with isolates of the PAV serotype. Isolates of the RPV serotype were less common, and were detected only in samples from the central region at El Encin, Madrid. Only a single sample, collected from El Encin in 1987, was unequivocally diagnosed as containing an isolate of the MAV serotype.Aphid vector population dynamics was monitored during fall and winter of 1984–87 in the central region. Rhopalosiphum padi L. appeared to be the most abundant species during fall and winter months, infesting grasses and volunteer wheat. Other species present were Sitobion avenae (F.), Metopolophium dirhodum (Walker) and Rhopalosiphum maidis (Fitch). Both R. padi and S. avenae seem to be anholocyclic in the central region of Spain, and are able to remain and reproduce on wheat volunteers and grasses until the beginning of spring. S, avenae populations increase quickly on wheat volunteers in April, while populations of R. padi remain low. Therefore, spread of S. avenae‐transmitted BYDV types to neighbouring cereal fields seem more likely to occur than spread of other types. Other possible virus reservoirs, such as maize, also need investigation for a better understanding of BYDV epidemiology in the central and other cercal‐growing areas of Spain.

AMMONIUM SULPHATE ENHANCES CONTROL OF ANNUAL GRASS WEEDS IN CANOLA (Brassica campestris) WITH SETHOXYDIM

Field studies were conducted from 1984 to 1986 to determine the ability of ammonium sulphate to enhance the activity of sethoxydim on green foxtail (Setaria viridis (L.) Beauv.), wild oat (Avena fatua L.), volunteer wheat (Triticum aestivum L.) and volunteer barley (Hardeum vulgare L.) in canola (Brassica campestris L.). Considerable variation in control from year to year was observed. However, green foxtail control was 100% with 0.15 kg ha−1 of sethoxydim alone for the entire study. In 1984 and 1985, control of the other grass species was usually improved with the addition of 4.0 kg ha−1 of ammonium sulphate to 0.15 kg ha−1 of sethoxydim. In 1986, all grasses were completely killed. The high degree of weed control observed in 1986 was attributed to high temperatures at application time followed by more moderate temperatures, adequate relative humidity and rainfall which occurred the day of and the day after application. The lower level of control observed in 1985 was attributed to poor growing conditions including less rainfall and high temperatures in the days following application.Key words: Rapeseed, green foxtail, wild oat, volunteer cereals, adjuvants, environment

Postemergence Herbicide Suppression of Wheat, Triticum aestivum, Growing with Alfalfa, Medicago sativa

Two field experiments were conducted in 1984 and 1985 to determine the effects of fluazifop, haloxyfop, and sethoxydim on the suppression of water uptake and competition of wheat to seedling alfalfa. In all cases, suppression of wheat growth and stand led to significant reduction in soil water use. The amounts of conserved soil water significantly correlated with increased numbers of alfalfa plants; the correlation coefficients, respectively, for mid- and late-summer plantings were 0.47 and 0.41 in 1984 and 0.90 and 0.86 in 1985. Conservation of soil water was attributed to growth reduction or cessation of wheat growth by the herbicides and, to some extent, suppression of wheat leaf transpiration. All of the three herbicides would be effective in controlling volunteer wheat in a new alfalfa planting.

Long-Term Effects of No-tillage in a Winter Wheat (Triticum aestivum)-Sorghum (Sorghum bicolor)-Fallow Rotation

This research was conducted near North Platte, NE, over an 18-yr period to determine the feasibility of using herbicides to replace tillage as the weed control method in a winter wheat (Triticum aestivumL.)-sorghum [Sorghum bicolor(L.) Moench.]-fallow rotation. Five tillage treatments [two tillage and three reduced or no-till treatments] were used on the same plots during the duration of this experiment on a Holdrege silt loam (Typic Argiustolls). Herbicides effectively replaced tillage for weed control. The no-till plots treated with atrazine [6-chloro-N-ethyl-N′-(1-methylethyl)-1,3,5-triazine-2,4-diamine] after wheat harvest had higher sorghum and winter wheat yields, higher crop residue remaining on the soil surface, and lower weed yields than tilled plots. The most difficult weeds to control were volunteer wheat and barnyardgrass [Echinochloa crus-galli(L.) Beauv. # ECHCG]. Soil surface pH decreased over time because of increased use of nitrogen. The pH in nontilled plots was significantly lower than in tilled plots due to lack of soil mixing. Exchangeable calcium was the predominant cation leached from the top 5 cm but showed accumulation between the 5- to 12.5-cm depth. Organic matter content showed little change over time.

Effects of Application Variables on Glyphosate Phytotoxicity

Glyphosate [N-(phosphonomethyl)glycine] toxicity to volunteer wheat (Triticum aestivumL.) and large crabgrass [Digitaria sanguinalis(L.) Scop. # DIGSA] was influenced more by carrier volume than application method. Glyphosate phytotoxicity increased when carrier volume was reduced with both application methods. When compared at equal carrier volumes, there was little difference in volunteer wheat or large crabgrass control when glyphosate was applied with a controlled droplet applicator or flat fan nozzles. Volunteer wheat and large crabgrass control with controlled droplet applicators was influenced by application factors. At a given carrier volume, application factors which yielded larger droplets generally resulted in superior vegetation control.

Summer survival of Puccinia striiformis f.sp tritici in Victoria, Australia.

The ability of Puccinia striiforrnis f.sp. tritici to oversummer in the field in Victoria was studied. The pathogen survived on volunteer wheat plants. The only accessory host that could have a role in summer survival appeared to be Hordeurn hystrix.

The role of vesicular–arbuscular mycorrhizal fungi in the growth of Kansas winter wheat

In field experiments, fall-planted hard red winter wheat plants failed to become mycorrhizal until May or June just prior to harvest. No benefit to yield was evident from this late-season colonization, and in-furrow infestation with Glomus mosseae or Glomus epigaeum failed to provide earlier colonization or any increased yield. Neither were these mycorrhizal fungi successful in reducing the soil-borne diseases Cephalosporium stripe and take-all in the field. All eight wheat cultivars tested became mycorrhizal under greenhouse conditions whether nonsterile field soil was amended or not with a vesicular–arbuscular (VAM) fungus. Volunteer wheat plants collected from the field during summer also showed some limited level of colonization. Plants grown at 10 °C failed to be colonized, but plants grown at 25 °C were mycorrhizal after 10 weeks. Therefore, the observed failure of winter wheat in the field to become mycorrhizal until late in the growing season could not be explained by cultivar resistance or insufficient inoculum levels in field soils but may be attributed to low fall soil temperatures which may inhibit spore germination or root colonization. Thus, under field conditions it appears that mycorrhizal fungi have little or no effect on winter wheat in Kansas, but the isolation of cold-tolerant, highly efficient isolates should be pursued.

Control of Winter Annual Grasses in South Central Kansas (1984)

Volunteer wheat and winter annual grasses (Downy Brame, Japanese Brame, and Cheat} are major weeds in winter wheat fields in south central Kansas. Volunteer wheat must be classed as a weed because it presents a wheat-streak mosaic threat to planted wheat. The winter annual grasses have the same life cycle as wheat. Herbicides are not avaUable to control winter annual grasses in growing wheat on sandy soils, so tillage or herbicides not compatible with growing wheat must be used. However, significant control can be obtained by planting (rotating) infested fields to a row crop like grain sorghum with effective tillage before planting. Control of volunteer wheat in continuous wheat, a difficult and weather-related problem, is not covered in this report.

Control of Wheat Streak Mosaic Virus with Vector Resistance in Wheat

Martin, T. J., Harvey, T. L., Bender, C. G., and Seifers, D. L. 1984. Control of wheat streak mosaic virus with vector resistance in wheat. Phytopathology 74:963-964. Resistance to the wheat curl mite (WCM), Eriophyes tulipae, derived KS80H4200 was reduced by 74% compared to WCM-susceptible cultivar from cultivar Salmon wheat, reduced the incidence of wheat streak mosaic Sage in greenhouse seedling tests. Reduced transmission of WSMV to by 58% in naturally infested wheat nurseries in 1979, 1981, and 1982. The WCM-resistant cultivars coupled with WCM control in WCM-resistant transmission of wheat streak mosaic virus (WSMV) to WCM-resistant volunteer wheat should give effective levels of WSM control. Wheat streak mosaic (WSM) is one of the most destructive line was replicated three times, as was the WCM-susceptible parent diseases of wheat ( Triticum aestivum L.) in the Great Plains region. Sage and the WCM-resistant parent Salmon. One of these Estimates of losses caused by wheat streak mosaic virus (WSMV) segregates, KS78H 1054, was identified previously as homozygous in Kansas include 816>X 106 kg in 1974 (9) and 571 X 106 kg in 1981 resistant to WCM and therefore, it was the only Sage/ Salmon (12). Cultural practices recommended to reduce WSM losses are derivative for which WSM incidence had been determined. The planting late and, destruction of volunteer wheat, the major WCM reaction for the remaining lines was unknown. Total oversummering ho'st for WSMV and its vector, the wheat curl mite number of plants in each row was determined by direct count. The (WCM) (Eriophyes tulipae Keifer) (13). These procedures are not number of WSMV-infected plants in each row was recorded in late always effective. In western Kansas many wheat producers do not May. follow either of these recommendations because volunteer wheat In 1981, WSM again occurred in the breeding nurseries at Hays. often is used for winter grazing and planting date usually is dictated The incidence of WSM was determined on four replications of both by the availability of soil moisture rather than WSM control WCM-resistant and -susceptible lines. The WCM-resistant lines considerations. were derived from the cross Sage/ Salmon/ 3/ Larned/ Eagle/ / Sage. Wheat cultivars with reliable WSMV resistance levels are not There were 10 WCM-resistant lines in the 1981 nursery. Data are available. Low levels of resistance exist in several cultivars under presented for KS80H4200 only, because it was representative of all certain conditions (6), but in many years these cultivars are WCM-resistant lines and was used in the 1982 tests. KS80H4200 damaged severely. High-level WSMV resistance was transferred to was released as germ plasm in 1982 by Kansas State University in wheat from two Agropyron species (5,11). Due to genetic linkage cooperation with USDA-ARS (7). All cultivars used in these tests between WSMV resistance and undesirable agronomic are susceptible to mechanical inoculation with WSMV (6).

Effect of No-till Systems on Weed Control and Yields of Continuous Winter Wheat (Triticum aestivum)

Experiments were conducted from 1979 to 1982 to determine whether selected herbicide treatments applied before or after harvest would provide adequate weed control without the use of tillage between crops in continuous winter wheat (Triticum aestivumL.) production systems. of the herbicide treatments evaluated, only oryzalin (3,5-dinitro-N4,N4-dipropylsulfanilamide) at 2.2 kg ai/ha applied prior to wheat maturity adequately controlled summer annual weeds each year. Populations of yellow nutsedge (Cyperus esculentusL. # CYPES) and/or clammy groundcherry (Physalis heterophyllaNees) increased from continued preharvest use of oryzalin in no-till treatments and were greater than those resulting from conventional tillage or various postharvest no-till treatments containing glyphosate [N-(phosphonomethyl)glycine]. After 4 yr, populations of winter annualCruciferaespp. at one location were lower in treatments that had poorer control of summer annual weeds or volunteer wheat. At a second location, winter annual broadleaf species were more numerous in conventionally tilled than in no-till treatments. Wheat yields obtained with no-till treatments were lower than yields obtained with conventional tillage in seasons favorable for high yields.

Fallow Systems for Winter Wheat in Western Nebraska1

AbstractThe need for conservation of soil and water and the energy situation makes it imperative to develop more efficient fallow systems for controlling weeds, to utilize moisture efficiently, and maximize wheat production under limited rainfall.Research was conducted at North Platte and Sidney, Nebr. from 1972 through 1977 to develop a weed control program in a limited and no‐tillage winter wheat (Triticum aestivum L.)‐fallow rotation. The experimental areas in fallow were sprayed with glyphosate [N‐(phosphonomethyl)glycine] at 0.8 kg/ha after harvest to eliminate soil water loss from existing weeds in wheat stubble. Six tillage and/or herbicide treatments were applied to separate replicated plots the first few days of August, October, and April.Atrazine [2‐chloro‐4‐(ethylamino)‐6‐(isopropylamino)‐s‐triazine] + glyphosate at 0.8 + 0.8 kg/ha at Sidney and 1.3 + 0.8 kg/ha at North Platte was the most effective fallow weed control treatment but allowed too much weed growth 65 and 77 Mg/ha, respectively. Downy brome (Bromus tectorum L.) control at North Platte was unsatisfactory with August application of atrazine which left 40 plants/m2. Russian thistle (Salsola kali L. var. tenuifolia Tausch) and volunteer winter wheat were not always controlled in April by herbicides that were applied in August or October. The earlier the herbicides were applied during the fallow period the sooner subsequently emerging weeds appeared the following spring. Tillage reduced wheat residues 42% at Sidney and 78% at North Platte when compared to the no‐tillage plots. April tillage at North Platte had less weed growth because August and October tillage planted volunteer wheat and downy brome. Plots treated with residual herbicides stored 24 and 21% more soil water at Sidney and North Platte than tillage treatments. Wheat yields were increased 11% on no‐till plots only at North Platte when compared to tillage. Grain yields were not significantly different when comparing time of initial fallow treatments.

Grain Yields, Soil Water Storage, and Weed Growth in a Winter Wheat‐Corn‐Fallow Rotation1

AbstractThis research involves factors affecting crop production in a no‐till crop rotation of winter wheat (Triticum aestivum L.)−corn (Zea mays L.)−fallow. Experiments were conducted in the field at North Platte, Nebr. during 1974 to 1977 on a Holdrege silt loam (fine−silty, mixed, mesic Typic Argiustolls) to determine the effect of weed control in growing winter wheat and stubble after harvest on annual weed growth, soil water storage, and winter wheat and corn yields. Winter wheat was an excellent competitor to weeds. Winter wheat allowed to grow until harvest (10 July) reduced weed weight taken 7 weeks after harvest (1 September) 56% as compared with plots where winter wheat and weeds were removed on 22 May. Weed competition reduced winter wheat yields by 15% in 1975 but not in 1976 when weeds succumbed to drought and competition from winter wheat. Glyphosate [N−(phosphonomethyl)glycine] applied after winter wheat harvest did not immediately kill weeds which resulted in unnecessary soil water loss when compared to plots receiving tillage. Volunteer wheat and weeds emerged after an application of glyphosate or one tillage after harvest. A residual herbicide should be applied to prevent these weeds from using soil water. Weeds in plots that were allowed to produce viable seed in the winter wheat or in the stubble after harvest significantly reduced weed control in corn planted the following spring as compared with plots in which weeds were not allowed to produce viable seed. Escaped weeds that produce seed during any period of a crop rotation will provide competition to subsequent crops. Standing stubble trapped snow which increased corn yields as compared to plots where tillage had knocked stubble down. Removal of winter wheat stubble after corn planting caused less brace root penetration, more lodging. and reduced corn yields 15% as compared to plots where stubble was left undisturbed.

Control of Volunteer Wheat (Triticum aestivum) in Fall-Planted Perennial Ryegrass (Lolium perennne) with Ethofumesate

Ethofumesate [(±)-2-ethoxy-2,3-dihydro-3,3-dimethyl-5-benzofuranyl methanesulfonate] was evaluated in field experiments at rates from 0.6 to 4.5 kg/ha for control of volunteer wheat (Triticum aestivumL. ‘Hyslop’, ‘Stephens’) in fall-planted perennial ryegrass (Lolium perenneL. ‘Cropper’, ‘Pelo’, ‘Pennfine’, ‘Omega’). Ethofumesate applied at 1.7 kg/ha or more in mid-November to wheat in the one-to three-leaf stage eliminated the wheat. Wheat was not eliminated when ethofumesate was applied preemergence soon after planting or when applied at the end of November to wheat in the four-leaf to four-tiller stage. In four experiments in which wheat was present, ethofumesate significantly increased perennial ryegrass seed production. In one experiment in which wheat was not present, ethofumesate did not affect perennial ryegrass seed production. Ethofumesate applied in the fall at rates to 4.5 kg/ha to newly-seeded perennial ryegrass or to well-established bentgrass (Agrostis tenuisSibth. ‘Highland’), Kentucky bluegrass (Poa pratensisL. ‘Newport’), and Italian ryegrass (Lolium multiflorumLam.) did not adversely affect germination of the following seed crop.

Herbicide Applications in Tillered Winter Wheat for Doublecrop Soybean Weed Control1

AbstractEffective, doublecrop soybean [Glycine max (L.) Merr.] weed control usually requires a foliar‐active herbicide to control emerged weeds and one or two residual herbicides to control those that emerge after planting. This combination is expensive in relation to the narrow profit margin frequently experienced. If timely rainfall does not occur shortly after application, poor weed control may occur, resulting in reduced soybean yields. Field studies were conducted on a Weir silt loam (fine, montmorillinic, mesic Typic Ochraqualfs) to evaluate alternative methods of herbicidal weed control in doublecrop soybeans.Oryzalin (3,5‐dinitro‐N4, N4‐dipropylsulfanilamide) and USB 3153 (N3,N3‐di‐N‐propyl‐2,4‐dinitro‐6‐trifluoromethyl‐M‐phenylenediamine) applied after the winter wheat (Triticum aestivum L.) was fully tillered but prior to the jointing stage (full‐tiller) did not cause any visual injury or yield reduction any of the 3 years of the study. Oryzalin at 2.8 kg/ha in 1976 and at 1.68 kg/ha in 1977 and 1978 controlled at least 85% of all weeds and volunteer wheat in the doublecrop soybeans that followed the wheat harvest. USB 3153 applied at 1.12 kg/ha in 1977 controlled more than 85% of the large crabgrass [Digitaria sanguinalis (L.) Scop.], ivyleaf morningglory (Ipomoea hederacea), and Pennsylvania smartweed (Polygonum pennsylvanicum L.) but common ragweed (Ambrosia artemisiifolia L.) and volunteer wheat control was not acceptable (<80%). In 1978, USB 3153 at 0.84 and 1.12 kg/ha controlled 95% or more of all weeds and volunteer wheat. Herbicides applied after doublecrop soybean planting provided acceptable weed control in 1976 and 1977 but poor control in 1978. These results indicate that oryzalin and USB 3153 applied over‐the‐top of tillered wheat provide good weed control in doublecrop soybeans and do not affect wheat yields at rates needed for acceptable weed control. Similar studies are needed at other locations to fully evaluate these treatments under different soil and environmental conditions.

Leptosphaeria nodoruminfection of wheat in New Zealand

Abstract Perithecia of Leptosphaeria nodorum Müller were found in autumn on leaf debris in stubble of the wheat cultivar Aotea, although no symptoms of Septoria nodorum (Berk.) Berk, apud Berk, and Br., the asexual stage, were found in the growing crop. Volunteer wheat plants did, however, produce symptoms of S. nodorum the following spring but pycnidia were produced only when the infected leaves were excised and placed in detached leaf culture under near ultraviolet light for 12 h per day. Conidia from these pycnidia and ascospores from the perithecia were cultured on a variety of agar media where they all produced cultures and pycnidia were identified as S. nodorum. Inoculation experiments with spore suspensions from both sources were successful and produced typical S. nodorum symptoms. Further tests showed that 18–24°c, light, senescing tissue, and humidity were all important factors governing the appearance of pycnidia in detached leaf cultures.

Straw‐mulch Rate Effect on Soil Water Storage and Sorghum Yield

AbstractA field study was conducted to determine the effects of straw mulch rates on soil water storage during fallow and on subsequent grain sorghum [Sorghum bicolor (L.) Moench] production. Wheat [Triticum aestivum (L.)] straw at rates of 0 (check), 1, 2, 4, 8, or 12 metric tons/ha was placed on field plots in July 1973, 1974, and 1975. A different area, previously cropped to dryland wheat, was used each year. Atrazine [2‐chloro‐4(ethylamino)‐6‐(isopropylamino)‐s‐triazine] was applied for volunteer wheat and weed control before mulch placement. Soil water content was measured periodically from July until the following May, when grain sorghum was planted, and during the sorghum growing season. Available soil water at planting averaged 12.3 and 21.4 cm for the 0‐ and 12‐metric tons/ha mulch treatments, respectively. The additional water, along with greater infiltration and lower evaporation during the growing season, increased grain yields, which averaged 1,780 and 3,990 kg/ha for the respective treatments. Water‐use efficiency increased from 55.6 kg/ha‐cm for no mulch to 115.0 kg/ha‐cm for 12 metric tons mulch/ha.