Control of Perennated Bermudagrass (Cynodon dactylon) and Johnsongrass (Sorghum halepense) in Sugarcane (Saccharumspp. hybrids)

1998 ◽  
Vol 12 (1) ◽  
pp. 128-133 ◽  
Author(s):  
Edward P. Richard
Keyword(s):  
Field Experiments ◽  
Cynodon Dactylon ◽  
Growing Season ◽  
Sorghum Halepense ◽  
Sugarcane Stalk ◽  
Crop Injury ◽  
Over Time ◽  
Levels Of Control

In two separate field experiments conducted over time, at-planting preemergence (PRE) applications of sulfometuron at 110 to 150 g ai/ha followed by March applications of sulfometuron at 30 g/ha or metribuzin at 2,580 g ai/ha at the start of the initial (plant cane) growing season controlled more bermudagrass and johnsongrass emerging in sugarcane from rhizome and stolon pieces than standard at-planting followed by March applications of atrazine at 2,240 g ai/ha (no control), metribuzin at 2,580 g ai/ha, or pendimethalin at 2,240 g ai/ha. Treatments containing at-planting applications of imazapyr at 280 g ai/ha or thiazopyr at 560 g ai/ha did not provide levels of control similar to sulfometuron. Crop injury in excess of 10% occurred only when imazapyr at 280 g/ha (18 to 42%) or sulfometuron at 30 g/ha (11 to 32%) was applied in March to emerging sugarcane. Sugarcane stalk numbers, stalk heights, and ultimately cane and sugar yields were increased when compared to the standards with all sulfometuron treatments and when thiazopyr was applied at planting and again in March.

Effects of Fallow Bermudagrass (Cynodon dactylon) Control Programs on Newly Planted Sugarcane (Saccharumspp. hybrids)

1997 ◽  
Vol 11 (4) ◽  
pp. 677-682 ◽  
Author(s):  
Edward P. Richard
Keyword(s):  
Field Experiments ◽  
Cynodon Dactylon ◽  
Sugar Yield ◽  
Treatment Programs ◽  
Infestation Level ◽  
Fallow Period ◽  
Control Programs ◽  
Sugarcane Stalk ◽  
Tillage Operation

Field experiments were conducted in Louisiana to evaluate the effectiveness of tillage, tillage plus herbicide, and herbicide-only fallow programs in controlling bermudagrass. Tillage of fallow fields three times at 3- to 4-wk intervals between row formation in late May and planting in late September or early October reduced bermudagrass infestations in the newly planted crop in December 44 to 51%. When the final tillage operation was replaced by glyphosate postemergence at either 2.24 or 3.36 kg ai/ha in late August, bermudagrass infestation level in December on the surface of the newly planted rows was reduced to below 20%. Two applications of glyphosate at 3.36 kg/ha were more effective than tillage only and as effective as tillage twice followed by glyphosate in reducing bermudagrass infestation levels in the newly planted crop. Application of atrazine at 3.36 kg ai/ha, imazapyr at 0.68 kg ai/ha, metribuzin at 1.68 kg ai/ha, or sulfometuron at 0.14 and 0.28 kg ai/ha to newly formed rows in late May of the fallow period did not reduce the need for tillage or an application of glyphosate during the fallow period to control bermudagrass, but imazapyr at 1.12 kg/ha did. Sugarcane shoot populations in December of the fallow year were similar for the treatment programs despite differences in bermudagrass infestation levels, which ranged from 11 to 94%. However, sugarcane stalk number and height and cane and sugar yield in the plant-cane crop the following year were highest when glyphosate was applied to bermudagrass as two applications either alone or following the application of atrazine or metribuzin, when tillage was followed with one application of glyphosate, and in 1 yr when imazapyr alone was applied to newly formed rows.

Mutual Influences of Seedling Johnsongrass (Sorghum halepense), Sicklepod (Cassia obtusifolia), and Soybean (Glycine max)

Weed Science ◽  
1990 ◽  
Vol 38 (2) ◽  
pp. 139-147 ◽  
Author(s):  
Barry D. Sims ◽  
Lawrence R. Oliver
Keyword(s):  
Glycine Max ◽  
Seed Production ◽  
Seed Yield ◽  
Dry Matter ◽  
Field Experiments ◽  
Growing Season ◽  
Growth And Yield ◽  
Sorghum Halepense ◽  
Competitive Effects ◽  
Matter Production

Field experiments were conducted to evaluate competitive effects of johnsongrass and sicklepod on growth and yield of irrigated and nonirrigated soybeans. Johnsongrass reduced soybean growth early in the growing season. Sicklepod was competitive all season, but competitiveness was greatest during the soybean reproductive stage. Soybean yields were reduced 31% by sicklepod, 14% by johnsongrass, and 36% by both weeds growing together. Nonirrigated soybeans yielded less than irrigated, but percent yield reductions were similar. Johnsongrass dry matter production and seed yield were reduced more than sicklepod by soybean interference. Soybean and sicklepod interference reduced johnsongrass seed production 73 to 95%. Johnsongrass produced 245 to 1238 seeds per plant when interfering with soybeans and sicklepod. Sicklepod seeds per plant were reduced 6 to 31% by johnsongrass interference and 47 to 75% by soybeans and soybeans plus johnsongrass.

Identity-Preserved Soybean Tolerance to Protoporphyrinogen Oxidase-Inhibiting Herbicides

2016 ◽  
Vol 30 (1) ◽  
pp. 137-147 ◽  
Author(s):  
Kimberly D. Belfry ◽  
Christy Shropshire ◽  
Peter H. Sikkema
Keyword(s):  
Active Ingredient ◽  
Field Experiments ◽  
Yield Losses ◽  
Protoporphyrinogen Oxidase ◽  
Soybean Yield ◽  
Soybean Cultivars ◽  
Crop Injury ◽  
Over Time

Field experiments were conducted from 2011 to 2013 near Ridgetown and Exeter, Ontario, Canada to evaluate the tolerance of seven identity-preserved (IP) soybean cultivars to protoporphyrinogen oxidase (PPO)-inhibiting herbicides flumioxazin, saflufenacil/dimethenamid-P, and sulfentrazone applied PRE; fomesafen applied POST; as well as PRE followed by (fb) POST application. Ridgetown sites demonstrated excellent tolerance (< 10% injury) to PRE treatments, whereas PRE sulfentrazone caused up to 36% injury at 1 and 2 wk after application (WAA) at Exeter. Of the PRE fb POST treatments evaluated, those containing saflufenacil/dimethenamid-P and sulfentrazone were most injurious to soybean, with cultivar being a further determinant of injury. At Exeter 1 WAA, cultivars ‘S03W4’ and ‘S23T5’ showed 23 to 27 and 45 to 46% injury for saflufenacil/dimethenamid-P and sulfentrazone when followed by POST fomesafen, respectively. Sulfentrazone application (PRE alone or fb fomesafen) consequently reduced S03W4 yield up to 38% and S23T5 up to 25%, whereas saflufenacil/dimethenamid-P fb fomesafen reduced S03W4 by 18%. In general, PRE fb POST caused more injury than PRE treatments; however, injury diminished over time and no significant reduction to soybean yield could be attributed to adding POST fomesafen. On the basis of this study, the injury from PPO herbicides applied PRE is active ingredient, cultivar, and environment specific. Although PPO herbicides have the potential to cause unacceptable crop injury in some IP soybean cultivars, selecting a tolerant cultivar will minimize yield losses.

Preemergence Control of Itchgrass (Rottboellia cochinchinensis) and Johnsongrass (Sorghum halepense) in Sugarcane (Saccharumspp hybrids) with Pendimethalin and Prodiamine

Weed Science ◽  
1993 ◽  
Vol 41 (4) ◽  
pp. 621-626 ◽  
Author(s):  
Rex W. Millhollon
Keyword(s):  
Weed Control ◽  
Field Experiments ◽  
Sorghum Halepense ◽  
Effective Control ◽  
Sugarcane Stalk ◽  
Preemergence Herbicides ◽  
Rottboellia Cochinchinensis

Preemergence control of itchgrass in sugarcane with nonincorporated pendimethalin and prodiamine increased as rate for each herbicide increased from 2.2 to 3.4 kg ai ha-1. Itchgrass control at 3.4 kg ha-1was similar for both herbicides, ranging from 78 to 94% (86% mean) for pendimethalin in six field experiments and 83 to 91% (86% mean) for prodiamine in three experiments. Incorporated trifluralin at 2.2 kg ha-1, the standard, gave 99% mean control of itchgrass. None of the nonincorporated treatments with pendimethalin or prodiamine consistently prevented a decrease in the sugarcane stalk population at harvest. Asulam applied postemergence at 3.7 kg ae ha-1controlled itchgrass that survived the preemergence herbicides, and sugarcane stalk populations were maintained. Preemergence control of johnsongrass with nonincorporated treatments of pendimethalin or prodiamine at 2.8 kg ha-1, in a mixture with atrazine at 2.2 kg ai ha-1, ranged from 86 to 95% (89% mean) for pendimethalin and 80 to 95% (88% mean) for prodiamine. Metribuzin at 2.2 kg ha-1, the standard, gave 97% mean control of johnsongrass. Mixtures of pendimethalin with metribuzin or terbacil generally gave more effective control of johnsongrass than mixtures with atrazine. When used in conjunction with other herbicides, nonincorporated pendimethalin and prodiamine were effective alternatives to soil-incorporated treatments for weed control in sugarcane.

Johnsongrass (Sorghum halepense) Control and Soil Moisture Relationships in No-Tillage, Doublecropped Soybeans (Glycine max)

Weed Science ◽  
1987 ◽  
Vol 35 (1) ◽  
pp. 108-114 ◽  
Author(s):  
Michael S. Defelice ◽  
William W. Witt ◽  
James R. Martin
Keyword(s):  
Soil Moisture ◽  
Glycine Max ◽  
Field Experiments ◽  
Growing Season ◽  
Sorghum Halepense ◽  
Propanoic Acid ◽  
No Tillage ◽  
Control Programs

Field experiments were conducted in Princeton, KY, in 1982, 1983, and 1984 to evaluate johnsongrass [Sorghum halepense(L.) Pers. # SORHA] control programs in no-tillage, doublecropped soybeans [Glycine max(L.) Merr. ‘Essex′]. Sequential applications of sethoxydim {2-[1-(ethoxyimino)butyl]-5-[2-(ethylthio)propyl]-3-hydroxy-2-cyclohexen-1-one} or fluazifop {(±)-2-[4-[[5-(trifluoromethyl)-2-pyridinyl] oxy] phenoxy] propanoic acid} at 0.2 kg ai/ha provided 36 to 94% johnsongrass control. The lower control values from these treatments were obtained in the droughty 1983 growing season while the higher and acceptable control ratings were obtained in 1982 and 1984 when rainfall was more plentiful. Preplant applications that contained glyphosate [N-(phosphonomethyl)glycine] provided johnsongrass control greater than those containing paraquat (1,1′-dimethyl-4,4′-bypyridinium ion). Soybean yields and soil moisture were greater with preplant applications of glyphosate than with preplant applications of paraquat or foliar applications of sethoxydim, fluazifop, or glyphosate. Greatest yields were obtained with a combination of a preplant application of glyphosate and a postemergence application of sethoxydim.

scholarly journals Estimating the Leaf Nitrogen Content with a New Feature Extracted from the Ultra-High Spectral and Spatial Resolution Images in Wheat

2021 ◽  
Vol 13 (4) ◽  
pp. 739
Author(s):  
Jiale Jiang ◽  
Jie Zhu ◽  
Xue Wang ◽  
Tao Cheng ◽  
Yongchao Tian ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Precision Agriculture ◽  
Field Experiments ◽  
Mean Squared Error ◽  
Growing Season ◽  
Leaf Nitrogen ◽  
Textural Analysis ◽  
Hyperspectral Images ◽  
Leaf Nitrogen Content ◽  
New Feature

Real-time and accurate monitoring of nitrogen content in crops is crucial for precision agriculture. Proximal sensing is the most common technique for monitoring crop traits, but it is often influenced by soil background and shadow effects. However, few studies have investigated the classification of different components of crop canopy, and the performance of spectral and textural indices from different components on estimating leaf nitrogen content (LNC) of wheat remains unexplored. This study aims to investigate a new feature extracted from near-ground hyperspectral imaging data to estimate precisely the LNC of wheat. In field experiments conducted over two years, we collected hyperspectral images at different rates of nitrogen and planting densities for several varieties of wheat throughout the growing season. We used traditional methods of classification (one unsupervised and one supervised method), spectral analysis (SA), textural analysis (TA), and integrated spectral and textural analysis (S-TA) to classify the images obtained as those of soil, panicles, sunlit leaves (SL), and shadowed leaves (SHL). The results show that the S-TA can provide a reasonable compromise between accuracy and efficiency (overall accuracy = 97.8%, Kappa coefficient = 0.971, and run time = 14 min), so the comparative results from S-TA were used to generate four target objects: the whole image (WI), all leaves (AL), SL, and SHL. Then, those objects were used to determine the relationships between the LNC and three types of indices: spectral indices (SIs), textural indices (TIs), and spectral and textural indices (STIs). All AL-derived indices achieved more stable relationships with the LNC than the WI-, SL-, and SHL-derived indices, and the AL-derived STI was the best index for estimating the LNC in terms of both calibration (Rc2 = 0.78, relative root mean-squared error (RRMSEc) = 13.5%) and validation (Rv2 = 0.83, RRMSEv = 10.9%). It suggests that extracting the spectral and textural features of all leaves from near-ground hyperspectral images can precisely estimate the LNC of wheat throughout the growing season. The workflow is promising for the LNC estimation of other crops and could be helpful for precision agriculture.

scholarly journals Rattail fescue (Vulpia myuros) interference and seed production as affected by sowing time and crop density in winter wheat

Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Seed Production ◽  
Yield Components ◽  
Field Experiments ◽  
Growing Season ◽  
Sowing Time ◽  
Growing Seasons ◽  
Crop Density ◽  
Wide Range

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.

Red Rice (Oryza sativa) Control in Drill-Seeded Rice (O. sativa)

Weed Science ◽  
1985 ◽  
Vol 33 (5) ◽  
pp. 703-707 ◽  
Author(s):  
Amadou Diarra ◽  
Roy J. Smith ◽  
Ronald E. Talbert
Keyword(s):  
Oryza Sativa ◽  
Grain Yield ◽  
Field Experiments ◽  
Growing Season ◽  
Rice Cultivar ◽  
Rice Grain ◽  
Rice Seed ◽  
Red Rice ◽  
Culm Density ◽  
High Yields

Field experiments were conducted to investigate methods of controlling red rice (Oryza sativaL. ♯ ORYSA) in drill-seeded rice (O. sativa). Treatments included the rice cultivar ‘Mars', coated with calcium peroxide (CaO2) at 40% (w/w) and a crop protectant, R-33865 (O,O-diethyl-O-phenyl phosphorothioate) at 0.5 and 1% (v/w). Molinate (S-ethyl hexahydro-1H-azepine-1-carbothioate) at 6.7 kg ai/ha was applied preplant incorporated (ppi). The land was flooded (2.5 to 5 cm deep) after seeding with rice (100 kg/ha, 2.5 cm deep), and the water was maintained throughout the growing season. CaO2, with or without molinate, increased rice grain yield 50% and increased rice culm density fivefold above untreated rice. Molinate applied ppi controlled 96% of the red rice. Rice seed coated with only CaO2or with CaO2plus R-33865 at 0.5%, each combined with ppi molinate, produced 5690 and 6030 kg/ha of grain, respectively. These high yields were associated with red rice control by molinate and good stands of rice provided by O2supplied by CaO2. R-33865 applied to rice seed at 1% (v/w) injured rice by reducing rice culm densities 41%, compared with rice without protectant.

Common Bermudagrass (Cynodon dactylon) Interference in Newly Planted Peach (Prunus persica) Trees

Weed Science ◽  
1985 ◽  
Vol 33 (1) ◽  
pp. 50-56 ◽  
Author(s):  
Stephen C. Weller ◽  
Walter A. Skroch ◽  
Thomas J. Monaco
Keyword(s):  
Field Experiments ◽  
Prunus Persica ◽  
Cynodon Dactylon ◽  
Ground Cover ◽  
First Year ◽  
Allelopathic Effect ◽  
Trunk Diameter ◽  
Leaf Chlorophyll ◽  
Tree Leaf ◽  
Common Bermudagrass

Field experiments conducted over a 2-yr period demonstrated that common bermudagrass [Cynodon dactylon (L.) Pers. # CYNDA] inhibited growth of newly planted peach (Prunus persica L. ‘Norman’) trees. Common bermudagrass densities of 100, 75, 50, and 25% ground cover reduced tree fresh weight by 86, 64, 43, and 19%, respectively, the first year (1978) and 87, 62, 44, and 28%, respectively, the second year (1979) after planting. Tree trunk diameter relative growth rate (RGR) was reduced by 75 and 100% common bermudagrass ground cover densities at all measurement dates only in 1978. Tree leaf N and K were reduced in both years by common bermudagrass; however, only at the 100% common bermudagrass density in 1978 was N at a deficient level. Leaf chlorophyll was reduced in trees grown in all densities of common bermudagrass only in 1978. Reduced tree growth cannot be explained entirely by competition for essential nutrients; thus an allelopathic effect of the bermudagrass on young peach roots is suspected.

Critical time for weed removal in glyphosate-resistant soybean as influenced by preemergence herbicides

2019 ◽  
Vol 33 (03) ◽  
pp. 393-399 ◽  
Author(s):  
Stevan Z. Knezevic ◽  
Pavle Pavlovic ◽  
O. Adewale Osipitan ◽  
Ethann R. Barnes ◽  
Clint Beiermann ◽  
...  
Keyword(s):  
Field Experiments ◽  
Critical Time ◽  
Growing Season ◽  
Control Programs ◽  
Main Plot ◽  
Repeated Use ◽  
Sites Of Action ◽  
Alternative Sites ◽  
Preemergence Herbicides ◽  
Weed Removal

AbstractWidespread and repeated use of glyphosate resulted in an increase in glyphosate-resistant (GR) weeds. This led to an urgent need for diversification of weed control programs and use of PRE herbicides with alternative sites of action. Field experiments were conducted over a 4-yr period (2015 to 2018) across three locations in Nebraska to evaluate the effects of PRE-applied herbicides on critical time for weed removal (CTWR) in GR soybean. The studies were laid out in a split-plot arrangement with herbicide regime as the main plot and weed removal timing as the subplot. The herbicide regimes used were either no PRE or premix of either sulfentrazone plus imazethapyr (350 + 70 g ai ha−1) or saflufenacil plus imazethapyr plus pyroxasulfone (26 + 70 + 120 g ai ha−1). The weed removal timings were at V1, V3, V6, R2, and R5 soybean stages, with weed-free and weedy season-long checks. Weeds were removed by application of glyphosate (1,400 g ae ha−1) or by hoeing. The results across all years and locations suggested that the use of PRE herbicides delayed CTWR in soybean. In particular, the CTWR without PRE herbicides was determined to be around the V1 to V2 (14 to 21 d after emergence [DAE]) growth stage, depending on the location and weed pressure. The use of PRE-applied herbicides delayed CTWR from about the V4 (28 DAE) stage up to the R5 (66 DAE) stage. These results suggest that the use of PRE herbicides in GR soybean could delay the need for POST application of glyphosate by 2 to 5 wk, thereby reducing the need for multiple applications of glyphosate during the growing season. Additionally, the use of PRE herbicides could provide additional modes of action needed to manage GR weeds in GR soybean.

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