scholarly journals USE OF SIMAZINE AS A PREVENTATIVE WEED CONTROL HERBICIDE FOR BIRDSFOOT TREFOIL

1968 ◽  
Vol 48 (4) ◽  
pp. 393-399 ◽  
Author(s):  
J. E. Winch ◽  
G. W. Anderson ◽  
G. E. Jones
Keyword(s):  
Control System ◽  
Weed Control ◽  
Birdsfoot Trefoil ◽  
Leaf Stage ◽  
The Third ◽  
True Leaf ◽  
Initial Application ◽  
Original Application ◽  
Annual Application

Simazine at 0.8, 1.1, 1.6 and 2.2 kg/ha (active) was applied in October of each of three years to an established stand of Empire birdsfoot trefoil infested with grass. These rates were used alone and with an original application of each of 1.1 kg/ha paraquat and a mixture of 3.4 kg/ha dalapon + 1.1 kg/ha 2,4-DB (active). In addition, 1.1 kg/ha simazine (active) was applied in October to a new sowing of Empire birdsfoot trefoil. This rate was used alone and where each of 4.5 kg/ha dalapon, 1.1 kg/ha 2,4-DB or their mixture had been applied at the third true leaf stage of trefoil development earlier in the establishment year. The purpose of these trials was to determine the effect of simazine on the yield of birdsfoot trefoil and on the control of grass and broadleaf weeds. Simazine at 0.8, and 1.1 kg/ha applied in the fall of each year had no deleterious effects upon the yield of Empire trefoil. At the 1.6- and 2.2-kg/ha rate, a reduction in yield did occur after the second, but did not occur after the third, annual application of simazine.Although the grass proportion in old stands of trefoil was reduced to 10% or less by initial application of 1.1, 1.6 and 2.2 kg/ha of simazine, an increase up to the 30% level occurred after the second application at the 1.1- and 1.6-kg/ha rates. This grass proportion was maintained by a further application at these rates. Only the 2.2-kg/ha rate of simazine maintained the grass proportion below 10% of the yield. The original reduction in the proportion of grass was improved and subsequently maintained at a level of 25% or below where simazine was used at any rate in conjunction with an initial application of a mixture of dalapon and 2,4-DB. Combination of paraquat and simazine resulted in a trefoil stand reduction and low trefoil yields.A preventative weed control system using simazine is discussed. The program involves the initial use of a mixture of 3.4 kg dalapon and 1.1 kg 2,4-DB per hectare on new seedlings or on established stands. This is followed by an annual October application of 0.8 to 1.1 kg/ha (active) simazine.

THE EFFECTS OF FUSARIUM WILT AND WEED CONTROL ON SURVIVAL OF BIRDSFOOT TREFOIL

1985 ◽  
Vol 65 (2) ◽  
pp. 329-334 ◽  
Author(s):  
W. M. MURPHY ◽  
A. R. GOTLIEB ◽  
D. T. DUGDALE
Keyword(s):  
Fusarium Oxysporum ◽  
Weed Control ◽  
Seed Production ◽  
Fusarium Wilt ◽  
Clay Soil ◽  
Lotus Corniculatus ◽  
Birdsfoot Trefoil ◽  
Seeding Rate ◽  
Trifoliate Leaf ◽  
Leaf Stage

Birdsfoot trefoil (Lotus corniculatus L.) seed production is no longer profitable for Champlain Valley farmers, partly because the plants do not grow or persist as well as they did in the past due to a Fusarium wilt disease (Fusarium oxysporum). This study was done to determine the effects of chemical and cultural weed control on birdsfoot trefoil seedlings in a Champlain-Valley clay soil containing Fusarium oxysporum. In a greenhouse experiment, 2,4-DB was applied to birdsfoot trefoil seedlings growing on pasteurized potting mix inoculated with F. oxysporum. When applied at label rate in the second trifoliate-leaf stage, and 14 days later, 2,4-DB increased seedling mortality additively with death due to F. oxysporum. When 2,4-DB was applied 7 days after the second trifoliate-leaf stage, it did not influence seedling survival. Applying 2,4-DB reduced dry weights of tops and roots of surviving seedlings. A field experiment was done on a clay soil (Glossaquic Hapludalf) being used for birdsfoot trefoil seed production and known to contain F. oxysporum. Raised beds were included as a variable to determine effects of improved root-zone drainage. Weeds were controlled by clipping or with 2,4-DB/dalapon postemergent herbicides in two birdsfoot trefoil seeding rates of 16.8 and 3.4 kg seed∙ha−1. The herbicides did not influence seedling death rate. By May of the second year plant populations within a seeding rate were the same, regardless of weed control practice and seedbed preparation.Key words: Dalapon, Fusarium oxysporum, Lotus corniculatus L., 2,4-DB

Herbicide Effectiveness, Soil Residues, and Phytotoxicity to Peach Trees

Weed Science ◽  
1971 ◽  
Vol 19 (3) ◽  
pp. 257-260 ◽  
Author(s):  
W. A. Skroch ◽  
T. J. Sheets ◽  
J. W. Smith
Keyword(s):  
Weed Control ◽  
Prunus Persica ◽  
Cynodon Dactylon ◽  
Soil Depth ◽  
Soil Layer ◽  
Soil Surface ◽  
The Third ◽  
Low Concentrations ◽  
Peach Trees ◽  
Annual Application

Dichlobenil (2,6-dichlorobenzonitrile), 3-tert-butyl-5-chloro-6-methyluracil (terbacil), and 3-tert-butyl-5-bromo-6-methyluracil (hereinafter referred to as DP-733) were applied annually for 3 years as soil surface or incorporated treatments for weed control in young peach (Prunus persica(L.) Batsch., var. Redhaven) trees. Average monthly ratings showed significant increases in bermudagrass (Cynodon dactylon(L.) Pers.) control with incorporation of all three herbicides. Treetrunk diameters in incorporated dichlobenil plots were greater than those in surface-applied dichlobenil plots. Incorporation in the soil reduced loss of dichlobenil, terbacil, and DP-733. The herbicides did not accumulate in the 0 to 15-cm soil layer. Low concentrations were detected in the 30 to 60-cm soil depth 1 year after the third annual application of 6.72 kg/ha of dichlobenil and 4.48 kg/ha of DP-733. Terbacil was not present in detectable amounts at 30 to 60 cm but was present in the 15 to 30-cm layer of 4.48 kg/ha plots.

scholarly journals Effectiveness of reduced doses of flumioxazin herbicide at weed control in direct sow onions

2019 ◽  
Vol 13 (1) ◽  
Author(s):  
Christiane Augusta Diniz Melo ◽  
Amanda Rocha Barbosa ◽  
Roque De Carvalho Dias ◽  
Gustavo Soares da Silva ◽  
Marcelo Rodrigues dos Reis
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Field Experiments ◽  
Effective Control ◽  
Phenological Stages ◽  
Alternative Management ◽  
Leaf Stage ◽  
True Leaf ◽  
Direct Sowing ◽  
Bulb Yield

The recommended application of most herbicides in onion crops is after transplanting seedlings with four true leaves. In the direct sowing system, this recommendation is considered late; an alternative management is the application of reduced doses starting with a true leaf. The objective of this study was to evaluate the use of reduced doses of flumioxazin in the early phenological stages of onions on bulb yield. Two field experiments were installed, and five doses of flumioxazin (5, 10, 15, 20, and 25 g ha-1) were applied in three phenological stages (1st, 2nd, and 1st+3rd true leaf); weed control was carried out. The results demonstrated the efficacy of reduced doses of flumioxazin on onion crop in the early stages. The dose of 20 g ha-1 showed use potential in the two experiments for the cvs. Perfecta and Sirius, enabling reductions of 77 to 88% of the commercial dose recommended for onions established with seedling transplanting. The application of flumioxazin in the 2nd leaf reduced commercial productivity and was ineffective in the control of weeds. The application in the 1st + 3rd leaf, despite being an effective control, caused greater phytotoxicity and, therefore, reduced commercial productivity. The best strategy for weed management is 20 g ha-1 flumioxazin applied to onion plants when they reach the true first leaf stage.

scholarly journals Aphids Stimulate Peroxidase Activity but Not ACC Oxidase Activity in Watermelon Plants Inoculated with Anthracnose

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 677d-677
Author(s):  
P. Perkins-Veazie ◽  
J.K. Collins ◽  
V. Russo ◽  
B. Cartwright
Keyword(s):  
Peroxidase Activity ◽  
Ethylene Production ◽  
Oxidase Activity ◽  
Acc Oxidase ◽  
Economic Damage ◽  
Leaf Stage ◽  
The Third ◽  
True Leaf ◽  
Leaf Disks

Individually, green melon aphids (Aphis gossypi) and anthracnose (Colletotricum lagenarium) can cause serious economic damage to watermelons by reducing stands and marketable yields. Greenhouse-grown watermelon seedlings at the third true leaf stage were infected with anthracnose (106 spores/mL) and/or infested with 30 aphids per plant. At the 5th leaf stage (about 7 days after inoculation/infestation), leaf disks were harvested from plants and indicators of stress measured. Peroxidase activity increased from 0.03 to 0.28 absorbance units/mg protein-minute in leaves with anthracnose. When plants were infested with aphids after anthracnose inoculation, peroxidase activity was 0.40 absorbance units/mg protein-minute. Plants having both aphids and anthracnose had more anthracnose lesions when leaves were infested with aphids prior to anthracnose inoculation. The presence of aphids and/or anthracnose stimulated 1-aminocyclopropane-1-caroxylic acid (ACC) oxidase activity from 28 to 44 nL/g-h, indicating enhanced ethylene production. However, aphids had to be present on plants at least 5 days before ACC oxidase activity was stimulated above control levels. Aphids combined with anthracnose failed to elevate ACC oxidase levels higher than either aphids or anthracnose alone. Both peroxidase activity and ACC oxidase activity in watermelon plants increased with anthracnose infection. Thus, watermelon plants stressed by aphids and anthracnose responded differently from plants stressed individually by aphids or anthracnose.

scholarly journals Optical Properties of Paper and Polyethylene Mulches Used for Weed Control in Lettuce

HortScience ◽  
2002 ◽  
Vol 37 (1) ◽  
pp. 87-91 ◽  
Author(s):  
D. Brault ◽  
K.A. Stewart ◽  
S. Jenni
Keyword(s):  
Optical Properties ◽  
Weed Control ◽  
Lactuca Sativa ◽  
Biodegradable Polymer ◽  
Organic Soil ◽  
The Other ◽  
Leaf Stage ◽  
True Leaf ◽  
Black Paper ◽  
Polyethylene Mulch

Optical properties of paper and plastic mulches were determined in experiments on mulched head lettuce (Lactuca sativa L.) grown in organic soil in 1997-98. Mulches used in 1997 were a coextruded white/black polyethylene, a beige paper coated with latex on both sides and a black paper coated with latex on both sides. Three supplementary mulches were added in the 1998 experiment: beige paper coated with a biodegradable polymer either coated on the underside, on the top side or on both sides. Optical properties of the polyethylene mulch remained stable over the course of the experiment. As the paper mulches aged, they changed structurally, spectrally, or both, but remained in place until harvest. The black paper was the only mulch that offered complete weed control, although the weeds under the other mulches did not develop beyond the cotyledonary or two-true-leaf stage.

scholarly journals Calibration of Transducers and of a Coil Compression Spring Constant on the Testing Equipment Simulating the Process of a Pallet Positioning in a Rack Cell

2019 ◽  
Vol 9 (1) ◽  
pp. 631-640 ◽  
Author(s):  
Leopold Hrabovský ◽  
David Dluhoš
Keyword(s):  
Control System ◽  
Strain Gauge ◽  
Testing Equipment ◽  
Pressure Force ◽  
The Third ◽  
Force Transducers ◽  
Compression Spring ◽  
Computer Controlled ◽  
Automated Process ◽  
Principal Design

AbstractIn a parking house with KOMA TOWER computer-controlled automated parking system it happens that a control system is locked out of service after a pallet has failed to reach the required position during the shifting of pallets, loaded with cars, into rack cells.In this paper is described testing equipment designed by the Institute of Transport, Faculty of Mechanical Engineering, VŠB Technical University of Ostrava for the purpose of simulating the process of pallets shifting into the rack cells in order that the frequency of error messages from the control system during the automated process of cars positioning in rack cells in the parking house may be limited.The paper details two completed parts of the designed testing equipment which provide for the calibration of strain-gauge force transducers and for the detection of coil compressive spring compression in relation to acting pressure force.The description of the third, principal design part will be provided in the next paper, together with the experimentally measured acting forces which generate, in both horizontal and vertical directions, as a pallet brake pulley rolls along a brake haunch length.

scholarly journals Integrating Economics in the Critical Period for Weed Control Concept in Corn

Weed Science ◽  
2014 ◽  
Vol 62 (4) ◽  
pp. 608-618 ◽  
Author(s):  
Martina Keller ◽  
Geoffroy Gantoli ◽  
Jens Möhring ◽  
Christoph Gutjahr ◽  
Roland Gerhards ◽  
...  
Keyword(s):  
Weed Control ◽  
Critical Period ◽  
Logistic Models ◽  
Crop Growth ◽  
Growth Stages ◽  
Corn Yield ◽  
Leaf Stage ◽  
Weed Interference ◽  
Free Interval ◽  
Crop Growth Stages

The effect of weed interference on corn yield and the critical period for weed control (CPWC) were determined in Germany and Benin. Treatments with weed control starting at different crop growth stages and continuously kept weed-free until harvest represented the “weed-infested interval.” Treatments that were kept weed-free from sowing until different crop growth stages represented the “weed-free interval.” Michaelis–Menten, Gompertz, logistic and log–logistic models were employed to model the weed interference on yield. Cross-validation revealed that the log–logistic model fitted the weed-infested interval data equally well as the logistic and slightly better than the Gompertz model fitted the weed-free interval. For Benin, economic calculations considered yield revenue and cost increase due to mechanical weeding operations. Weeding once at the ten-leaf stage of corn resulted already profitable in three out of four cases. One additional weeding operation may optimize and assure profit. Economic calculations for Germany determined a CPWC starting earlier than the four-leaf stage, challenging the decade-long propagated CPWC for corn. Differences between Germany and Benin are probably due to the higher yields and high costs in Germany. This study provides a straightforward method to implement economic data in the determination of the CPWC for chemical and nonchemical weed control strategies.

Effect of Imazethapyr on Legumes and the Effect of Legumes on Weeds

1994 ◽  
Vol 8 (3) ◽  
pp. 536-540 ◽  
Author(s):  
Robert G. Wilson
Keyword(s):  
Weed Control ◽  
Red Clover ◽  
The Other ◽  
Birdsfoot Trefoil ◽  
Weed Biomass

A three-year experiment was conducted near Scottsbluff, NE, to evaluate the selectivity of POST-applied imazethapyr for weed control in alfalfa, birdsfoot trefoil, cicer milkvetch, red clover, sainfoin, and yellow sweetclover. Imazethapyr injured all legumes 15 DAT. Imazethapyr also reduced the height of birdsfoot trefoil, cicer milkvetch, red clover, and yellow sweeclover 28 DAT. Legume first cutting yields were not reduced by imazethapyr and with alfalfa, birdsfoot trefoil, cicer milkvetch, and sainfoin, first cutting yields were increased by imazethapyr. Imazethapyr reduced weed biomass in all legume seedings. Weed biomass in new seedings of alfalfa was reduced more than that of the other legumes.

scholarly journals Inheritance of True Leaf Stage Downy Mildew Resistance in Broccoli

2001 ◽  
Vol 126 (6) ◽  
pp. 727-729 ◽  
Author(s):  
Min Wang ◽  
Mark W. Farnham ◽  
Claude E. Thomas
Keyword(s):  
Downy Mildew ◽  
Control Method ◽  
Recurrent Parent ◽  
Downy Mildew Resistance ◽  
Resistant Parent ◽  
Dh Population ◽  
Mildew Resistance ◽  
Leaf Stage ◽  
True Leaf ◽  
High Level

Downy mildew, incited by the biotrophic fungal parasite, Peronospora parasitica (Pers. Fr.) Fr., is one of the most destructive diseases of broccoli (Brassica oleracea L., Italica Group) and other related crop species throughout the world. Cultivation of resistant cultivars is the most desirable control method because it provides a practical, long-term, and environmentally benign means of limiting damage from this disease. The commercial hybrid cultivar, Everest, has been shown previously to contain a high level of downy mildew resistance. Doubled-haploid (DH) lines developed from that hybrid were also shown to exhibit a similar, high level of resistance at the three- to four-leaf stage. To determine the mode of inheritance of this true leaf resistance, the resistant DH line was crossed to a susceptible line (derived from `Marathon') to produce an F1 hybrid. Subsequently, F2 and backcross (BC) populations were developed from the hybrid. In addition, a DH population of ≈100 lines was developed from the same F1 used to create the F2 and BC. All populations were evaluated for response to artificial inoculation with P. parasitica at the three- to four-leaf stage. F1 plants were resistant like the resistant parent and F2 populations segregated approximately nine resistant to seven susceptible. Using the resistant parent as recurrent parent, BC populations contained all resistant plants, while the BC to the susceptible parent fit a 1 resistant: 3 susceptible segregation ratio. These results can be explained by a model with two complementary dominant genes. This model was confirmed by the DH population that segregated ≈1:3, resistant to susceptible. Due to the dominant nature of this resistance, controlling genes should be easily incorporated into F1 hybrids and used commercially to prevent downy mildew.

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