Germination ecology of winter annual grasses in Mediterranean climates: Applications for soil cover in olive groves

2018 ◽  
Vol 262 ◽  
pp. 29-35 ◽  
Author(s):  
Borja Jiménez-Alfaro ◽  
Matías Hernández-González ◽  
Eduardo Fernández-Pascual ◽  
Peter Toorop ◽  
Stephanie Frischie ◽  
...  
Keyword(s):  
Soil Cover ◽  
Germination Ecology ◽  
Annual Grasses ◽  
Olive Groves ◽  
Winter Annual

Palweed:Wheat: A Bioeconomic Decision Model for Postemergence Weed Management in Winter Wheat (Triticum aestivum)

Weed Science ◽  
1995 ◽  
Vol 43 (4) ◽  
pp. 595-603 ◽  
Author(s):  
Tae-Jin Kwon ◽  
Douglas L. Young ◽  
Frank L. Young ◽  
Chris M. Boerboom
Keyword(s):  
Winter Wheat ◽  
Weed Management ◽  
Decision Model ◽  
Damage Function ◽  
Yield Response ◽  
Density Functions ◽  
Yield Model ◽  
Weed Density ◽  
Annual Grasses ◽  
Winter Annual

Based on six years of data from a field experiment near Pullman, WA, a bioeconomic decision model was developed to annually estimate the optimal post-emergence herbicide types and rates to control multiple weed species in winter wheat under various tillage systems and crop rotations. The model name, PALWEED:WHEAT, signifies a Washington-Idaho Palouse region weed management model for winter wheat The model consists of linear preharvest weed density functions, a nonlinear yield response function, and a profit function. Preharvest weed density functions were estimated for four weed groups: summer annual grasses, winter annual grasses, summer annual broadleaves, and winter annual broadleaves. A single aggregated weed competition index was developed from the four density functions for use functions for use in the yield model. A yield model containing a logistic damage function performed better than a model containing a rectangular hyperbolic damage function. Herbicides were grouped into three categories: preplant nonselective, postemergence broadleaf, and postemergence grass. PALWEED:WHEAT was applied to average conditions of the 6-yr experiment to predict herbicide treatments that maximized profit. In comparison to average treatment rates in the 6-yr experiment, the bioeconomic decision model recommended less postemergence herbicide. The weed management recommendations of PALWEED:WHEAT behaved as expected by agronomic and economic theory in response to changes in assumed weed populations, herbicide costs, crop prices, and possible restrictions on herbicide application rates.

scholarly journals Green house studies on the biology of winter annual grasses and the use of cover crops and herbicides for their control

2013 ◽  
Vol 2 ◽  
pp. 139-148 ◽  
Author(s):  
JD Ranjit ◽  
R Bellinder ◽  
C Benidict ◽  
V Kumar
Keyword(s):  
Plant Growth ◽  
Cover Crops ◽  
Plant Biomass ◽  
Flag Leaf ◽  
Biological Study ◽  
Cornell University ◽  
Green House ◽  
Annual Grasses ◽  
Winter Annual ◽  
Preemergence Herbicides

Greenhouse studies were initiated in two small (Polypogon fugox) and large (Phalaris minor) seeded annual grasses in 2007 at Cornell University, Ithaca, NY USA. These two annual grasses were very common in wheat fields of midhills and terai regions of Nepal. P fugox was taken for biological study. Days to emergence took 8-11 days in green house. Early emerged panicles were longer than those emerged late. Panicle took 10-12 days to emerge completely from the flag leaf. Panicles per plant were 120. Seeds were very small having about 1091 seeds per panicle. So one fully matured plant could produce seeds about 130920. Study on eco-biology needs to continue in the future. P fugox and P minor responded differently to buckwheat residues. Among different treatments emergence and growth of both weeds were suppressed more by buckwheat residues when left on the surface than incorporated. P minor was less affected by buckwheat residues. It might be due to larger seed compared to P fugox. Post emergence herbicides clodinofop and pinoxaden were effective on both grasses. Isoproturon and tralkoxydim were effective on P fugox. Sulfosulfuron was good in reducing plant growth to some extent. Preemergence herbicides pendimethalin and s-metolochlor were effective in reducing emergence and growth of both weeds. Isoproturon and and sulfosulfuron suppressed plant growth reducing dry plant biomass. DOI: http://dx.doi.org/10.3126/ajn.v2i0.7529 Agronomy Journal of Nepal (Agron JN) Vol. 2: 2011 pp.139-148

scholarly journals Lack of Host Specialization on Winter Annual Grasses in the Fungal Seed Bank Pathogen Pyrenophora semeniperda

PLoS ONE ◽  
2016 ◽  
Vol 11 (3) ◽  
pp. e0151058 ◽  
Author(s):  
Julie Beckstead ◽  
Susan E. Meyer ◽  
Toby S. Ishizuka ◽  
Kelsey M. McEvoy ◽  
Craig E. Coleman
Keyword(s):  
Seed Bank ◽  
Host Specialization ◽  
Annual Grasses ◽  
Winter Annual

Cropping Systems to Control Winter Annual Grasses in Winter Wheat (Triticum aestivum)

1999 ◽  
Vol 13 (1) ◽  
pp. 120-126 ◽  
Author(s):  
Oleg Daugovish ◽  
Drew J. Lyon ◽  
David D. Baltensperger
Keyword(s):  
Winter Wheat ◽  
Cropping Systems ◽  
Field Studies ◽  
Downy Brome ◽  
Jointed Goatgrass ◽  
Long Term Effect ◽  
Annual Grasses ◽  
Winter Annual ◽  
Feral Rye

Field studies were conducted from 1990 through 1997 to evaluate the long-term effect of 2- and 3-yr rotations on the control of downy brome, jointed goatgrass, and feral rye in winter wheat. At the completion of the study, jointed goatgrass and feral rye densities averaged 8 plants/m2and < 0.1 plant/m2for the 2- and 3-yr rotations, respectively. Downy brome densities averaged < 0.5 plant/m2for both the 2- and 3-yr rotations, with no treatment differences observed. Winter annual grasses were not eradicated after two cycles of the 3-yr rotations, but weed densities were reduced 10-fold compared to densities after one cycle and more than 100-fold compared with the 2-yr rotations. Wheat grain contamination with dockage and foreign material followed a similar trend. The 3-yr rotations were economically competitive with 2-yr rotations and provided superior control of the winter annual grass weeds.

scholarly journals Study of C, N, P and K Release from Residues of Newly Proposed Cover Crops in a Spanish Olive Grove

Agronomy ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1041 ◽  
Author(s):  
Antonio Rodríguez-Lizana ◽  
Miguel Ángel Repullo-Ruibérriz de Torres ◽  
Rosa Carbonell-Bojollo ◽  
Manuel Moreno-García ◽  
Rafaela Ordóñez-Fernández
Keyword(s):  
Cover Crops ◽  
Cover Crop ◽  
Crop Residues ◽  
Soil Cover ◽  
Brachypodium Distachyon ◽  
Nutrient Release ◽  
Grab Sampling ◽  
P Release ◽  
Olive Groves ◽  
C And N

Cover crops (CC)s are increasingly employed by farmers in olive groves. Spontaneous soil cover is the most commonly used CC. Its continuous utilization changes ruderal flora. It is necessary to study new CCs. Living CCs provide C and nutrients to soil during decomposition. Information on this issue in olive groves is scarce. A 4-year field study involving grab sampling of Brachypodium distachyon, Sinapis alba and spontaneous CC residues was conducted to study C and nutrient release from cover crop residues. Throughout the decomposition cycles, C, N and P release accounted for 40 to 58% of the C, N and P amounts in the residues after mowing. Most K was released (80–90%). Expressed in kg per hectare, the release of C and N in Brachypodium (C: 4602, N: 181, P: 29, K: 231) and Sinapis (C: 4806, N: 152, P: 18, K: 195) was greater than that in spontaneous CC (C: 3115, N: 138, P: 21, K: 256). The opposite results were observed for K. The Rickman model, employed to estimate the amount of C, N and P in residues, yielded a good match between the simulated and measured values. In comparison to spontaneous CC, the newly proposed CCs have a higher potential to provide soil with C and N.

Nonvertical Spray Angles Optimize Graminicide Efficacy

2007 ◽  
Vol 21 (4) ◽  
pp. 1029-1034 ◽  
Author(s):  
Peter Kryger Jensen
Keyword(s):  
Growth Stage ◽  
Field Experiments ◽  
Cropping Systems ◽  
Standard Technique ◽  
Northern Europe ◽  
Optimum Growth ◽  
Vertical Leaf ◽  
Annual Crops ◽  
Annual Grasses ◽  
Winter Annual

Annual grasses constitute a major weed problem in winter annual crops in Northern Europe and especially in cropping systems where ploughing is omitted. At the optimum growth stage for control with POST herbicides, grasses have a predominantly vertical leaf orientation. This represents a very difficult spray target using the standard technique where nozzles are mounted more or less vertically downward. In this study, efficacy of the foliar-acting herbicide, haloxyfop, on perennial ryegrass at the two- to three-leaf stage was investigated in field experiments using some alternative configurations of nozzle mounting on the sprayer. Angling the spray either forward or backward relative to the direction of travel increased herbicide efficacy using standard commercially available flat-fan and pre-orifice nozzles. Efficacy increased generally with increasing angling relative to vertically downward and the forward-angled spray improved efficacy most. The largest improvement in efficacy was obtained using a 60° forward-angled spray in combination with a reduced boom height. Using this configuration, herbicide dose could be reduced by approximately 30% without loss of efficacy in comparison with the standard vertical mounting of nozzles. There was no advantage of using combinations of forward- and backward-angled nozzles.

Cover Crop and Postemergence Herbicide Integration for Palmer amaranth Control in Cotton

2017 ◽  
Vol 31 (3) ◽  
pp. 348-355 ◽  
Author(s):  
Matthew S. Wiggins ◽  
Robert M. Hayes ◽  
Robert L. Nichols ◽  
Lawrence E. Steckel
Keyword(s):  
Cover Crops ◽  
Weed Management ◽  
Cover Crop ◽  
Field Experiments ◽  
Palmer Amaranth ◽  
Cereal Rye ◽  
Crimson Clover ◽  
Annual Grasses ◽  
Winter Annual ◽  
Hand Weeding

Field experiments were conducted to evaluate the integration of cover crops and POST herbicides to control glyphosate-resistant Palmer amaranth in cotton. The winter-annual grasses accumulated the greatest amount of biomass and provided the most Palmer amaranth control. The estimates for the logistic regression would indicate that 1540 kg ha−1would delay Palmer amaranth emerging and growing to 10 cm by an estimated 16.5 days. The Palmer amaranth that emerged in the cereal rye and wheat cover crop treatments took a longer time to reach 10 cm compared to the hairy vetch and crimson clover treatments. POST herbicides were needed for adequate control of Palmer amaranth. The glufosinate-based weed control system provided greater control (75% vs 31%) of Palmer amaranth than did the glyphosate system. These results indicate that a POST only herbicide weed management system did not provide sufficient control of Palmer amaranth, even when used in conjunction with cover crops that produced a moderate level of biomass. Therefore, future recommendations for GR Palmer amaranth control will include integrating cover crops with PRE herbicides, overlaying residual herbicides in-season, timely POST herbicide applications, and hand weeding in order to achieve season-long control of this pest.

Ecological Characteristics of Three Winter Annual Grasses

1998 ◽  
Vol 12 (3) ◽  
pp. 478-483 ◽  
Author(s):  
R. L. Anderson
Keyword(s):  
Winter Wheat ◽  
Seed Production ◽  
Cultural Practices ◽  
Seedling Emergence ◽  
Cultural Control ◽  
Downy Brome ◽  
Jointed Goatgrass ◽  
Annual Grasses ◽  
Winter Annual ◽  
Feral Rye

Producers rely on cultural practices to manage downy brome, jointed goatgrass, and feral rye in winter wheat because there are no effective herbicides for in-crop control. This study characterized seedling emergence, growth, and development of these winter annual grasses, with the goal of suggesting or improving cultural control strategies. Feral rye seedlings emerged within 4 wk, whereas downy brome and jointed goatgrass seedlings emerged over a 10-wk period. Emergence patterns of these grasses suggest that delay of winter wheat planting may be effective in reducing feral rye densities, but this strategy most likely will be ineffective with downy brome or jointed goatgrass. Downy brome began anthesis 1 to 2 wk earlier than the other two grasses and winter wheat. Both downy brome and jointed goatgrass were shorter than winter wheat during the growing season, whereas feral rye was at least as tall as wheat. Producers mow infested wheat to prevent weed seed production, but this practice may not be effective with jointed goatgrass and downy brome because of their short stature and downy brome's earlier development. Conversely, mowing has potential in preventing feral rye seed production. The grasses produced between 340 and 770 seeds/ plant.

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