Biological Control of Ducksalad (Heteranthera limosa) by the Waterlily Aphid (Rhopalosiphum nymphaeae) in Rice (Oryza sativa)

Weed Science ◽  
1992 ◽  
Vol 40 (2) ◽  
pp. 333-336 ◽  
Author(s):  
Michael J. Oraze ◽  
Albert A. Grigarick
Keyword(s):  
Biological Control ◽  
Oryza Sativa ◽  
Field Experiments ◽  
Weed Biomass ◽  
Water Vegetation

Ducksalad, an annual broadleaf weed in rice, was infested by waterlily aphid which destroyed much of the above-water vegetation. Field experiments showed aphids reduced total weed biomass by 58 and 87% in 1985 and 1986, respectively. Biomass of seed pods was reduced by more than 82% in both years.

Evolving appropriate zinc fertilization strategy for rice-rice (Oryza sativa) cropping system in Cauvery Delta Zone

2019 ◽  
Vol 56 (3) ◽  
pp. 294-304
Author(s):  
C Sharmila Rahale
Keyword(s):  
Oryza Sativa ◽  
Tamil Nadu ◽  
Field Experiments ◽  
Foliar Spray ◽  
Cropping System ◽  
Green Leaf ◽  
Farm Yard Manure ◽  
Zinc Fertilization ◽  
Initiation Stage ◽  
Cauvery Delta

Six field experiments were conducted at Tamil Nadu Rice Research Institute, Aduthurai to evolve suitable zinc fertilization method for rice - rice (Oryza sativa L.) cropping system in Cauvery delta zone. The treatment includes: T1 : Control, T2 : 100 g zinc sulphate (ZnSO4)/cent in nursery alone., T3 : root dipping alone in 2 % zinc oxide (ZnO) solution, T4 : 25 kg ZnSO4 ha-1, T5 : 37.5 kg ZnSO4 ha-1, T6 : 25 kg ZnSO4 ha-1+ Farm Yard Manure (FYM) 12.5 t ha-1, T7 : 25 kg ZnSO4 ha-1 + Green Leaf Manure (GLM) 6.5 t ha-1, T8 : Tamil Nadu Agricultural University Micro Nutrient (TNAU MN) mixture 25 kg ha-1 as Enriched Farm Yard Manure (EFYM), T9 : TNAU MN mixture 37.5 kg ha-1 as EFYM, T10 : Foliar spray of 0.5% ZnSO4 + 1 % urea at tillering and panicle initiation stage, T11 : 100g ZnSO4 /cent in nursery alone + Foliar spray of 0.5 % ZnSO4 + 1 % urea at tillering and panicle initiation stage (T2+ T10), T12 : root dipping alone in 2 % ZnO solution + Foliar spray of 0.5 % ZnSO4 + 1 % urea at tillering and panicle initiation stage (T3 + T10), T13: 100 g ZnSO4 /cent in nursery alone + root dipping alone in 2 % ZnO solution + Foliar spray of 0.5 % ZnSO4 + 1 % urea at tillering and panicle initiation stage (T2 + T3 + T10). The treatments T5, T6, T7 and T9 were skipped in rabi season to know the residual effect of these treatments in the subsequent season. Among the treatment combinations, application of 25 kg ZnSO4 ha-1 + FYM 12.5 t ha-1 recorded higher grain yield in both kharif (6232 kg ha-1) and rabi (6236 kg ha-1) seasons. The same treatment combination recorded higher Zn content and Zn uptake as well. Regarding soil nutrient content, the same treatment recorded higher N, P and K content. This treatment was followed by application of 25 kg ZnSO4 ha-1 + green leaf manure 6.5 t ha-1. The experimental findings suggested that combination of organic and inorganic sources not only increased the yield but also improves soil health in Cauvery delta zone.

Control of Winged Waterprimrose (Jussiaea decurrens) and Northern Jointvetch (Aeschynomene virginica) with Fungal Pathogens

Weed Science ◽  
1979 ◽  
Vol 27 (5) ◽  
pp. 497-501 ◽  
Author(s):  
C. D. Boyette ◽  
G. E. Templeton ◽  
R. J. Smith
Keyword(s):  
Oryza Sativa ◽  
Glycine Max ◽  
Fungal Pathogens ◽  
Liquid Culture ◽  
Field Experiments ◽  
Colletotrichum Gloeosporioides ◽  
Pathogenic Fungus ◽  
Field Tests ◽  
Wide Range ◽  
Growing Region

An indigenous, host-specific, pathogenic fungus that parasitizes winged waterprimrose [Jussiaea decurrens(Walt.) DC.] is endemic in the rice growing region of Arkansas. The fungus was isolated and identified asColletotrichum gloeosporioides(Penz.) Sacc. f.sp. jussiaeae(CGJ). It is highly specific for parasitism of winged waterprimrose and not parasitic on creeping waterprimrose (J. repensL. var.glabrescensKtze.), rice (Oryza sativaL.), soybeans [Glycine max(L.) Merr.], cotton (Gossypium hirsutumL.), or 4 other crops and 13 other weeds. The fungus was physiologically distinct from C.gloeosporioides(Penz.) Sacc. f. sp.aeschynomene(CGA), an endemic anthracnose pathogen of northern jointvetch[Aeschynomene virginica(L.) B.S.P.], as indicated by cross inoculations of both weeds. Culture in the laboratory and inoculation of winged waterprimrose in greenhouse, growth chamber and field experiments indicated that the pathogen was stable, specific, and virulent in a wide range of environments. The pathogen yielded large quantities of spores in liquid culture. It is suitable for control of winged waterprimrose. Winged waterprimrose and northern jointvetch were controlled in greenhouse and field tests by application of spore mixtures of CGJ and CGA at concentrations of 1 to 2 million spores/ml of each fungus in 94 L/ha of water; the fungi did not damage rice or nontarget crops.

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.

The critical weed-free period in glyphosate-resistant soybean in Ontario is similar to previous estimates using glyphosate-susceptible soybean

2019 ◽  
Vol 99 (4) ◽  
pp. 437-443
Author(s):  
Nader Soltani ◽  
Robert E. Nurse ◽  
Amit J. Jhala ◽  
Peter H. Sikkema
Keyword(s):  
Growth Stage ◽  
Field Experiments ◽  
Yield Loss ◽  
Growth Stages ◽  
Weed Species ◽  
Weed Biomass ◽  
Weed Density ◽  
Weed Interference ◽  
Beginning Of Flowering ◽  
Minimal Reduction

A study consisting of 13 field experiments was conducted during 2014–2016 in southwestern Ontario and southcentral Nebraska (Clay Center) to determine the effect of late-emerging weeds on the yield of glyphosate-resistant soybean. Soybean was maintained weed-free with glyphosate (900 g ae ha−1) up to the VC (cotyledon), V1 (first trifoliate), V2 (second trifoliate), V3 (third trifoliate), V4 (fourth trifoliate), and R1 (beginning of flowering) growth stages, after which weeds were allowed to naturally infest the soybean plots. The total weed density was reduced to 24%, 63%, 67%, 72%, 76%, and 92% in Environment 1 (Exeter, Harrow, and Ridgetown) when soybean was maintained weed-free up to the VC, V1, V2, V3, V4, and R1 soybean growth stages, respectively. The total weed biomass was reduced by 33%, 82%, 95%, 97%, 97%, and 100% in Environment 1 (Exeter, Harrow, and Ridgetown) and 28%, 100%, 100%, 100%, 100%, and 100% in Environment 2 (Clay Center) when soybean was maintained weed-free up to the VC, V1, V2, V3, V4, and R1 stages, respectively. The critical weed-free periods for a 2.5%, 5%, and 10% yield loss in soybean were the V1–V2, VC–V1, and VC–V1 soybean stages in Environment 1 (Exeter, Harrow, and Ridgetown) and V2–V3, V2–V3, and V1–V2 soybean stages in Environment 2 (Clay Center), respectively. For the weed species evaluated, there was a minimal reduction in weed biomass (5% or less) when soybean was maintained weed-free beyond the V3 soybean growth stage. These results shows that soybean must be maintained weed-free up to the V3 growth stage to minimize yield loss due to weed interference.

Red Rice (Oryza sativa) Control and Suppression in Rice (O. sativa)

1991 ◽  
Vol 5 (4) ◽  
pp. 811-816 ◽  
Author(s):  
Sam L. Kwon ◽  
Roy J. Smith ◽  
Ronald E. Talbert
Keyword(s):  
Oryza Sativa ◽  
Plant Growth ◽  
Grain Quality ◽  
Field Experiments ◽  
Red Rice ◽  
Two Cultures ◽  
The Two Cultures ◽  
Rice Yields ◽  
Sequential Treatments ◽  
High Yields

Two field experiments were conducted from 1986 to 1988 to determine efficacy of herbidices and plant growth regulators for red rice control and suppression in water- and drill-seeded rice. Molinate applied PPI with fenoxaprop applied at panicle initiation (PI) of rice controlled 94 and 86% of red rice in water- and drill-seeded rice, respectively, compared with 79 and 49%, respectively, for molinate PPI alone in the two cultures. Although this treatment injured rice slightly (< 30%), rice so treated produced high yields with improved grain quality. Sequential treatments of molinate PPI followed by sethoxydim applied at PI or amidochlor applied at > 90% heading produced comparable rice yields with improved red rice control or suppression and grain quality in both cultures, compared with PPI molinate. Drill-seeded rice treated with molinate PPI followed by fenoxaprop applied at late boot or MH (maleic hydazide) applied 7 d after heading produced higher yield than rice treated with molinate PPI.

Band sowing with hoeing in organic grains: I. Comparisons with alternative weed management practices in spring barley

Weed Science ◽  
2019 ◽  
Vol 68 (3) ◽  
pp. 285-293 ◽  
Author(s):  
Margaret R. McCollough ◽  
Eric R. Gallandt ◽  
Heather M. Darby ◽  
Thomas Molloy
Keyword(s):  
Crop Yield ◽  
Grain Quality ◽  
Management Practices ◽  
Field Experiments ◽  
Spring Barley ◽  
Kernel Weight ◽  
Weed Biomass ◽  
Standard Practice ◽  
Crop Density ◽  
Adverse Weather

AbstractWeeds remain the foremost production challenge for organic small grain farmers in the northeastern United States. Instead of crops sown in narrow, single-line rows, band sowing offers a more uniform spatial arrangement of the crop, maximizing interspecific while reducing intraspecific competition. Weeds in the inter-band zone are controlled by cultivating with aggressive sweeps; tine harrowing can target weeds in both intra- and inter-band zones. Field experiments in Maine and Vermont in 2016 and 2017 evaluated band sowing for improved weed control, crop yield, and grain quality in organic spring barley (Hordeum vulgare L. ‘Newdale’). Specifically, we compared: (1) the standard practice of sowing 16.5-cm rows at a target crop density of 325 plants m−2, (2) narrow-row sowing with increased crop density, (3) wide-row sowing with interrow hoeing, and (4) band sowing both with and (5) without inter-band hoeing. Mustard (Sinapis alba L. ‘Ida Gold’) was planted throughout the experiment as a surrogate weed. Compared with the standard practice, band sowing with hoeing reduced surrogate weed density on average by 45% across site-years. However, effects on weed biomass and yield were inconsistent, perhaps due to suboptimal timing of hoeing and adverse weather conditions. In 1 out of 4 site-years, band sowing with hoeing reduced surrogate weed biomass by 67% and increased crop yield compared with the standard treatment. Results also indicate that band sowing with hoeing may improve 1,000-kernel weight and plump kernel grain-quality parameters.

Genetic main effect and genotype×environment interaction for cooking quality traits in a diallel set of Indica rice (Oryza sativa L.) varieties

2010 ◽  
Vol 61 (6) ◽  
pp. 475 ◽  
Author(s):  
Peyman Sharifi ◽  
Hamid Dehghani ◽  
Ali Moumeni ◽  
Mohammad Moghaddam
Keyword(s):  
Oryza Sativa ◽  
Field Experiments ◽  
Cooking Quality ◽  
Oryza Sativa L ◽  
Block Design ◽  
Environment Interaction ◽  
Quality Traits ◽  
Narrow Sense ◽  
Ge Interaction ◽  
Main Effects

Genetic main effects and genotype × environment (GE) interactions were determined for cooking quality traits of rice (Oryza sativa L.) using a complete diallel cross of seven. The field experiments were carried out over 2 years as a randomised complete block design with two replications. Amylose content (AC), gel consistency (GC) and gelatinisation temperature (GT) were affected by both genetic effects and GE interaction. Grain elongation (GEL) was found to be controlled by genetic main effects and general combining ability (GCA) × environment interaction. The high magnitude of GCA variances for all traits indicated that additive effects were more prominent in the determination of these characteristics. Narrow-sense heritabilities for AC, GT, GC and GEL were 61.21, 60.83, 29.98 and 52.29%, respectively. Among the genetic and GE interaction effects, GCA and GCA × environment were the main components for all traits. Relatively large narrow-sense heritabilities for AC, GT and GEL indicated that selection for these traits could be possible. However, due to the significance of genotype × year effects for AC, GT, and GEL genetic materials should be evaluated over several years in breeding programs.

Interspecific and Intraspecific Interference of Broadleaf Signalgrass (Brachiaria platyphylla) in Rice (Oryza sativa)

Weed Science ◽  
1988 ◽  
Vol 36 (5) ◽  
pp. 589-593 ◽  
Author(s):  
John T. McGregor ◽  
Roy J. Smith ◽  
Ronald E. Talbert
Keyword(s):  
Oryza Sativa ◽  
Field Experiments ◽  
Rice Yield ◽  
Dry Weight ◽  
Quadratic Equation ◽  
Regression Equations ◽  
Area Index ◽  
Rough Rice ◽  
Plant Densities ◽  
Brachiaria Platyphylla

Field experiments were conducted in 1984 and 1985 at Stuttgart, AR, to investigate the interspecific and intraspecific interference of broadleaf signalgrass densities of 0, 10, 50, 100, and 150 plants/m2with rice. In 1984, significant reductions in rice leaf area index (LAI) occurred 6 weeks after emergence with all broadleaf signalgrass densities. The first reduction in LAI occurred 8 weeks after emergence at the density of 150 plants/m2in 1985. Densities of 50 plants/m2or greater reduced rice dry weight 6 weeks after emergence in 1984, and the highest density of 150 plants/m2reduced rice dry weight 12 weeks after emergence in 1985. Height of rice was reduced by densities of 100 and 150 plants/m2. Linear regression equations indicated that each broadleaf signalgrass plant/m2reduced rough rice yield 18 kg/ha both years. Growth of broadleaf signalgrass was reduced by interspecific and intraspecific interference. The dry weight of broadleaf signalgrass increased at a decreasing rate at plant densities of 100 to 150/m2when grown alone in 1984 and 1985, when a quadratic equation best described the response. Regression equations indicated interspecific interference from rice reduced broadleaf signalgrass dry weight an average of 48 and 81% in 1984 and 1985, respectively. The height of broadleaf signalgrass was greater when grown with rice than when grown alone.

Full-season Palmer amaranth (Amaranthus palmeri) interference with cotton (Gossypium hirsutum)

Weed Science ◽  
1999 ◽  
Vol 47 (3) ◽  
pp. 305-309 ◽  
Author(s):  
Matt W. Rowland ◽  
Don S. Murray ◽  
Laval M. Verhalen
Keyword(s):  
Linear Model ◽  
Field Experiments ◽  
Palmer Amaranth ◽  
Lint Yield ◽  
Cotton Lint ◽  
Weed Biomass ◽  
Weed Density ◽  
Fiber Properties ◽  
Fiber Fineness ◽  
Cotton Lint Yield

Four field experiments were conducted in Oklahoma to measure full-season Palmer amaranth interference on cotton lint yield and fiber properties. Density of the weed ranged from 0 to 12 plants 10 m−1of row. Cotton lint yield vs. weed density fit a linear model for densities ⩽ 8 weeds row−1at Perkins and Chickasha in 1996 and at Alms in 1997. At Perkins in 1997, all densities fit a linear model. For each increase of 1 weed row−1, lint yield reductions were 62 kg ha−1(or 10.7%) and 58 kg ha−1(or 11.5%) at Perkins and at Chickasha in 1996, respectively. At Perkins and Alms in 1997, for each 1 weed row−1, lint yield was reduced 71 kg ha−1(or 5.9%) and 112 kg ha−1(or 8.7%), respectively. Lint yield vs. end-of-season weed volume fit a linear model except at Alms in 1997. For each increase of 1 m3of weed plot−1, cotton lint yield in 1996 was reduced by 1.6 and 1.5% at Perkins and Chickasha, respectively. In 1997 at Perkins and Altus (⩽ 6 weeds), each increase of 1 m3of weed plot−1reduced lint yield 1.6 and 2.3%, respectively. Lint yield vs. end-of-season weed biomass fit a linear model in all four experiments. Lint yield was reduced 5.2 to 9.3% for each increase of 1 kg of weed biomass plot−1. Fiber analyses revealed significant differences for micronaire (fiber fineness) among weed densities in two experiments, marginal significance in a third, and none in a fourth. An intermediate number of weeds often resulted in improved fiber micronaires in these environments. No other fiber properties were influenced by weed density.

Propanil Plus Methyl Parathion on Rice (Oryza sativa)

Weed Science ◽  
1988 ◽  
Vol 36 (3) ◽  
pp. 335-339 ◽  
Author(s):  
Gene D. Wills ◽  
Joe E. Street
Keyword(s):  
Oryza Sativa ◽  
Soil Moisture ◽  
Environmental Conditions ◽  
Methyl Parathion ◽  
Field Experiments ◽  
Controlled Environment ◽  
Planting Dates ◽  
Effects Of Temperature ◽  
Effect On Yield ◽  
Wilting Point

Effects of propanil [N-(3,4-dichlorophenyl)propanamide] applied to three- to four-leaf rice (Oryza sativaL.) 1 or 7 days before, after, or tank mixed with methyl parathion (O,O-dimethyl-O-4-nitrophenyl phosphorothioate) were determined under different environmental conditions. Field experiments determined the effect on yield of drill-seeded rice, ‘Labelle’ for two planting dates in 1982 and ‘Lemont’ for one planting date in 1986. Treatments were applied at sunrise and at noon. Growth chamber and greenhouse experiments determined the effects of temperature, relative humidity (RH), and soil moisture on response of Labelle rice. In all experiments, propanil, both alone and with methyl parathion, resulted in 20 to 30% leaf burn during the first week after treatment with rapid recovery to less than 10% injury after 3 to 4 weeks. In field experiments, yields were not reduced in the treated rice below that in the untreated controls. In controlled-environment experiments, rice was not injured by propanil plus methyl parathion more than by propanil alone after 2 to 4 weeks. Both treated and untreated rice were injured more by the environmental conditions of high (40 C) temperature, low (40%) RH, and low (near the wilting point) soil moisture than by low (30 C) temperature, high (100%) RH, and flooded soil.

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