The effect of benomyl on Gloeotinia temulenta under laboratory and field conditions

1971 ◽  
Vol 11 (53) ◽  
pp. 693 ◽  
Author(s):  
DC McGee
Keyword(s):  
Lolium Perenne ◽  
No Reduction ◽  
Field Studies ◽  
Field Conditions ◽  
Seed Infection ◽  
Laboratory Studies ◽  
Causal Organism ◽  
Infected Seed ◽  
Application Rates ◽  
Seed Crops

Laboratory studies confirmed that benomyl can completely suppress apothecial formation of Gloeotinia temulenta, the causal organism of blind seed disease in grasses. Field studies in Lolium perenne seed crops showed that benomyl, applied at 2.80 and 5.60 kg/hectare, reduced the numbers of apothecia formed by 80 and 90 per cent respectively, while no reduction was apparent at 0.56 kg/hectare. Better results were obtained when the compound was applied in November, just before flowering, than when applied in September or October. At the application rates used, benomyl did not protect plants against seed infection. However, the degree of suppression of apothecial formation possible with benomyl suggests that, in areas where reinfestation of fields with infected seed after harvest is light, the compound should control blind seed disease by limiting formation of apothecia, which are the source of ascospore inoculum, to insignificant proportions.

Persistence of Rimsulfuron on Perennial Ryegrass (Lolium perenne) and Annual Bluegrass (Poa annua) Foliage

2006 ◽  
Vol 20 (2) ◽  
pp. 345-350 ◽  
Author(s):  
Whitnee L. Barker ◽  
Josh B. Beam ◽  
Shawn D. Askew
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Field Studies ◽  
Poa Annua ◽  
Laboratory Studies ◽  
Cool Season ◽  
Annual Bluegrass ◽  
Rinse Water ◽  
Viable Method ◽  
Water Rinse

Field studies have shown that rimsulfuron can move laterally with mower tires and injure neighboring cool-season grasses, indicating that persistent chemical can dislodge from turfgrass foliage. Laboratory studies were conducted to evaluate persistence and stability of14C rimsulfuron on perennial ryegrass and annual bluegrass foliage. Rimsulfuron was absorbed by annual bluegrass and perennial ryegrass equivalently, and persisted equally on foliage of each species. When extracted with a water rinse, 57% of applied rimsulfuron was recovered after 10 min, and 42% of applied rimsulfuron was recovered after 96 h. Rimsulfuron was stable 4 d after application based on comparison of rinse water chromatograms to stock solution chromatograms. These data indicate that appreciable rimsulfuron persists on turf foliage for 4 d. Thus, limiting traffic on treated areas for several hours to allow drying is not a viable method to prevent lateral relocation of rimsulfuron, and subsequent injury to cool-season turfgrasses.

scholarly journals 003 Epidemiology and Control of Pepper Stip

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 441B-441
Author(s):  
Richard Smith ◽  
Robert Mullen ◽  
Tim Hartz
Keyword(s):  
Total Nitrogen ◽  
Mineral Nutrition ◽  
No Reduction ◽  
Nitrogen Nutrition ◽  
Field Studies ◽  
Nitrogen Application ◽  
Physiological Disorder ◽  
Resistant Cultivars ◽  
Application Rates ◽  
And Control

Pepper stip is a physiological disorder manifested as gray-brown to greenish spots occurring on the fruit of bell, pimento, Anaheim, and other types of peppers, most noticeably on red fruit that mature under fall conditions. Most hybrid bell cultivars are resistant to the malady; the problem is most severe for pepper growers reliant on less-expensive, open-pollinated cultivars. In 1995, we initiated studies to evaluate the possible link between mineral nutrition and this disorder. Two susceptible open-pollinated cultivars and two resistant hybrid cultivars were grown in randomized plots at seven sites. Significant correlations were seen between the levels of potassium (r = 0.59) and calcium (r = -0.37) in whole leaves and the incidence of stip (P = 0.05). The stip-resistant cultivars also maintained less total nitrogen in the whole leaves than susceptible cultivars (P = 0.05). In 1996 and 1997, we undertook field studies to evaluate the effects of varying calcium and nitrogen application rates. Inconsistent results were observed with calcium applications. Moderate reductions in stip incidence was observed at some sites and no reduction at others following foliar calcium applications. Nitrogen nutrition had no effect on stip severity. In 1998, evaluation of a large number of open-pollinated cultivars was undertaken; `Gusto' showed excellent tolerance to pepper stip, followed by `Taurus' and `Cal Wonder 300'. We conclude that growers that are reliant on open-pollinated cultivars can utilize these cultivars to minimize the incidence of pepper stip.

Comparison Of Field And Laboratory Studies Results Of The Clay Soils Deformability Characteristics

2019 ◽  
pp. 40-45
Keyword(s):  
Low Cost ◽  
Field Studies ◽  
Field Conditions ◽  
Clay Soils ◽  
Saturated Soils ◽  
Natural Occurrence ◽  
Laboratory Studies ◽  
Load Tests ◽  
Definition Of ◽  
Water Saturated

Determination of the deformability characteristics of weak water-saturated soils is a complex process. Firstly, it is difficult to preserve the natural structure of the soil sample taken for the study in the laboratory. Secondly, according to the latest studies, in natural occurrence there is a constant pore pressure, which must be taken into account when determining the characteristics of deformability and strength of clay soils. During many years it was established that the compressibility characteristic of soils obtained under laboratory conditions differs sharply from the result of characterization in field conditions. It is proposed to use the characteristics of compressibility and strength of soils obtained in the course of low-cost laboratory studies, compared with the definition of these characteristics in expensive field conditions. The results of the comparison of numerous laboratory and field studies of the properties of weak water-saturated soils of the base of various regions of Russia are presented. On the basis of the data obtained, when studying the characteristics of deformability of weak water-saturated clay soils, it is recommended to use only laboratory methods and not to conduct additional field plate load tests, except in the case of construction of unique structures,

The role of seed infection in the spread of blackleg of rape in Western Australia

1977 ◽  
Vol 17 (89) ◽  
pp. 1040 ◽  
Author(s):  
PMcR Wood ◽  
MJ Barbetti
Keyword(s):  
Western Australia ◽  
Leptosphaeria Maculans ◽  
Field Conditions ◽  
In Vitro Test ◽  
Seed Infection ◽  
Infected Seed ◽  
Vitro Test

A survey of rapeseed crops in Western Australia for blackleg (Leptosphaeria maculans (Desm.) Ces and de Not) infection was conducted in November 1972. No correlation between levels of pod infection in November and seed infection at maturity was established. An in vitro test showed that 67 per cent of L. maculans infected seeds gave rise to seedlings with one or both cotyledons infected. Under field conditions in 1974, a plot grown from 5.9 per cent infected seed resulted in 19.0 per cent of plants developing blackleg crown cankers, whereas a plot containing 0.08 per cent infected seed gave 1.1 per cent of plants infected. The following year at a different location, a sample assessed at 0.5 per cent infection produced only 0.06 per cent of plants with crown cankers, and, 0.08 per cent infected seed yielded 0.08 per cent infected plants.

scholarly journals Plant growth regulators: a success story in perennial ryegrass seed crops

2010 ◽  
Vol 14 ◽  
pp. 47-57
Author(s):  
R.J. Chynoweth ◽  
M.P. Rolston ◽  
B.L. Mccloy
Keyword(s):  
Plant Growth ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Dry Matter ◽  
Success Story ◽  
Dry Matter Partitioning ◽  
Seed Retention ◽  
Application Rates ◽  
Seed Crops ◽  
Seed Yields

The introduction of the plant growth regulator trinexapac-ethyl (Moddus) has increased seed yields in perennial ryegrass (Lolium perenne) by up to 50% in New Zealand. Application rates from ten trials have confirmed that approximately 1.6 l/ha are optimum. Yield increases are a result of increased harvest index and better dry matter partitioning to the harvested parts. The resulting changes in harvest components include increasing seed head density and seeds per spikelet (better seed retention) associated with delayed lodging. Keywords: Lolium perenne, lodging, Moddus, seeds/spikelet, trinexapac-ethyl

Efficacy of Flazasulfuron for Control of Annual Bluegrass (Poa annua) and Perennial Ryegrass (Lolium perenne) as Influenced by Nitrogen

Weed Science ◽  
2010 ◽  
Vol 58 (4) ◽  
pp. 449-456 ◽  
Author(s):  
James T. Brosnan ◽  
Adam W. Thoms ◽  
Patrick E. McCullough ◽  
Gregory R. Armel ◽  
Gregory K. Breeden ◽  
...  
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
N Fertilizer ◽  
Poa Annua ◽  
Laboratory Studies ◽  
Cool Season ◽  
Annual Bluegrass ◽  
Herbicide Treatment ◽  
Application Rates ◽  
N Fertility

Certain sulfonylurea (SU) herbicides are used to remove overseeded cool-season species from bermudagrass. The effects of nitrogen (N) on the efficacy of a new SU herbicide, flazasulfuron, have not been determined. Field and laboratory studies were conducted in 2008 and 2009 evaluating the efficacy of flazasulfuron for control of overseeded perennial ryegrass contaminated with annual bluegrass. Flazasulfuron was applied at rates of 4.4, 8.8, and 17.5 g ha−1alone, and in between sequential applications of N fertilizer at 73 kg N ha−1. N was granularly applied immediately prior to herbicide treatment and 4 wk later. In both years, the level of annual bluegrass control with flazasulfuron and two applications of N at 73 kg N ha−1was significantly greater than following treatment with flazasulfuron alone. This response was observed for all application rates of flazasulfuron on every rating date. The level of annual bluegrass control with flazasulfuron at 4.4 g ha−1and two applications of N at 73 kg ha−1was greater than flazasulfuron at 17.5 g ha−1alone each year. No significant differences in perennial ryegrass control were observed for flazasulfuron with and without N fertility. In laboratory studies with annual bluegrass, treatment with N fertilizer at 73 kg N ha−1increased translocation of14C flazasulfuron (and any potential metabolites) from treated annual bluegrass leaves to other shoot tissues by 18% at 1 h after treatment and 22% at 4 h after treatment compared to plants not treated with N fertilizer. This increase in translocation may explain the increased level of annual bluegrass control observed in the field.

Foliar Penetration and Phytotoxicity of Paraquat as Influenced by Peanut Cultivar1

1991 ◽  
Vol 18 (2) ◽  
pp. 67-71 ◽  
Author(s):  
G. Wehtje ◽  
J. W. Wilcut ◽  
J. A. McGuire ◽  
T. V. Hicks
Keyword(s):  
Arachis Hypogaea ◽  
Untreated Control ◽  
Field Studies ◽  
Yield Potential ◽  
Laboratory Studies ◽  
Foliar Absorption ◽  
Arachis Hypogaea L ◽  
Herbicide Treatments ◽  
Peanut Cultivars

Abstract Field studies were conducted over a three year period to examine the sensitivity of four peanut (Arachis hypogaea L.) cultivars (Florunner, Sunrunner, Southern runner, and NC 7) to foliar applications of paraquat (1, 1′-dimethyl-4, 4′-bipyridinium ion). Treatments included an untreated control and four herbicide treatments: paraquat applied alone at 0.14 and 0.28 kg/ha, or tank mixed with alachlor [2-chloro-N-(2, 6-diethylphenyl)-N-(methoxymethyl)acetamide] at 4.40 kg/ha. Weeds were hand-removed so that only herbicidal treatments were variables. Paraquat phytotoxicity did not differ between cultivars. No cultivar evaluated was abnormally sensitive nor tolerant to any paraquat-containing treatment. Laboratory studies utilizing radio labelled paraquat revealed that foliar absorption and translocation of paraquat did not vary between peanut cultivars. Yield differences were attributed to differences in yield potential between cultivars.

scholarly journals Comparison of Herbicides for Control of Diclofop-Resistant Italian Ryegrass in Wheat

Agriculture ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 135 ◽  
Author(s):  
Taghi Bararpour ◽  
Ralph Hale ◽  
Gurpreet Kaur ◽  
Jason Bond ◽  
Nilda Burgos ◽  
...  
Keyword(s):  
Triticum Aestivum ◽  
Winter Wheat ◽  
Lolium Perenne ◽  
Wheat Yield ◽  
Field Studies ◽  
Triticum Aestivum L ◽  
Italian Ryegrass ◽  
Lolium Perenne L

Diclofop-resistant Italian ryegrass (Lolium perenne L. ssp. Multiflorum (Lam.) Husnot) is a dominant weed problem in non-irrigated winter wheat (Triticum aestivum L.) in mid-south USA. Field studies were conducted from 2001 to 2007 to evaluate the efficacy of herbicides for diclofop-resistant ryegrass control and effect on wheat yield. In 2001 through 2004, chlorsulfuron/metsulfuron at 0.026 kg ha−1 preemergence (PRE) followed by (fb) mesosulfuron at 0.048 kg ha−1 at 4-leaf to 2-tiller ryegrass provided 89% control of diclofop-resistant Italian ryegrass, resulting in the highest wheat yield (3201 kg ha−1). Flufenacet/metribuzin at 0.476 kg ha−1 applied at 1- to 2-leaf wheat had equivalent Italian ryegrass control (87%), but lesser yield (3013 kg ha−1). In 2005–2006, best treatments for Italian ryegrass control were chlorsulfuron/metsulfuron, 0.013 kg ha−1 PRE fb mesosulfuron 0.015 kg ha−1 at 3- to 4-leaf ryegrass (92%); metribuzin, 0.280 kg ha−1 at 2- to 3- leaf wheat fb metribuzin at 2- to 3-tiller ryegrass (94%); chlorsulfuron/metsulfuron (0.026 kg ha−1) (89%); and flufenacet/metribuzin at 1- to 2-leaf wheat (89%). Chlorsulfuron/metsulfuron fb mesosulfuron provided higher yield (3515 kg ha−1) than all other treatments, except metribuzin fb metribuzin.

scholarly journals Estimation of ascochytosis infection of samples and lines of chickpea sorts in natural field conditions in Uzbekistan

2020 ◽  
pp. 74-77
Author(s):  
J. T. Nakhalbaev ◽  
I. Kh. Khamdamov
Keyword(s):  
Field Conditions ◽  
Seed Infection ◽  
Natural Field ◽  
The Third ◽  
Experimental Station ◽  
Leguminous Crops ◽  
Sowing Period ◽  
Research Institute

Relevance and methods. The information on the influence of samples of chickpea sorts, time of planting the lines of chickpeas on seed infection with ascochytosis and on the weight of grain on one plant bush is presented in this article. Samples of chickpea sorts and lines were studied during the first sowing period — the first decade of March and the second sowing period — the third decade of March. Ascochytosis infection was evaluated in natural field conditions. The study was conducted at the Central Experimental Station of the Galaaral Research Institute of Grain and Leguminous Crops in 2015–2017 in Uzbekistan.Results. According to the three-year study, it was found that in the years when there was a lot of precipitation days, sorts Yulduz, ILC 263 and MП 2015/1 of the lines during the first sowing were determined to be infected with acochytosis up to 6 points. During the first sowing period of this cv., there was a decrease in the weight of grains on one plant bush compared to the second sowing period. Cv. ILC 3279, Umid and line 14442 were found to be virtually undamaged in natural field conditions with ascohitosis during both planting periods. It wasfound our that the weight of cv. Мustaqillik-20, line 14442 grain on one plant bush remained high during both planting periods.

scholarly journals STUDI LALAT PENGOROK DAUN LIRIOMYZA SPP. PADA PERTANAMAN BAWANG DAUN, DAN PARASITOID OPIUS CHROMATOMYIAE BELOKOBYLSKIJ & WHARTON (HYMENOPTERA: BRACONIDAE)

2009 ◽  
Vol 9 (1) ◽  
pp. 22-31
Author(s):  
Rusli Rustam ◽  
Aunu Rauf ◽  
Nina Maryana ◽  
Pudjianto Pudjianto ◽  
Dadang Dadang
Keyword(s):  
Age Distribution ◽  
Host Density ◽  
Field Studies ◽  
Reproductive Value ◽  
Laboratory Studies ◽  
Demographic Parameter ◽  
Liriomyza Huidobrensis ◽  
Stable Age Distribution ◽  
Net Reproduction ◽  
Density Results

Studies on Leafminer Liriomyza spp. in Green Onion Fields, and Parasitoid Opius chromatomyiae Belokobylskij & Wharton (Hymenoptera: Braconidae).  Field studies were conducted to determine population abundance of leafminers and their parasitoids in green onion fields in Puncak, West Java. In addition to that, laboratory studies were carried out to determine demographic parameter of Opius chromatomyiae as well as response of parasitoid to increasing host density. Results revealed that green onions were infested by two species of leafminers, Liriomyza huidobrensis and Liriomyza chinensis.  Leafminer flies emerged from Erwor leaves (54.5) were significantly higher than those of RP leaves (18.65) (P = 0.0005). However, number of  leafminer flies caught on sticky traps was not statistically different (P = 0.297).  Two species of parasitoid, Hemiptarsenus varicornis and O. chromatomyiae, were associated with leafminers in green onion fields. Higher number of parasitoids emerged from Erwor leaves (13.68) as compared to RP (6.90) (P =0.0007 ). However, level of parasitization were 24.36% on Erwor and 28.45% on RP, and was not significantly different (P = 0.387). Laboratory studies indicated that net reproduction (Ro) of O. chromatomyiae was 28.55, generation time (T) 15.96 days, intrinsic growth rate 0.21, and total of reproductive value 223.64.  The stable age distribution of parasitoid were 37.93% eggs, 24.92% larvae, 20.36% pupae and 16.78% adults.  The parasitoid showed functional response type II to increasing host density, with a = 0.08 and Th = 2.58.

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