Rice weed control: current technology and emerging issues in temperate rice

1994 ◽  
Vol 34 (7) ◽  
pp. 1021 ◽  
Author(s):  
JE Hill ◽  
RJ Jr Smith ◽  
DE Bayer
Keyword(s):  
United States ◽  
Weed Control ◽  
Cultural Practices ◽  
Management Strategies ◽  
The United States ◽  
Weed Species ◽  
Rice Culture ◽  
Emerging Issues ◽  
Direct Seeded ◽  
The Cost

Among temperate rice areas, the United States and Australia are most similar in climate and in the mechanisation of rice culture. Many weed problems, even weed species invading rice, are common to both countries; and the present technology for weed control as well as concern for the impact of these technologies to environmental quality, herbicide resistance, and other weed-related issues bear many similarities. Application of current, and any new, technologies to emerging issues in US rice weed control will therefore be directly relevant to rice production in Australia and all other temperate areas struggling with the same challenges. Weeds are a significant problem in temperate rice culture. In the United States, rice is mechanically direct-seeded, allowing weeds to germinate and establish with the crop. In the last 15 years weed growth and competition has been increased by the adoption of semi-dwarf cultivars, high N fertilisation, and, in water-seeded rice, shallow flooding. High rates, and often multiple applications, of herbicides have been necessary to maximise the yield potential of these cultural systems. Advances in cultural practices and herbicide technology have maintained, if not improved, weed control; but nearly 30 years of propanil use in the southern USA resulted in propanil-resistant barnyard grass Echinochloa crus-galli (L.) Beauv., and after 4 years of continuous use, bensulfuron resistance to 4 aquatic weed species was discovered in California. Although herbicides with different mechanisms of action are needed for alternation in resistance management strategies, fewer are likely to be available. Social and environmental concerns have slowed the development and registration of rice herbicides and increased the cost of controlling weeds. Water quality deterioration from ricefield tailwaters, drift to sensitive crops, the cost of renewing registration in aquatic systems, and weed resistance all forecast reduced herbicide use in rice. Neither cultural practices nor herbicides alone can solve weed problems in direct-seeded, mechanised rice culture. With fewer herbicides and a cultural system highly vulnerable to weed losses, integrated management strategies with better information on which to base weed control decisions will be needed to solve weed problems in temperate rice.

Significance and Distribution of Herbicide Resistance

1990 ◽  
Vol 4 (1) ◽  
pp. 141-149 ◽  
Author(s):  
Jodie S. Holt ◽  
Homer M. Lebaron
Keyword(s):  
United States ◽  
United Kingdom ◽  
Herbicide Resistance ◽  
Management Strategies ◽  
The United States ◽  
West Germany ◽  
Weed Species ◽  
Research Education ◽  
Resistant Species ◽  
The United Kingdom

Herbicide-resistant weed species have become widespread in recent years. Fifty-five weed species, including 40 dicots and 15 grasses, are known to have biotypes resistant to the triazine herbicides. One or more resistant species have arisen in 31 states of the United States, four provinces of Canada, 18 countries in Europe, and Israel, Japan, Australia, and New Zealand. Resistance to other classes of herbicides is more restricted in distribution and recent in detection but is becoming more widespread. Trifluralin resistance has spread in the southeastern United States and has been detected in Canada, while 11 species with biotypes resistant to paraquat have been reported around the world. Diclofop-methyl-resistant weed species are problems in cereal production in Australia and have been found in Oregon, South Africa, and the United Kingdom. Resistance to the substituted ureas also is present in the United Kingdom, West Germany, and Hungary. Within the last 2 yr, biotypes of at least four weed species resistant to the sulfonylurea herbicides have arisen following several annual applications of these herbicides in wheat. Some resistant biotypes have multiple resistance to different classes of herbicides, which greatly exacerbates the threat of resistance. Herbicide resistance has reached the level where more concerted efforts are needed in research, education, and development of effective management strategies to preserve herbicides as essential tools of agricultural technology.

Evaluation of Thermal Implements and Organic Herbicides for Weed Control in a Nonbearing Almond (Prunus dulcis) Orchard

2012 ◽  
Vol 26 (1) ◽  
pp. 110-116 ◽  
Author(s):  
Anil Shrestha ◽  
Marcelo Moretti ◽  
Nathalia Mourad
Keyword(s):  
Weed Control ◽  
Weed Management ◽  
Management Strategies ◽  
Prunus Dulcis ◽  
Weed Species ◽  
Weed Biomass ◽  
Lemongrass Oil ◽  
Almond Orchards ◽  
Treatment Comparisons ◽  
The Cost

Sustainable weed management strategies are needed for organic orchard systems. A study was conducted in an almond orchard in Fresno, CA from 2009 to 2011. Treatment comparisons included steam, flame, and broad applications of either lemongrass oil or D-limonene. An untreated control was also included. The experimental design was a randomized complete block with four replications. Weekly evaluations on percent weed control were taken and weed biomass was sampled 4 to 8 wk after treatment (WAT). Weed control and biomass differed between seasons but, in general, steam and flame provided as much as 95% control 1 WAT. However, the effects lasted only 3 to 4 wk as new weeds emerged or the treated weeds overcame the suppressive effects of the thermal treatments. Weed biomass was 95% lower in the steam- and flame-treated plots compared with the untreated plots in summer. Both steam and flame were more effective on certain erect-growing broad-leaved weed species than on prostrate-growing weeds and grasses. Lemongrass oil provided very little weed control. However, D-limonene provided up to 95% weed control 1 WAT and in one experiment 53% control was observed up to 5 WAT. This herbicide also resulted in lower weed biomass than the untreated and the thermal-treated plots. Monthly applications of steam or flame or applications of D-limonene every 5 to 6 wk may have to be made to adequately suppress weeds in organic almond orchards. Cost estimates of propane use were $41 to 56 ha−1 and $26 ha−1 for the steam and flame treatments, respectively. The cost of D-limonene was estimated as $275 ha−1. To optimize weed control and costs, these tools may need to be used in combination rather than by themselves.

Biology, ecology, and management of dogwood borer in eastern apple orchards

2003 ◽  
Vol 135 (5) ◽  
pp. 615-635 ◽  
Author(s):  
J. Christopher Bergh ◽  
Tracy C. Leskey
Keyword(s):  
United States ◽  
Vascular Tissue ◽  
Cultural Practices ◽  
Management Strategies ◽  
The United States ◽  
Larval Feeding ◽  
Geographical Regions ◽  
Important Pest ◽  
Important Host ◽  
Dogwood Borer

AbstractThe dogwood borer, Synanthedon scitula (Harris) (Lepidoptera: Sesiidae), has the broadest host range of the clearwing moths and is considered to be an economically important pest of many ornamental, fruit, and nut trees. Since the 1980s, dogwood borer has been recognized as an increasingly important, indirect pest of apple, Malus domestica Borkh. (Rosaceae), in eastern North America, owing mainly to increased plantings of apple on size-controlling rootstocks that promote the formation of adventitious root initials (burr knots) on the rootstock and scion. Burr knots appear to be preferred oviposition sites for dogwood borer females, although infestations can also be initiated in wounds, pruning cuts, and crotches on the branches and trunk. Larval feeding in burr knots does not adversely affect the growth and vigor of apple trees, but their mining outward from burr knots into vascular tissue can ultimately cause tree decline and death. Chlorpyrifos is the most effective insecticide for controlling dogwood borer. A supplemental label in the United States permits post-bloom, trunk drench applications of chlorpyrifos specifically for control of borers in apple, with several restrictions that preclude control of infestations higher in the tree. The ongoing review of pesticide tolerances dictated by the 1996 Food Quality Protection Act of the United States of America makes the long-term availability of this chemical uncertain. Cultural practices, such as deeper planting or berming, can reduce the likelihood of infestation of new apple plantings by dogwood borer, although they do not preclude infestations from developing above the graft union. This review and discussion is based on our contention that research toward the development of alternative, behaviorally based management strategies for dogwood borer in apple and other economically important host plants is warranted. Our review and synthesis of the dogwood borer literature revealed important gaps in knowledge about basic aspects of its biology that pertain directly to the development of alternative control tactics based on behavioral manipulation. There is considerable confusion surrounding the sex pheromone of dogwood borer and conflicting results on the response of males to isomers and blends of isomers of its purported pheromone. Studies using sex attractants to monitor its phenology in apple and non-apple habitats have yielded discrepant results and conclusions. Differences in the effectiveness of commercially available pheromone lures for trapping dogwood borer have been reported and the ability of pheromone traps to accurately reflect emergence or population density remains in question. Regardless of pronounced differences in the duration and modality of the seasonal flight of dogwood borer among different geographical regions within its range, the conclusion of univoltinism across most of its range has been perpetuated, based on extremely limited developmental data collected exclusively from individuals that developed on dogwood.

Future Needs in Weed Science

Weed Science ◽  
1984 ◽  
Vol 32 (6) ◽  
pp. 850-855 ◽  
Author(s):  
C. G. McWhorter
Keyword(s):  
United States ◽  
Weed Control ◽  
Agricultural Production ◽  
Crop Yields ◽  
The United States ◽  
Grain Drying ◽  
Direct Competition ◽  
The Cost ◽  
And Storage

Losses due to weeds in the United States and the cost of their control are now more than $20 billion annually (35). Of this total, $13 billion represents a 10% annual loss in agricultural production that includes not only the direct competition of weeds to reduce crop yields but also the reduced quality of produce, livestock losses, and increased cost of fertilizer, irrigation, harvesting, grain drying, transportation, and storage. In addition, farmers spend more than $7.2 billion to control weeds each year. About 43% of the expenditures to control weeds is the retail cost of herbicides, $3.1 billion, in 1980 (15). The value of herbicides sold in 1984 will probably be about 15% higher than in 1980. An additional $4.1 billion represents the cost of tillage and hand labor required for weed control (35). The total loss of over $20 billion represents an indirect annual weed tax of about $85 on each individual living in the United States.

scholarly journals The Anti-Jewish Narrative

Philosophia ◽  
2021 ◽  
Author(s):  
Nathan Cofnas
Keyword(s):  
United States ◽  
Jewish Identity ◽  
Cultural Practices ◽  
The United States ◽  
Recent History ◽  
High Intelligence ◽  
Liberal Multiculturalism ◽  
Anti Jewish ◽  
Intellectual Movements

AbstractAccording to the mainstream narrative about race, all groups have the same innate dispositions and potential, and all disparities—at least those favoring whites—are due to past or present racism. Some people who reject this narrative gravitate toward an alternative, anti-Jewish narrative, which sees recent history in terms of a Jewish/gentile conflict. The most sophisticated promoter of the anti-Jewish narrative is the evolutionary psychologist Kevin MacDonald. MacDonald argues that Jews have a suite of genetic adaptations—including high intelligence and ethnocentrism—and cultural practices that lead them to undermine gentile society to advance their own evolutionary interests. He says that Jewish-designed intellectual movements have weakened gentile identity and culture while preserving Jewish identity and separatism. Cofnas recently argued that MacDonald’s theory is based on “systematically misrepresented sources and cherry-picked facts.” However, Cofnas gave short shrift to at least three key claims: (a) Jews are highly ethnocentric, (b) liberal Jews hypocritically advocate liberal multiculturalism for gentiles/gentile countries but racial purity and separatism for Jews/Israel, and (c) Jews are responsible for liberalism and mass immigration to the United States. The present paper examines these claims and concludes that MacDonald’s views are not supported.

scholarly journals SWK-11. ASSESSMENT OF THE INDIRECT COSTS ASSOCIATED WITH PROTON THERAPY TREATMENT FOR ALBERTA PATIENTS REFERRED OUT OF COUNTRY

2020 ◽  
Vol 22 (Supplement_3) ◽  
pp. iii466-iii466
Author(s):  
Karina Black ◽  
Jackie Middleton ◽  
Sunita Ghosh ◽  
David Eisenstat ◽  
Samor Patel
Keyword(s):  
United States ◽  
Proton Therapy ◽  
Malignant Tumors ◽  
Indirect Costs ◽  
The United States ◽  
Current Data ◽  
Opportunity Costs ◽  
Proton Treatment ◽  
Out Of Pocket Expenses ◽  
The Cost

Abstract BACKGROUND Proton therapy for benign and malignant tumors has dosimetric and clinical advantages over photon therapy. Patients in Alberta, Canada are referred to the United States for proton treatment. The Alberta Heath Care Insurance Plan (AHCIP) pays for the proton treatment and the cost of flights to and from the United States (direct costs). This study aimed to determine the out-of-pocket expenses incurred by patients or their families (indirect costs). METHODS Invitation letters linked to an electronic survey were mailed to patients treated with protons between 2008 and 2018. Expenses for flights for other family members, accommodations, transportation, food, passports, insurance, and opportunity costs including lost wages and productivity were measured. RESULTS Fifty-nine invitation letters were mailed. Seventeen surveys were completed (28.8% response rate). One paper survey was mailed at participant request. Nine respondents were from parent/guardian, 8 from patients. All patients were accompanied to the US by a family member/friend. Considerable variability in costs and reimbursements were reported. Many of the accompanying family/friends had to miss work; only 3 patients themselves reported missed work. Time away from work varied, and varied as to whether it was paid or unpaid time off. CONCLUSIONS Respondents incurred indirect monetary and opportunity costs which were not covered by AHCIP when traveling out of country for proton therapy. Prospective studies could help provide current data minimizing recall bias. These data may be helpful for administrators in assessing the societal cost of out-of-country referral of patients for proton therapy.

Converging cultures of communication: A comparative study of Internet use in China, Europe, and the United States

2021 ◽  
Vol 23 (7) ◽  
pp. 1751-1772
Author(s):  
Jacob Ørmen ◽  
Rasmus Helles ◽  
Klaus Bruhn Jensen
Keyword(s):  
United States ◽  
Comparative Study ◽  
Interpersonal Communication ◽  
Internet Use ◽  
Cultural Practices ◽  
The United States ◽  
Human Communication ◽  
Shared Reality ◽  
Cultural Research ◽  
Media Systems

Global Internet use is circumscribed by local political and economic institutions and inscribed in distinctive cultural practices. This article presents a comparative study of Internet use in China, the United States, and five European countries. The empirical findings suggest a convergence of cultures, specifically regarding interpersonal communication, alongside characteristic national and sociodemographic configurations of different prototypes of human communication. Drawing on the classic understanding of communication as a cultural process producing, maintaining, repairing, and transforming a shared reality, we interpret such configurations as cultures of communication, which can be seen to differ, overlap, and converge across regions in distinctive ways. Looking beyond traditional media systems, we call for further cross-cultural research on the Internet as a generic communication system joining global and local forms of interaction.

scholarly journals Preservice Teachers’ Discursive Constructions of Cultural Practices in a Multicultural Telecollaboration

2019 ◽  
Vol 21 (1) ◽  
pp. 82 ◽  
Author(s):  
Baburhan Uzum ◽  
Bedrettin Yazan ◽  
Netta Avineri ◽  
Sedat Akayoglu
Keyword(s):  
United States ◽  
Teacher Education ◽  
Preservice Teachers ◽  
Social Justice ◽  
Cultural Practices ◽  
The United States ◽  
Discursive Constructions

The study reports on a telecollaboration exchange between two teacher education classes in the United States and Turkey. In synchronous and asynchronous conversations, preservice teachers (PTs) engaged in social justice issues and made discourse choices that captured culture(s) and communities as diverse or essentialized. These choices were affected by PTs’ positionings and impacted how PTs connected to individuals only and/or to broader society.  PTs asked questions that created space for critical discussions and facilitated awareness of diversity, yet sometimes led to overgeneralizations. The study has implications for designing telecollaborations that promote language and practices to unpack the issues of social justice.

scholarly journals The Effect of Massachusetts' Health Reform on Employer-Sponsored Insurance Premiums

2010 ◽  
Vol 13 (2) ◽  
Author(s):  
John F Cogan ◽  
R. Glenn Hubbard ◽  
Daniel Kessler
Keyword(s):  
United States ◽  
Health Reform ◽  
Medical Expenditure Panel Survey ◽  
Private Insurance ◽  
The United States ◽  
Medical Expenditure ◽  
Insurance Premiums ◽  
Reform Plan ◽  
The Difference ◽  
The Cost

In this paper, we use publicly available data from the Medical Expenditure Panel Survey - Insurance Component (MEPS-IC) to investigate the effect of Massachusetts' health reform plan on employer-sponsored insurance premiums. We tabulate premium growth for private-sector employers in Massachusetts and the United States as a whole for 2004 - 2008. We estimate the effect of the plan as the difference in premium growth between Massachusetts and the United States between 2006 and 2008—that is, before versus after the plan—over and above the difference in premium growth for 2004 to 2006. We find that health reform in Massachusetts increased single-coverage employer-sponsored insurance premiums by about 6 percent, or $262. Although our research design has important limitations, it does suggest that policy makers should be concerned about the consequences of health reform for the cost of private insurance.

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