Status of Weedy Rice (Oryza sativa L.) Infestation and Management Practices in Southern Brazil

Weed Science ◽  
2021 ◽  
pp. 1-35
Author(s):  
Luis A. Avila ◽  
José A. Noldin ◽  
Carlos H. P. Mariot ◽  
Paulo F.S. Massoni ◽  
Marcus V. Fipke ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Management Practices ◽  
Oryza Sativa L ◽  
Conventional Tillage ◽  
Weedy Rice ◽  
Extension Agents ◽  
Southern Brazil ◽  
Herbicide Resistant ◽  
Rice Area ◽  
Infestation Status

Abstract Weedy rice (WR) (Oryza sativa L.) is the most troublesome weed infesting rice paddies in Brazil. Several changes have occurred in this region regarding crop management, especially WR control based on the Clearfield™ (CL) Rice Production System launched in 2003. This survey’s objective was to evaluate the WR infestation status by assessing the producers’ perception and the management practices used in southern Brazil after eighteen years of CL use in Brazil. Rice consultants and extension agents distributed a questionnaire with 213 producers in the Rio Grande do Sul (RS) and Santa Catarina (SC) state in the 2018/19 growing season. In RS, most farms are larger than 150 ha, farmers use minimal or conventional tillage, permanent flooding, adopted the CL system for more than two years, use clomazone PRE tank-mixed with glyphosate at the rice spiking stage, and use crop rotation with soybean [Glycine max (L.) Merr.] or pasture. In SC, rice farms are small, averaging from 20 to 30 ha, farmers predominantly plant pre-germinated rice and do not rotate rice with other crops and roguing is practiced. Comparing both states, the CL System is used in 99.5, and 69.3% of the total surveyed rice area in RS and SC, respectively. Imidazolinone-resistant WR is present in 68.4 and 26.6% of rice farms in RS and SC, respectively. Rice cultivation in Brazil is currently coexisting with WR with minimal integration of control methods. However, integrated practices can control this weed and are fundamental to the sustainability of systems based on herbicide-resistant rice cultivars.

Weedy Rice Update in Arkansas, USA and Adjacent Locales

Weed Science ◽  
2021 ◽  
pp. 1-40
Author(s):  
Nilda Roma-Burgos ◽  
Thomas R. Butts ◽  
Isabel S. Werle ◽  
Sunny Bottoms ◽  
Andy Mauromoustakos
Keyword(s):  
Oryza Sativa ◽  
Crop Rotation ◽  
Control Strategies ◽  
Weedy Rice ◽  
Extension Agents ◽  
County Extension Agents ◽  
Herbicide Resistant ◽  
Resistance Evolution ◽  
Production Practices ◽  
E Mail

Abstract Weedy rice (Oryza sativa L.) is among the most problematic weeds in rice (Oryza sativa L.) production. The commercialization of herbicide-resistant (HR) rice nearly two decades ago provided an effective tool to manage weedy rice; however, resistance evolution and volunteer HR hybrid rice kept weedy rice at the forefront of rice weed control needs. This research aimed to assess the prevalence and severity of weedy rice infestations, identify production practices that may have contributed to an increase in weedy rice, and identify control strategies that may still be effective on weedy rice across Arkansas and adjacent US mid-south locales. Two questionnaires, one for rice growers and consultants and one for County Extension Agents (CEAs), were distributed through e-mail and physical copies in 2020. Thirty-three respondents returned the rice grower (25) and consultant (8) survey representing 26 and seven counties in Arkansas and the Bootheel Missouri area, respectively, as well as four parishes in northeast Louisiana. Eighteen respondents returned the CEA survey. Respondents ranked weedy rice the third most problematic weed in rice, behind Echinochloa spp. and Cyperus spp. The most common infestation levels reported in 78% of fields was less than 12 m−2. Crop rotation (64% growers/consultants, 50% CEAs) and HR rice technology (27% growers/consultants, 50% CEAs) were the top-two most effective methods for weedy rice management, respectively. Tillage and crop rotation practices significantly influenced weedy rice infestation. Rice-soybean [Glycine max (L.) Merr.] rotation had the lowest weedy rice infestation compared to monoculture rice and other crop rotation practices. Crop rotation was not practiced on 26% of reported fields, primarily due to poor drainage. The imidazolinone (IMI)-resistant rice technology was still effective (>70% control) in 60% of fields, but quizalofop-resistant rice is needed to control IMI-resistant weedy rice. Overall, weedy rice remains a challenging weed in rice production.

Spread of herbicide-resistant weedy rice (red rice, Oryza sativa L.) after 5 years of Clearfield rice cultivation in Italy

Plant Biology ◽  
2012 ◽  
Vol 14 (5) ◽  
pp. 751-759 ◽  
Author(s):  
M. Busconi ◽  
D. Rossi ◽  
C. Lorenzoni ◽  
G. Baldi ◽  
C. Fogher
Keyword(s):  
Oryza Sativa ◽  
Oryza Sativa L ◽  
Rice Cultivation ◽  
Weedy Rice ◽  
Red Rice ◽  
Herbicide Resistant ◽  
Clearfield Rice

Surveys of Weed Management on Flooded Rice Yields in Southern Brazil

Weed Science ◽  
2021 ◽  
pp. 1-26
Author(s):  
Anelise L. Silva ◽  
Nereu A. Streck ◽  
Alencar J. Zanon ◽  
Giovana G. Ribas ◽  
Bruno L. Fruet ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Weed Control ◽  
Weed Management ◽  
Management Practices ◽  
Limiting Factors ◽  
Weedy Rice ◽  
Southern Brazil ◽  
Average Yield ◽  
Flooded Rice ◽  
Rice Yields

Abstract One of the main limiting factors for high yields of flooded rice (Oryza sativa L.) is the presence of weeds, especially herbicide-resistant weeds. The aim of this study was to evaluate the association of weed management practices adopted by flooded rice farmers in the State of Rio Grande do Sul (RS) to grain yield. For this purpose, 324 interview surveys were administered to farmers who supplied information about the history of weed management and yields. The answers to the survey indicated that weedy rice (Oryza sativa L.) and Echinochloa sp. were the most important weeds that occurred in flooded rice areas in RS. Advanced growth stage of weeds and inadequate environmental conditions such as air temperature and relative humidity were listed as the main reasons for the low weed control efficacy. Farmers achieved greater rice yields when adopted rice-soybean [Glycine max (L.) Merr.] (9,140 kg ha−1 average yield) and herbicide site of action rotations (8,801 kg ha−1 average yield) along with tank-mixes (8,580 kg ha−1 average yield) as specific management practices for resistant weed control. The use of glyphosate with residual herbicides in tank-mix in rice spiking stage is the main factor related to greater yields. The postemergence applications and their relations with delaying of flooded rice is a factor that reduces rice yield when no spiking glyphosate applications was made. Identification of the most important weeds in terms of occurrence, as well as the knowledge of the main agronomic practices adopted by the farmers, are essential so that recommendations for integrated management practices can be adopted in an increasingly accurate and sustainable-flooded rice areas in Southern Brazil.

scholarly journals Bioherbicidal Properties of Parthenium hysterophorus, Cleome rutidosperma and Borreria alata Extracts on Selected Crop and Weed Species

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 643
Author(s):  
Mst. Motmainna ◽  
Abdul Shukor Juraimi ◽  
Md. Kamal Uddin ◽  
Norhayu Binti Asib ◽  
A. K. M. Mominul Islam ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Plant Extracts ◽  
Oryza Sativa L ◽  
Block Design ◽  
Parthenium Hysterophorus ◽  
Weedy Rice ◽  
Test Plant ◽  
Ageratum Conyzoides ◽  
Natural Herbicide ◽  
Cleome Rutidosperma

Natural product-based herbicides could be the effective alternatives to synthetic chemical herbicides for eco-friendly weed management. This research, therefore, was conducted to identify the phytotoxic properties of Parthenium hysterophorus L., Cleome rutidosperma DC. and Borreria alata (Aubl.) DC. with a view to introducing them as a tool for natural herbicide development. The methanol extracts of these plants were examined on the germination and growth of Zea mays L., Oryza sativa L., Abelmoschus esculentus (L.) Moench and Amaranthus gangeticus L., Oryza sativa f. Spontanea Roshev. (Weedy rice), Echinochloa colona (L.) Link., Euphorbia hirta L., and Ageratum conyzoides L. under laboratory and glasshouse conditions. A complete randomized design (CRD) with five replications and randomized complete block design (RCBD) with four replications were laid out for laboratory and glasshouse experiments, respectively. In the laboratory experiment, three plant extracts of 0, 6.25, 12.5, 50, and 100 g L−1 were tested on survival rate, hypocotyl, and radicle length of eight test plant species. No seed germination of A. conzyoides, E. hirta, and A. gangeticus were recorded when P. hysterophorus extract was applied at 50 g L−1. C. rutidosperma had the same effect on those plants at 100 g L−1. In the glasshouse, similar extracts and concentrations used in the laboratory experiments were sprayed on at the 2–3 leaf stage for grasses and 4–6 for the broadleaf species. Tested plants were less sensitive to C. rutidosperma and B. alata compared to P. hysterophorus extract. Among the weeds and crops, A. conyzoides, E. hirta, A. esculentus and A. gangeticus were mostly inhibited by P. hysterophorus extract at 100 g L−1. Based on these results, P. hysterophorus was the most phytotoxic among the tested plant extracts and could be used for developing a new natural herbicide for green agriculture.

Weedy Rice Diversity in Southern Brazil

Weed Science ◽  
2021 ◽  
pp. 1-37
Author(s):  
Leonard Bonilla Piveta ◽  
José Alberto Noldin ◽  
Nilda Roma-Burgos ◽  
Vívian Ebeling Viana ◽  
Lariza Benedetti ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Flowering Time ◽  
Weed Management ◽  
Phenotypic Diversity ◽  
Weedy Rice ◽  
Phenotypic Traits ◽  
Southern Brazil ◽  
Variable Response ◽  
Cultivated Rice ◽  
Flowering Synchrony

Abstract Weedy rice (Oryza sativa L.) is one of the most troublesome weeds affecting rice (Oryza sativa L.) production in many countries. Weedy rice control is difficult in rice fields because the weed and crop are phenotypically and morphologically similar. Weedy rice can be a source of genetic diversity to cultivated rice. Thus, this study aimed to characterize the morphological diversity of weedy rice in Southern Brazil. Qualitative and quantitative traits of 249 accessions from eight rice growing mesoregions in Rio Grande do Sul (RS) and Santa Catarina (SC) states were analyzed. For each accession, 24 morphological descriptors (14 qualitative and 10 quantitative) were evaluated. All the 249 accessions from RS and SC are of indica lineage. Considering all the phenotypic traits evaluated, the accessions separated into 14 distinct groups. One of the largest groups consisted of plants that were predominantly tall and with green leaves, intermediate shattering, and variable in flowering time. Distinct subgroups exist within larger clusters, showing discernable phenotypic diversity within the main clusters. The variability in flowering time was high (77 to 110 d after emergence), indicating high potential for flowering synchrony with rice cultivars and, consequently, gene flow. This indicates the need to remove escapes when planting herbicide-resistant rice. Thus, weedy rice populations in Southern Brazil are highly diverse and this diversity could result in variable response to weed management.

Genetic characteristics of Korean weedy rice (Oryza sativa L.) by RFLP analysis

Euphytica ◽  
1995 ◽  
Vol 86 (2) ◽  
pp. 103-110 ◽  
Author(s):  
Young-Chan Cho ◽  
Tae-Young Chung ◽  
Hak-Soo Suh
Keyword(s):  
Oryza Sativa ◽  
Oryza Sativa L ◽  
Rflp Analysis ◽  
Weedy Rice ◽  
Genetic Characteristics

Effects of winter flooding on weedy rice (Oryza sativa L.)

2010 ◽  
Vol 29 (11) ◽  
pp. 1232-1240 ◽  
Author(s):  
S. Fogliatto ◽  
F. Vidotto ◽  
A. Ferrero
Keyword(s):  
Oryza Sativa ◽  
Oryza Sativa L ◽  
Weedy Rice ◽  
Winter Flooding

scholarly journals Gene flow from single and stacked herbicide-resistant rice (Oryza sativa): modeling occurrence of multiple herbicide-resistant weedy rice

2017 ◽  
Vol 74 (2) ◽  
pp. 348-355 ◽  
Author(s):  
Joseph Dauer ◽  
Andrew Hulting ◽  
Dale Carlson ◽  
Luke Mankin ◽  
John Harden ◽  
...  
Keyword(s):  
Oryza Sativa ◽  
Gene Flow ◽  
Weedy Rice ◽  
Herbicide Resistant
Sign in / Sign up

Export Citation Format

Share Document