|
|
|
| Registros recuperados: 12 | |
|
|
| Richter,Gean Leonardo; Streck,Nereu Augusto; Zanon,Alencar Junior; Ulguim,André da Rosa; Kruse,Nelson Diehl; Santos,Gionei Alves de Assis dos; Cera,Jossana Ceolin; Ribas,Giovana Ghisleni; Duarte Junior,Ary José; Pilecco,Isabela Bulegon. |
| Abstract: The objective of this work was to model weedy rice (Oryza sativa) and barnyard grass (Echinochloa spp.) competition with flood-irrigated rice, introducing it as a submodule into the SimulArroz model. The competition of both weeds with irrigated rice was modeled using the rectangular hyperbola equation. The “i” and “a” coefficients of the rectangular hyperbola for each of these weeds were obtained from the literature and from field experiments carried out in the state of Rio Grande do Sul, Brazil. In SimulArroz, yield loss was applied to penalize yield in all three technological levels (high, medium, and low) of physiological maturity. For weedy rice, the coefficient values of imean for the high, medium, and low technological levels were 1.04,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Oryza sativa; Barnyard grass; Modeling; Weedy rice; Yield loss. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-204X2019000102508 |
| |
|
| |
|
|
| Rehman,Abdul; Qamar,Rafi; E. Safdar,Muhammad; ,Atique-ur-Rehman; M.R. Javeed,Hafiz; Maqbool,Rizwan; Farooq,Naila; Shahzad,Muhammad; Ali,Mazhar; H. Tarar,Zahid. |
| Abstract Background: Parthenium hysterophorus L., commonly known as parthenium weed, poses severe economic and environmental hazards to the agro-ecosystems of Pakistan. Objective: To estimate the yield loss and critical competition period of this weed in the spring sown maize crop. Method: Field studies were conducted at an agronomic research area in the College of Agriculture at the University of Sargodha in Punjab-Pakistan during two consecutive year spring seasons (2014 and 2015). Treatments were comprised of viz., control plots (weed free), and parthenium competition durations of 2, 3, 4, 5 and 6 weeks after crop emergence (WAE), as well as weedy check for the full growing season of the crop. Results: Study results showed that the prolongation... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Competition duration; Parthenium; Spring maize; Yield loss; Logistic model. |
| Ano: 2020 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582020000100327 |
| |
|
|
| Monteiro,A.; Henriques,I.; Moreira,I.. |
| The effects of different weed management periods on potatoes were studied in three areas (Bailundo, Chianga and Calenga) of the central highlands of Angola and in three cropping seasons, from June 2005 to May 2007. Six weed-management treatments were used to identify critical periods of competition and to allow the development of more precise management recommendations. Total potato yield ranged from about 22 t ha-1 in weed-free plots to about 3 t ha-1 with no weed control a yield loss of 86%. Major weed species Galinsoga parviflora, Cyperus esculentus, Bidens biternata, Amaranthus hybridus, Nicandra physaloides, Portulaca oleracea and Datura stramonium differed from area to area. The species G. parviflora dominated the weed flora in all three areas 73, 97... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Solanum tuberosum; Tropical Africa; Yield loss. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582011000200013 |
| |
|
|
| JAVAID,M.M.; TANVEER,A.; ALI,H.H.; SHAHID,M.A.; BALAL,R.M.; AQEEL,M.A.. |
| Emex australis and E. spinosa are significant weed species in wheat and other crops. Information on the extent of competition of the Emex species will be helpful to access yield losses in wheat. Field experiments were conducted to quantify the interference of tested weed densities each as single or mixture of both at 1:1 on their growth and yield, wheat yield components and wheat grain yield losses in two consecutive years. Dry weight of both weed species increased from 3-6 g m-2 with every additional plant of weed, whereas seed number and weight per plant decreased with increasing density of either weed. Both weed species caused considerable decrease in yield components like spike bearing tillers, number of grains per spike, 1000-grain weight of wheat... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Triticum aestivum; Yield loss; Weed competition; Emex australis; Emex spinosa. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582016000100035 |
| |
|
|
| ASHRAF,U.; ABBAS,R.N.; HUSSAIN,S.; MO,Z.W.; ANJUM,S.A.; KHAN,I.; TANG,X.R.. |
| ABSTRACT Adjustment of planting geometry along with reduced applications of herbicides can be a viable tool for effective weed management in rice. This present study has examined the effects of three planting geometries (20 cm x 20 cm, 20 cm x 10 cm and 10 cm x 10 cm); along with early post emergence herbicides, viz; bispyribac sodium 20% WP at 39.50 g a.i. ha-1, bispyribac sodium 100 SC at 39.50 g a.i. ha-1, cyhalofop-butyle 10% EC at 49.50 g a.i. ha-1, and penoxulam 240 EC at 15 g a.i. ha-1 on weed growth, and rice performance under semi-arid climate. A weedy check was maintained as control where no herbicide was applied. Results showed that the narrowest plant spacing (10 cm x 10 cm) effectively controlled weeds; however, it also resulted in reduced... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Herbicides; Plant spacings; Rice growth; Weed interference; Yield loss. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-83582016000400737 |
| |
|
| |
|
|
| Singh, Rajinder Pal; Brennan, John P.; Farrell, Tim; Williams, Robert L.; Rienke, Russell; Lewin, Laurie; Mullen, John D.. |
| The occurrence of low night temperatures during reproductive development is one of the factors most limiting rice yields in southern Australia. Yield losses due to cold temperature are the result of incomplete pollen formation and subsequent floret sterility. Researchers have found that in 75% of years, rice farmers suffer losses between 0.5 and 2.5 t/ha. Research is being undertaken to identify overseas rice varieties, that are cold tolerant under the local weather conditions and by using those genotypes as parent material, develop cold tolerance varieties of rice. A yield simulation model was used to measure reduction in losses due to cold at different minimum threshold temperatures, while the SAMBOY Rice model was used to measure the costs and returns... |
| Tipo: Conference Paper or Presentation |
Palavras-chave: Rice; Cold; Yield loss; Breeding; Crop Production/Industries. |
| Ano: 2003 |
URL: http://purl.umn.edu/57925 |
| |
|
| |
|
| |
|
| |
|
|
| Souza,Brígida; Santa-Cecília,Lenira V.C.; Sousa,Luís O.V. de. |
| This work was carried out to evaluate the damages caused by Grapholita molesta (Busck) in twigs and fruits of peach trees (Prunus persicae) in Caldas, MG, during the growing seasons of 1995/96 and 1996/97. Fruits and twigs from three branches of fifteen plants were examined every 15 days. A great variation in the percentage of twigs damage was obtained throughout each season, especially in the second year, when a peak was observed in the end of January. The averages of the porcentage of damage were estimated in 22,9% and 19,4% in 1995/96 and 1996/97, respectively. The total incidence in fruits was 28,1% during the first year and 21,6% during the second year with peaks well definided in the end of October and beginning of November of 1995/96. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Insecta; Oriental fruit moth; Yield loss; Prunus persicae. |
| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0301-80592000000100023 |
| |
| Registros recuperados: 12 | |
|
|
|
