Search

The genus Echinochloa constitutes some of the most prominent weed species found in rice (Oryza sativa L.) production worldwide. The taxonomy of Echinochloa is complex due to its morphological variations. The morphophysiological diversity and taxonomic characteristics of Echinochloa ecotypes infesting rice fields in Texas are unknown. A total of 54 Echinochloa ecotypes collected during late-season field surveys in 2015 and 2016 were characterized in a common garden in 2017. Plants were characterized for 14 morphophysiological traits, including stem angle; stem color; plant height; leaf color; leaf texture; flag leaf length, width, and angle; days to flowering; panicle length; plant biomass; seed shattering; seed yield; and seed dormancy. Principal component analysis indicated that 4 (plant height, flag leaf length, seed shattering, and seed germination) of the 14 phenological traits characterized here had significantly contributed to the overall morphological diversity of Echinochloa spp. Results showed wide interpopulation diversity for the measured traits among the E. colona ecotypes, as well as diverse intrapopulation variability in all three Echinochloa species studied, including barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.], junglerice [Echinochloa colona (L.) Link], and rough barnyardgrass [Echinochloa muricata (P. Beauv.) Fernald]. Taxonomical classification revealed that the collection consisted of three Echinochloa species, with E. colona being the most dominant (96%), followed by E. crus-galli (2%), and E. muricata (2%). Correlation analysis of morphophysiological traits and resistance status to commonly used preemergence (clomazone, quinclorac) and postemergence herbicides (propanil, quinclorac, imazethapyr, and fenoxaprop-ethyl) failed

The genus Echinochloa constitutes some of the most prominent weed species found in rice (Oryza sativa L.) production worldwide. The taxonomy of Echinochloa is complex due to its morphological variations. The morphophysiological diversity and taxonomic characteristics of Echinochloa ecotypes infesting rice fields in Texas are unknown. A total of 54 Echinochloa ecotypes collected during late-season field surveys in 2015 and 2016 were characterized in a common garden in 2017. Plants were characterized for 14 morphophysiological traits, including stem angle; stem color; plant height; leaf color; leaf texture; flag leaf length, width, and angle; days to flowering; panicle length; plant biomass; seed shattering; seed yield; and seed dormancy. Principal component analysis indicated that 4 (plant height, flag leaf length, seed shattering, and seed germination) of the 14 phenological traits characterized here had significantly contributed to the overall morphological diversity of Echinochloa spp. Results showed wide interpopulation diversity for the measured traits among the E. colona ecotypes, as well as diverse intrapopulation variability in all three Echinochloa species studied, including barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.], junglerice [Echinochloa colona (L.) Link], and rough barnyardgrass [Echinochloa muricata (P. Beauv.) Fernald]. Taxonomical classification revealed that the collection consisted of three Echinochloa species, with E. colona being the most dominant (96%), followed by E. crus-galli (2%), and E. muricata (2%). Correlation analysis of morphophysiological traits and resistance status to commonly used preemergence (clomazone, quinclorac) and postemergence herbicides (propanil, quinclorac, imazethapyr, and fenoxaprop-ethyl) failed

A better understanding of weed seed production is a key element for any long-term management allowing some weeds to shed seeds. The challenge with measuring seed production in weeds is the large effort required in terms of time and labour. For the weed species Echinochloa crus-galli, it was tested whether the number of seeds per panicle dry weight or per panicle length can be used to estimate seed production. Experiments were conducted in three maize fields in north-eastern Germany. The effect of factors that could influence this relationship, such as the time of seedling emergence, the density of E. crus-galli, the control intensity of other weeds, seed predation and field, was included. A few days before maize harvest, all panicles were removed and weighed, panicle length was measured, and for a subsample of 178 panicles, the number of seeds was counted manually. Panicle dry weight predicted the number of seeds per panicle better (R2 = 0.92) than did panicle length (R2 = 0.69). The other factors except for ‘field’ and ‘seed predation’ had no effect on these relationships. The relationships between seed number and panicle dry weight found in this study closely resembled those reported in an earlier study. Based on our results, we conclude that both plant traits are appropriate for the estimatation of seed production, depending on required level of precision and availablilty of resources for the evaluation of sustainable weed management strategies.

[CA] El cultiu de l’arròs és un tret d’identitat de l’agricultura del sud de la ciutat de València, coincidint en gran part amb el terme del Parc Natural de l’Albufera. Un dels reptes més importants d’aquest cultiu és el control d’herbes adventícies. El serreig (Echinochloa spp.) és una de les herbes adventícies més importants al cultiu de l’arròs a València i el seu control es basa principalment en la utilització d’herbicides. El propanil va ser el primer herbicida d’alta efectivitat utilitzat a la zona valenciana però darrerament té una efectivitat que sembla decreixent. Recentment el penoxsulam, introduït a Espanya des de l’any 2007, ha cobrat importància. Altres regions arrosseres del món han confirmat la presència de biotips d’Echinochloa spp. que mostren resistència front a aquestes matèries actives. Amb aquests antecedents aquest treball avalua, mitjançant bio-assajos de laboratori amb 18 poblacions valencianes d’Echinochloa, si el desenvolupament de resistència al propanil i penoxsulam pot estar implicat en les fallades de control detectades en camp. La metodologia utilitzada serà amb un doble assaig per separat: una primera prova en què les llavors es fan germinar sobre placa petri dins d’una cambra de germinació, directament amb la dosi d’herbicida incorporada, i una segona, sobre planter amb safates de poliestirè, en què l’herbicida s’aplica amb una polvorització quan les llavors ja han germinat i les plantes tenen entre 1 i 3 fulles. El coneixement de la sensibilitat a diferents herbicides dels diferents biotips d’Echinochloa spp. és important per a planificar el programa de maneig i control de les brosses als arrossars., [EN] Rice farming is characteristic of the south of Valencia city area, largely coinciding with Albufera Natural Park. One of the biggest challenges of this crop is weed control. Barnyard grass (Echinochloa spp.) is a major weed of Valencian rice paddies and its control is based on the use of herbicides. Propanil has been used for weed control in this area but lately seems to have a decreasing effectiveness. Recently penoxsulam, introduced in Spain in 2007, has become important too. Other rice regions around the world have confirmed the presence of Echinochloa spp. biotypes showing resistance against these herbicides. With this background, this paper evaluates, by laboratory tests with 18 Echinochloa spp. biotypes from Valencia, if the development of propanil and penoxsulam resistance may be involved in the control failures identified on the paddies. A double test has been used: a first one in which the seeds are germinated on Petri dishes placed inside a germination chamber with a dose of herbicide added, and a second test with seedbed polystyrene trays, in which the herbicide is sprayed when seeds have germinated and plants have 1 to 3 leaves. Knowledge about multiple herbicide sensitivity of these Echinochloa spp. biotypes is important in order to plan weeds management and control program in paddy fields.

[CA] El cultiu de l’arròs és un tret d’identitat de l’agricultura del sud de la ciutat de València, coincidint en gran part amb el terme del Parc Natural de l’Albufera. Un dels reptes més importants d’aquest cultiu és el control d’herbes adventícies. El serreig (Echinochloa spp.) és una de les herbes adventícies més importants al cultiu de l’arròs a València i el seu control es basa principalment en la utilització d’herbicides. El propanil va ser el primer herbicida d’alta efectivitat utilitzat a la zona valenciana però darrerament té una efectivitat que sembla decreixent. Recentment el penoxsulam, introduït a Espanya des de l’any 2007, ha cobrat importància. Altres regions arrosseres del món han confirmat la presència de biotips d’Echinochloa spp. que mostren resistència front a aquestes matèries actives. Amb aquests antecedents aquest treball avalua, mitjançant bio-assajos de laboratori amb 18 poblacions valencianes d’Echinochloa, si el desenvolupament de resistència al propanil i penoxsulam pot estar implicat en les fallades de control detectades en camp. La metodologia utilitzada serà amb un doble assaig per separat: una primera prova en què les llavors es fan germinar sobre placa petri dins d’una cambra de germinació, directament amb la dosi d’herbicida incorporada, i una segona, sobre planter amb safates de poliestirè, en què l’herbicida s’aplica amb una polvorització quan les llavors ja han germinat i les plantes tenen entre 1 i 3 fulles. El coneixement de la sensibilitat a diferents herbicides dels diferents biotips d’Echinochloa spp. és important per a planificar el programa de maneig i control de les brosses als arrossars., [EN] Rice farming is characteristic of the south of Valencia city area, largely coinciding with Albufera Natural Park. One of the biggest challenges of this crop is weed control. Barnyard grass (Echinochloa spp.) is a major weed of Valencian rice paddies and its control is based on the use of herbicides. Propanil has been used for weed control in this area but lately seems to have a decreasing effectiveness. Recently penoxsulam, introduced in Spain in 2007, has become important too. Other rice regions around the world have confirmed the presence of Echinochloa spp. biotypes showing resistance against these herbicides. With this background, this paper evaluates, by laboratory tests with 18 Echinochloa spp. biotypes from Valencia, if the development of propanil and penoxsulam resistance may be involved in the control failures identified on the paddies. A double test has been used: a first one in which the seeds are germinated on Petri dishes placed inside a germination chamber with a dose of herbicide added, and a second test with seedbed polystyrene trays, in which the herbicide is sprayed when seeds have germinated and plants have 1 to 3 leaves. Knowledge about multiple herbicide sensitivity of these Echinochloa spp. biotypes is important in order to plan weeds management and control program in paddy fields.

[CA] El cultiu de l’arròs és un tret d’identitat de l’agricultura del sud de la ciutat de València, coincidint en gran part amb el terme del Parc Natural de l’Albufera. Un dels reptes més importants d’aquest cultiu és el control d’herbes adventícies. El serreig (Echinochloa spp.) és una de les herbes adventícies més importants al cultiu de l’arròs a València i el seu control es basa principalment en la utilització d’herbicides. El propanil va ser el primer herbicida d’alta efectivitat utilitzat a la zona valenciana però darrerament té una efectivitat que sembla decreixent. Recentment el penoxsulam, introduït a Espanya des de l’any 2007, ha cobrat importància. Altres regions arrosseres del món han confirmat la presència de biotips d’Echinochloa spp. que mostren resistència front a aquestes matèries actives. Amb aquests antecedents aquest treball avalua, mitjançant bio-assajos de laboratori amb 18 poblacions valencianes d’Echinochloa, si el desenvolupament de resistència al propanil i penoxsulam pot estar implicat en les fallades de control detectades en camp. La metodologia utilitzada serà amb un doble assaig per separat: una primera prova en què les llavors es fan germinar sobre placa petri dins d’una cambra de germinació, directament amb la dosi d’herbicida incorporada, i una segona, sobre planter amb safates de poliestirè, en què l’herbicida s’aplica amb una polvorització quan les llavors ja han germinat i les plantes tenen entre 1 i 3 fulles. El coneixement de la sensibilitat a diferents herbicides dels diferents biotips d’Echinochloa spp. és important per a planificar el programa de maneig i control de les brosses als arrossars., [EN] Rice farming is characteristic of the south of Valencia city area, largely coinciding with Albufera Natural Park. One of the biggest challenges of this crop is weed control. Barnyard grass (Echinochloa spp.) is a major weed of Valencian rice paddies and its control is based on the use of herbicides. Propanil has been used for weed control in this area but lately seems to have a decreasing effectiveness. Recently penoxsulam, introduced in Spain in 2007, has become important too. Other rice regions around the world have confirmed the presence of Echinochloa spp. biotypes showing resistance against these herbicides. With this background, this paper evaluates, by laboratory tests with 18 Echinochloa spp. biotypes from Valencia, if the development of propanil and penoxsulam resistance may be involved in the control failures identified on the paddies. A double test has been used: a first one in which the seeds are germinated on Petri dishes placed inside a germination chamber with a dose of herbicide added, and a second test with seedbed polystyrene trays, in which the herbicide is sprayed when seeds have germinated and plants have 1 to 3 leaves. Knowledge about multiple herbicide sensitivity of these Echinochloa spp. biotypes is important in order to plan weeds management and control program in paddy fields.

[CA] El cultiu de l’arròs és un tret d’identitat de l’agricultura del sud de la ciutat de València, coincidint en gran part amb el terme del Parc Natural de l’Albufera. Un dels reptes més importants d’aquest cultiu és el control d’herbes adventícies. El serreig (Echinochloa spp.) és una de les herbes adventícies més importants al cultiu de l’arròs a València i el seu control es basa principalment en la utilització d’herbicides. El propanil va ser el primer herbicida d’alta efectivitat utilitzat a la zona valenciana però darrerament té una efectivitat que sembla decreixent. Recentment el penoxsulam, introduït a Espanya des de l’any 2007, ha cobrat importància. Altres regions arrosseres del món han confirmat la presència de biotips d’Echinochloa spp. que mostren resistència front a aquestes matèries actives. Amb aquests antecedents aquest treball avalua, mitjançant bio-assajos de laboratori amb 18 poblacions valencianes d’Echinochloa, si el desenvolupament de resistència al propanil i penoxsulam pot estar implicat en les fallades de control detectades en camp. La metodologia utilitzada serà amb un doble assaig per separat: una primera prova en què les llavors es fan germinar sobre placa petri dins d’una cambra de germinació, directament amb la dosi d’herbicida incorporada, i una segona, sobre planter amb safates de poliestirè, en què l’herbicida s’aplica amb una polvorització quan les llavors ja han germinat i les plantes tenen entre 1 i 3 fulles. El coneixement de la sensibilitat a diferents herbicides dels diferents biotips d’Echinochloa spp. és important per a planificar el programa de maneig i control de les brosses als arrossars., [EN] Rice farming is characteristic of the south of Valencia city area, largely coinciding with Albufera Natural Park. One of the biggest challenges of this crop is weed control. Barnyard grass (Echinochloa spp.) is a major weed of Valencian rice paddies and its control is based on the use of herbicides. Propanil has been used for weed control in this area but lately seems to have a decreasing effectiveness. Recently penoxsulam, introduced in Spain in 2007, has become important too. Other rice regions around the world have confirmed the presence of Echinochloa spp. biotypes showing resistance against these herbicides. With this background, this paper evaluates, by laboratory tests with 18 Echinochloa spp. biotypes from Valencia, if the development of propanil and penoxsulam resistance may be involved in the control failures identified on the paddies. A double test has been used: a first one in which the seeds are germinated on Petri dishes placed inside a germination chamber with a dose of herbicide added, and a second test with seedbed polystyrene trays, in which the herbicide is sprayed when seeds have germinated and plants have 1 to 3 leaves. Knowledge about multiple herbicide sensitivity of these Echinochloa spp. biotypes is important in order to plan weeds management and control program in paddy fields.

This NebGuide discusses the use of ecofarming to control weeds and manage crop residues. Ecofarming is defined as a system of controlling weeds and managing crop residues throughout a crop rotation with minimum use of tillage so as to reduce soil erosion and production costs while increasing weed control, water infiltration, moisture conservation and crop yields. Energy requirements are much lower with ecofallow than with normal fallow systems. The ecofallow period in the 3-year rotation is the period between wheat or other small grain harvest and the planting of corn or sorghum. The fallow period in the 2-year rotation occurs between wheat harvest and the planting of winter wheat 14 months later. Ecofallow means controlling weeds during the fallow period by using herbicides and/or tillage with minimum disturbance of crop residues and soils. We have been working on the ecofallow concept for 20 years, and it is presently being used in the winter wheat-fallow rotation and the winter wheat-corn or sorghum-fallow rotations. The winter wheat-fallow rotation is commonly used in western Nebraska. The 3-year rotation consists of winter wheat-ecofallow-sorghum or corn-fallow. The fallow period after corn or sorghum is followed by winter wheat. This rotation is generally used in the areas that receive 16 to 20 inches of precipitation. In eastern Nebraska, this could be an oats-ecofallow-corn, sorghum or soybean rotation.