Cultivar and Weeding Effects on Weeds and Rice Yields in a Degraded Upland Environment of the Coastal Savanna

2011 ◽  
Vol 25 (3) ◽  
pp. 322-329 ◽  
Author(s):  
Amadou Touré ◽  
Jonne Rodenburg ◽  
Kazuki Saito ◽  
Sylvester Oikeh ◽  
Koichi Futakuchi ◽  
...  
Keyword(s):  
West Africa ◽  
Rice Yield ◽  
Upland Rice ◽  
Biomass Accumulation ◽  
Rice Cultivars ◽  
Weed Species ◽  
Weed Growth ◽  
Weed Suppressive Ability ◽  
Rice Yields ◽  
Growing Conditions

Weeds are a major constraint to rice production in labor-limited, upland rice-based systems in West Africa. The effects of weeding regimes and rice cultivars on weed growth and rice yield were investigated at two upland locations (Abomey-Calavi and Niaouli) in the degraded coastal savanna zone of Benin in 2005 and 2006 with below-average rainfall. Four weeding regimes (hoe weeding at 21 d after sowing [DAS], delayed hoe weeding at 31 DAS, hoe weeding at 21 and 42 DAS, and a no weeding control) were the main plot treatments. Cultivars comprising three interspecific upland rice cultivars (NERICA 1, NERICA 2, and NERICA 7) and the parents (Oryza sativaWAB56-104 andO. glaberrimaCG14) were tested in subplots. The most dominant weed species identified were Jamaican crabgrass,Mariscus, and silver spinach. Rice yield was generally low because of drought stress; none of the experiments had a higher mean yield than 1,400 kg ha−1across cultivars. Across cultivars, the best weeding regimes in terms of weed control and rice yields were single weeding at 31 DAS (W31) and double weeding at 21 and 42 DAS (W21+42). Under these weeding regimes, WAB56-104 out-yielded the three NERICA cultivars. CG14 showed the strongest weed suppressive ability (WSA) in Abomey-Calavi but did not have strong WSA in Niaouli because of lower biomass accumulation. WSA of WAB56-104 was similar to that of the three NERICA cultivars. Single weeding at 31 DAS, together with the use of cultivars with good adaptation to unfavorable rice growing conditions, would increase land and labor productivity of upland rice-based systems in West Africa.

Differential Tolerance of Clearfield Rice Cultivars to Imazamox

2011 ◽  
Vol 25 (2) ◽  
pp. 192-197 ◽  
Author(s):  
Jason A. Bond ◽  
Timothy W. Walker
Keyword(s):  
Growth Stage ◽  
Rice Yield ◽  
Field Studies ◽  
First Year ◽  
Growth Stages ◽  
Rice Cultivars ◽  
Rough Rice ◽  
Rice Yields ◽  
Clearfield Rice ◽  
Two Hybrid

Field studies were conducted to compare the response of one inbred (‘CL161’) and two hybrid (‘CLXL729’ and ‘CLXL745’) Clearfield (CL) rice cultivars to imazamox. Imazamox was applied at 44 and 88 g ai ha−1to rice in the panicle initiation (PI) and PI plus 14 d (PI + 14) growth stages and at 44 g ha−1to rice in the midboot growth stage. Maturity of hybrid CL cultivars was delayed following imazamox at 44 g ha−1applied at PI + 14 and midboot. Furthermore, imazamox at 44 g ha−1, applied at midboot, delayed maturity of CLXL745 more than CLXL729. Expressed as a percentage of the weed-free control plots, rough rice yields for CLXL729 were 91% following imazamox at 44 g ha−1applied at PI + 14, 78% following imazamox at 44 g ha−1applied at midboot, and 77% for imazamox at 88 g ha−1applied at PI + 14. Rough rice yield for CLXL745 was 77 to 92% of the control following all imazamox treatments. All imazamox treatments reduced CLXL745 rough rice yield compared with CL161. Rough rice yield, pooled across CL cultivar, varied with imazamox treatment between years, and these differences may have been a consequence of lower temperatures and solar radiation in the first year. Hybrid CL cultivars CLXL729 and CLXL745 were less tolerant than was CL161 when imazamox was applied at nonlabeled rates (88 g ha−1) and/or timings (PI + 14 or midboot). Because of variability in rice growth stages and irregularities in imazamox application in commercial fields, inbred CL cultivars should be planted where an imazamox application will likely be required.

CERES-Rice model-based simulations of climate change impacts on rice yields and efficacy of adaptive options in Northeast China

2014 ◽  
Vol 65 (12) ◽  
pp. 1267 ◽  
Author(s):  
Wenxiang Wu ◽  
Qian Fang ◽  
Quansheng Ge ◽  
Mengzi Zhou ◽  
Yumei Lin
Keyword(s):  
Climate Change ◽  
Northeast China ◽  
Rice Yield ◽  
Adaptive Strategies ◽  
Future Climate ◽  
Future Climate Change ◽  
Rice Cultivars ◽  
Rice Yields ◽  
The Impact ◽  
Impacts Of Climate Change

Global temperatures are rising, and concerns about the response of agricultural production to climate change are increasing. Adaptation is a key factor that will shape the severity of impacts of future climate change on food production. Based on actual meteorological, soil and agricultural management data at site scale, the CERES-Rice model, combined with the Regional Climate Model (RCM)-PRECIS, was used to simulate both the effects of climate change on rice yields and the efficacy of adaptive options in Northeast China. The impact simulation showed that rice yield changes ranged from +0.1% to –44.9% (A2 scenario) and from –0.3% to –40.1% (B2 scenario) without considering CO2 fertilisation effects. When considering CO2 fertilisation effects, rice yield reductions induced by temperature increases were decreased at all sites. The CO2 fertilisation effects may partly offset the negative impacts of climate change on rice yields. Adaptive option results revealed that the adverse impacts of climate change on rice yields could be mitigated by advancing the planting dates, transplanting mid–late-maturing rice cultivars to replace early-maturing ones, and breeding new rice cultivars with high thermal requirements. Our findings provide insight into the possible impacts of climate change on rice production, and we suggest which adaptive strategies could be used to cope with future climate change, thus providing evidence-based suggestions for government policy on adaptive strategies.

Response of upland rice cultivars to weed competition in the savannas of West Africa

2009 ◽  
Vol 28 (1) ◽  
pp. 90-96 ◽  
Author(s):  
Friday Ekeleme ◽  
Alpha Y. Kamara ◽  
Sylvester O. Oikeh ◽  
Lucky O. Omoigui ◽  
Paul Amaza ◽  
...  
Keyword(s):  
West Africa ◽  
Upland Rice ◽  
Weed Competition ◽  
Rice Cultivars

Management of Meloidogyne graminicola and yield of upland rice in South-Luzon, Philippines

Nematology ◽  
2003 ◽  
Vol 5 (6) ◽  
pp. 879-884 ◽  
Author(s):  
Imelda Soriano ◽  
Georges Reversat
Keyword(s):  
Rice Yield ◽  
Upland Rice ◽  
Rice Crop ◽  
Yield Potential ◽  
Root Knot Nematode ◽  
Short Life ◽  
Meloidogyne Graminicola ◽  
Asian Rice ◽  
Rice Yields ◽  
Single Rice

AbstractMeloidogyne graminicola, the rice root-knot nematode, has become a constraint on Asian rice production due to rice cropping intensification and increasing scarcity of water. This work relates to the assessment of crop rotation, fallow and nematicide treatments in naturally infested fields to manage M. graminicola populations and prevent yield losses. One or two consecutive crops of cowpea or seasons of fallow before a rice crop lowered nematode populations and improved rice yield by 30-80%. Methyl bromide was used to determine yield potential and almost eradicated the nematode, trebling rice yield. Carbofuran improved yield of the first rice crop but did not affect the second rice crop. Due to its short life cycle, M. graminicola populations were similar after only a single rice crop and after three consecutive crops. It is recommended that, to ensure higher rice yields, M. graminicola populations should be maintained at low density by non-host crop rotations or fallows, ideally for two seasons before planting rice.

scholarly journals Evaluation of Different Nutrient Management Practices in Yield of Different Rice Cultivars in Lamjung District of Nepal

2016 ◽  
Vol 4 (2) ◽  
pp. 223-227
Author(s):  
S. Ranabhat ◽  
L.P. Amgain
Keyword(s):  
Grain Yield ◽  
Management Practices ◽  
Nutrient Management ◽  
Rice Yield ◽  
Block Design ◽  
Rice Cultivars ◽  
Rice Varieties ◽  
Fertilizer Recommendations ◽  
Rice Yields ◽  
Biological Yield

A field experiment was conducted on farmer’s field at two sites of Lamjung district of Nepal viz. Bhotewodar and Sundarbazaar to evaluate the performance of two commonly grown rice varieties viz US-382(hybrid) and Ramdhan (improved) under two nutrient management practices [Nutrient Expert®(NE) rice model recommendation, and government recommendation(GR)].Four replicates of four treatments were arranged in randomized completely block design. Rice varieties responded differently under the different nutrient management practices in terms of plant height, grains per panicle, sterility%, panicle weight, grain yield at 15% moisture, straw yield and harvesting index. The highest grain yield was obtained from NE field of US-382 variety which was followed by GR for US-382, NE for Ramdhan and GR for Ramdhan variety. NE based practices for US-382 variety produced higher biological yield as compared to GR. NE estimated attainable rice yield provided by the software compared with actual rice yield from the trials in farmer’s field and NE-based fertilizer recommendations proved the validity in reaching the yield targets estimated by the software. The observed rice yields recorded in the trials were higher than the NE estimated attainable yields, so NE recommendation for US-382 variety was found better over GR.Int J Appl Sci Biotechnol, Vol 4(2): 223-227

scholarly journals Soil management and nitrogen fertilization for sprinkler-irrigated upland rice cultivars

2003 ◽  
Vol 60 (2) ◽  
pp. 345-352 ◽  
Author(s):  
Orivaldo Arf ◽  
Ricardo Antonio Ferreira Rodrigues ◽  
Carlos Alexandre Costa Crusciol ◽  
Marco Eustáquio de Sá ◽  
Salatiér Buzetti
Keyword(s):  
Management Practices ◽  
Rice Yield ◽  
Upland Rice ◽  
Block Design ◽  
Soil Management ◽  
Soil Tillage ◽  
Rice Cultivars ◽  
Milled Rice ◽  
No Till ◽  
Moldboard Plow

The use of sprinkler irrigation for rice (Oryza sativa L.) crop is a relatively recent practice in Brazil. Therefore, crop soil and fertilization management are still not very well defined. Another problem is the inexistence of specific cultivars adapted to this cropping system. This study aimed to evaluate sprinkler-irrigated upland rice cultivars under different soil management practices and nitrogen sidedressing rates in relation to yield and grain quality. A randomized block design was used, arranged as a 3 x 3 x 5 factorial scheme, totaling 45 treatments consisting of the combination of three rice cultivars (Primavera, Confiança and Maravilha), three soil management systems (disk harrow + levelling harrow, moldboard plow + levelling harrow and no-till) and five nitrogen rates, applied as sidedressing (0, 25, 50, 75 and 100 kg ha-1), with four replicates. The experiment was set up during the 1999/2000 and 2000/2001 cropping seasons, in Selvíria, MS, Brazil, on a Typic Haplustox of clayey texture. Cultivars Primavera and Maravilha presented higher grain yield than Confiança; on the other hand the latter showed higher milled and head rice yields during seed processing. Soil tillage with the moldboard plow and no-till interfered positively in the agronomic and productive characteristics of the crop. In relation to milled rice yield, tilling with the levelling disk + moldboard plow showed better results in relation to no-till. Nitrogen sidedressing did not interfere with the agronomic and productive characteristcs as well as with the milled rice yield of all cultivars.

Effect of Postflood Quinclorac Applications on Commercial Rice Cultivars

2012 ◽  
Vol 26 (2) ◽  
pp. 183-188 ◽  
Author(s):  
Jason A. Bond ◽  
Timothy W. Walker
Keyword(s):  
Growth Stage ◽  
Developmental Stages ◽  
Rice Yield ◽  
Field Studies ◽  
Rice Cultivar ◽  
Rice Cultivars ◽  
Rough Rice ◽  
Rice Yields

Rice cultivar, growth stage at application, or both may influence rice tolerance to quinclorac. Field studies were conducted to compare the response of five rice cultivars ‘Bowman’, ‘Cheniere’, ‘CL161’, ‘Cocodrie’, and ‘XL723’ to postflood quinclorac applications. Quinclorac at 0.56 kg ai ha−1was applied 2 and 4 wk after flood (WAF). Pooled across quinclorac application timings, no differences in maturity were detected among the cultivars in 2008, but maturity of Cheniere and XL723 were delayed compared with CL161 and Cocodrie in 2007. Maturity of Cheniere and XL723 was delayed in 2007 compared with 2008. Pooled over cultivar, maturity was similar for 2 and 4 WAF applications in 2007 but was delayed for 2 WAF treatments in 2008. Regardless of year, postflood quinclorac applications reduced rough rice yield of all cultivars except Bowman. Cheniere and XL723 had lower rough rice yields compared with other cultivars in 2007; however, in 2008, rough rice yields of Cheniere, CL161, Cocodrie, and XL723 were similar, but still lower, than that of Bowman. Pooled over cultivar, postflood quinclorac reduced rough rice yields more when applied 4 WAF than at 2 WAF during both years. Our results demonstrate that Cheniere and XL723 are less tolerant than Bowman is to postflood quinclorac applications and that all evaluated cultivars are more susceptible to quinclorac applied at later developmental stages. Consequently, if circumstances necessitate a postflood quinclorac application, the herbicide should be applied no later than panicle initiation and should not be applied to Cheniere or XL723.

scholarly journals Agronomic performance of upland rice cultivars in the southern region of the state of Tocantins

2016 ◽  
Vol 37 (4) ◽  
pp. 1699
Author(s):  
Leila Paula Tonello ◽  
Taynar Coelho de Oliveira Tavares ◽  
Ricardo De Oliveira Rocha ◽  
Gil Rodrigues dos Santos ◽  
Sérgio Alves de Sousa ◽  
...  
Keyword(s):  
Grain Yield ◽  
Rice Yield ◽  
Upland Rice ◽  
Regional Growth ◽  
The State ◽  
Southern Region ◽  
Flowering Plant ◽  
Agronomic Performance ◽  
Rice Cultivars ◽  
Cerrado Vegetation

Behavioural assessment of cultivars adapted to climate and soil variations is essential for recommending genetic materials to producers, achieving higher profitability, and, mainly, targeting regional growth. The aim of this study was to evaluate the agronomic performance of upland rice cultivars in different cropping periods and Cerrado vegetation soil in the southern region of the state of Tocantins. The experiments were conducted in a field at the Chaparral Farm and at the Experimental Station of the Federal University of Tocantins in the agricultural years of 2008/2009, 2009/2010, 2010/2011, 2011/2012, and 2012/2013 with cultivars BRS-Bonança, BRS-Primavera, and BRSMG-Conai. A randomized block experimental design was used with four replications in a factorial scheme of 3 × 5, comprising three genotypes and five years. The evaluated characteristics were as follows: number of days to flowering, plant height, weight of hundred grains, and grain yield. The highest upland rice yield was observed in the cropping period of 2012/13, which also had the highest volume and better distribution of rainfall; flowering time was lesser and greater for BRSMG-Conai and BRS-Bonança cultivars, respectively. The BRS-Primavera cultivar showed the highest grain yield in different years in Cerrado soil in the southern region of the state of Tocantins.

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