Effect of Flood Timing on Red Rice (Oryzaspp.) Control with Imazethapyr Applied at Different Dry-Seeded Rice Growth Stages

2005 ◽  
Vol 19 (2) ◽  
pp. 476-480 ◽  
Author(s):  
Luis A. Avila ◽  
Scott A. Senseman ◽  
Garry N. McCauley ◽  
James M. Chandler ◽  
John H. O'Barr

Field experiments were conducted in 2002 and 2003 in Beaumont, TX, to evaluate the effect of flood timing on red rice control with imazethapyr applied at different cultivated rice growth stages. Treatments included flood establishment at 1, 7, 14, and 21 d after postemergence (POST) herbicide treatment (DAT). Imazethapyr was applied preemergence at 70 g ai/ha followed by 70 g/ ha POST when imidazolinone-tolerant rice cultivar ‘CL-161’ had three- to four-leaf stage (EPOST) or five-leaf stage (LPOST). Flood needed to be established within 14 DAT to achieve at least 95% red rice control when imazethapyr was applied EPOST. However, flood needed to be established within 7 DAT to provide at least 95% red rice control when imazethapyr was applied LPOST. Delaying the flood up to 21 DAT reduced rice grain yield for both application timings.

Weed Science ◽  
1985 ◽  
Vol 33 (5) ◽  
pp. 703-707 ◽  
Author(s):  
Amadou Diarra ◽  
Roy J. Smith ◽  
Ronald E. Talbert

Field experiments were conducted to investigate methods of controlling red rice (Oryza sativaL. ♯ ORYSA) in drill-seeded rice (O. sativa). Treatments included the rice cultivar ‘Mars', coated with calcium peroxide (CaO2) at 40% (w/w) and a crop protectant, R-33865 (O,O-diethyl-O-phenyl phosphorothioate) at 0.5 and 1% (v/w). Molinate (S-ethyl hexahydro-1H-azepine-1-carbothioate) at 6.7 kg ai/ha was applied preplant incorporated (ppi). The land was flooded (2.5 to 5 cm deep) after seeding with rice (100 kg/ha, 2.5 cm deep), and the water was maintained throughout the growing season. CaO2, with or without molinate, increased rice grain yield 50% and increased rice culm density fivefold above untreated rice. Molinate applied ppi controlled 96% of the red rice. Rice seed coated with only CaO2or with CaO2plus R-33865 at 0.5%, each combined with ppi molinate, produced 5690 and 6030 kg/ha of grain, respectively. These high yields were associated with red rice control by molinate and good stands of rice provided by O2supplied by CaO2. R-33865 applied to rice seed at 1% (v/w) injured rice by reducing rice culm densities 41%, compared with rice without protectant.


Weed Science ◽  
1992 ◽  
Vol 40 (2) ◽  
pp. 313-319 ◽  
Author(s):  
D. J. Pantone ◽  
J. B. Baker ◽  
P. W. Jordan

During 1985 to 1989, a series of field experiments were conducted at the Rice Research Station in Crowley, LA. Path analysis was employed to evaluate the competitive interaction between a weed (red rice) and cultivated rice (Mars). The path analysis quantified direct effects of red rice and Mars rice densities on the yield components (grain weight, percent filled florets, number of florets panicle−1, and panicles plant−1) of red rice and Mars rice. The model illustrated the direct and indirect effects of the yield components on fecundity and grain yield plant−1. The direct effects of Mars and red rice densities on panicles plant−1and florets panicle−1were always negative. In contrast, the effects of density on percent filled florets and grain weight varied from positive to negative and were relatively small, implying that they were determined primarily by density-independent factors. Path analysis indicated that the number of panicles plant−1and florets panicle−1were the most important yield components determining the responses of fecundity and grain yield to competition.


Agronomy ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 106 ◽  
Author(s):  
Ke Zhang ◽  
Xiaojun Liu ◽  
Syed Tahir Ata-Ul-Karim ◽  
Jingshan Lu ◽  
Brian Krienke ◽  
...  

Accurate estimation of the nitrogen (N) spatial distribution of rice (Oryza sativa L.) is imperative when it is sought to maintain regional and global carbon balances. We systematically evaluated the normalized differences of the soil and plant analysis development (SPAD) index (the normalized difference SPAD indexes, NDSIs) between the upper (the first and second leaves from the top), and lower (the third and fourth leaves from the top) leaves of Japonica rice. Four multi-location, multi-N rate (0–390 kg ha−1) field experiments were conducted using seven Japonica rice cultivars (9915, 27123, Wuxiangjing14, Wunyunjing19, Wunyunjing24, Liangyou9, and Yongyou8). Growth analyses were performed at different growth stages ranging from tillering (TI) to the ripening period (RP). We measured leaf N concentration (LNC), the N nutrition index (NNI), the NDSI, and rice grain yield at maturity. The relationships among the NDSI, LNC, and NNI at different growth stages showed that the NDSI values of the third and fourth fully expanded leaves more reliably reflected the N nutritional status than those of the first and second fully expanded leaves (LNC: NDSIL3,4, R2 > 0.81; NDSIothers, 0.77 > R2 > 0.06; NNI: NDSIL3,4, R2 > 0.83; NDSIothers, 0.76 > R2 > 0.07; all p < 0.01). Two new diagnostic models based on the NDSIL3,4 (from the tillering to the ripening period) can be used for effective diagnosis of the LNC and NNI, which exhibited reasonable distributions of residuals (LNC: relative root mean square error (RRMSE) = 0.0683; NNI: RRMSE = 0.0688; p < 0.01). The relationship between grain yield, predicted yield, and NDSIL3,4 were established during critical growth stages (from the stem elongation to the heading stages; R2 = 0.53, p < 0.01, RRMSE = 0.106). An NDSIL3,4 high-yield change curve was drawn to describe critical NDSIL3,4 values for a high-yield target (10.28 t ha−1). Furthermore, dynamic-critical curve models based on the NDSIL3,4 allowed a precise description of rice N status, facilitating the timing of fertilization decisions to optimize yields in the intensive rice cropping systems of eastern China.


Weed Science ◽  
2005 ◽  
Vol 53 (5) ◽  
pp. 683-689 ◽  
Author(s):  
Leopoldo E. Estorninos ◽  
David R. Gealy ◽  
Edward E. Gbur ◽  
Ronald E. Talbert ◽  
Marilyn R. McClelland

Red rice, which grows taller and produces more tillers than domestic rice and shatters most of its seeds early, is a major weed in many rice-growing areas of the world. Field experiments were conducted at Stuttgart, AR in 1997 and 1998 to evaluate the growth response of the Kaybonnet (KBNT) rice cultivar to various population densities of three red rice ecotypes. The ecotypes tested were Louisiana3 (LA3), Stuttgart strawhull (Stgstraw), and Katy red rice (KatyRR). Compared with KBNT alone, LA3, the tallest of the three red rice ecotypes, reduced tiller density of KBNT 51%, aboveground biomass at 91 d after emergence (DAE) 35%, and yield 80%. Stgstraw, a medium-height red rice, reduced KBNT tiller density 49%, aboveground biomass 26%, and yield 61%. KatyRR, the shortest red rice, reduced KBNT tiller density 30%, aboveground biomass 16%, and yield 21%. Tiller density of rice was reduced by 20 to 48% when red rice density increased from 25 to 51 plants m−2. Rice biomass at 91 DAE was reduced by 9 and 44% when red rice densities were 16 and 51 plants m−2. Rice yield was reduced by 60 and 70% at red rice densities of 25 and 51 plants m−2, respectively. These results demonstrate that low populations of red rice can greatly reduce rice growth and yield and that short-statured red rice types may affect rice growth less than taller ecotypes.


2018 ◽  
Vol 10 (8) ◽  
pp. 1249 ◽  
Author(s):  
Kensuke Kawamura ◽  
Hiroshi Ikeura ◽  
Sengthong Phongchanmaixay ◽  
Phanthasin Khanthavong

Canopy hyperspectral (HS) sensing is a promising tool for estimating rice (Oryza sativa L.) yield. However, the timing of HS measurements is crucial for assessing grain yield prior to harvest because rice growth stages strongly influence the sensitivity to different wavelengths and the evaluation performance. To clarify the optimum growth stage for HS sensing-based yield assessments, the grain yield of paddy fields during the reproductive phase to the ripening phase was evaluated from field HS data in conjunction with iterative stepwise elimination partial least squares (ISE-PLS) regression. The field experiments involved three different transplanting dates (12 July, 26 July, and 9 August) in 2017 for six cultivars with three replicates (n = 3 × 6 × 3 = 54). Field HS measurements were performed on 2 October 2017, during the panicle initiation, booting, and ripening growth stages. The predictive accuracy of ISE-PLS was compared with that of the standard full-spectrum PLS (FS-PLS) via coefficient of determination (R2) values and root mean squared errors of cross-validation (RMSECV), and the robustness was evaluated by the residual predictive deviation (RPD). Compared with the FS-PLS models, the ISE-PLS models exhibited higher R2 values and lower RMSECV values for all data sets. Overall, the highest R2 values and the lowest RMSECV values were obtained from the ISE-PLS model at the booting stage (R2 = 0.873, RMSECV = 22.903); the RPD was >2.4. Selected HS wavebands in the ISE-PLS model were identified in the red-edge (710–740 nm) and near-infrared (830 nm) regions. Overall, these results suggest that the booting stage might be the best time for in-season rice grain assessment and that rice yield could be evaluated accurately from the HS sensing data via the ISE-PLS model.


2010 ◽  
Vol 24 (4) ◽  
pp. 411-415 ◽  
Author(s):  
D. Shane Hennigh ◽  
Kassim Al-Khatib ◽  
Mitchell R. Tuinstra

The lack of POST herbicides to control grasses in grain sorghum prompted researchers to develop acetolactate synthase (ALS)–resistant grain sorghum. Field experiments were conducted to evaluate the differential response of ALS-resistant grain sorghum to POST application of nicosulfuron + rimsulfuron applied at three growth stages. ALS-resistant grain sorghum was treated with 0, 13 + 7, 26 + 13, 39 + 20, 52 + 26, 65 + 33, 78 + 39, and 91 + 46 g ai ha−1of nicosulfuron + rimsulfuron when plants were at the three- to five-leaf, seven- to nine-leaf, or 11- to 13-leaf stage. In general, as nicosulfuron + rimsulfuron rates increased, visible injury increased at the three- to five-leaf and seven- to nine-leaf stages. Injury was greatest 1 wk after treatment for the three- to five-leaf and seven- to nine-leaf stages across all ratings, and plants then began to recover. No injury was observed at any rating time for the 11- to 13-leaf stage. Plant height and sorghum grain yield were reduced as nicosulfuron + rimsulfuron rates increased when applied at the three- to five-leaf stage. However, nicosulfuron + rimsulfuron applied at the seven- to nine-leaf and 11- to 13-leaf stages did not decrease sorghum yield. This research indicated that nicosulfuron + rimsulfuron application at the three- to five-leaf stage injured ALS-resistant grain sorghum; however, application at the seven- to nine-leaf or 11- to 13-leaf stages did not result in grain yield reduction.


Weed Science ◽  
1991 ◽  
Vol 39 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Dan J. Pantone ◽  
John B. Baker

Four years of field experiments were used to assess the competitive ability of red rice, a weedy variety of rice, and ‘Mars’, a cultivar of rice. Red rice was the dominant competitor each of the 4 yr, and an average of one red rice plant reduced Mars grain yield per plant equal to the effect of four Mars plants. Intervarietal competition was more important than intravarietal competition for Mars, whereas the reverse was true for red rice. The product of the coefficients for intravarietal competition did not significantly exceed the product of the coefficients for intervarietal competition, indicating that the two varieties were competing for the same resources. Using the reciprocal yield model coefficients from 1989, grain yield losses of Mars, due to red rice densities of 4, 16, 25, and 300 plants m−2, were predicted to approximate 13, 37, 48, and 92%, respectively, at a fixed cultivar density of 100 plants m−2.


Weed Science ◽  
1985 ◽  
Vol 33 (5) ◽  
pp. 644-649 ◽  
Author(s):  
Amadou Diarra ◽  
Roy J. Smith ◽  
Ronald E. Talbert

Red rice (Oryza sativaL. ♯ ORYSA) densities of 5, 108, and 215 plants/m2reduced grain yield of commercial rice (Oryza sativaL.) 22, 77, and 82%, respectively. At a cultivated rice density of 195 plants/m2, red rice at 5, 108, and 215 plants/m2reduced straw dry weight of cultivated rice 18, 66, and 68%, respectively. At a red rice density of 5 plants/m2, reduction in number of cultivated rice grains per panicle ranged from 8 to 18%, whereas densities of 108 and 215 plants/m2reduced grains per panicle 56 to 70%. Red rice grain yield was 24 to 33% lower in ‘Mars' rice than in ‘Lebonnet’. Mars, a medium-grain cultivar that matures in 138 days, competed better with red rice than Lebonnet, a long-grain cultivar that matures in 126 days.


Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 584
Author(s):  
Omnia M. Elshayb ◽  
Khaled Y. Farroh ◽  
Heba E. Amin ◽  
Ayman M. Atta

Applications of metal oxide nanoparticles in the agriculture sector are being extensively included as the materials are considered superior. In the present work, zinc oxide nanoparticle (ZnO NPs), with a developing fertilizer, is applied in the fortification of rice grain yield and nutrient uptake enhancement. To evaluate the role of ZnO NP, two field experiments were conducted during the 2018 and 2019 seasons. ZnO NPs were small, nearly spherical, and their sizes equal to 31.4 nm, as proved via the dynamic light scattering technique. ZnO NPs were applied as a fertilizer in different concentrations, varying between 20 and 60 mg/L as a foliar spray. The mixture of ZnSO4 and ZnO NP40 ameliorated yield component and nutrients (N, K, and Zn) uptake was enhanced compared to traditional ZnSO4 treatment. Nevertheless, the uptake of the phosphorous element (P) was adversely affected by the treatment of ZnO NPs. Thus, treatment via utilizing ZnO NPs as a foliar with a very small amount (40 ppm) with of basal ZnSO4 led to a good improvement in agronomic and physiological features; eventually, higher yield and nutrient-enriched rice grain were obtained.


Weed Science ◽  
1994 ◽  
Vol 42 (4) ◽  
pp. 568-573 ◽  
Author(s):  
Stevan Z. Knezevic ◽  
Stephan F. Weise ◽  
Clarence J. Swanton

Redroot pigweed is a major weed in corn throughout Ontario. Field experiments were conducted at two locations in 1991 and 1992 to determine the influence of selected densities and emergence times of redroot pigweed on corn growth and grain yield. Redroot pigweed densities of 0.5, 1, 2, 4 and 8 plants per m of row were established within 12.5 cm on either side of the corn row. In both years, redroot pigweed seeds were planted concurrently and with corn at the 3- to 5-leaf stage of corn growth. A density of 0.5 redroot pigweed per m of row from the first (earlier) emergence date of pigweed (in most cases, up to the 4-leaf stage of corn) or four redroot pigweed per m of row from the second (later) emergence date of pigweed (in most cases, between the 4- and 7-leaf stage of corn) reduced corn yield by 5%. Redroot pigweed emerging after the 7-leaf stage of corn growth did not reduce yield. Redroot pigweed seed production was dependent upon its density and time of emergence. The time of redroot pigweed emergence, relative to corn, may be more important than its density in assessing the need for postemergence control.


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