scholarly journals Effect of Cultural Management Practices on the Severity of False Smut and Kernel Smut of Rice

Plant Disease ◽  
2009 ◽  
Vol 93 (11) ◽  
pp. 1202-1208 ◽  
Author(s):  
Steven A. Brooks ◽  
Merle M. Anders ◽  
Kathleen M. Yeater

False smut (Ustilaginoidea virens) and kernel smut (Neovossia horrida) are diseases of rice (Oryza sativa) that reduce both grain yield and quality. False smut is an emerging disease worldwide that is rapidly gaining in importance, whereas kernel smut has historically been a chronic minor disease with sporadic outbreaks that cause considerable losses. Highly effective disease control was obtained for susceptible cultivars by employing conservation tillage (69% reduction in false smut), continuous rice cropping (88% reduction in false smut), and moderate nitrogen fertility rates (34 and 60% reductions in false smut and kernel smut, respectively). Combining these treatments nearly eliminated smuts from cultivars that were fully susceptible under conventional cultivation practices. Furthermore, using a nursery designed to promote smut diseases, two rice hybrids were identified that possessed kernel smut resistance under the most favorable disease conditions. The genetic basis of the resistance is unknown. However, the utility for disease control is great because hybrids occupy significant portions of production rice acreage.

2021 ◽  
Author(s):  
Guo-Bang Li ◽  
Jing Fan ◽  
Jie Liu ◽  
Jin-Long Wu ◽  
Xiao-Hong Hu ◽  
...  

Crop floral diseases are economically important as they reduce grain yield and quality and even introduce food toxins. Rice false smut has emerged as a serious floral disease producing mycotoxins. However, very little is known on the interaction mechanisms between rice flower and the causal fungus Ustilaginoidea virens. Here we show that a conserved anti-fungal immunity in rice flower is disarmed by U. virens via a secreted protein UvChi1. UvChi1 functioned as an essential virulence factor and directly interacted with the chitin receptor CEBiP and co-receptor CERK1 in rice to disrupt their oligomerizations and subsequent immune responses. Moreover, intraspecific-conserved UvChi1 could target OsCEBiP/OsCERK1 receptor complex in at least 98.5% of 5232 surveyed rice accessions. These results demonstrate that U. virens utilizes a crucial virulence factor to subvert chitin-triggered flower immunity in most rice varieties, providing new insights into the susceptibility of rice to false smut disease.


2016 ◽  
Vol 4 (3) ◽  
Author(s):  
Toshitaka Kumagai ◽  
Tomoko Ishii ◽  
Goro Terai ◽  
Myco Umemura ◽  
Masayuki Machida ◽  
...  

Ustilaginoidea virens is a rice pathogenic fungus that causes false smut disease, a disease that seriously damages the yield and quality of the grain. Analysis of the U. virens IPU010 33.6-Mb genome sequence will aid in the understanding of the pathogenicity of the strain, particularly in regard to effector proteins and secondary metabolic genes.


2021 ◽  
Vol 13 (16) ◽  
pp. 3185
Author(s):  
Gangqiang An ◽  
Minfeng Xing ◽  
Binbin He ◽  
Haiqi Kang ◽  
Jiali Shang ◽  
...  

Rice false smut (RFS), caused by Ustilaginoidea virens, is a significant grain disease in rice that can lead to reduced yield and quality. In order to obtain spatiotemporal change information, multitemporal hyperspectral UAV data were used in this study to determine the sensitive wavebands for RFS identification, 665–685 and 705–880 nm. Then, two methods were used for the extraction of rice false smut-infected areas, one based on spectral similarity analysis and one based on spectral and temporal characteristics. The final overall accuracy of the two methods was 74.23 and 85.19%, respectively, showing that the second method had better prediction accuracy. In addition, the classification results of the two methods show that the areas of rice false smut infection had an expanding trend over time, which is consistent with the natural development law of rice false smut, and also shows the scientific nature of the two methods.


Agronomy ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 266
Author(s):  
Anestis Karkanis ◽  
Despoina Athanasiadou ◽  
Kyriakos Giannoulis ◽  
Konstantina Karanasou ◽  
Spyridon Zografos ◽  
...  

Maize is an important crop grown on significant acreage around the world, and a major constraint for its growth is weed interference. Thus, field studies were conducted to examine johnsongrass interference, control, and recovery under different management practices and its effects on maize. Our results indicated that the most johnsongrass aboveground biomass was recorded in the nontreated and weed-infested for 55 days after sowing (DAS) treatments, while the lowest values were in nicosulfuron treatments (48 and 60 g a.i./ha). Among the various herbicide treatments, the greatest johnsongrass aboveground biomass was recorded in the isoxaflutole (applied pre-emergence at 99 g a.i./ha) + 1 hoeing treatment. Johnsongrass aboveground biomass at 78–85 DAS was 1.4- to 6.0-fold greater than that at 55 DAS, revealing johnsongrass recovery after nicosulfuron treatments. Johnsongrass competition had a significant impact on maize growth and grain yield. The main crop parameters, such as aboveground biomass, grain yield, and protein content, were lowest in the nontreated and weed-infested for 55 DAS treatments, while the greatest values of these parameters were recorded in the weed-free and nicosulfuron treatments. In conclusion, our results indicated that timely and effective chemical control of johnsongrass is essential for improving grain yield and quality of maize.


Plant Disease ◽  
2000 ◽  
Vol 84 (1) ◽  
pp. 100-100 ◽  
Author(s):  
M. C. Rush ◽  
A. K. M. Shahjahan ◽  
J. P. Jones ◽  
D. E. Groth

False smut, caused by Ustilaginoidea virens (Cooke) Takah., has been occurring in Louisiana rice since at least 1906 (4). A color plate (no. 69) of the disease was published in the Compendium of Rice Diseases published by the American Phytopathological Society (3). The slide for this plate was taken by M. C. Rush in 1976 of rice grown at the Rice Research Station at Crowley, LA. Since that time, the disease has been sporadic and light in Louisiana. In 1997, however, incidence was high. False smut was present on many germ plasms at the Rice Research Station in Crowley and was observed on commercial cultivars in several growers' fields in southwestern Louisiana. Incidence ranged from 1 to 15% of tillers infected with at least two to three spore balls per infected panicle. The disease occurred on both long- and medium-grain cultivars. False smut of rice occurs in the field at the hard dough to mature stages of the crop. A few spikelets in a panicle transform into globose, yellowish green, velvety spore balls that are 2 to 5 cm in diameter and covered by a thin orange membrane. The membrane bursts open and releases powdery dark green spores. The chlamydospores formed in the spore balls are spherical to elliptical, warty, olivaceous, and 3 to 5 × 4 to 6 μm in dimension. Some of the spore balls develop one or more sclerotia, which are the overwintering structure, in the center. False smut has been considered a minor disease of rice that occurs sporadically in Louisiana. The recent discovery of ustilotoxin, a phytotoxin and mycotoxin, produced by this pathogen on diseased tissues suggests that the fungus may be of concern as a contaminant on rice products consumed by livestock and humans (1,2). This increases the need to monitor the incidence of this disease. References: (1) Koiso et al. Ustiloxin: A phytotoxin and a mycotoxin from false smut balls on rice panicles. Tetrahedron Lett. 33:4157, 1992. (2) Koiso et al. Ustiloxins, antimitotic cyclic peptides from false smut balls on rice panicles caused by Ustilaginoidea virens. J. Antibiot. 47:765, 1994. (3) F. N. Lee and P. S. Gunnel. 1992. Compendium of Rice Diseases. The American Phytopathological Society, St. Paul, MN. p. 28. (4) W. A. Orton. 1907. Plant diseases of 1906. Yearbook U.S. Department of Agriculture. U.S. Government Printing Office, Washington, DC, pp. 499–508.


Author(s):  
V. Dumych ◽  

The purpose of research: to improve the technology of growing flax in the Western region of Ukraine on the basis of the introduction of systems for minimizing tillage, which will increase the yield of trusts and seeds. Research methods: field, laboratory, visual and comparative calculation method. Research results: Field experiments included the study of three tillage systems (traditional, canning and mulching) and determining their impact on growth and development and yields of trusts and flax seeds. The traditional tillage system included the following operations: plowing with a reversible plow to a depth of 27 cm, cultivation with simultaneous harrowing and pre-sowing tillage. The conservation system is based on deep shelfless loosening of the soil and provided for chiseling to a depth of 40 cm, disking to a depth of 15 cm, cultivation with simultaneous harrowing, pre-sowing tillage. During the implementation of the mulching system, disking to a depth of 15 cm, cultivation with simultaneous harrowing and pre-sowing tillage with a combined unit was carried out. Tillage implements and machines were used to perform tillage operations: disc harrow BDVP-3,6, reversible plow PON-5/4, chisel PCh-3, cultivator KPSP-4, pre-sowing tillage unit LK-4. The SZ-3,6 ASTPA grain seeder was used for sowing long flax of the Kamenyar variety. Simultaneously with the sowing of flax seeds, local application of mineral fertilizers (nitroammophoska 2 c/ha) was carried out. The application of conservation tillage allows to obtain the yield of flax trust at the level of 3,5 t/ha, which is 0,4 t/ha (12.9 %) more than from the area of traditional tillage and 0,7 t/ha (25 %) in comparison with mulching. In the area with canning treatment, the seed yield was the highest and amounted to 0,64 t/ha. The difference between this option and traditional and mulching tillage reaches 0,06 t/ha (10,3 %) and 0.10 t/ha (18.5 %), respectively. Conclusions. Preservation tillage, which is based on shelf-free tillage to a depth of 40 cm and disking to a depth of 15 cm has a positive effect on plant growth and development, yield and quality of flax.


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