scholarly journals Azoxystrobin Rate and Timing Effects on Rice Head Blast Incidence and Rice Grain and Milling Yields

Plant Disease ◽  
2006 ◽  
Vol 90 (8) ◽  
pp. 1055-1058 ◽  
Author(s):  
D. E. Groth
Keyword(s):  
Disease Incidence ◽  
Pressure Head ◽  
Growth Stages ◽  
Rice Grain ◽  
Blast Pressure ◽  
Head Rice ◽  
Timing Effects ◽  
Rice Milling ◽  
Disease Pressure ◽  
Field Plots

Growing blast susceptible rice (Oryza sativa) cultivars often requires farmers to use fungicides to prevent significant reductions in rice grain and milling yields. Studies were conducted to determine the optimum rate and rice growth stage for single or multiple applications of azoxystrobin to control blast (Pyricularia grisea). Azoxystrobin was applied foliarly to naturally infected field plots in 2001 to 2005 at rates of 0.11, 0.17, and 0.22 kg a.i. ha-1 at boot (B) and heading (H) or only at H growth stages, and at 0.17 kg a.i. ha-1 at 5 (H+5), 10 (H+10), and 15 (H+15) days after H and B with low or high blast pressure. Head blast incidence (percent heads infected) was assessed 1 to 2 weeks before harvest. A fungicide application made at H, H+5, and B+H significantly reduced blast incidence with high and low disease pressure, resulting in significantly higher grain and head rice milling yields compared with unsprayed plots with high blast pressure. There were no significant effects of fungicide rate on blast development or yield following the H, B+H, and H+5 applications. With fungicide applications made at B, H+10, and H+15 days postheading, rice had higher disease incidence, resulting in lower grain and milling yields compared with rice receiving a heading application.

scholarly journals Azoxystrobin Rate and Timing Effects on Rice Sheath Blight Incidence and Severity and Rice Grain and Milling Yields

Plant Disease ◽  
2005 ◽  
Vol 89 (11) ◽  
pp. 1171-1174 ◽  
Author(s):  
D. E. Groth
Keyword(s):  
Sheath Blight ◽  
Growth Stages ◽  
Rice Grain ◽  
Fungicide Application ◽  
Head Rice ◽  
Resistant Varieties ◽  
Timing Effects ◽  
Rice Milling ◽  
Milling Yield ◽  
Field Plots

Lack of sheath blight resistant varieties requires rice (Oryza sativa) farmers to use fungicides to avoid significant reductions in grain yield and milling yield. Studies were conducted to determine the best rate and rice growth stage for a single application of azoxystrobin, a fungicide recently labeled for this use, to effectively control sheath blight. Azoxystrobin was applied foliarly to inoculated field plots in 2000 to 2002 using rates of 0.22, 0.17, and 0.11 kg a.i. ha -1 at 7 days after panicle differentiation (PD+7), boot (B), and heading (H) growth stages and at 0.17 kg a.i. ha-1 at 5, 10, and 15 days after heading. Sheath blight severity (measured on a 0 to 9 scale) and incidence (percent tillers infected) were assessed 1 to 2 weeks before harvest. A fungicide application made between PD+7 and H significantly reduced sheath blight severity, which resulted in significantly higher yield and head rice milling yield compared with inoculated unsprayed plots. There were no significant effects of fungicide rate at the PD+7, B, and H growth stages. Fungicide-treated plots had yield and milling yield similar to the very lightly diseased, uninoculated check plots included for comparison. With fungicide application made postheading, rice had higher disease severity, resulting in lower yields and milling yield compared with rice receiving earlier applications.

scholarly journals Initiation of Rice Sheath Blight Epidemics and Effect of Application Timing of Azoxystrobin on Disease Incidence, Severity, Yield, and Milling Quality

Plant Disease ◽  
2006 ◽  
Vol 90 (8) ◽  
pp. 1073-1076 ◽  
Author(s):  
D. E. Groth ◽  
J. A. Bond
Keyword(s):  
Disease Incidence ◽  
Sheath Blight ◽  
Crop Damage ◽  
Growth Stages ◽  
Milling Quality ◽  
Application Timing ◽  
Green Ring ◽  
Head Rice ◽  
Rice Milling ◽  
Milling Yield

The lack of sheath blight-resistant cultivars requires rice (Oryza sativa) farmers to use fungicides to control the disease and avoid significant reductions in grain and milling yield. Sheath blight (Rhizoctonia solani) epidemics can begin over a period of weeks during the growing season, and initiation date can have significant effects on crop damage and fungicide application timing. Studies were conducted to determine how different epidemic initiation and azoxystrobin application timings affect disease development, rice yield, and milling quality. Sheath blight epidemics in field plots were initiated by inoculation at the green ring (GR), panicle differentiation (PD), early boot (EB), and late boot (LB) growth stages in 2002 to 2004. Azoxystrobin was applied to the foliage at 0.17 kg a.i. ha-1 at 7 days after PD (PD+7), midboot (B), and 50% heading (H). Inoculation significantly increased sheath blight severity and incidence and reduced yield and milling quality. There were no significant effects of inoculation timing at the GR, PD, EB, and LB growth stages. Fungicide applications made between PD+7 and H reduced sheath blight severity and incidence, resulting in higher yield and head rice milling yield compared with inoculated but nonsprayed plots.

scholarly journals Suppression of Sclerotinia Stem Rot of Soybean by Lactofen Herbicide Treatment

1999 ◽  
Vol 89 (7) ◽  
pp. 598-602 ◽  
Author(s):  
E. K. Dann ◽  
B. W. Diers ◽  
R. Hammerschmidt
Keyword(s):  
Disease Severity ◽  
Field Experiments ◽  
Lesion Size ◽  
Stem Rot ◽  
Growth Stages ◽  
Sclerotinia Stem Rot ◽  
High Disease Severity ◽  
Disease Pressure ◽  
Seed Yields ◽  
Field Plots

Severity of Sclerotinia stem rot of soybean after treatment with lactofen (Cobra) and other herbicides was assessed in field experiments conducted in Michigan from 1995 to 1997. At sites where disease pressure was high, disease severity was reduced 40 to 60% compared with controls when lactofen was applied at the V3 (1995 and 1996) or R1 (1997) growth stages. Corresponding seed yields were unchanged or up to 20% greater when lactofen was applied at the R1 stage in 1997. Disease severity was not reduced by lactofen treatments in years and at sites where disease pressure was low to medium, and corresponding yields often were reduced by ≈10%. High levels of glyceollin accumulated in lactofen-injured leaves collected from field plots in 1996 and 1997. High glyceollin content in lactofen-treated leaves was associated with significant reductions in lesion size when leaves were challenge-inoculated with Sclerotinia sclerotiorum.

Rice: Parboiling and Milling Properties

2015 ◽  
Vol 11 (6) ◽  
pp. 777-787 ◽  
Author(s):  
Shabir Ahmad Mir ◽  
Sowriappan John Don Bosco ◽  
Manzoor Ahmad Shah ◽  
Mohammad Maqbool Mir ◽  
Shaiq Ahmad Ganai
Keyword(s):  
Processing Technique ◽  
Quality Parameters ◽  
Characteristic Change ◽  
Rice Grain ◽  
Milled Rice ◽  
Nutritional Profile ◽  
Head Rice ◽  
Rice Milling ◽  
Pass Through ◽  
Milling Properties

Abstract Parboiling is a hydrothermal processing technique during rice has to pass through many stages which alter the physicochemical properties and nutritional profile of grain. Different parboiling techniques have been developed for preparation and industrialization of rice. During parboiling process, starch granules are gelatinized and retrograded as a result various changes occur in rice kernel, which affects its quality parameters. Parboiling has marked influence on organoleptic properties, improved the strength and nutritional profile of grain. Parboiling treatment principally brings the characteristic change in rice grain such as milling, cooking, storage and eating qualities. Milling is an important unit operation for removing the husk and bran from the rough rice. Milling significantly affects the cooking and nutritional properties of rice. The important parameters focussed during milling are the head rice yield and kernel hardness. Milling technology is therefore geared to obtain maximum outturn of milled rice and to reduce breakage.

Rice Response to Sub-Lethal Concentrations of Paraquat, Glyphosate, Saflufenacil, and Sodium Chlorate at Multiple Late-Season Application Timing as Influenced by Exposure

2021 ◽  
pp. 1-36
Author(s):  
Justin McCoy ◽  
Bobby Golden ◽  
Jason Bond ◽  
Darrin Dodds ◽  
Taghi Bararpour ◽  
...  
Keyword(s):  
Grain Yield ◽  
Rice Yield ◽  
Sodium Chlorate ◽  
Growth Stages ◽  
Rice Grain ◽  
Application Timing ◽  
Late Season ◽  
Head Rice ◽  
Rough Rice ◽  
Head Rice Yield

In Mississippi, rice reproduction and ripening often overlaps with soybean maturation creating potential for herbicide exposure from desiccants applied to soybeans onto rice. Six independent studies were conducted concurrently at the Delta Research and Extension Center in Stoneville, MS from 2016 to 2018 to determine the response of rice to sub-lethal concentrations of soybean desiccants during rice reproductive and ripening growth stages. Studies included the desiccants paraquat, glyphosate, saflufenacil, sodium chlorate, paraquat+saflufenacil, and paraquat+sodium chlorate applied at a rate equal to 1/10 of Mississippi recommendations. Treatments were applied at five different rice growth stages beginning at 50% heading (defined as 0 d after heading (DAH)), with subsequent applications at one week intervals (0, 7, 14, 21, and 28 DAH) up to harvest. Injury was observed 7 days after application (DAA) with five of six desiccants at all application timings. No injury was observed with glyphosate application across all rating intervals. Rough rice grain yield following all glyphosate applications was reduced by >6%. In the studies evaluating paraquat injury ranged from 5 to 18% at all evaluations, regardless of application timing. Rough rice grain yield was reduced >12% 0 to 21 DAH, following paraquat application. Similar trends were observed with paraquat+saflufenacil and paraquat+sodium chlorate, with rice exhibiting yield decreases >6% following an application 0 to 14 and 0 to 21 DAH, respectively. In studies evaluating saflufenacil and sodium chlorate rough rice grain yield was >95% of the untreated across all application timings Yield component trends closely resembled reductions observed in rough rice grain yield. Reductions in head rice yield were >5% following applications of paraquat or paraquat+saflufenacil 0 to 14 and 0 to 21 DAH respectively. Late-season exposure to sub-lethal concentrations of desiccant from 50% heading (0 DAH) to 28 DAH has an impact on rough rice grain yield, yield components, and head rice yield.

scholarly journals Effects of Rootstock and Budding Height on Bacterial Canker in French Prune

Plant Disease ◽  
2002 ◽  
Vol 86 (5) ◽  
pp. 543-546 ◽  
Author(s):  
R. J. Sayler ◽  
S. M. Southwick ◽  
J. T. Yeager ◽  
K. Glozer ◽  
E. L. Little ◽  
...  
Keyword(s):  
Tree Mortality ◽  
Prunus Persica ◽  
Disease Incidence ◽  
Fruit Trees ◽  
Field Trials ◽  
Bacterial Canker ◽  
Prunus Domestica ◽  
Severity Of Disease ◽  
Prunus Cerasifera ◽  
Disease Pressure

Bacterial canker is one of the most economically important diseases of stone fruit trees, including ‘French’ prune (Prunus domestica). Field trials were conducted to evaluate the effect of rootstock selection and budding height on the incidence and severity of bacterial canker in four orchards with low to high disease pressure. Treatments included French prune scions low-grafted on ‘Lovell’ peach (Prunus persica) rootstocks as well as Myrobalan 29C (Prunus cerasifera) plum rootstocks grafted at 15, 50, and 90 cm above the rootstock crown. Another treatment consisted of growing Myrobalan 29C plum rootstocks in the field for one growing season, then field-grafting French prune buds onto rootstock scaffolds. Lovell peach rootstock provided the greatest protection from bacterial canker as measured by disease incidence and tree mortality in all orchards. Field-budded rootstocks and rootstocks grafted at the highest budding height provided moderate levels of resistance to bacterial canker. These treatments reduced the incidence but not the severity of disease.

scholarly journals Reaction of Select Peanut (Arachis hypogaea L.) Lines to Southern Stem Rot and Pythium Pod Rot Under Varied Disease Pressure

1989 ◽  
Vol 16 (1) ◽  
pp. 9-14 ◽  
Author(s):  
O. D. Smith ◽  
T. E. Boswell ◽  
W. J. Grichar ◽  
C. E. Simpson
Keyword(s):  
Arachis Hypogaea ◽  
Disease Incidence ◽  
Sclerotium Rolfsii ◽  
Stem Rot ◽  
Resistant Parent ◽  
Breeding Lines ◽  
Arachis Hypogaea L ◽  
Significant Yield ◽  
Considerable Resistance ◽  
Disease Pressure

Abstract Eight breeding lines, three parents, and the cultivar Florunner were compared under two levels of disease pressure induced by Sclerotium rolfsii Sacc., or Pythium myriotylum Drechs. at each of two locations for three years to ascertain the effectiveness of the host plant resistance to each pathogen. Varied disease pressures were created by application of fungicides and supplement of fungal inoculum. Mean Florunner pod yields varied more than 1000 kg/ha as a result of the S. rolfsii treatments but the yields of the resistant TxAG-3 were not affected. Disease incidence, as measured by frequency of S. rolfsii infection sites and diseased pods, was much higher for Florunner than TxAG-3. Breeding lines for which TxAG-3 was a parent sustained significant yield reductions. The disease incidence in these lines was higher than the resistant parent, equal or less than Tamnut 74, their other parent, and less than Florunner. The grades of TxAG-3 and its derivatives were lower than Florunner. Pod rot incidence differed for the P. myriotylum treatments but pod yields were not different. TxAG-3 and Toalson sustained less pod disease than Florunner and Tamnut 74. The percent of diseased pod tissue for one derivative of Toalson was lower than Toalson and TxAG-3, and that of one TxAG-3 derivative was equal to its best parent. The breeding lines varied in reaction to the two diseases and some lines showed considerable resistance to both organisms.

scholarly journals Population Dynamics of Released Potato Psyllids and their Bacteriliferous Status in Relation to Zebra Chip Incidence in Caged Field Plots

Plant Disease ◽  
2016 ◽  
Vol 100 (8) ◽  
pp. 1762-1767 ◽  
Author(s):  
F. Workneh ◽  
L. Paetzold ◽  
A. Rashed ◽  
C. M. Rush
Keyword(s):  
Disease Incidence ◽  
Sticky Trap ◽  
Research Station ◽  
Zebra Chip ◽  
Sticky Traps ◽  
Monitoring Tools ◽  
Candidatus Liberibacter ◽  
Yellow Sticky Trap ◽  
Successive Generations ◽  
Field Plots

Potato psyllids vector ‘Candidatus Liberibacter solanacearum’ (Lso), the putative causal agent of potato zebra chip (ZC). Currently, sticky traps are the primary psyllid monitoring tools used by growers for making management decisions. However, the reliability of sticky traps in predicting psyllid numbers in potato fields has always been questioned. In 2013 and 2014, experiments were conducted in covered field plots at the Texas A&M AgriLife Research Station at Bushland to investigate the relationships among initial psyllid numbers, psyllids captured on sticky traps and their Lso status, and zebra chip incidence. Three densities of Lso-positive psyllids (5, 15, or 30/cage) were released under 2-week-old potato canopies with four replications in plot sizes of 7.6 to 9 m by 5 rows. Psyllids were released under the first plant in the center row and monitored weekly with a yellow sticky trap from the opposite end. Number of plants with zebra chip symptoms also was counted weekly beginning one month after infestation with psyllids. The total number of psyllids captured on sticky traps and disease incidence levels generally corresponded to the levels of psyllid density treatments (5 < 15 < 30), but the differences became more apparent toward the end of the experiments. Psyllid numbers in the different density treatments fluctuated more or less in synchrony over time, which appeared to reflect periodic emergence of new generations of psyllids. Initially, all captured psyllids tested positive for Lso. However, the proportions of psyllids testing positive declined dramatically after a few weeks, which suggested that the new generations of psyllids were devoid of Lso. Over all, less than 50% of captured psyllids tested positive for the pathogen. The decline in proportions of psyllids testing positive for Lso following successive generations has significant relevance to field situations and may partly explain why there are generally low percentages of Lso-positive psyllids under field conditions.

scholarly journals Extrusion cooking of immature rice grain: under-utilized by-product of rice milling process

2020 ◽  
Vol 57 (8) ◽  
pp. 2905-2915
Author(s):  
Barış Burak Albayrak ◽  
Necati Barış Tuncel ◽  
Neşe Yılmaz Tuncel ◽  
Mustafa Tuğrul Masatcıoğlu
Keyword(s):  
Milling Process ◽  
Extrusion Cooking ◽  
Rice Grain ◽  
Rice Milling

Competition of Bearded Sprangletop (Leptochloa fascicularis) with Rice (Oryza sativa)

Weed Science ◽  
1983 ◽  
Vol 31 (1) ◽  
pp. 120-123 ◽  
Author(s):  
Roy J. Smith
Keyword(s):  
Oryza Sativa ◽  
Grain Yield ◽  
Paddy Rice ◽  
Rice Grain ◽  
Rice Seed ◽  
Weed Density ◽  
Weed Plant ◽  
Linear Decrease ◽  
Head Rice ◽  
Rice Yields

Yields of drill-seeded paddy rice (Oryza sativaL. ‘Lebonnet’) at optimum stands of 215 to 270 plants/m2at Stuttgart, Arkansas, were reduced 9, 18, 20, and 36% by bearded sprangletop [Leptochloa fascicularis(Lam.) Gray] densities of 11, 22, 54, and 108 plants/m2, respectively. There was a linear decrease in rice grain yield of 21 kg/ha for each bearded sprangletop plant per square meter. Weed densities of 54 and 108 plants/m2reduced head-rice yields (whole milled kernels) and a density of 108 plants/m2reduced germination of rice seed. The number of bearded sprangletop panicles produced per weed plant decreased as the weed density increased.

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