scholarly journals Identification of Wheat Yellow Rust Using Optimal Three-Band Spectral Indices in Different Growth Stages

Sensors ◽  
2018 ◽  
Vol 19 (1) ◽  
pp. 35 ◽  
Author(s):  
Qiong Zheng ◽  
Wenjiang Huang ◽  
Ximin Cui ◽  
Yingying Dong ◽  
Yue Shi ◽  
...  
Keyword(s):  
Classification Accuracy ◽  
Growth Stage ◽  
Yellow Rust ◽  
Kappa Coefficient ◽  
Economic Losses ◽  
Growth Stages ◽  
Spectral Indices ◽  
Rust Disease ◽  
Late Growth ◽  
Different Growth Stages

Yellow rust, a widely known destructive wheat disease, affects wheat quality and causes large economic losses in wheat production. Hyperspectral remote sensing has shown potential for the detection of plant disease. This study aimed to analyze the spectral reflectance of the wheat canopy in the range of 350–1000 nm and to develop optimal spectral indices to detect yellow rust disease in wheat at different growth stages. The sensitive wavebands of healthy and infected wheat were located in the range 460–720 nm in the early-mid growth stage (from booting to anthesis), and in the ranges 568–709 nm and 725–1000 nm in the mid-late growth stage (from filling to milky ripeness), respectively. All possible three-band combinations over these sensitive wavebands were calculated as the forms of PRI (Photochemical Reflectance Index) and ARI (Anthocyanin Reflectance Index) at different growth stages and assessed to determine whether they could be used for estimating the severity of yellow rust disease. The optimal spectral index for estimating wheat infected by yellow rust disease was PRI (570, 525, 705) during the early-mid growth stage with R2 of 0.669, and ARI (860, 790, 750) during the mid-late growth stage with R2 of 0.888. Comparison of the proposed spectral indices with previously reported vegetation indices were able to satisfactorily discriminate wheat yellow rust. The classification accuracy for PRI (570, 525, 705) was 80.6% and the kappa coefficient was 0.61 in early-mid growth stage, and the classification accuracy for ARI (860, 790, 750) was 91.9% and the kappa coefficient was 0.75 in mid-late growth stage. The classification accuracy of the two indices reached 84.1% and 93.2% in the early-mid and mid-late growth stages in the validated dataset, respectively. We conclude that the three-band spectral indices PRI (570, 525, 705) and ARI (860, 790, 750) are optimal for monitoring yellow rust infection in these two growth stages, respectively. Our method is expected to provide a technical basis for wheat disease detection and prevention in the early-mid growth stage, and the estimation of yield losses in the mid-late growth stage.

scholarly journals Effect of Herbicides on the Management of the Invasive Weed Solanum rostratum Dunal (Solanaceae)

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 284
Author(s):  
Jackline Abu-Nassar ◽  
Maor Matzrafi
Keyword(s):  
Growth Stage ◽  
Late Summer ◽  
Early Spring ◽  
Growth Stages ◽  
Weed Species ◽  
Invasive Weed ◽  
Solanum Rostratum ◽  
Stage 4 ◽  
Chemical Solutions ◽  
Late Growth

Solanum rostratum Dunal is an invasive weed species that invaded Israel in the 1950s. The weed appears in several germination flashes, from early spring until late summer. Recently, an increase in its distribution range was observed, alongside the identification of new populations in the northern part of Israel. This study aimed to investigate the efficacy of herbicide application for the control of S. rostratum using two field populations originated from the Golan Heights and the Jezreel Valley. While minor differences in herbicide efficacy were recorded between populations, plant growth stage had a significant effect on herbicide response. Carfentrazone-ethyl was found to be highly effective in controlling plants at both early and late growth stages. Metribuzin, oxadiazon, oxyfluorfen and tembutrione showed reduced efficacy when applied at later growth stage (8–9 cm height), as compared to the application at an early growth stage (4–5 cm height). Tank mixes of oxadiazon and oxyfluorfen with different concentrations of surfactant improved later growth stage plant control. Taken together, our study highlights several herbicides that can improve weed control and may be used as chemical solutions alongside diversified crop rotation options. Thus, they may aid in preventing the spread and further buildup of S. rostratum field populations.

Development of new bread wheat resistant mutants for Ug99 rust disease (Puccinia graminis f. sp. tritici).

2021 ◽  
pp. 312-319
Author(s):  
Abdulwahid Saif ◽  
Aref Al-Shamiri ◽  
Abdulnour Shaher
Keyword(s):  
Bread Wheat ◽  
Adult Stage ◽  
Yellow Rust ◽  
Seedling Stage ◽  
Yield Potential ◽  
Growth Stages ◽  
Rust Disease ◽  
Wheat Varieties ◽  
Rust Diseases ◽  
Mutant Lines

Abstract M3 derived mutants from two bread wheat varieties, namely, 'Giza 186' and 'Saha 93', were screened for resistance to the rust Ug99 at two locations in Njoro (Kenya) and in Tihama (Yemen). At Tihama, two mutants of 'Giza 186' (G-M2-2010-1-28 and G-M2-2010-41-52) and four mutants of 'Saha 93' (S-M2-2010-16-12, S-M2-2010-21-13, S-M2-2010-22-14 and S-M2-2010-27-15) were seen to be resistant at both seedling and adult stages while their parents were resistant at seedling stage and susceptible at adult stage. In Kenya, the resistance score of the mutants was slightly different from those obtained at Tihama. The mutants G-M2-2010-1-28 and G-M2-2010-41-52 were stable in their level of resistance recorded at Tihama, but only two mutants of 'Saha 93' (S-M2-2010-16-12 and S-M2-2010-27-15) were resistant at both growth stages. S-M2-2010-22-14 and S-M2-2010-21-13 were resistant at the seedling stage while susceptible at adult stage. Further selection on these mutants for yield potential, agronomic performance and yellow rust disease resistance, as well as on selected mutants of both 'Giza 186' and 'Saha 93', at M5-M6 stages identified superior mutant lines compared with the two parents 'Saha 93' and 'Giza 186'. These included the line Erra-010-GM2w-41-52-40, which ranked first in yield (3768 kg/ha), followed by the lines Erra-010-SwM2-16-12-19, Erra-010-GM2w-1-28-18 and Erra-010-SwM2-22-14-6. Moreover, it can be concluded that Erra-010-GM2w-41-52-40 and Erra-010-SwM2-16-12-19 are highly recommended for their resistance to stem and yellow rust diseases as well as for yield potential and preference by farmers. Therefore, efforts are in progress to increase their seeds for dissemination over a wide range of farmers and wheat areas where rust diseases are an epidemic, and for registration of the lines as improved mutant varieties.

scholarly journals Evaluation of Rice Responses to the Blast Fungus Magnaporthe oryzae at Different Growth Stages

Plant Disease ◽  
2019 ◽  
Vol 103 (1) ◽  
pp. 132-136 ◽  
Author(s):  
Xinglong Chen ◽  
Yulin Jia ◽  
Bo Ming Wu
Keyword(s):  
Disease Severity ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Growth Stage ◽  
Disease Index ◽  
Blast Disease ◽  
Growth Stages ◽  
Japonica Rice ◽  
Rice Cultivars ◽  
Different Growth Stages

Rice blast, caused by the fungus Magnaporthe oryzae, is the most damaging disease for rice worldwide. However, the reactions of rice to M. oryzae at different growth stages are largely unknown. In the present study, two temperate japonica rice cultivars, M-202 and Nipponbare, were inoculated synchronously at different vegetative growth stages, V1 to V10. Plants of M-202 at each stage from V1 to reproductive stage R8 were inoculated with M. oryzae race (isolate) IB-49 (ZN61) under controlled conditions. Disease reactions were recorded 7 days postinoculation by measuring the percentage of diseased area of all leaves, excluding the youngest leaf. The results showed that the plants were significantly susceptible at the V1 to V4 stages with a disease severity of 26.7 to 46.8% and disease index of 18.62 to 37.76 for M-202. At the V1 to V2 stages, the plants were significantly susceptible with a disease a severity of 28.6 to 39.3% and disease index of 23.65 to 29.82 for Nipponbare. Similar results were observed when plants of M-202 were inoculated at each growth stage with a disease severity of 29.7 to 60.6% and disease index of 21.93 to 59.25 from V1 to V4. Susceptibility decreased after the V5 stage (severity 4.6% and index 2.17) and became completely resistant at the V9 to V10 stages and after the reproductive stages, suggesting that plants have enhanced disease resistance at later growth stages. These findings are useful for managing rice blast disease in commercial rice production worldwide.

Irrigation of field peas (Pisum sativum): response to timing at different crop growth stages

1999 ◽  
Vol 132 (4) ◽  
pp. 417-424 ◽  
Author(s):  
C. M. KNOTT
Keyword(s):  
Pisum Sativum ◽  
Vegetative Growth ◽  
Growth Stage ◽  
Crop Growth ◽  
Yield Response ◽  
Growth Stages ◽  
Field Peas ◽  
Crop Growth Stages ◽  
Different Growth Stages

The response of two cultivars of dry harvest field peas (Pisum sativum), Solara and Bohatyr, to irrigation at different growth stages was studied on light soils overlying sand in Nottinghamshire, England in 1990, when the spring was particularly dry, in 1991 which had a dry spring and summer and in contrast, 1992, when rainfall was greater compared with the long-term (40 year) mean.Solara, short haulmed and semi-leafless was more sensitive to drought than the tall conventional-leaved cultivar Bohatyr and gave a greater yield response to irrigation, particularly at the vegetative growth stage in the first two dry years 1990 and 1991, of 108% and 55% respectively, compared with unirrigated plots. Bohatyr was less sensitive to the timing of single applications.In all years, peas irrigated throughout on several occasions produced the highest yields, but this was the least efficient use of water.

Nutrient digestibility of alfalfa at different growth stages on sheep and goat

2003 ◽  
Vol 2003 ◽  
pp. 193-193
Author(s):  
M. M. Moeini ◽  
M. Souri ◽  
F. Hozabri ◽  
M. R. Sanjabi
Keyword(s):  
Dry Matter ◽  
Growth Stage ◽  
Animal Feed ◽  
Maximum Yield ◽  
Nutrient Digestibility ◽  
Growth Stages ◽  
Preparation Methods ◽  
Nutritive Values ◽  
High Forage ◽  
Different Growth Stages

The nutritive values of animal feed are dependents on plant species, stages of maturity, harvesting and preparation methods. Legumes provide maximum yield, high forage quality (protein, mineral and digestible energy). Legumes decrease in protein and digestible dry matter and increase in fibre as they increase in growth or in maturity (Hochensmith et al., 1997). Alfalfa (medica sativa) is world unique forage in livestock food. This study was conducted to examine the chemical composition and nutrient digestibility of Hamadanian alfalfa forage at different growth stage on two local Iranian sheep and goat breeds.

Control of Early Watergrass (Echinochloa Oryzoides) and Late Watergrass (Echinochloa Phyllopogon) with Cyhalofop, Clefoxydim, and Penoxsulam Applied Alone and in Mixture with Broadleaf Herbicides

2006 ◽  
Vol 20 (4) ◽  
pp. 992-998 ◽  
Author(s):  
Christos A. Damalas ◽  
Kico V. Dhima ◽  
Ilias G. Eleftherohorinos
Keyword(s):  
Growth Stage ◽  
Leaf Growth ◽  
Application Rate ◽  
Early Growth ◽  
Rice Fields ◽  
Growth Stages ◽  
Early Growth Stage ◽  
Late Growth ◽  
Echinochloa Phyllopogon

Experiments were conducted to study the effect of application rate, growth stage, and tank-mixing azimsulfuron or bentazon on the activity of cyhalofop, clefoxydim, and penoxsulam against two morphologically distinctEchinochloaspecies from rice fields in Greece. Mixtures of penoxsulam with MCPA were also evaluated. Cyhalofop (300 to 600 g ai/ha) applied at the three- to four-leaf growth stage provided 62 to 85% control of early watergrass but 41 to 83% control of late watergrass averaged over mixture treatments. Control ranged from 37 to 80% for early watergrass and from 35 to 78% for late watergrass when cyhalofop was applied at the five- to six-leaf growth stage averaged over mixture treatments. Mixtures of cyhalofop with azimsulfuron or bentazon reduced efficacy on both species irrespective of growth stage or cyhalofop application rate compared with cyhalofop alone. Clefoxydim (100 to 250 g ai/ha) applied alone at the three- to four-leaf growth stage provided 98 to 100% control of early watergrass and 91 to 100% control of late watergrass; when clefoxydim was applied alone at the five- to six-leaf growth stage the control obtained was 91 to 100% for early watergrass and 79 to 100% for late watergrass. Mixtures of clefoxydim with azimsulfuron or bentazon reduced efficacy on late watergrass at the early growth stage and on both species at the late growth stage. Penoxsulam (20 to 40 g ai/ha) applied alone provided 94 to 100% control of both species at both growth stages. Mixtures of MCPA with penoxsulam reduced efficacy on late watergrass at the early growth stage and on both species at the late growth stage. Mixtures of penoxsulam with azimsulfuron or bentazon reduced efficacy only on late watergrass at the late growth stage.

scholarly journals Salmonella in healthy pigs: prevalence, serotype diversity and antimicrobial resistance observed during 1998–1999 and 2004–2005 in Japan

2007 ◽  
Vol 136 (8) ◽  
pp. 1118-1123 ◽  
Author(s):  
K. FUTAGAWA-SAITO ◽  
S. HIRATSUKA ◽  
M. KAMIBEPPU ◽  
T. HIROSAWA ◽  
K. OYABU ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Growth Stage ◽  
Growth Stages ◽  
Finishing Pigs ◽  
Weaned Pigs ◽  
Farm Level ◽  
Faecal Samples ◽  
National Estimates ◽  
Fattening Pigs ◽  
Different Growth Stages

SUMMARYTo determine prevalence, serotype diversity and antimicrobial resistance of Salmonella in healthy pigs, faecal samples from 6771 pigs on 73 farms collected during 1998–1999 and 2004–2005 were examined. Salmonella isolates were serotyped and tested for susceptibility to 22 antimicrobials: benzylpenicillin, ampicillin, amoxicillin, cefazolin, cephaloridine, gentamicin, kanamycin, streptomycin, fradiomycin, colistin, tetracycline, chlortetracycline, oxytetracycline, chloramphenicol, thiamphenicol, sulfadimethoxine, sulfamethoxazole, sulfamethoxypyridazine, trimethoprim, sulfamethoxazole/trimethoprim, norfloxacin and ofloxacin. Farm-level and pig-level Salmonella prevalences were 35·5% and 2·2% in 1998–1999, and 35·7% and 3·3% in 2004–2005. Prevalence by growth stage was 2·4% for sows, 3·3% for weaned pigs, 2·7% for fattening pigs and 3·8% for finishing pigs. The predominant serotypes identified were Agona (28·4%), Typhimurium (17·9%) and Infantis (16·4%) in 1998–1999, and Typhimurium (32·5%), Anatum (24·6%) and Infantis (13·5%) in 2004–2005. Compared with the 1998–1999 isolates, the 2004–2005 isolates showed significantly higher rates of resistance to all the antimicrobials except tetracyclines (P<0·01 to P<0·05) and resistance to ⩾2 antimicrobials [19·4% (13/67) vs. 39·7% (50/126), P<0·01]. This study provides national estimates of Salmonella prevalence in healthy pigs of different growth stages in Japan.

scholarly journals Effect of Different Durations of Water-Logging at Different Growth Stages on Seed Yield of Sesame

2018 ◽  
Vol 1 (2) ◽  
pp. p68
Author(s):  
M. H. Ali
Keyword(s):  
Seed Yield ◽  
Growth Stage ◽  
Field Trials ◽  
Growth Stages ◽  
Differential Effects ◽  
Growing Period ◽  
Water Logging ◽  
Different Growth Stages

In Bangladesh, sesame suffers from water-logging during its growing period. Multi-year and multi-location field trials were carried out to study the effect of different durations of water-logging at different growth stages on seed yield of sesame. From two years results, it is revealed that the effects of water-logging during a particular growth stage or particular duration of water-logging on seed yield depends on pre- and/or post water-logging from the rainfall. Differential effects of the cultivars were also observed. The cultivar Binatil-2 and Binatil-3 showed reasonable seed yield under water-logging at flowering and mid pod-formation stages for 24 to36 hours.

scholarly journals Changes in Essential Oil Content and Composition of Salvia Limbata C.A. Mey at Different Growth Stages and Altitudes

2020 ◽  
Author(s):  
Maryam Saffariha ◽  
Hossein Azarnivand ◽  
Mohammad Ali Zare Chahouki ◽  
Ali Tavili ◽  
Samad Nejad Ebrahimi ◽  
...  
Keyword(s):  
Essential Oil ◽  
Growth Stage ◽  
Volatile Oil ◽  
Growth Stages ◽  
Harvest Time ◽  
Total Volatile ◽  
Oil Composition ◽  
Optimal Harvest ◽  
Germacrene D ◽  
Different Growth Stages

Abstract BackgroundThe present study investigates the effect of growth stage (vegetative, flowering and seed ripening) and altitude (1500, 2000 and 2500 m above sea level) on the content and chemical composition of S. limbata essential oil which belongs to Lamiaceae family.ResultsAccording to the oil analysis, 28 components representing 96.5% to 99.7% of the total volatile oil composition were characterized. The main compounds of S. limbata oils were α-pinene (14.7-38.7%), β-pinene (12.5-26.2%), allo-aromadendrene (9.2-21.7%), germacrene D (4.2-8.3%), bicyclogermacrene (6.5-14.5 %), and spathulenol (7.5-25.4 %).DiscussionThe obtained results showed that the content and constituents of S. limbata essential oil strongly depend on the growth stage and altitude. Our findings revealed that the vegetative stage at 1500 m is the optimal harvest time to obtain the highest content of oil yield. Results of the current study helps to find the optimum situation to gain the highest content of S. limbata essential oil but more researches are needed.

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