Yield loss and fungicide control of stem rust of wheat

2005 ◽  
Vol 56 (1) ◽  
pp. 91 ◽  
Author(s):  
R. Loughman ◽  
K. Jayasena ◽  
J. Majewski

Yield loss in wheat from natural infections with Puccinia graminis f.sp. tritici ranged from 10 to 45% in 3 experiments over 2 years. Fungicide reduced subsequent stem rust severity on plant parts that were only slightly infected at the time of fungicide application, but was not effective on plant parts that were more heavily infected when treated. Fungicide control of stem rust was economic in a range of situations. Fungicide applied at head emergence with low disease incidence (5% of stems) increased yield by 0.3 t/ha. When applied prior to head emergence with high disease incidence at low disease severity, yield increased by 0.8–1.5 t/ha, depending on duration of control. At a high disease incidence and moderate disease severity, yield increases of 0.4–0.6 t/ha were observed. Grain quality was also significantly improved with fungicide. Fungicide was more effective when applied immediately following detection compared with a 3-week delay. Folicur was more effective at reducing disease and increasing yield or quality than Impact or Triad.

2016 ◽  
Vol 106 (11) ◽  
pp. 1335-1343 ◽  
Author(s):  
Thomas Miedaner ◽  
Ann-Kristin Schmitt ◽  
Bettina Klocke ◽  
Brigitta Schmiedchen ◽  
Peer Wilde ◽  
...  

Stem rust (Puccinia graminis f. sp. secalis) leads to considerable yield losses in rye-growing areas with continental climate, from Eastern Germany to Siberia. For implementing resistance breeding, it is of utmost importance to (i) analyze the diversity of stem rust populations in terms of pathotypes (= virulence combinations) and (ii) identify resistance sources in winter rye populations. We analyzed 323 single-uredinial isolates mainly collected from German rye-growing areas across 3 years for their avirulence/virulence on 15 rye inbred differentials. Out of these, 226 pathotypes were detected and only 56 pathotypes occurred more than once. This high diversity was confirmed by a Simpson index of 1.0, a high Shannon index (5.27), and an evenness index of 0.97. In parallel, we investigated stem rust resistance among and within 121 heterogeneous rye populations originating mainly from Russia, Poland, Austria, and the United States across 3 to 15 environments (location−year combinations). While German rye populations had an average stem rust severity of 49.7%, 23 nonadapted populations were significantly (P < 0.01) more resistant with a stem rust severity ranging from 3 to 40%. Out of these, two modern Russian breeding populations and two old Austrian landraces were the best harboring 32 to 70% fully resistant plants across 8 to 10 environments. These populations with the lowest disease severity in adult-plant stage in the field also displayed resistance in leaf segment tests. In conclusion, stem rust populations are highly diverse and the majority of resistances in rye populations seems to be race specific.


2016 ◽  
Vol 83 (2) ◽  
Author(s):  
Abdul WAHAB ◽  
Muhammad TAUFIK ◽  
La Ode Santiaji BANDE ◽  
Irma KRESNAWATY

AbstractVarious factors causing the decreasing in the cocoa  production, and one of them is the infection of cocoa pod disease (CPD) caused by the pathogen of  Phytophthora palmivora. Plastic covered and coating with biokaolin can be used as techniques for the prevention of the diseases. The aim of  the research was to evaluate several techniques to control cocoa pod disease in order to reduce disease incidence, disease severity and yield loss of 100 seeds cocoa. This research was conducted in the village of Tokai, District of Poli-Polia, East Kolaka Southeast Sulawesi, from April to August 2013. The research was conducted according completely Randomized Block Design (RBD) with five treatments and four groups in order to obtain 20 experimental units. Each experimental unit consisted of  20 trees which each has five fruits so in total each unit consist of 100 fruit samples. The treatments tested were as follows; control (M0), biokaolin application every two weeks (M1), biokaolin application every four weeks (M2), plastic covered (M3), and mankozeb fungicide application every two weeks (M4). Variables observed in this study were the incidence of disease, severity of disease and yield loss was calculated by weighing the dry weight of 100 seeds. The results showed that the application of biokaolin every two weeks was more  effective to reduce disease incidence (26.12%) and disease severity (11.04%) while the average weight of the highest dry bean yield loss was on category of severe infection that is 74.96% with the lowest dry weight is 26.6 g in 100 seeds.  Abstrak   Berbagai faktor menjadi penyebab turunnya produksi buah kakao, salah satunya adanya infeksi penyakit busuk buah kakao (BBK) yang disebabkan oleh pathogen  Phytophthora palmivora. Teknik yang dapat dikembangkan untuk penanggulangan penyakit antara lain teknik penyelubungan dan pelapisan dengan biokaolin. Penelitian ini  ber-tujuan untuk mengevaluasi berbagai teknik pengendalian penyakit busuk buah kakao yang efektif menekan kejadian penyakit, keparahan penyakit dan besarnya kehilangan hasil berat 100 biji kering. Penelitian dilaksanakan di Desa Tokai, Kecamatan Poli-Polia, Kabupaten Kolaka Timur, Sulawesi Tenggara pada bulan April sampai Agustus 2013. Metode yang digunakan berdasar-kan Rancangan Acak Kelompok (RAK) dengan lima perlakuan dalam empat kelompok sehingga diperoleh 20 unit percobaan.  Setiap unit percobaan terdiri dari 20 pohon, dalam satu pohon terdiri dari lima sampel sehingga dalam 1 unit terdiri dari 100 sampel.  Perlakuan yang dicobakan adalah sebagai berikut; tanpa penyemprotan/penyelubungan (kontrol)  (M0), penyemprotan dengan biokaolin setiap dua minggu (M1), penyemprotan dengan biokaolin setiap empat minggu (M2), penyelubung-an dengan kantong plastik (M3), penyemprotan dengan fungisida mankozeb setiap dua minggu (M4). Parameter yang diamati  adalah kejadian penyakit, keparahan penyakit dan besarnya kehilangan hasil dihitung dengan menimbang berat 100 biji kering. Hasil penelitian menunjukkan bahwa teknik pengendalian penyakit busuk buah dengan aplikasi biokaolin setiap dua minggu rata-rata lebih efektif dalam menekan kejadian   penyakit yaitu (26,12%)  dan  keparahan  penyakit  (11,04%), sedangkan rata-rata besarnya kehilanganhasil berat biji kering tertinggi terlihat pada kategori infeksi berat yaitu 74,96%  dengan berat kering terendah yaitu 26,6 g dalam100 biji.


2018 ◽  
Vol 17 (2) ◽  
pp. 55-63
Author(s):  
Nurhayati DAMIRI ◽  
Amat NURKHOLIS ◽  
Yulia PUJIASTUTI ◽  
Supli Effendi RAHIM

Disease caused by Tobacco Mosaic Virus (TMV) is an important disease in tomato plants, and is transmitted through both natural and artificial wounds. TMV attacking tomato plants can cause qualitatively and quantitatively lower production. The decline in production by TMV attack can reach    60 %. This research was conducted at the greenhouse of the Plant Protection Department, Faculty of Agriculture, University of Sriwijaya, Indralaya, Ogan Ilir, South Sumatra, Indonesia, from January to June 2016. The purpose of this study was to assess TMV attack on different varieties and ages of tomato plants. This study was conducted using a factorial in Factorial Randomized Complete Block Design (FRCBD), with the first factor, namely plant varieties, and the second factor, age stage of plants, repeated 3 times. The results showed that the most susceptible tomato was “Permata”, with the fastest incubation period and moderate disease severity. Age 8 weeks, when inoculation took place, was the most vulnerable time, with the highest disease severity. A combination of the tomato variety of Permata and an age stage of 8 weeks at the time of inoculation had the highest disease incidence.


1986 ◽  
Vol 28 (1) ◽  
pp. 12-16
Author(s):  
D. R. Knott

Studies were done in an attempt to determine the inheritance of adult plant resistance to stem rust (Puccinia graminis f. sp. tritici Eriks. and E. Henn.) in the wheat (Triticum aestivum L.) cultivars 'Hope' and 'Thatcher'. 'Chinese Spring' substitution lines carrying individual chromosomes from 'Hope' and 'Thatcher' were tested in field rust nurseries, three times each with races 15B-1 and 56, and twice with multirace mixtures. In 1976 it was found that the date of heading often had a significant effect on rust severity, with early lines showing less rust. In 1977 and 1984 the lines were divided into three groups based on maturity and were planted on three dates about 10 days apart to make heading dates more uniform. The data indicate that 'Hope' has genes for resistance to race 56 on chromosomes 3B (Sr2) and 4D, and to a multirace mixture on 1B, 3B, and 7B. 'Thatcher' possibly has genes for resistance to race 56 on chromosomes 6A and 3B (Sr12). The results show that the resistance of both cultivars is complex and most genes have only small effects.Key words: Triticum, Puccinia, rust resistance, substitution lines.


2017 ◽  
Vol 9 (1) ◽  
pp. 562-567
Author(s):  
Shilpa Shilpa ◽  
Rajinder Kaur ◽  
Monica Sharma ◽  
M. N. Adarsh

Buckeye rot disease of tomato which is one of the most devastating diseases of tomato crop is caused by soil born fungus Phytophthora nicotianae var. parasitica. In present study, the pathogen was isolated, morphologically identified and its pathogenicity was proved on susceptible commercial variety Solan Lalima and resistant line EC-251649 of tomato. Isolation of pathogen from the infected tomato fruit was achieved on Corn Meal Agar (CMA) out of two different media viz., Potato Dextrose Agar (PDA) and CMA. Fungal inoculum was prepared on Corn Meal broth. Inoculation with 10 ml of inoculum was found optimum in plant parts namely, stem, leaves and fruits. Parental lines were inoculated to test their disease reaction to buckeye rot. Symptoms of infection appeared on leaves and fruits only. Solan Lalima was found to be highly susceptible to with disease severity of 92 % and 100 % disease incidence, while EC-251649 was found moderately resistant on the basis of 16 % disease severity and 10 % disease incidence to the disease. After confirmation of resistance and susceptibility, the parental lines were surveyed for polymorphism using 42 primers and 32 were recorded to be polymorphic revealing that the differences are present at DNA level also. This is the very first study which evaluated parental lines for buckeye rot disease reaction on morphological as well as molecular basis. These lines will be further used for quantitative trait loci (QTL) analysis/gene tagging for buckeye rot and marker assisted selection to provide improved varieties to the farmers.


2016 ◽  
Vol 83 (2) ◽  
Author(s):  
Abdul WAHAB ◽  
Muhammad TAUFIK ◽  
La Ode Santiaji BANDE ◽  
Irma KRESNAWATY

AbstractVarious factors causing the decreasing in the cocoa  production, and one of them is the infection of cocoa pod disease (CPD) caused by the pathogen of  Phytophthora palmivora. Plastic covered and coating with biokaolin can be used as techniques for the prevention of the diseases. The aim of  the research was to evaluate several techniques to control cocoa pod disease in order to reduce disease incidence, disease severity and yield loss of 100 seeds cocoa. This research was conducted in the village of Tokai, District of Poli-Polia, East Kolaka Southeast Sulawesi, from April to August 2013. The research was conducted according completely Randomized Block Design (RBD) with five treatments and four groups in order to obtain 20 experimental units. Each experimental unit consisted of  20 trees which each has five fruits so in total each unit consist of 100 fruit samples. The treatments tested were as follows; control (M0), biokaolin application every two weeks (M1), biokaolin application every four weeks (M2), plastic covered (M3), and mankozeb fungicide application every two weeks (M4). Variables observed in this study were the incidence of disease, severity of disease and yield loss was calculated by weighing the dry weight of 100 seeds. The results showed that the application of biokaolin every two weeks was more  effective to reduce disease incidence (26.12%) and disease severity (11.04%) while the average weight of the highest dry bean yield loss was on category of severe infection that is 74.96% with the lowest dry weight is 26.6 g in 100 seeds.  Abstrak   Berbagai faktor menjadi penyebab turunnya produksi buah kakao, salah satunya adanya infeksi penyakit busuk buah kakao (BBK) yang disebabkan oleh pathogen  Phytophthora palmivora. Teknik yang dapat dikembangkan untuk penanggulangan penyakit antara lain teknik penyelubungan dan pelapisan dengan biokaolin. Penelitian ini  ber-tujuan untuk mengevaluasi berbagai teknik pengendalian penyakit busuk buah kakao yang efektif menekan kejadian penyakit, keparahan penyakit dan besarnya kehilangan hasil berat 100 biji kering. Penelitian dilaksanakan di Desa Tokai, Kecamatan Poli-Polia, Kabupaten Kolaka Timur, Sulawesi Tenggara pada bulan April sampai Agustus 2013. Metode yang digunakan berdasar-kan Rancangan Acak Kelompok (RAK) dengan lima perlakuan dalam empat kelompok sehingga diperoleh 20 unit percobaan.  Setiap unit percobaan terdiri dari 20 pohon, dalam satu pohon terdiri dari lima sampel sehingga dalam 1 unit terdiri dari 100 sampel.  Perlakuan yang dicobakan adalah sebagai berikut; tanpa penyemprotan/penyelubungan (kontrol)  (M0), penyemprotan dengan biokaolin setiap dua minggu (M1), penyemprotan dengan biokaolin setiap empat minggu (M2), penyelubung-an dengan kantong plastik (M3), penyemprotan dengan fungisida mankozeb setiap dua minggu (M4). Parameter yang diamati  adalah kejadian penyakit, keparahan penyakit dan besarnya kehilangan hasil dihitung dengan menimbang berat 100 biji kering. Hasil penelitian menunjukkan bahwa teknik pengendalian penyakit busuk buah dengan aplikasi biokaolin setiap dua minggu rata-rata lebih efektif dalam menekan kejadian   penyakit yaitu (26,12%)  dan  keparahan  penyakit  (11,04%), sedangkan rata-rata besarnya kehilanganhasil berat biji kering tertinggi terlihat pada kategori infeksi berat yaitu 74,96%  dengan berat kering terendah yaitu 26,6 g dalam100 biji.


2009 ◽  
Vol 99 (5) ◽  
pp. 498-505 ◽  
Author(s):  
W. Pfender

Observations of naturally occurring stem rust epidemics and seed yields in perennial ryegrass were taken in 19 field experiments conducted over the course of 9 years. Epidemic severity differed among years and also among experimental treatments (fungicide regimes) within years. In each experiment, attainable yield was represented by the nondiseased treatment, and yields of other treatments were expressed as relative yield (a proportion of the attainable yield). Yield loss (difference between attainable and actual yield) in the nonprotected treatments was 0 to 98% due to yearly differences in epidemic conditions. Fungicides were effective in reducing stem rust injury and damage when properly timed. Disease severity in the upper canopy was estimated at approximately weekly intervals and converted to proportion of the plant area diseased. The complementary value, proportion of area healthy, and its integral over time, healthy area duration (HAD), were calculated. Regression analyses were conducted using various phenological time intervals of HAD as the independent variable. The best intervals of HAD for predicting relative yield were centered on the midpoint time between anthesis and harvest. The regression equation (r2 = 0.89) for relative yield as a function of HAD during the 3-week interval was selected and rearranged to produce a quadratic damage function. This damage function estimates yield loss at 5, 22, and 42% for critical-interval diseased proportions of 1, 5, and 10%, respectively. Yield data collected from field experiments not used in model development correlated well (r2 = 0.9) with yields predicted by the damage function from their observed disease severity.


1985 ◽  
Vol 25 (2) ◽  
pp. 440 ◽  
Author(s):  
AH Mayfield

The potential commercial use of fungicides for control of stem rust (Puccinia graminis) of wheat was assessed in field experiments at two sites. Foliar sprays containing either triadimefon or propiconazole were the most effective in reducing disease severity. Chlorothalonil was effective only when applied at an early stage of disease development and where stem rust was not severe in control plots. Dichlone, fenarimol, nuarimol and 2-(thiocyanomethylthio) benzothiazole did not significantly reduce stem rust severity at either site. Even though treatments were applied at an early stage ofthe disease epidemic at one site, disease control on heads, peduncles and sheaths did not exceed 63,36 and 19%, respectively, with any treatment. Increases in grain yield and density, of up to 0.27 t/ha and 8.6 kg/hectolitre, respectively, were barely sufficient to cover the cost of treatment.


1988 ◽  
Vol 39 (4) ◽  
pp. 563 ◽  
Author(s):  
JS Brown

The relationship between stripe rust severity and grain yield loss in wheat was studied in two field experiments. Wheat cultivars varying in response to the disease were used to produce epidemics of differing severity. Regression models were used to examine the relationship between disease severity and yield loss. The best estimator of yield loss was an estimate of disease severity at the end of anthesis-early berry growth stage. The relationship between per cent yield loss (YL) and per cent disease severity (DS) at that growth stage was established to be YL = 0.479DS + 0.84.


Plant Disease ◽  
2004 ◽  
Vol 88 (9) ◽  
pp. 1017-1020 ◽  
Author(s):  
W. F. Pfender

Perennial ryegrass (Lolium perenne) grown for seed is planted in autumn for July harvest (first-year seed crop), then kept in production for subsequent yearly harvests. Plots of first-year perennial ryegrass planted in early November had only 3% as much stem rust in June as plots planted in mid-September. In other plots where fungicides were used to prevent rust development, seed yield from the November-planted plots was reduced by 23% compared with September-planted plots. In the second-year seed crop, stem rust severity in June was intermediate between severities in early- and late-planted first-year plots. The association of reduced stem rust severity with late planting for first-year crops was observed for five of six perennial ryegrass cultivars tested. Degree of reduction in disease severity due to planting date was greatest for the cultivars that had the highest disease severity in early-planted stands. Delay of autumn planting date may provide a useful cultural control method for first-year stands of perennial ryegrass seed crops.


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