scholarly journals Simulating Eyespot Disease Development and Yield Loss Using APSIM for UK Wheat

2015 ◽  
Vol 29 ◽  
pp. 256-257
Author(s):  
M. Al-Azri ◽  
D. Leibovici ◽  
A. Karunaratne ◽  
R.V. Ray
Keyword(s):  
Yield Loss ◽  
Disease Development ◽  
Eyespot Disease

Role of foliage component and host age on severity of Alternaria leaf spot (caused by Alternaria japonica and A. brassicae) in canola (Brassica napus) and mustard (B. juncea) and yield loss in canola

2019 ◽  
Vol 70 (11) ◽  
pp. 969 ◽  
Author(s):  
H. F. D. Al-lami ◽  
M. P. You ◽  
M. J. Barbetti
Keyword(s):  
Brassica Napus ◽  
Leaf Area ◽  
Seed Yield ◽  
Leaf Spot ◽  
Yield Loss ◽  
Disease Incidence ◽  
Brassica Species ◽  
Leaf Spot Disease ◽  
Disease Development ◽  
Alternaria Leaf Spot

Studies were undertaken under controlled conditions into the effects of different foliage components (cotyledon, first, second and third leaf) at three plant ages (3, 5 and 7 weeks old) on development of Alternaria leaf spot disease, caused by Alternaria japonica or A. brassicae, in canola (Brassica napus cv. Thunder TT) and mustard (B. juncea cv. Dune). Alternaria japonica generally showed percentage disease index (%DI) values similar to A. brassicae across the two Brassica species, different foliage components and plant ages. %DI from either pathogen was greater in older plants than younger plants for the same foliage components in both cultivars. Field studies were then undertaken with canola to compare disease development from A. japonica and A. brassicae across different plant components (leaf, pod and stem) and the consequent adverse impact on seed yield. Alternaria japonica was more severe in terms of leaf area diseased (%LAD 62.6) and stem area diseased (%SAD 69.8) than pod area diseased (%PAD 25.5), whereas A. brassicae was more severe on leaves (%LAD 61.9) than on pods (%PAD 47.4) or stems (%SAD 41.0). Stem disease incidence was greater for A. japonica (%SDI 94.0) than for A. brassicae (%SDI 56.5), but pod disease incidence was greater for A. brassicae (%PDI 93.5) than for A. japonica (%PDI 86.1). For A. japonica, AUDPC values of leaf disease incidence (LDI, 283.5), leaf area diseased (LAD, 253.3) and leaf collapse (LCI, 149.5) resulted in a yield loss of 58.1%, similar to A. brassicae, where AUDPC values of LDI (277.8), LAD (247.2) and LCI (111.0) caused a yield loss of 59.4%. These findings explain observed acceleration of Alternaria leaf spot severity from A. japonica, as from A. brassicae, through the growing season as plants become more susceptible with increasing age, and as more susceptible, later developing leaves become abundant. For the first time, we demonstrate that under conducive field conditions for disease development, A. japonica can cause serious seed-yield losses of a magnitude similar to those occurring with A. brassicae.

scholarly journals Yield Loss Caused by Bacterial Streak in Winter Wheat

Plant Disease ◽  
1999 ◽  
Vol 83 (7) ◽  
pp. 609-614 ◽  
Author(s):  
B. L. Tillman ◽  
W. S. Kursell ◽  
S. A. Harrison ◽  
J. S. Russin
Keyword(s):  
Winter Wheat ◽  
Yield Loss ◽  
Regression Line ◽  
Weather Conditions ◽  
Grain Weight ◽  
Disease Development ◽  
Susceptible Cultivar ◽  
Field Plot ◽  
The Relationship ◽  
Field Plots

The relationship between severity of bacterial streak and yield in winter wheat was studied in field plots and using a single-tiller method. Regression analysis from single-tiller studies showed that the grain weight per spike decreased as bacterial streak severity increased in cvs. Florida 304 and Savannah. The number of kernels per spike decreased as bacterial streak severity increased in Savannah but not in Florida 304. There was no difference in slope of the regression line between different years, locations, or cultivars for grain weight per spike. However, grain weight per spike at 0% bacterial streak (intercept) was different for different years, locations, and cultivars. The average reduction in grain weight per spike was 0.012 g for every 1% increase in bacterial streak severity. Using this relationship for cv. Savannah, average bacterial streak severity of 10% would result in about a 9% reduction in the grain weight per spike. In Florida 304, bacterial streak severity of 10% would result in about a 7% reduction in the grain weight per spike. During 1993-94, the largest difference in bacterial streak severity between inoculated and noninoculated plots was 4% in cv. Pioneer 2548, and the smallest difference was less than 1% in cvs. Terral 101 and Florida 304. There were no yield differences between inoculated and noninoculated treatments for any genotype. In field plot studies at two locations during 1989-90, bacterial streak severity did not differ between inoculated and noninoculated plots in Alexandria, Louisiana; but in Winnsboro, Louisiana, bacterial streak severity was 18 to 40% in inoculated plots and less than 5% in noninoculated plots. Differences in yield between inoculated and noninoculated plots ranged from 1,370 kg/ha (24% loss) to -121 kg/ha in Winns-boro. During the three seasons in which these studies were conducted, bacterial streak severity averaged about 10% or less in susceptible cultivars in all experiments except one. Based on the relationships derived from single-tiller studies, this suggests that yield loss is likely to be low most years. As indicated by the experiment in Winnsboro, however, more severe yield reductions could occur in a susceptible cultivar if weather conditions are favorable for disease development.

scholarly journals Loss and Disease Development of Monilinia fructigena (Aderh. & Ruhl.) Honey in an Organic Apple Orchard

2004 ◽  
pp. 6-8
Author(s):  
Imre Holb
Keyword(s):  
Yield Loss ◽  
Cydia Pomonella ◽  
Codling Moth ◽  
Apple Orchard ◽  
Mechanical Injury ◽  
Disease Development ◽  
Apple Orchards ◽  
Forficula Auricularia ◽  
Monilinia Fructigena ◽  
Fruit Harvest

In a two-year-study, yield loss and temporal development of incidence of Monilinia fructigena were quantified in organic apple orchards and the importance of fruit wounding agents was determined. The first infected fruits were observed at the beginning of August in 2001 and 2002. Disease development was continuous until fruit harvest in both years. Pre-harvest yield loss caused by Monilinia fructigena amounted on average 27.2% in 2001 and 41.6% in 2002 by fruit harvest. The growth rate of disease development was almost double in 2002 compared to 2001. All infected fruits were injured by wounding agents such as aboitic and mechanical injury factors, codling moth (Cydia pomonella), common earwig (Forficula auricularia) and birds. In this study, the most important wounding agents were codling moth and mechanical injury factors in organic apple orchards. In both years, our results showed that 70-80% of the infected fruits were damaged by codling moth in organic apple production. Moreover, 10-15% of the infected fruits were mechanically injured in the two years. Our results indicated that most of the damaged fruits fell on the orchard floor before harvest and they became an important secondary inoculum source of M. fructigena. Biological and practical implications of the results are discussed.

Development of mould fungi on the substrate blocks of oyster mushroom (Pleurotus Ostreatus (Jack.) Р. Kumm.) during fructification period

2021 ◽  
Vol 12 (2) ◽  
Author(s):  
M Kyryk ◽  
◽  
A Gryganskyi ◽  
A Vuek ◽  
M Pikovskyi ◽  
...  
Keyword(s):  
Pleurotus Ostreatus ◽  
Yield Loss ◽  
Oyster Mushroom ◽  
Disease Development ◽  
Lesion Score ◽  
Fruiting Bodies ◽  
Green Mold ◽  
Oyster Mushrooms ◽  
Second Tier ◽  
Second Wave

The results of studies conducted during the harvest of fruiting bodies of oyster mushrooms indicate that the development of harmful micromycetes during the first wave of fruiting was less than in the second about twice. It is established that the distribution of microorganisms is also influenced by the placement of substrate blocks in the fructification premises. In the first wave of fruiting, the number of affected blocks varied depending on the tier location. The least affected blocks were found on the 3rd tier, which is the highest – 3,6 %. The yield loss on this tier was 3.1 kg of mushrooms. On the second tier, the percentage of the contaminated blocks was 10,4. The largest amount of infected substrate was observed on the 1st tier – 27,1 %. The increase in the affected blocks on the 1st and 2nd tiers is due to excessive moisture, which leads to the flow of drops from the upper bags to the lower ones. Observation during the second wave of fructification has shown, that the dissemination and development of the diseases was considerably bigger. In the 1st tier, the substrate blocks were infected with the micromycetes by 34,6 %, and the rate of disease development was 13,4 %. The smallest amount of infected substrate was found on the 3rd tier – 4,4 %, and the rate of micromycetes was 1,8 %. Substrate blocks having infection with 4-5 point development were removed and disposed. The average lesion score ranged from 2 to 3. During the first and second waves of fruiting, the frequency of micromycetes on substrate blocks increases due to the development of Trichoderma (up to 69,4 %), Penicillium (up to 15,7 %), and Aspergillus spp. (up to 8,3 %), commonly known as green mold substrate pathogens.

Elemental chlorine-free bleaching of North American hardwood kraft pulps: Evaluation of oxidant-reinforced extraction variables on overall bleaching optimization

TAPPI Journal ◽  
2013 ◽  
Vol 12 (10) ◽  
pp. 33-41 ◽  
Author(s):  
BRIAN N. BROGDON
Keyword(s):  
Response Surface ◽  
Chlorine Dioxide ◽  
North American ◽  
Yield Loss ◽  
Alkaline Extraction ◽  
Kraft Pulps ◽  
Pulp Bleaching ◽  
Response Surface Models ◽  
Elemental Chlorine ◽  
Surface Models

This investigation evaluates how higher reaction temperatures or oxidant reinforcement of caustic extraction affects chlorine dioxide consumption during elemental chlorine-free bleaching of North American hardwood pulps. Bleaching data from the published literature were used to develop statistical response surface models for chlorine dioxide delignification and brightening sequences for a variety of hardwood pulps. The effects of higher (EO) temperature and of peroxide reinforcement were estimated from observations reported in the literature. The addition of peroxide to an (EO) stage roughly displaces 0.6 to 1.2 kg chlorine dioxide per kilogram peroxide used in elemental chlorine-free (ECF) bleach sequences. Increasing the (EO) temperature by Δ20°C (e.g., 70°C to 90°C) lowers the overall chlorine dioxide demand by 0.4 to 1.5 kg. Unlike what is observed for ECF softwood bleaching, the presented findings suggest that hot oxidant-reinforced extraction stages result in somewhat higher bleaching costs when compared to milder alkaline extraction stages for hardwoods. The substitution of an (EOP) in place of (EO) resulted in small changes to the overall bleaching cost. The models employed in this study did not take into account pulp bleaching shrinkage (yield loss), to simplify the calculations.

RESISTANCE TO MILDEW OF SELECTION FAMILY OF RED CURRANT THE BELAYA POTAPENKO × № 1426-21-80

1970 ◽  
pp. 38-40
Author(s):  
O. O. Kalinina ◽  
O. D. Golyaeva ◽  
O. V. Panfilova ◽  
А. V. Pikunova
Keyword(s):  
Powdery Mildew ◽  
Field Resistance ◽  
Disease Development ◽  
Artificial Infection ◽  
Sources Of Resistance ◽  
Climate Conditions ◽  
High Productivity ◽  
Local Soil ◽  
The Family ◽  
Red Currant

Powdery mildew is one of the most harmful fungal diseases that causes economically significant damage to berry plantations. The disease is common in all areas of currant cultivation in the Russian Federation. In this regard, in modern conditions of intensive berry growing, the problem of breeding cultivars that are highly resistant to diseases and pests becomes urgent. Breeders have a difficult task to combine the adaptive potential of the cultivar with its annual high productivity and resistance to biotic environmental factors. When studying the adaptability of introduced cultivars of red currant and selected forms of the Institute to local soil and climate conditions, the following cultivars were identified as sources of economic and useful characteristics and involved in selection: ‘Belaya Potapenko’ as a complex source of resistance powdery mildew and high marketable and taste qualities of berries; SS 1426-21-80 as a source of high productivity and long racemes (raceme length 11-13 cm; up to 20 berries in the raceme). On their base the selection family of red currant has been developed: Belaya Potapenko × ♂SS 1426-21-80. The study of data on the destruction of hybrid seedlings of the selection family by powdery mildew showed that in epiphytotic conditions, the percentage of intensity of the disease development varies over the periods of screening from 0.2% in May to 20.4% in June. Such indicators served as a prerequisite for conducting a comparative test of breeding material in the field under artificial infection with powdery mildew. After artificial infection on the background of epiphytosis, the rate of intensity of the disease development increased slightly and amounted to 35.6% for the family. There were 30 highly resistant seedlings in the family, 10 of which have remained stable and highly resistant since 2018. In these plants we can assume the presence of the so-called field resistance, controlled by polygens, each of which does not give a visible effect of stability, but with different combinations determines one or another of its degree. Highly resistant seedlings will be used in further breeding studies to identify new sources of resistance to powdery mildew.

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