scholarly journals Temperature effect on rose downy mildew development under environmental controlled conditions

2014 ◽  
Vol 32 (1) ◽  
pp. 29-35 ◽  
Author(s):  
Juan José Filgueira D. ◽  
Angélica Zambrano
Keyword(s):  
Temperature Effect ◽  
Downy Mildew ◽  
Wide Temperature Range ◽  
Environmental Conditions ◽  
Commercial Variety ◽  
Inoculum Concentration ◽  
Controlled Conditions ◽  
Different Temperatures ◽  
The Rose ◽  
Downy Mildew Disease

The rose downy mildew disease, caused by Peronospora sparsa Berkeley, is one of the most important that affect rose crops in Colombia. To manage this disease, flower growers must deal with high-costs due to the excessive application of fungicides, but without good results. Studies on P. sparsa behavior have shown its narrow relationship with environmental conditions. In this study, the temperature effect was evaluated during the infection and sporulation of P. sparsa in Charlotte leaflets, a susceptible commercial variety, through an environmental controlled conditions system. Infection and sporulation were observed at different temperatures in a range of from 4 to 40°C. Infection with the absence of or very low sporulation was observed at 4°C. The most favorable pathogen responses were between 15 and 18°C in terms of inoculum concentration and sporulation percentage. There was no infection or leaflet change above 35°C. According to the results, sporulation can occur from 4 to 33°C, confirming the fact that P. sparsa is able to reproduce throughout a wide temperature range.

scholarly journals Risk Analysis of Brown Rot Blossom Blight of Prune Caused by Monilinia fructicola

2001 ◽  
Vol 91 (8) ◽  
pp. 759-768 ◽  
Author(s):  
Y. Luo ◽  
D. P. Morgan ◽  
T. J. Michailides
Keyword(s):  
Environmental Conditions ◽  
Brown Rot ◽  
Stochastic Simulations ◽  
Monilinia Fructicola ◽  
Prunus Domestica ◽  
Inoculum Concentration ◽  
Different Temperatures ◽  
The Relationship ◽  
Late Stages ◽  
Linear Regressions

Experiments under controlled environmental conditions were conducted during bloom of prune (Prunus domestica, L.) in 1999 and 2000 to assess the effects of inoculum concentration (IC), wetness duration (WD), temperature, and bloom stages on development of brown rot blossom blight of prunes. Branches from trees of a prune orchard were inoculated with Monilinia fructicola at different bloom stages and incubated at different temperatures with different periods of WD. The proportion of blighted blossoms (PBB) for each inoculated branch was determined. Bloom stage, IC, temperature, and WD significantly affected blossom blight of prunes. PBB at popcorn and full bloom stages was significantly greater than PBB at later bloom stages (P ≤0.05). The optimal temperatures for blossom blight development were 22 to 26°C, and Gaussian functions were used to describe the relationship between PBB and temperature. PBB linearly increased with increased IC. Linear regressions of PBB on WD were obtained for each combination of bloom stage, IC, and temperature. The parameters of these regressions were used in a computer program to produce the possible maximum PBB with 90% probability (PBB90) using stochastic simulations. Early bloom stages with a higher IC at temperatures from 20 to 25°C were associated with more severe blossom blight than late stages with a lower IC at nonoptimal temperatures. Blossom blight did not occur at <10 or >30°C and less than 4-h WD. However, longer than 4-h WD linearly increased incidence of blossom blight. A risk assessment table of blossom blight was produced for different environmental conditions to guide the control of prune brown rot.

scholarly journals Effect of different inoculum levels of P. arborescens in disease development and yield losses of opium poppy

2021 ◽  
Vol 16 (2) ◽  
pp. 93-98
Author(s):  
Roop Singh ◽  
Pokhar Rawal ◽  
Irfan Khan
Keyword(s):  
Downy Mildew ◽  
Disease Severity ◽  
Seed Yield ◽  
Opium Poppy ◽  
Yield Losses ◽  
Inoculum Concentration ◽  
Pooled Data ◽  
Cent Disease ◽  
Latex Yield ◽  
Downy Mildew Disease

Downy mildew (DM) caused by Peronospora arborescens is the most alarming disease of opium poppy which hampered the production of opium crop in major growing areas of India. The pooled data taken from Rabi 2016-17 and 2017-18 demonstrated that chemical protected un-inoculated plot had a minimum per cent disease severity (9.83) with maximum dry latex yield (31.25 kg ha-1), seed yield (801.31 kg ha-1) and husk yield (889.66 kg ha-1). However, plots inoculated with Peronospora arborescens at high inoculum density of 9×105 spores ml-1 had considerably higher per cent disease severity (67.00) and minimum dry latex yield (6.94 kg ha-1), seed yield (548.42 kg ha-1) and husk yield (590.86 kg ha-1) with maximum 77.79,31.56 and 33.58 per cent loss as compared to un-inoculated chemical protected plot, respectively. The severity of the downy mildew disease was found to rise in direct conflict with the level of inoculum concentration with significant reduction in dry latex yield, seed yield and husk yield.

Symptoms Development as Tools to Differentiate Dorizontal Resistance in Sunflower

Agrotek ◽  
2018 ◽  
Vol 2 (6) ◽  
Author(s):  
Cipta Meliala ◽  
Felicity Fear ◽  
Denis Tourvieille de Labrouhe
Keyword(s):  
Downy Mildew ◽  
Natural Infection ◽  
Resistance Mechanism ◽  
Good Method ◽  
Vegetative Stage ◽  
Horizontal Resistance ◽  
Symptom Development ◽  
Plasmopara Halstedii ◽  
Controlled Conditions ◽  
Symptom Progression

Downy mildew symptoms caused by Plasmopara halstedii encountered in sunflower plantation are varied. This variation may be related to the resistance mechanism presented by plant to the invasion of the fungus. Our objectives were firstly is to evaluate symptom development after fungus race 710 inoculation on some vegetative stage of susceptible hybrid. Second objective is to evaluate the reaction some sunflower genotypes after fungus inoculation. The study was conducted under controlled conditions or under netting cages in the field. The development of downy mildew symptoms were affected by all factors studied. Shoot inoculation may present a good method to produce downy mildew symptom similar to the natural infection. Downy mildew symptom progression may be used to screen a genotype with a horizontal resistance.

Involvement of silicon in pearl millet resistance to downy mildew disease and its interplay with cell wall proline/hydroxyproline-rich glycoproteins

2008 ◽  
Vol 37 (5) ◽  
pp. 498 ◽  
Author(s):  
S. Deepak ◽  
G. Manjunath ◽  
S. Manjula ◽  
S. Niranjan-Raj ◽  
N. P. Geetha ◽  
...  
Keyword(s):  
Cell Wall ◽  
Downy Mildew ◽  
Pearl Millet ◽  
Downy Mildew Disease

scholarly journals Exogenous Trehalose Treatment Enhances the Activities of Defense-Related Enzymes and Triggers Resistance against Downy Mildew Disease of Pearl Millet

2016 ◽  
Vol 7 ◽  
Author(s):  
Sharathchandra R. Govind ◽  
Sudisha Jogaiah ◽  
Mostafa Abdelrahman ◽  
Hunthrike S. Shetty ◽  
Lam-Son P. Tran
Keyword(s):  
Downy Mildew ◽  
Pearl Millet ◽  
Downy Mildew Disease

Temperature Effect on Seed Germination Performance of a Local Variety of Onion in Bangladesh

2021 ◽  
Vol 1 (01) ◽  
pp. 27-30
Author(s):  
IRANI KHATUN ◽  
RIYAD HOSSEN
Keyword(s):  
Seed Germination ◽  
Temperature Effect ◽  
Performance Test ◽  
Germination Rate ◽  
Germination Percentage ◽  
Optimum Range ◽  
Local Variety ◽  
Different Temperatures ◽  
Local Farmers

Seed germination performance test of Taherpuri onion (a local variety of onion) under six different temperatures (15, 20, 25, 30, 35 and 40°C) was the main goal of this experiment. Germination percentage (GP) was calculated at highest 60.25% at 25°C, and the highest germination rate 20.08 was observed in the same temperature condition. The lowest germination performance (13.25 % germi-nation and 3.32 seeds per day as germination rate) was found at 40°C temperature. Finally, the authors mentioned the temperature 20 to 30°C as optimum range, and suggested the temperature 25°C as best suited for obtaining highest results in case of both germination percentage and germination rate of these seeds. To produce maximum seedlings of the local variety of onion, the mentioned temperature should be followed by the local farmers.

Sintering Temperature Effect on Hardness of Self-Synthetisized Porcelain Made from Natural Sumatran Sand without Kaolin

2018 ◽  
Vol 782 ◽  
pp. 227-232
Author(s):  
Sianny Surya Putri Kurnia ◽  
Dede Taufik ◽  
Veni Takarini ◽  
Zulia Hasratiningsih
Keyword(s):  
Temperature Effect ◽  
Potassium Salt ◽  
Sintering Temperature ◽  
The Self ◽  
The Other ◽  
P Value ◽  
Natural Sand ◽  
Average Hardness ◽  
Different Temperatures ◽  
Statistic Result

Dental porcelain is one of the indirect restoration material with excellent aesthetic properties,on the other hand porcelain hardness frequently causing excessive wear of antagonist teeth. This study aiming to evaluate the effect of sintering temperature on the self-synthesized porcelain hardness. In this experiment, 25 porcelain samples were synthesized using Sumatran sand from Pangaribuan and Belitung regions, with the composition of 65 wt% Pangaribuan feldspar, 25 wt% Belitung silica and 10 wt% potassium salt. The samples were sintered in five different temperatures, which were 1110°C (A), 1120°C (B), 1130°C (C), 1140°C (D), and 1150°C (E). These samples were then invested on 5cm diameter resin each. The hardness was tested using Zwick Roell ZHμ Micro Vickers with 900 gram load for 15 seconds in 5 different indented areas for each sample. The result shows average hardness of 435.8 VHN (A), 461.0 VHN (B), 472.0 VHN (C), 487.6 VHN (D), and 528.7 VHN (E), which were increasing as the sintering temperature increased. Statistic result shows that sintering temperature significantly affected the hardness value of the porcelain (p value < 0.05). In conclusion sintering temperature affects the hardness of self-synthesized porcelain made from Sumatran natural sand without kaolin, although the average hardness of self-synthesized porcelain is still higher than average hardness of teeth enamel.

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