scholarly journals SPATIAL DISTRIBUTION OF EARLY BLIGHT DISEASE ON TOMATO, CLIMATIC FACTORS AND BIOEFFICACY OF PLANT EXTRACTS AGAINST Alternaria solani

2019 ◽  
Vol 18 (6) ◽  
pp. 29-38
Author(s):  
Azhar Hussain ◽  
Shaukat Ali ◽  
Haider Abbas ◽  
Haibat Ali ◽  
Alamdar Hussain ◽  
...  

Information on the spatial variability in plant disease is essential for location-based disease management. In the current study, the spatial distribution of tomato early blight disease was ascertained in District Gilgit, GilgitBaltistan, Pakistan. The comprehensive field survey was carried in two growing seasons (2014–2015), whereas in each growing season, 62 tomato fields were surveyed. Based on the distribution of disease, the respective thematic maps (incidence and severity) were prepared using Arc Map 10.1 with spatial analyst function of  Arc GIS software by means of the inverse distance weight (IDW) interpolation method. Results indicate that early blight of tomato is spatially distributed in both growing seasons. However, in the first growing season, the disease incidence ranged from 10.22% to 44.16% and during later season 14.03–49.16%, whereas 5.37–16.40% and 6.52–26.94% severity was recorded. Furthermore, this information indicates that higher disease infestation occurred in 2015 in relation to 2014. This information linked to metrological data (temperature, precipitation and relative humidity), seemingly favored the early blight development during the growing period. Seven botanical extracts were tested against pathogen Alternaria solani at different concentrations (4, 6 and 8%). Results revealed that all tested plant extracts showed antifungal activities. However, at 8% concentration of plant extract, Datura starmonium, Berberis orthobotry, Podophyllum emodi and Uretica dioica exhibited >60%, while Peganum harmala, Artemisia maritima and Capparis spinosa <60% antifungal properties. The information generated due to this study could help the tomato growers regarding disease management and selection of resistant cultivars, improving profitability and food security in the Gilgit region.

2021 ◽  
Author(s):  
Sapna Devi ◽  
Manish Sharma ◽  
Rajesh kumari Manhas

Abstract Background: Early blight (EB), caused by Alternaria solani, is one of the alarming diseases that restrict tomato production globally. Existing cultural practices and fungicide applications are not enough to control the early blight diseases. Therefore, the study aimed to isolate, identify, and characterize an endophytic Streptomyces strain exhibiting the potential to control early blight in tomato and also promote plant growth. Results: From a Citrus jambhiri leaf, an endophytic Streptomyces sp. SP5 isolated with antagonistic activity against Alternaria solani, Colletotrichum acutatum, Cladosporium herbarum, Alternaria brassicicola, Alternaria alternata, Fusarium oxysporum and Fusarium moniliforme. It was identified as a Streptomyces sp. designated as SP5 through 16S ribosomal DNA sequence analysis. It also produced 40μg/ml indole acetic acid which was further confirmed by TLC and HPLC analyses. Treatment of pathogen infected plants with Streptomyces sp. SP5 antagonist (culture cells/culture supernatant/solvent extract/ acetone precipitates) decreased the early blight disease incidence and significantly increased the various agronomic traits Conclusion: The present study concluded that Streptomyces sp. SP5 possessed antifungal activity against different fungal pathogens and had significant potential to control early blight disease in tomatoes and also promote plant growth by producing IAA.


2011 ◽  
Vol 10 (42) ◽  
pp. 8291-8295 ◽  
Author(s):  
Yanar Yusuf ◽  
Gouml kccedil e Ayhan ◽  
Kadioglu Izzet ◽  
Ccedil am Halit ◽  
Whalon Mark

2016 ◽  
Vol 11 (1) ◽  
pp. 48-52 ◽  
Author(s):  
Abiodun Joseph ◽  
Efe-Imafidon Akere Ese ◽  
Benson Oluwafemi Ademiluyi ◽  
Patrick Ajibola Aluko

2012 ◽  
Vol 48 (No. 2) ◽  
pp. 74-79 ◽  
Author(s):  
S.M.A. Nashwa ◽  
K.A.M. Abo-Elyousr

The antimicrobial activity of six plant extracts from Ocimum basilicum (Sweat Basil), Azadirachta indica (Neem), Eucalyptus chamadulonsis (Eucalyptus), Datura stramonium (Jimsonweed), Nerium oleander (Oleander), and Allium sativum (Garlic) was tested for controlling Alternaria solani in vitro and in vivo. In in vitro study the leaf extracts of D. stramonium, A. indica, and A. sativum at 5% concentration caused the highest reduction of mycelial growth of A. solani (44.4, 43.3 and 42.2%, respectively), while O. basilicum at 1% and 5% concentration and N. oleander at 5% concentration caused the lowest inhibition of mycelial growth of the pathogen. In greenhouse experiments the highest reduction of disease severity was achieved by the extracts of A. sativum at 5% concentration and D. stramonium at 1% and 5% concentration. The greatest reduction of disease severity was achieved by A. sativum at 5% concentration and the smallest reduction was obtained when tomato plants were treated with O. basilicum at 1% and 5% concentration (46.1 and 45.2 %, respectively). D. stramonium and A. sativum at 5% concentration increased the fruit yield by 76.2% and 66.7% compared to the infected control. All treatments with plant extracts significantly reduced the early blight disease as well as increased the yield of tomato compared to the infected control under field conditions.


2019 ◽  
Vol 101 (4) ◽  
pp. 1159-1170
Author(s):  
Khalid Pervaiz Akhtar ◽  
Najeeb Ullah ◽  
Muhammad Yussouf Saleem ◽  
Qumer Iqbal ◽  
Muhammad Asghar ◽  
...  

Plant Disease ◽  
2012 ◽  
Vol 96 (1) ◽  
pp. 124-130 ◽  
Author(s):  
J. H. Leiminger ◽  
H. Hausladen

Epidemics of early blight caused by Alternaria spp. can cause significant economic damage to potato production if not adequately controlled. In order to improve control of Alternaria spp. in potato, studies were conducted to identify the optimal fungicide strategy and, if possible, to reduce the number of fungicide applications per growing season. Therefore, a disease-threshold-based framework was tested to define the optimal timing of fungicide application. The initiation and subsequent applications of fungicides were based on increases in disease incidence or severity. Adequate disease control was achieved by a three-time application with azoxystrobin, given that the applications were carried out at pivotal times in the epidemic. Targeted applications of fungicides reduced the number of sprayings required to protect starch yield. Results indicate that early blight can be effectively managed by using fungicide application thresholds based on disease progress.


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