Minimum Disease Intensity Research Articles

Effect of Neem Oil in Combination with Propiconazole and Organic Amendments on Anthracnose (Colletotrichum lindemuthianum) of Cowpea (Vigna unguiculata L.)

The cowpea (Vigna unguiculata) is an annual herbaceous legume from the genus Vigna. Anthracnoses (Colletotrichum lindemuthianum) is a serious disease in cowpea growing areas and occurs as pre-harvest as well as post-harvest brown to black spots appear on the leaves. Neem oil at different concentrations (0.5%, 1%,1.5%, and 2%) along with Propiconazole were tested @ 0.1% in vivo during Kharif 2023 for their efficacy against disease incidence, plant growth and yield parameters of Cowpea at the Central Research Field of the Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj. The results of the present investigation revealed that it significantly reduced the disease incidence. Among the treatments the minimum disease intensity (%) at 75 DAS was recorded in T5 – Neem oil (2 ml/L) + Propiconazole 25 EC (0.1%) + VC@10gm/kg +SMC@10gm/kg (Foliar spray) was found to be significantly most effective treatment against Anthracnose (Colletotrichum lindemuthianum) on Cowpea and recorded minimum disease intensity (%) at 30, 45, 60 and 75 DAS, maximum plant height (cm), maximum number of branches, maximum yield (t/ha) and highest B:C ratio. The findings of the present experiment are limited to one crop season under Prayagraj agro-climatic conditions, as such to validate the present findings; more such experiments should be carried out in the future.

Evaluation of Phyto Extracts for the Management of Alternaria Leaf Spot of Black Gram (Vigna mungo L.) Caused by Alternaria alternata (Fr.) Keissler

The present study was carried out to evaluate the effect of selected phyto-extracts for the management of alternaria leaf spot on black gram caused by Alternaria alternata (Fr.) Keissler, under field conditions. Three replications of black gram were planted in a randomized block design. At the research plot of the Central Research Field, Department of Plant Pathology, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj during Zaid season of 2023. Neem leaf extract, onion bulb extract, ginger rhizome extract, garlic clove extract, ashoka leaf extract and Mancozeb were applied as foliar spray. All the treatments were found significantly reduced the disease severity and increased the yield. Among all the treatments garlic clove extract @ 10% was recorded minimum disease intensity (25.62) and maximum yield (7.45 q/ha) and cost benefit ratio (1: 2.54), as compared to treated check mancozeb @ 0.2% and untreated check control.

Phyto-extracts for Managing Alternaria Leaf Spot on Mung Bean

The present study was investigated to evaluate the effect of selected phyto-extracts for the management of Alternaria leaf spot on mung bean caused by Alternaria alternata (Fr.) Keissler, under field conditions. Three replications of mung bean were planted in a randomized block design. At the research plot of the Central Research Field, Department of Plant Pathology, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj during Zaid season of 2023. The effect of neem leaf extract, onion bulb extract, ginger rhizome extract, garlic bulb extract, turmeric rhizome extract and Mancozeb were compared and tested the plant height (cm), pod length (cm), disease intensity (%) and B:C ratio recorded at 45, 60 and 75 DAS interval. The effect of foliar spray of T4–garlic bulb extract @ 10% was found the best for managing Alternaria leaf spot of mung bean under field conditions as minimum disease intensity (34.4%), maximum plant height (65.4cm), pod length significantly increased (8.4cm) and highest B:C ratio (1:2.05). Followed by minimum disease intensity (35.5%), plant height (60.9cm), pod length (7.8 cm) and highest B:C ratio (1:1.97) was recorded in T1–neem leaf extract @ 10% followed by T5–turmeric rhizome extract @ 10% when compared to (Treated check) T6–Mancozeb @ 0.2% and (Untreated check) T0–control. Overall results revealed that T4–garlic bulb extract @10% is significantly effective against A. alternata (Fr.) Kessler.

Effect of Bacillus subtilis, Soil Amendments and Microalgae Treatment on Fusarium equiseti of Turmeric (Curcuma longa L.) Prayagraj, India

Rhizome rot of turmeric caused by Fusarium equiseti emerge as a significant soil-borne threat to crop health. An experiment was conducted to evaluate the effect of Bacillus subtilis, soil amendments and microalgae treatment on Fusarium equiseti of Turmeric (Curcuma longa L). Experiment was conducted under field condition at the courtyard of department of Plant Pathology, SHUATS, Prayagraj, during kharif season of 2022. Various soil treatments including farm yard manure (FYM), spent mushroom compost (SMC), and microalgae were used, along with rhizome treatment utilizing Bacillus subtilis. The experiment was carried out in Randomized Block design (RBD) with three (3) replications. Results revealed that in the soil application, (T5) i.e., the combination of all the treatments recorded minimum disease intensity (59.26%) which was significant over other treatments and control (T0) (33.86%). To evaluate the radial growth (mm) of Fusarium equiseti in turmeric, seven botanicals from Manipur viz., Zanthoxylum acanthopodium, Phlogacanthus thyrsiformis, Solanum xanthocarpum, Centella asiatica, Drymaria cordata, Persicaria chinensis and Gynura cusimbua were investigated in vitro at 10% and 30% concentration. The antagonistic effects of various botanicals were evaluated in vitro, demonstrating inhibition of mycelial growth. Among the tested botanicals, Zanthoxylum acanthopodium inhibited the highest inhibition rate (86.27%), followed by Phlogacanthus thyrsiformis (77.45%), Solanum xanthocarpum (75.48%), Persicaria chinensis (68.62%), Drymaria cordata (65.68%), Gynura cusimbua (62.74%) with Centella asiatica displaying the lowest inhibition rate (57.84%), all at a concentration of 30%. Overall, our findings highlight the potential of integrated management strategies involving biological control agents and soil amendments for sustainable management of Fusarium equiseti in turmeric cultivation. Implementation of these strategies holds promise for improving crop health, productivity, and sustainability in turmeric production systems.

Management of Early Blight of Tomato (Alternaria solani) through Application of Plant Extracts and Fungicides

In the present work, plant extracts and fungicides were evaluated for an effective management of early blight of tomato caused by Alternaria solani under in vitro and in vivo condition and determine yield losses and cost benefit ratio. The present investigations revealed that Hexaconazole and Azoxystrobin were most effective it produced 100.0 per cent mycelia growth inhibition, whereas minimum mycelia growth was recorded in Difenoconazole (1.89 mm) and Trifloxystrobin + Tebuconazole (4.0 mm). Calotropis gigantea extract @ 20 per cent was found best as it produced 77.0 per cent mycelia growth inhibition of Alternaria solani followed by Azadirachta indica (74.26%).The effect of foliar spray of Calotropis gigantea @ 20.0 per cent was found the best for managing early blight of tomato in field condition as minimum disease intensity (39.83%) and highest yield (15.25 t/ha) was recorded with highest benefit cost ratio (1.62). The minimum disease intensity (15.43%), highest yield (22.40 t/ha) and highest benefit cost ratio (2.75) was recorded in Hexaconazole @ 0.1 per cent followed by Azoxystrobin @ 0.1 per cent.

Estimation of Disease Intensity against Cercospora Leaf Spot of Okra (Abelmoschus esculentus L.) Moench through Bio-control Agents with Chemical Fungicides under Prayagraj Condition of India

Okra (Abelmoschus esculentus L.) also known as bhendi is one of the most common vegetable preferred in every household of India. Cercospora leaf spot incited by Cercospora abelmoschi. is one of the emerging disease in Uttar Pradesh Region. An experiment was conducted in Central Research Farm ,SHUATS , Prayagraj in Kharif season of 2022 to evaluate the efficacy of bioagents and chemicals viz., T0 – Untreated control,T1 Mancozeb (1%) + Trichoderma(4%) , T2 - Mancozeb (1%) + Pseudomonas(4%) , T3 Mancozeb (1%) + Bacillus subtilis(4%), T4 - Mancozeb (1%) + Trichoderma (2%) + Pseudomonas(2%) ,T5 - Mancozeb (1%) + Pseudomonas(2%) + Bacillus subtilis(2%), T6 Mancozeb (1%) + Bacillus subtilis(2%) + Trichoderma(2%), T7 - Mancozeb (1%) against Cercospora leaf spot of okra. C. abelmoschi initiates with sooty black, angular spots and cause heavy defoliation Studies revealed that minimum disease intensity was observed in T4 - Mancozeb (1%) + Trichoderma (2%) + Pseudomonas (2%) and is hereby considered as the best treatment out of all the treatments.

Evaluation of the Growth Parameters with Respect to Bio-control Agents with Chemical Fungicides against Cercospora Leaf Spot of Okra (Abelmoschus esculentus L.) Moench

Okra (Abelmoschus esculentus L.) is one of the fore most vegetable crop grown during kharif as well as summer seasons. Cercospora leaf spot incited by Cercospora spp. is one of the emerging disease in all regions wherever okra is grown. C. abelmoschi causes sooty black, angular spots and cause severe defoliation common during humid seasons. An experiment was conducted to evaluate the efficacy of bioagents and chemicals viz., T0 – Untreated control,T1 Mancozeb (1%) + Trichoderma (4%), T2 - Mancozeb (1%) + Pseudomonas (4%), T3 Mancozeb (1%) + Bacillus subtilis (4%), T4 - Mancozeb (1%) + Trichoderma(2%) + Pseudomonas(2%) ,T5 - Mancozeb (1%) + Pseudomonas (2%) + Bacillus subtilis (2%), T6 Mancozeb (1%) + Bacillus subtilis (2%) + Trichoderma (2%), T7 - Mancozeb (1%) against Cercospora leaf spot of okra. Studies revealed that minimum disease intensity , Maximum plant height , maximum no. of branches per plant and Maximum no. of fruits was observed in T4 - Mancozeb (1%) + Trichoderma (2%) + Pseudomonas (2%) and is hereby considered as the best treatment.

Management of Anthracnose Disease of Chilli caused by Colletotrichum capsici

Chilli crop suffers from various diseases in which anthracnose caused by Colletotrichum capsici is a very serious one, causes huge yield losses in India. The present investigation was carried out to find out its suitable control measures by evaluating different fungicides including botanicals and bio-agent first in vitro followed by in field at MES, Vegetable Science, ANDUAT, Kumarganj, Ayodhya. In vitro propiconazole @ 0.1% and hexaconazole @ 0.1% completely inhibited growth of the fungus followed by copper oxychloride @ 0.4%, garlic bulb extract @5% and NSKE @ 5% and Trichoderma harzianum @5% which inhibited (80.88%) mycelial growth of the fungus. In field conditions seed treatment with T. harzianum + Foliar spray with propiconazole was found best with minimum disease intensity (9.37%) and highest yield (151.42 q/ha) in comparison to other treatments.

Effect of Bio-Agents and Fungicides in Management of EAF Spot of Chilli (Capsicum annuum L.) Caused by Alternaria alternata (Fr.) Keissler

The study entitled “Effect of bio-agents and fungicides in management of leaf spot of chilli (Capsicum annuum L.) caused by Alternaria alternata (Fr.) Keissler” was carried out during the rabi season of 2022-2023 at the Central Research Field, Department of Plant Pathology, Sam Higginbottom University of Agriculture, Technology & Sciences, Prayagraj. The experiment was carried out in Randomized Block Design (RBD). Among the treatments taken up for research Mancozeb (1g/L)+Carbendazim (1g/L for foliar spray) was found most effective against Alternaria alternata. The minimum disease intensity (11.21, 14.42 and 18.97) was obtained in Mancozeb (1g/L)+Carbendazim (1g/L as foliar spray). It can be concluded that foliar spray treatment of chilli with Mancozeb (1g/L)+Carbendazim (1g/L as foliar spray) recorded higher plant height (61.63), number of leaves per plant (184.60), number of branches per plant (12.07), number of fruit per plant (55.93), fruit weight (g) (4.61), fruit yield (g) per plant (258.70), fruit yield (g) per plot (1293.49) and fruit yield (t ha-1) (6.47).

Biorational Approaches for Purple Blotch Disease of Garlic (Allium sativum L.) Incited by Alternaria porri (Ellis) Cif

Garlic (Allium sativum L.) is the second most important bulb crop after onion. It is a major spice crop. Garlic is attacked by many diseases, one of which is Purple blotch. This study was aimed to determine the effect of botanicals and bio-agent on purple blotch disease of garlic caused by Alternaria porri. The research work was undertaken at Central Research Farm (CRF) Sam Higginbottom University of Agriculture, Technology and Sciences, SHUATS, Naini, Prayagraj during Rabi in 2022-23. A randomized block design with eight treatments was employed including T0 (Control - untreated) , T1 ( Azoxystrobin @0.1% as treated check), T2 (Trichoderma harzianum @10g/litre) , T3 (Lantana camara leaf extract @10%), T4 (Azadirachta indica leaf extract @10%), T5 (Henna leaf extract @2% + Licorice root extract @2% + Rosemary leaf extract @2% ), T6 (Licorice root extract @10%) and T7 (Neem cake @50g/m2). The treatments led to significant decrease in purple blotch severity in garlic.The results revealed that among the treatments, T7 showed minimum disease intensity (4.33, 18.74 and 26.35%) at 30, 60 and 90 days after sowing (DAS) respectively; while maximum disease intensity was recorded in T0 (10.42, 25.52 and 34.68%). T7 also recorded maximum plant height (24.02, 34.01 and 45.71cm) at 30, 60 and 90 DAS, respectively and highest yield of 4.46t/ha. Maximum number of leaves were recorded with T3 (5.53, 7.5 and 9.4) at 30, 60 and 90 DAS respectively. Fungicide usage is increasing day by day that can lead to negative effect on human and soil health in the long run, so there is need to find effective and economic alternatives preferably some bio-agents and botanicals.

Efficacy of eco-friendly treatments on yield attributes in Indian mustard (Brassica juncea L.) against alternaria blight

Indian Mustard that is emerged as the core oilseed crop is cultivated in the northern regions of India during Rabi season. Alternaria blight is one of the most destructive pathogens for Indian Mustard resulting in huge losses in quality and quantity of the produce. A research study was taken up to control the alternaria blight in Indian Mustard with selected eco-friendly treatments by monitoring disease intensity and yield attributes. It is noted that T2 – Trichoderma viride has shown significant results on disease intensity and yield attributes, where disease intensity has significantly minimised in T2 may be due to the mycoparasitic nature and ability to generate volatile and non-volatile compounds against pathogen with great anti-microbial activity. The results showed that maximum plant height (56.10 cm), test weight (4.11 g) and seed yield (1.21 t/ha) of Indian Mustard with minimum disease intensity (40.21 %) were recorded in the treatment T2 and followed by T6­­ – neem leaf extract @15% that has shown significant results on Alternaria blight.

Effect of different dates of sowing on the severity of blast disease of pearl millet under field conditions

Pearl millet is infected by many diseases, which cause yield reduction and economic losses to the grower. Among several diseases, blast disease has emerged as a serious one, affecting both forage and grain production of pearl millet. The research work has been carried out at the Center for Crop Improvement, S. D. Agricultural University, S. K. Nagar, during the Kharif seasons of 2018 and 2019. The experiment comprising susceptible cultivars of pearl millet was conducted on varied planting dates (D1: 27th June, D2: 4th July, D3: 11th July, and D4: 18th July) to find out the appropriate date of sowing for management of blast under natural conditions. The minimum disease intensity (63.27%) was observed in the 4th July sown crop, followed by the 11th July sown crop (70.47%). The next treatment in merit was the 27th June sown crop (70.77%). The maximum intensity (72.49%) was recorded in the 18th July sown crop.

Effect of Selected Bio-agents and Botanical on Alternarial Leafspot of Coriander (Coriandrum sativum L.) Caused by Alternaria alternata (Fries) Keissler

Coriander (Coriandrum sativum L.) is one of the important spice crops of Apiaceae family. Coriander seeds are used as medicine to cure indigestion, dysentery, vomiting as well as cold and like all other green leafy vegetables, its leaves are a rich source of vitamins, minerals and iron. The country's annual production of coriander seeds in the year 2021 was over 822 thousand metric tons cultivated over 2.92 lakh hectares. Alternarial leaf spot of Coriander which is caused by Alternaria alternata is one major disease in the coriander. The Trichoderma viride, Pseudomonas fluorescens, Bacillus subtillis and Garlic extract were tested under field conditions during rabi season 2021 for their efficacy against the disease and growth & yield parameters. Among the treatments the maximum plant height (cm) at 90 DAS was recorded in T2 – Trichoderma viride+ Pseudomonas fluorescens followed by T3 – Pseudomonas fluorescens as compared to untreated check control T0. The maximum number of branches at 45 DAS was recorded in T2 – Trichoderma viride+ Pseudomonas fluorescens followed by T3 – Pseudomonas fluorescens as compared to untreated check control T0. The maximum root length at 90 DAS was recorded in T5– Trichoderma viride+ Bacillus subtillis followed by T2 – Trichoderma viride + Pseudomonas fluorescens as compared to untreated check control T0. The minimum disease intensity (%) at 75 DAS was recorded in T2 – Trichoderma viride+ Pseudomonas fluorescens, followed by T1–Trichoderma viride as compared to untreated check control T0. The maximum yield (q/acre) of onion was recorded T4 –Trichoderma viride +Pseudomonas fluorescens followed by T1 – Trichoderma viride as compared to untreated control T0.

Efficacy of Bio-agents and Neem Oil against Alternaria porri (Ellis) in Onion (Allium cepa L.)

Onion (Allium cepa L.) is one of the important cultivated vegetable crops and can be grown in temperate, tropical and sub-tropical climates. It is the important vegetable and spice crop and known as “Queen of the kitchen”. Area, Production and Productivity on onion in India (2020-21) was 16.54 million ha, 26.92 million Tones and 19.40 t/ha. There are many diseases and pests affecting onion. Among the diseases, majorly purple blotch, downy mildew, Stemphylium blight and basal rot attacks the onion and among the pests, onion thrips, red spider mite, onion fly attacks the onion. Among them, purple blotch of onion is one of the most severe diseases, which is caused by Alternaria porri which causes heavy losses in the onion. The treatments viz., Trichoderma viride, Pseudomonas fluorescens, Bacillus subtilis and neem oil were tested under field conditions against Alternaria porri during Zaid for their efficacy against the growth and disease parameters and an untreated plot will serve as control. At desired interval of days (45,60,75 DAT) readings were taken for growth parameters and disease intensity. Based on single trail, it was observed that among all treatments, seedling treatment with Trichoderma viride + Pseudomonas fluorescens + neem oil @ 5% showed the most significant results with maximum growth parameters and minimum disease intensity results followed by Trichoderma viride + Bacillus subtilis + neem oil @ 5% and the minimum growth parameters and maximum disease intensity was shown in untreated (control) plot.

Evaluation of newer fungicides against neck blast disease of rice under field condition in south-eastern Rajasthan

Neck blast is considered as the most destructive phase of the blast disease in rice under south-eastern Rajasthan. Eight new generation fungicides viz., Tebuconazole, Difenconazole Propiconazole , Hexaconazole Azoxystrobin , Azoxystrobin +Tebuconazole ,Azoxystrobin Mancozeb Trifloxystrobin +Tebuconazole were evaluated under field conditions during Kharif 2021. Result revealed that the combination of Trifloxystrobin (25%) + Tebuconazole (50 WG @ 0.4g/lit) gave minimum disease intensity (3.2%) and maximum disease control (80.8%) with higher yield (4482.3 kg/ha) which was at par with Propiconazole with a grain yield of 4400.0 kg/ha.

Efficacy of Selected Bioagents against Alternaria Leaf Spot of French Bean (Phaseolous vulgaris L.)

French bean (Phaseolous vulgaris L.) is a significant food, legume crop utilized as a pulse and green vegetable crop, belongs to family fabaceae. The French bean is a cool-season, day- neutral vegetable that can withstand extreme temperatures. Area, production and productivity on French bean in India (2019-20) were 22.1 Mha, 2226 million Tonnes and 7-10 t/ha. They are high in protein and have a similar texture to meat. Green pods have 1.7 g protein, 0.1 g fat, 4.5 g carbohydrate, 1.8 g fibre, and are high in minerals and vitamins in a 100 g serving. Several diseases affects French bean crop majorly and cause yield loss Alternaria leaf spot (Alternaria alternata), Angular leaf spot (ALS) (Phaeoisariopsis griseola), Bean rust (Uromyces appendiculatus), Anthracnose (Colletotrichum lindemuthianum), Aschochyta leaf spot (Ascochyta phaseolorum) and Cercospora leaf spot (Cercospora canescens). Among them, Alternaria leaf spot of French bean is one of the most severe disease, which is caused by A. alternata in the French bean. An experiment was conducted in the Zaid season to check the efficacy of bioagents against A. alternata on field conditions. Bioagents viz.,Trichoderma viride, Pseudomonas fluorescens, Bacillus subtilis as seed treatment. An untreated replication served as control. Among the treatments, the maximum germination percentage maximum plant height (cm) at 90 DAS , maximum no. of primary branches and secondary branches at 60 DAS was recorded in T4 – T. viride @2.5%+ P. fluorescens @ 2.5% followed by T1 – T. viride @ 5% as compared to untreated check control T0 . The minimum disease intensity (%) at 75 DAS was recorded in T4 – T. viride @ 2.5% + P. fluorescens @ 2.5 %, followed by T1 – T. viride @ 5% as compared to untreated check control T0.

Eco-friendly Approaches against Alternaria alternata Causing Leaf Spot of Stevia (Stevia rebaudiana)

Stevia (Stevia rebaudiana) is a small perennial and herbaceous shrub that originated from South America and belongs to the Asteraceae family. Stevia is also known “sugar substitute, sweet weed, candy leaf and sweet herb” and also a chief source of vitamin ‘C’. Stevia leaves are high in folic acid and rich in carbohydrates and reducing sugars estimated to be 300 times sweeter than sugarcane. Alternaria leaf spot caused by Alternaria alternata is the most common disease in stevia, An experimental trial was taken up to evaluate the efficacy of selected eco-friendly treatments on the growth parameters in stevia over Alternaria alternata at Central Research Farm, Division of Plant Pathology, Naini Agricultural Institute, U.P. Maximum plant height (50.40 cm), Maximum number of branches (23) and minimum disease intensity (22.79%) are recorded in the treatment combination of T8 - Microalgae + neem cake + vermicompost followed by T6 – Microalgae + vermicompost.

Effect of Selected Essential Oils and Botanicals on Alternaria Blight (Alternaria brassicae (Berk) Sacc) of Mustard (Brassica juncea (Linn) Czern and Coss

Indian mustard (Brassica juncea (L.) Czern.coss) is also known as sarson, rai or raya, toria or Lahi.it is a herbaceous annual plant. Mustard is the second important oilseed crop in the world after sunflower, soybean and palm oil. Alternaria blight disease caused by Alternaria brassicae (Berk.) Sacc. It has been reported from all the continents of the world. Average yield losses occur due to various pest and diseases among which Alternaria blight is an important disease. Field experiment was conducted at the research plot of the Department of Plant Pathology, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj, Uttar Pradesh during the rabi season of 2020-2021 to test, Effect of selected essential oils and botanicals against Alternaria blight (Alternaria brassicae (Berk.) Sacc) of mustard (Brassica juncea (Linn.) Czern and Coss), by foliar spray of certain essential oil, plant extracts and fungicide. The treatments were Neem oil @2%, Eucalyptus oil @2%, Pongamia oil @2%, Lawsonia inermis extract @15%, Chenopodium album extract @15% Mancozeb (treated check) @ 0.2% and control (untreated check). The percent disease intensity on leaves at 45, 60 and 75 DAS, number of siliquae per plant, number of seeds per siliquae, length of siliquae (cm), test weight of seed (1000 number), biological yield (gm) and seed yield were recorded. Among the treatments, maximum number of number of siliquaes (243.13), maximum number of seeds per siliquae (12.27), length of siliquae (5.16 cm), minimum disease intensity (%) (29.01 %), maximum test weight (3.57 gm), maximum yield (9.43 qt) and biological yield (24.70 gm) were recorded in the treatment T2 Eucalyptus oil @2% followed by T1 Neem oil @2%, T4 Lawsonia inermis extract @15%, T3 Pongamia oil @2%, T5 Chenopodium extract @15%, when compared to treated check T6 Mancozeb @ 0.2% and untreated check T0. Higher gross return value (Rs. 66295), net return value (Rs. 29295), and B: C ratio (1.7:1) was found in the treatment T2 – Eucalyptus oil @2% as compared to T5–mancozeb and T0–control.

Efficacy of different dose of fungicide Mancozeb against purple blotch complex (Alternaria porri) of Shallot

Shallot (Allium ascalonicum L) is subjected to attack by a number of diseases caused by fungi, bacteria, and viruses which are the major constraints for higher production. Among the several diseases which attacked shallot, purple blotch disease of shallot caused by Alternaria porri (Ellis) Cif, is one of the most destructive disease; causing accountable losses of about 57 percent. Present study was aimed to determine the efficacies of different doses of fungicide (Mancozeb) against Alternaria leaf blight in shallot. A field experiment for the evaluation of different doses of mancozeb was conducted at Subang, West Java. The research used randomized complete block design (RCBD), with 6 treatments and 5 replications. The treatments were six doses of mancozeb (3 g/L; 2.25 g/L; 1.5 g/L; 0.75 g/L; 0.5 g/L and 0 g/L of water) were applied after 7 days intervals. All Mancozeb doses reduce the disease severity compared to untreated control. Among the different treatments, minimum disease intensity (13.33 %) was observed when the plots were sprayed with mancozeb 3 g/L followed by mancozeb 2.25 g/L (20.27%), mancozeb 1.5 g/l (20.53%), mancozeb 0.75 g/L (21.07%) and mancozeb 0.50 g/L of water respectively.

Efficacy of botanical extracts against early blight disease of tomato incited by Alternaria solani

Early blight is one of the most common and destructive diseases in tomatoes caused by the fungus Alternaria solani. Antifungal activity of six botanical extracts, namely (Datura stramonium) Datura, (Polyalthia longifolia) Ashoka, (Clerodendrum viscosum) wild jasmine, (Eucalyptus globulus) eucalyptus, (Chromolaena odorata), Siam weed extract, (Lantana camera) wild sage extract was antifungal. Each plant extract tested against Alternaria solani, with two concentrations, 5% and 10%, under in vitro and in vivo. The maximum decrease in the growth of mycelium of Alternaria solani with Eucalyptus globulus and Lantana camara (67.68% and 36.72%, respectively) and the minimum disease intensity under in vivo were recorded with Eucalyptus globulus (27.42%).