Maximum Disease Incidence Research Articles

A modified and effective stem inoculation technique for artificial screening against Sclerotinia sclerotiorum in mustard

AbstractSclerotinia stem rot (SR) disease emerged as a potential threat in most mustard‐growing regions globally. Sclerotinia sclerotiorum, a necrotrophic pathogen, causes considerable damage to the crop under congenial environments. The sclerotia even under adverse conditions can survive up to 5 years in the soil. The use of resistant sources is the only mean to combat the pathogen. The development of an effective inoculation technique can facilitate the identification of new sources of resistance rapidly. Investigations on resistant sources using Potato Dextrose Agar (PDA) medium for artificial stem inoculation are ongoing under the All India Coordinated Research Project (AICRP) on rapeseed‐mustard for many years but no resistant sources could been identified. In the present study, two non‐injury stem inoculation techniques using sorghum grains and PDA medium as a basal medium were tested on 11 brassica entries for up to three consecutive years. Results revealed that sorghum grain‐based inoculum was found efficient for disease development and lesion formation in brassica entries compared with PDA‐based inoculum. Among the entries, a maximum disease incidence of 42.3% was recorded in entry DRMR 5206 followed by DRMRSJ‐20, DRMRSJ‐22 and DRMR 2017‐8 with 42.1%, 41.8% and 41.3% SR incidence, respectively. In PDA disc inoculation maximum SR incidence of 30.8% was observed in DRMRSJ‐26 followed by DRMR 5206, DRMRSJ‐25 and DRMRSJ‐2017‐18 with 27.5%–24.9%, respectively. Lesion length was more in entries inoculated with fungal mycelium multiplied on sorghum grains compared with the PDA disc inoculation method. The statistical analysis and results of p‐value (<.00001) showed a significant difference between tested methodologies. Thus, the sorghum grain‐based inoculation technique is an appropriate, economic and effective non‐injury inoculation technique for artificial screening against S. sclerotiorum in the mustard crop. This technique can be used to screen a large number of brassica entries more efficiently with less labour and time.

Prevalence of rhizome rot complex in major ginger growing regions of Karnataka

Rhizome rot complex is one of the most destructive and economically important diseases of ginger. In this study,a roving survey was conducted during kharif - 2021 to assess the disease incidence of rhizome rot complex in major gingergrowing parts of Karnataka,viz., Haveri, Shivamogga and UttaraKannada districts. Among the various taluk as surveyed,the maximum disease incidence (35.99%) was recorded in Sirsi taluk of Uttara Kannada district and the minimum of21.50 per cent was observed in Byadagi taluk of Haveri district. Among the surveyed districts, the highest incidence of31.62 per cent was observed in Uttara Kannada district followed by Shivamogga district (28.81%) and the minimumincidence was observed in Haveri district (25.45%). Further, from the survey it was revealed that, selection of improperplanting material, poor drainage of fields, mono cropping, lack of crop rotation, indiscriminate use of fertilizers and lack ofknowledge on managing the disease could be the possible reasons for higher occurrence of rhizomerot complex in gingergrowing regions of Karnataka.

“Medicinal plant extracts enhanced the shelf life of chilli fruits against the anthracnose disease through defense modulation”

Colletotrichum capsici is a severe concern for the post-harvest management of chilli fruit. Mostly synthetic fungicide is used to protect chilli fruits after harvesting, which contain many toxic compounds, and it's become the most significant issue for the consumers' health. In the current study, antifungal activity of leaf and stem extracts of different medicinally important plants such as Acalypha indica, Adhatoda vasica, Alternanthera sessilis, and Peristrophe paniculata were examined against the C. capsici on chilli fruits. The chilli fruits were treated with plant extracts ‘before’ and ‘after’ the inoculation of the fungal pathogen at two different temperatures (25 °C and 4 °C). The plant extract treatment ‘before pathogen inoculation’ was more effective than ‘after pathogen inoculation in controlling the anthracnose disease of chilli fruits. Results revealed that most plant extracts showed better disease resistance (small size of lesions, low weight loss, higher pH, and increased titrable acidity) at 4 °C than 25 °C. The maximum disease incidence (33.88%) resulted in leaf extract of A. sessilis ‘before pathogen inoculation’, and it minimized the lesion size up to 15 mm. Similarity reduced the decay by 53% at 25 °C, and a similar manner of disease reduction was followed by A. vasica, P. paniculata, and A. indica. Further, PPO, POD, CAT, SOD, and PAL enzyme quantification showed leaf extract of A. sessilis ‘before pathogen inoculation’ significantly induced the plant defense against the C. capsici. In conclusion, A. sessilis leaf extract treatment ‘before pathogen inoculation’ was found most efficient in reducing anthracnose disease in chilli fruits. The bioactive compounds of the leaf extract of A. sessilis could function in C. capsici growth inhibition and defense activation of chilli fruits.

Prevalence of Citrus Canker caused by Xanthomonas axonopodis pv.citri. in Eastern and Northern region of Madhya Pradesh, India

Bacterial canker is one of the most common citrus diseases, causing widespread losses throughout the citrus growing regions of the world, including India. Madhya Pradesh is one among the leading states in India for citrus production. Therefore, to Keep track of the disease prevalence on lime, lemon, malta, grapefruit, and other citrus fruits, a survey was conducted in eastern (Baghelkhand) and northern (Gird) regions of Madhya Pradesh during the months of February to March 2022. Various crucial data were collected on disease severity (percentage) and disease incidence (percentage). During the survey, disease incidence was recorded from 0% to 40% range, and disease severity from 0% to 37%, with a maximum mean disease incidence (36.5%) and severity (34%), respectively, in Chinor tahsil of Gwalior district and a minimum disease incidence (18%) and severity (17.3%) in Satna district of Madhya Pradesh. Disease samples of Xanthomonas axonopodis pv.citri were collected from various villages in the chosen district during the survey (Turari, Bhanduli, Khohar, Ambha, and Panihar). After three days of purification, all five isolates showed a light yellow to yellow colour, a mucoid surface, and a circular colony with a diameter of 4 to 5.5 mm. The biochemical characteristics of bacterial isolates subjected to various biochemical tests, including the catalase test, KOH solubility test, H2 S production, and Gram reaction, were studied. All isolates were positive in catalase, KOH solubility, and H2 S production tests, but negative in Gram’s reaction. The virulence behaviour of the isolates, namely Xacl, Xac2, Xac3, Xac4, and Xac5, was diagnosed during the pathogenicity test by spraying the isolate suspension on the citrus plant. Symptoms appear 12-17 days after inoculation with a different isolate. Lesions appear on the leaf’s bottom surface as small, translucent, round spots. A yellow halo surrounded the lesions. Isolate Xac3 develops water-soaked lesions on the leaves 12 days after inoculation. Other isolates, such as Xac4, had low virulence, with symptoms showing up after16days.Xac1, Xac2, and Xac5 were all partially virulent isolates.

Dinâmica temporal de Plasmopara viticola em função do aumento da carga de gemas em 'Sauvignon Blanc'

Abstract The objective of this work was to evaluate the effect of increasing bud load per plant on epidemiological variables of downy mildew on 'Sauvignon Blanc'. The study was carried out in a commercial vineyard in a high-altitude region of the municipality of São Joaquim, in the state of Santa Catarina, Brazil, during the 2016/2017 and 2017/2018 vintages. The treatments consisted of four bud loads: 15, 30, 50, and 75 per vine. The maximum incidence, maximum severity, beginning of symptom appearance, time to reach maximum disease incidence and severity, area under the incidence and severity disease progress curve were determined. Increasing bud load over 50 per vine results in higher incidence and severity of downy mildew (Plasmopara viticola) in 'Sauvignon Blanc' leaves but does not influence the time to reach maximum disease incidence and severity. Increasing bud load over 50 per vine results in an increase in the area under the disease incidence and severity progress curve for downy mildew in 'Sauvignon Blanc' leaves. To adopt over 50 buds per vine treatment, it is necessary additional disease control measures, with an emphasis on integrated management to control downy mildew.

Studies on Antimicrobial Effect of Botanicals on Leaf Blight of Indian mustard Caused By Alternaria brassicae

The present study was conducted at ANDU&T Kumarganj Ayodhya at student instructional form (SIF). As in the investigation it was observed that foliar spray with Carbendazim (0.1%), Neem oil (5%), followed by Neem leaf extract (5%) found to be more effective on growth parameters like Number of branches/plants, number of leaves/ plants, plant height (cm), number of pods/plants,) and increased the yield (1000-seed weight, per plant yield (g), per hectare yield) and also significantly reduced the Alternaria blight in Indian mustard. Carbendazim (0.1%), Trichoderma harzianum (2%) followed by garlic bulb extract (5%) was found most effective in reducing Alternaria blight, recorded maximum disease incidence i.e. percent Disease intensity, percent Leaf area disease (LAD), percent leaf infection, number of spots per pods, seed infection percent respectively.

Effectiveness of botanicals, inorganic salts and fungicide against Fusarium wilt of muskmelon under hot arid region of Rajasthan

Investigation was undertaken to screen out the extract of botanicals viz., Neem leaf, Tumba fruit, NSKE and Aak leaf and inorganic salts against Fusarium wilt of muskmelon. This disease caused by Fusarium acuminatum is a major fungal disease causing serious losses to muskmelon growing areas in Rajasthan. The field trials were carried out on muskmelon susceptible variety ‘RM-50’ against Fusarium wilt during summer season of 2019 and 2020 at this Institute. Among 11 treatments, carbendazim (0.1%) was found the most effective treatment for management of Fusarium wilt with minimum disease incidence (PDI) of 15.83% and 60.84% disease reduction, followed by neem leaf extract @ 10% with disease incidence of 21.89% and 45.84% disease reduction. Maximum disease incidence (40.42% PDI) was found in case of control.

Occurrence of Purple Blotch Disease Associated with Selected Garlic Varieties and its Management Through Bio-Agent, Botanicals and Fungicides

Purple blotch of garlic caused by Alternaria porri is recognized as a prominent diseases posing threat to garlic cultivation throughout the world including Bangladesh. The experiments were conducted to determine the prevalence of purple blotch disease on garlic varieties in field condition, to test the pathogenicity of isolated causal organism and to find out the suitable management options of the disease. Eight garlic varieties viz. BAU Rashun-1, BAU Rashun-2, BARI Rashun-1, BARI Rashun-2, BARI Rashun-3, BARI Rashun-4, Local Deshi and Local Indian were explored in prevalence study and nine management option comprising a bio-agent Trichoderma harzianum (T1), five botanicals viz. Lantana camara (T2), Spilanthes paniculata (T3), Ocimum sanctum (T4), Raphanas raphanistrum (T5) and Azadirachta indica (T6), two fungicides Mancozeb 80% WP (T7) and Sulcox 50% WP (T8) and, an untreated control (T9) were explored in the experiments. BARI Rashun-3 showed the highest disease incidence (40.00%) and severity (92.00%) of purple blotch disease. Isolation, identification of pathogen and pathogenicity test was carried out as well. In case of management, all botanicals and bio-agent were tested significantly beneficial in lessening the disease incidence and severity of purple blotch disease. The results revealed that Lantana camara (T2) was found most effective for minimizing the disease incidence (26.67, 26.67 and 33.33%) at 30, 45 and 60 DAS, respectively while maximum disease incidence was recorded in control (T9) (86.67, 96.67 and 100.00%). T2 also reduced disease severity at 30 DAS (11.00%) whereas, at 45 DAS (18.67%) and 60 DAS (19.33%) T1 performed well against the disease.

Effect of different fungicides against stem and root rot of sesame (Sesamum indicum L.) caused by Macrophomina phaseolina (Tassi) Goid

Stem and root rot disease caused by Macrophomina phaseolina is the serious soil-borne disease in sesame. The present study was conducted at College of Agriculture, Jodhpur during kharif season 2020-21 to evaluate the nine different fungicides under in vitro condition and five different fungicides under in vivo against M. phaseolina. Result of in vitro study indicated that the fungicide, carbendazim (50% WP) gave complete mycelial growth inhibition (100%) at 500 and 1000 ppm concentrations, respectively. Second best of pyraclostrobin 5% + metiram 55% WG, carbendazim12% + mancozeb 63%, then propiconazole 25% EC, thiophanate methyl (70% WP) and cymoxanil 8% + mancozeb 64% also gave 100% inhibition of mycelial growth at 1000 ppm respectively. The lowest disease per cent was recorded in combination fungicide of tebuconazole 50% + trifloxystrobin 25% WG (8.91%) followed by 9.14% with cymoxanil 8% + mancozeb 64%, pyraclostrobin 5% + metiram 55% WG (11.02%) whereas, maximum disease incidence was recorded in control plot (55.32%) when tested under in vivo condition.

Preliminary Selection and Evaluation of Fungicides and Natural Compounds to Control Grey Mold Disease of Rose Caused by Botrytis cinerea

Botrytis cinerea is a plant fungal pathogen causing the grey mold disease of rose ‎‎(Rosa indica L.). Finding new and alternative environment-friendly control strategies than ‎hazardous chemicals on different crop diseases is a crucial and healthy step to cope with ‎the current challenges of climate change. ‎ Therefore, this study aimed to evaluate the efficacy of different botanical extracts and biocontrol agents (biopesticides) along with different fungicides against B. cinerea under in-vitro conditions. Three different concentrations i.e., 100, 200, and 300 ppm of five fungicides namely Acrobate, Melody, Cabrio top, Antracol, and Copper oxychloride, botanical extracts of eight plants Dhatura, Ginger, Aak, Neem and Onion, at three different doses of 5, 10, and 15%, and eleven biocontrol fungal agents were used as antagonistic under in-vitro on rose plants, The survey of ‎disease incidence% of grey mold on the rose crop in the region shows that the Hyderabad region has a maximum (60%) disease incidence as compared to Tandojam region ‎‎(40%). Among fungicides, the Cabrio top significantly reduced linear colony growth (31 mm) of B. cinerea at 300 ppm concentration. Among botanicals, extract of neem plant exhibited significantly lowest colony growth (23.33 mm) followed by the ginger plant (25 mm) and dhatura plant (26 mm). The higher concentration of fungicides and higher doses (15%) of botanicals extracts appeared significantly efficient to control the pathogen B. cinerea. Among biopesticides, Fusarium solani appeared prominent in reducing colony growth (25.16 mm) of the pathogen but the difference was not significant 300 with most of the tested biocontrol agents. The recommendation in this study is the high ability of botanical extracts and biocontrol agents in reducing the growth of grey mold, potentially considering using them instead of synthetic fungicides and more safety for the ecosystem. Keywords: Trichoderma, Fusarium, dhatura, botanical, biological control, synthetic fungicides.

Impact of Spent Mushroom Substrate Integration with Trichoderma harzianum on Yield and Gummosis Disease Incidence in Bottle Gourd (Lagenaria siceraria)

Bottle gourd is a commonly grown cucurbitaceous vegetable crop in India. It is affected by various pathogens but gummosis, a soil borne fungal disease is a serious disease of bottle gourd. The symptoms are color change to reddish brown at the collar region. The oozing of brownish gum on affected part is the first sign of disease. The research work carried out in the world has proved that soil application of spent mushroom substrate (SMS) after weathering increased yield and decreased soil borne diseases in different vegetable crops. Keeping in view of its importance, it was felt to study the impact of soil application of SMS enriched with T. harzianum on seed germination, yield and gummosis disease incidence of bottle gourd. The twelve months old SMS and well rotten farm yard manure (FYM) were applied in soil alone as well as enriched with T. harzianum in the experimental trials conducted from 2019 to 2021. It revealed that soil application of SMS and FYM applied alone or enriched with T. harzianum didn’t have adverse effect on its germination. The maximum yield at 5752 kg/ha was obtained when SMS enriched with T. harzianum was applied followed by 5630 kg/ha when SMS was applied alone in soil. The minimum yield at 4806 kg/ha was obtained in control. A minimum disease incidence of 4.8 per cent was observed when SMS enriched with T. harzianum was applied, followed by 6.5 per cent when it was applied alone. The maximum disease incidence of 11.7 per cent was observed in control. Therefore, soil application of SMS enriched with T. harzianum before sowing at 25 tonnes/ha significantly increased yield and decreased disease incidence at the maximum rate as compared to other treatments and control.

OCCURRENCE AND PREVALENCE OF MANGO DECLINE IN THE PUNJAB PROVINCE OF PAKISTAN

Mango (Mangifera indica) is a popular fruit in Pakistan and ranks second to citrus. Pakistani mangoes have a large export potential in overseas markets that has yet to be realized. In Pakistan, important fruit trees such as citrus, mango, guava, etc. are facing a decline. Among these fruits, mango decline has been addressed strongly as they are important foreign exchange earnings and export items. In the case of mango, the decline has different forms, generally known as progressive, slow decline, or dieback; quick dieback, and sudden death. This type of condition is most common in poorly managed orchards that do not follow correct nutrition, plant protection, or irrigation techniques. Such a drop can be easily addressed if orchards are cultivated using the greatest possible production methods. The updated studies on the occurrence of mango decline are necessary to become a reference for further research and management strategies. Therefore, the present study was designed for disease estimation in the mango-growing areas of the Punjab province of Pakistan. According to the results, maximum mean disease severity of 2.70 was observed in district Bahawalpur followed by Khanewal (2.30), Multan (2.11), and Muzaffar Garh (2.00). The minimum disease severity (1.90) was recorded in Rahim Yar Khan district. Similarly, the maximum mean disease incidence (100%) was found in Khanewal followed by Bahawalpur (99.30%), Muzaffar Garh (96.00%), and Multan (96.00%) while the minimum disease incidence (90.00%) was observed in Rahim Yar Khan. The disease index which gives the actual picture of the disease was found to be the maximum in Bahawalpur (53.30%) followed by Khanewal (46.50%), Rahim Yar Khan (39.10%), and Muzaffar Garh (37.30%) while the minimum disease index of 36.89 was found in Multan district. This information will serve as the baseline information for research and management strategies in mango decline.

Scenario of Early Blight and Leaf Curl of Tomato in Gwalior Districts of Madhya Pradesh

Alternaria solani fruit rot of tomato. Among them, early blight is the most destructive. Present investigations were undertaken to study the disease incidence of early blight in Gwalior districts, which ranged from 12.50 to 51.30%. Maximum disease incidence was recorded in Shyawari (51.30%), while minimum incidence was recorded in Duhiya (12.50%). The leaf curl disease of tomato ranged from 15.33 to 63.20% and maximum disease incidence of tomato leaf curl disease on tomato recorded in Ganpatpura (63.20%) while minimum disease incidence was recorded in Birampura (15.33%).

Survey on the incidence of rice sheath blight disease incited by Rhizoctonia solani and assessing their characters

Rice sheath blight is one of the prominent diseases caused by Rhizoctonia solani causes significant losses in rice growing regions of Tamil Nadu. The present study was undertaken with an objective to assess the prevalence and incidence of rice sheath blight in different regions of Tamil Nadu, India during 2018–2019 and assess the cultural, morphological characters and pathogenic variability among ten numbers of isolates of R. solani. The survey in different regions of Tamil Nadu revealed the endemic nature of the sheath blight disease with the maximum disease incidence (19.97%) recorded in Chitrakudi of Thanjavur region (RS5). Also, the isolates of R. solani exhibited cultural, morphological and pathogenic variability among them the isolate RS5 was exhibit faster mycelial growth, maximum sclerotial production and sclerotial size and recorded the maximum incidence of root rot disease under pot culture conditions. Also, in this study potato dextrose agar medium was found to be as best medium for supporting the mycelial growth and sclerotial production of isolate RS5. Hence, RS5 was found to be most virulent isolate and may be taken up for further studies.

​​Incidence of Collar Rot of Groundnut in Rajasthan and its Management

Background: Groundnut (Arachis hypogaea L.) is an important legume crop of tropical and sub-tropical areas of the world. This crop suffers from several diseases like early leaf spot, late leaf spot, rust, groundnut bud necrosis, peanut clump and collar rot etc. But collar rot caused by Aspergillus niger van Teighem is one of the most important seed and soil borne diseases causing huge economic (40-50 per cent) loss in India and abroad. Methods: A roving survey was conducted to assess the incidence of collar rot in eight major groundnut growing districts of western Rajasthan i.e. Bikaner, Jodhpur, Churu, Jalore, Jaipur, Sikar, Nagaur and Dausa during Kharif 2018. A field experiment was carried out for two consecutive years (2019 and 2020) to manage the disease through altering micro-climate under canopy with six levels of seed rates (80, 85, 90, 95, 100 and 105 kg/ha). Result: Our investigations cleared that this disease is prevalent in all the 200 fields surveyed in eight districts of Rajasthan with 22.99 per cent overall disease incidence which varied from 17.84 to 32.38 per cent with monetary losses. Maximum disease incidence was recorded in Jaipur (28.85%) district while it was lowest in Nagaur district (20.15%). Higher disease reduction (12.97%) with increased pod yield (27.65%) was observed with higher seed rate of 105 kg/ha as compared to standard recommended seed rate (80 kg/ha) as this pathogen is favoured by higher temperature and low soil moisture, dense canopy provides shade that increases humidity under the cropped area and lowers temperature. As a result of this, plant mortality can be compensated by increasing plant population through seed rate, as it modifies the microclimate and generate an environment which is less favourable for developing collar rot disease of groundnut.

Effect of Inoculum Levels on Disease Development and Survival Potential of Sclerotinia sclerotiorum Sclerotia

Sclerotinia stem rot is constantly appearing from moderate to severe form in major mustard growing tracts. Most of life S. sclerotiorum passes in form of sclerotia in the soil. Present study was carried out in order to determine effect of inoculum level on disease development and survival of S. sclerotiorum. Different inoculum levels were prepared from culture of S. sclerotiorum and 10 sclerotia/ pot were buried at various depths ranging from 1 to 20 cm for 60 days. The maximum disease incidence (93.67%) was observed with 10 per cent inoculum level; however disease incidence was least (6.34%) in 1 per cent inoculum level. Disease incidence increased with increasing in inoculum levels. In case of plant mortality, maximum plant mortality (43.00%) was recorded at 10 per cent inoculum level followed by 32.67 and 29.34 per cent @ 9 and 8 per cent, respectively. No plant mortality was noticed at 1 and 2 per cent inoculum level. Maximum amount of sclerotia germination (83.33%) was observed at 1 cm soil depth followed by 75.65, 73.34, 70.34 per cent germination @ 2, 3 and 4 cm depth of soil, respectively. It was observed that sclerotial germination decreased in tune with increase in soil depth. Lowest sclerotial germination (10%) was observed in 20 cm vertical soil depth. Findings of this study can be harnessed in varietal screening and formulation of disease management modules.

Integrated use of Propiconazole, Pseudomonas fluorescens and Bacillus subtilis for the management of rice brown leaf spot

The present investigation was carried out to study the effect of integrated use of propiconazole and bacterial bio control agents (Pseudomonas fluorescens and Bacillus subtilis) on the incidence of rice (Oryza sativa L) brown leaf spot during 2020-2021 at Annamalai University, Chidambaram. Among the various treatments tested in pot culture, seed treatment with consortia of P. fluorescens and B. subtilis + 1st foliar spray with Consortia of P. fluorescens and B. subtilis at 45 DAT + 2nd foliar spray with Propiconazole 25% EC at 60 DAT (T7) recorded minimum disease incidence (7.45%) and maximum number of productive tillers/ clump (17), grain (76.0 g/pot) and straw (127 g/pot) yield. In field studies also T7 treatment produced least disease incidence of brown spot (8.50%) and maximum growth parameters (17 productive tillers/clump) grain (74 qha-1) straw (86.30 qha-1) yield. Per cent disease incidence increased regularly with age of the crop, irrespective of treatments and maximum values were recorded at harvest. The maximum disease incidence and minimum values of growth and yield of rice recorded under control in both pot culture and field condition.

Integrated use of Propiconazole, Pseudomonas fluorescens and Bacillus subtilis for the management of rice brown leaf spot

The present investigation was carried out to study the effect of integrated use of propiconazole and bacterial bio control agents (Pseudomonas fluorescens and Bacillus subtilis) on the incidence of rice (Oryza sativa L) brown leaf spot during 2020-2021 at Annamalai University, Chidambaram. Among the various treatments tested in pot culture, seed treatment with consortia of P. fluorescens and B. subtilis + 1st foliar spray with Consortia of P. fluorescens and B. subtilis at 45 DAT + 2nd foliar spray with Propiconazole 25% EC at 60 DAT (T7) recorded minimum disease incidence (7.45%) and maximum number of productive tillers/ clump (17), grain (76.0 g/pot) and straw (127 g/pot) yield. In field studies also T7 treatment produced least disease incidence of brown spot (8.50%) and maximum growth parameters (17 productive tillers/clump) grain (74 qha-1) straw (86.30 qha-1) yield. Per cent disease incidence increased regularly with age of the crop, irrespective of treatments and maximum values were recorded at harvest. The maximum disease incidence and minimum values of growth and yield of rice recorded under control in both pot culture and field condition.

Effect of Abiotic Factors on the Incidence of Dry Root Rot in Chickpea (Cicer arietinum L.)

An investigation was conducted on chickpea (Cicer arietinum L.) genotype JG-62 to study the effect of different abiotic factors on the incidence of dry root rot. Maximum disease incidence was observed at 35°C temperature while minimum disease incidence was observed at 20°C. More disease incidence was observed at low moisture conditions while low at high moisture conditions. Soil pH also influenced the disease incidence. Maximum disease incidence was observed at pH 4.5 while minimum disease incidence was observed at pH 7.5. The results are useful for managing the incidence of dry root rot in chickpea.

Wilt in Cucumber-An Emerging Disease in Mid Hills of Himachal Pradesh

Fusarium wilt of cucumber caused by Fusarium oxysporum was found to occur in major cucumber growing areas of mid hills of Himachal Pradesh. During surveys conducted in 2018–2019, maximum disease incidence was recorded at Dedghrat (43%) followed by Jadari (31%). Symptoms of disease appeared as chlorosis followed by necrosis from lower to middle leaves leading to complete wilting of the plant. Associated fungus, from the diseased samples was isolated in pure form and designated as Fusarium oxysporum on the basis of cultural and morphological characters. Pathogenicity test was carried out with three different methods of inoculation, where soil inoculation with mass culture method was found most effective with an incubation period of about 10 days. Five cucurbits (bottle gourd, bitter gourd, zucchini, sponge gourd and pumpkin) were evaluated against Fusarium oxysporum to study its host range and it was found that all the cucurbits were susceptible to the disease except bitter gourd.