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A study was conducted to find out the influence of weather factors, soil temperature and soil moisture on the incidence of Sclerotium rolfsii Sacc. induced collar rot disease in betelvine (Piper betle L.), during 2016 to 2018. Fourteen soil and weather factors, taken from the agrometeorological observatory located at instructional farm of Ramkrishna Ashram Krishi Vigyan Kendra, Nimpith and recorded from a nearby betelvine boroj, were subjected to multiple regression, binary logistic regression and canonical discriminant analysis to develop a suitable disease forewarning model. The binary logistic model, Y(0/1) = 5.899 + 0.865 (Tmax) – 0.569 (SM) + 0.097 (BRHmin) was able to predict the disease risk with 78 per cent accuracy and correctly classified 94 per cent of cases during model validation in 2018. The weekly averages of maximum temperature (Tmax), soil moisture (SM) and minimum relative humidity inside the boroj (BRHmin) were found to be the most significant predictors of disease incidence, in this model. The soil moisture at 69 - 72 per cent of field capacity, minimum temperature of 25 - 27oC, maximum temperature of 33 - 36oC, average soil temperature of 28 - 30oC, minimum relative humidity of 60 - 72 per cent inside the boroj and maximum relative humidity of 83 - 89 per cent inside the boroj were found to be highly congenial for collar rot disease incidence in betelvine under coastal saline zone of West Bengal.

Biofumigation is an environmentally benign and promising technique for suppressing soil borne pathogens. The objective of the study was to find out the efficacy of biofumigation with Indian mustard (Brassica juncea L., var. Pusa Mahak) against Sclerotium rolfsii Sacc., causing collar rot disease in betelvine (Piper betle L.). Culture of S. rolfsii, isolated from collar rot infected betelvine tissue, sclerotia of S. rolfsii and the culture of Trichoderma sp. T-Nam, a native isolate, were separately exposed to different doses of macerated fresh mustard leaf (MFML) of four phenotypic stages, without any contact. The saprophytic colonization ability of the pathogen and the collar rot disease incidence were studied in soil system under different doses of biofumigation, both alone and in combination with soil amendment with Trichoderma. The mustard leaves showed best biofumigation activity at 50% flowering stage, with IC99 values (99% inhibitory concentration) of 2.49 g and 3.86 g MFML per 127 ml air space for S. rolfsii mycelial growth inhibition and sclerotial germination inhibition, respectively. The native isolate, Trichoderma sp. T-Nam, was highly tolerant to such biofumigation treatment (IC99 value of 9.46 g MFML per 127 ml air space). The significant (p

Among the vegetables, cucurbits form one of the largest groups with their wide adaptation from arid climates to the humid tropics. The family Cucurbitaceae consists of about 825 species in around 118 genera. In Asia, nearly 23 edible major and minor cucurbits are grown and consumed. They are grown mainly in summer and rainy seasons in India and even in winter in some parts of southern and western India as both annual and perennial crops. Important genera of this family are Lagenaria, Momordica, Luffa, Cucurbita, Cucumis and Citrullus. Cucurbits are actively used as traditional herbal remedies for various diseases such as anti-inflammatory, antitumor, hepatoprotective, cardiovascular and immunoregulatory activities. Due to their low carbohydrate content and the ability to supply of certain amount of minerals and vitamins, it is highly recommended for diabetics. As the cucurbit species are mostly unisexual and male and female flowers are borne separately, the pollination and fruit setting are governed by insect pollinators. Spray of plant growth regulators helps a lot in modifying sex expression and inducing femaleness. Being viny crop, cucurbits require special attention regarding crop management. This chapter unfurls basic know-how about cucurbits including its cultivation protocols.

One of the key impediments for the cultivation of cucurbit vegetables is the pathogenic infestation. Besides, some abiotic causes are also involved in lowering crop yields in terms of both quality and quantity. Cucurbits are suffering from different kinds of pre- and post-harvest biotic stresses like fungi, bacteria, virus, phytoplasma, nematodes, etc. The abiotic factors are related to excess or deficient supply of nutrients, adverse edaphological and climatological conditions, etc. Some of the economically important and destructive diseases are downy mildew, powdery mildew, damping-off, fruit and vine rot, cottony leak, gummosis, Phytophthora blight, anthracnose, Cercospora leaf spot, phoma blight, collar rot, charcoal rot, Fusarium wilt, white rot, root knot, bacterial wilt, watermelon bud necrosis and leaf distortion virus, mosaic, phyllody, etc. Most of the diseases are of national importance and cause significant losses of the crops. A comprehensive catalogue on biotic diseases of cucurbits and their eco-friendly management strategies are presented in this chapter.

The field experiments were conducted during Rabi season of 2014-15 and 2015-2016 in Birbhum district under Lateritic Red and Undulating Agro-climatic region of West Bengal to find out the field efficacy of different fungicides against late blight of potato (cv. Kufri Jyoti). During 2014-15, among seven fungicides, Chlorothalonil 75% WP at 2 g/litre of water was recorded more efficacious. In 2015-16, three fungicides were evaluated in different doses to standardize the effective dose of Ethaboxam 40% SC and its bioefficacy in field condition against late blight of potato. Foliage and tuber infection were significantly lower and tuber yield recorded higher in Ethaboxam treatments when applied at 1.33 ml/litre of water. There were no significant differences between two different doses (1 ml and 1.33 ml/ litre of water) of Ethaboxam. Among eleven fungicides tested, Ethaboxam were also recorded superior in case of seed-tuber treatment-cum-spraying experiment.

Aim: To develop method for rapid and simple laboratory evaluation of fungicides against Phytophthora infestans, the causal pathogen of late blight of potato. Study Design: Descriptive statistics and analysis of variance. Each treatment was replicated thrice. Place and Duration of Study: Department of Plant Protection, Palli-Siksha Bhavana (Institute of Agriculture), Visva-Bharati, India in February, 2014. Methodology: Small portion of potato leaf tissue from advancing margin of late bight lesion is placed on water since Phytophthora infestans (Mont.) de Bary grow well in water producing hypha and sporangium. Using this property, performance of fungicides on mycelial growth and sporangia production/formation was assayed by placing a small bit of infected leaf tissue in different Short Research Article Mondal et al.; JSRR, 4(2): 168-173, 2015; Article no. JSRR.2015.019 169 concentration of fungicides. Results: Among the seventeen fungicides tested, chlorothalonil, fenamidone + mancozeb and tricyclazole inhibited mycelial growth and sporangia production but dimethomorph, tebuconazole + trifloxystrobin inhibited sporangia production only. Metalaxyl + mancozeb totally inhibited mycelial growth at higher concentration. Conclusion: This method can be useful for evaluating and comparing performance of different fungicides and even same formulations of a fungicide, produced by different companies within a very short time period. The experimental work can be completed within 48 –72h if late blight infected leaves are available.

Sclerotinia rot of Ocimum sanctum caused by Sclerotinia sclerotiorum has been recorded for last three years during winter season (2011–2014) at Kalyani, Nadia, West Bengal. The disease appeared in first week of December and progress of the disease continued up to the end of February. Drooping of leaves in one or more young twigs was the first symptom of the disease. Light brown discolouration on the twig and presence of white sclerotia might be associated with the initial symptom. Gradually more and more twigs were affected followed by death and drying of the infected twigs. In humid condition, prominent cottony white mycelia developed on the affected tissue. Towards end of February many plants became dead. Black matured sclerotia were found on the dead branches. On artificial inoculation the causal organism, Sclerotinia sclerotiorum infected fifty plants indicating that the pathogen did not have host specificity. But susceptibility of seventeen plants (Capsicum annum var. grossum, Trichosanthes dioica, Cucurbita pepo, Abelmoschus esculentus, Raphanus sativus, Trigonella foenumgraecum, Amaranthus tricolor, Portulaca oleracea, Pachyrrhizus erosus, Ipomoea batatas, Lathyrus sativus, Ricinus communis, Allium sativum, Foeniculum vulgare, Carica papaya, Chrysanthemum indicum, Chenopodium album) is recorded first time in India.

Incidence of Foot rot disease of Elephant foot yam [Amorphophallus campanulatus Blume, syn: A. paeoniifolius (Dennst.) Nicolson] caused by Sclerotium rolfsii Sacc. is common in West Bengal. Occasionally it causes severe damage of the crop. When Plaster of Paris used on the diseased tissue in standing crop, it showed strong adverse effect on mycelial growth and survival of sclerotia. White mycelia and sclerotia produced on disease tissue lost their viability. Plant with small lesion grew normally indicating that the disease was checked without causing any phytotoxic effect. Plaster of Paris of commercial grade (CaSO4.½ H2O), available in synthetic bag in hardware shop. In laboratory test on viability of sclerotia, Plaster of Paris showed similar adverse effect. Eight fungicides (Indofil M-45, Bavistin, Blitox, Vitavax Power, Kavach, Curzet, Krilaxyl MZ) used in this test reduced sclerotial germination. Vitavax Power (Carboxin 37.5% + Thiram 37.5% WP) totally inhibited sclerotial germination. Kavach (Chlorothalonil 75%) and Krilaxyl MZ (Metalaxyl 8% + Mancozeb 64%) reduced germination upto 95%. Application of Plaster of Paris at three different doses at the base of the plant (2.0, 5.0 and 10.0 grams/plant) did not cause any phytotoxic symptoms like necrosis, epinasty, hyponasty, wilting, leaf tip injury, leaf surface injury, vein clearing, rotting at collar region on six different crops i.e. elephant foot yam, groundnut, brinjal, chilli, basella and radish. Hence, it may be incorporated in Integrated Disease Management (IDM) programme.