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Open Access
Impact of physico-chemical properties and microbial dynamics of casing on sporophore development and yield of Calocybe indica P&C
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2009-06) Pandey, Vandana; Mishra, K.K.
White milky mushroom (Calocybe indica), is an edible mushroom having white sporophore, large sized fruiting body and delicious flavor. The ability of this mushroom to grow at temperature of about 30-350C, accompanied by its excellent shelf –life makes it highly attractive market venture among the growers. Milky mushroom cultivation involves a number of operations. Once the spawn run is complete, the crop enters into reproductive phase leading to production of fruiting bodies. Even after the colonization of substrate, fructification will not take place unless the colonized substrate is covered with casing layer. Several practical aspects pertaining to casing have also been determined. However, the exact nature of stimulus /stimuli created and imparted leading to sporophore development are not well understood. Investigations carried out all over the world have revealed that the presence and activities of microbial component in the casing layer, is one of the contributing factors. The question, whether the casing micro-flora have a direct effect on the vegetative growth within the casing layer or act indirectly by producing fruiting stimulus or other intrinsic or extrinsic factors, is not clear. Keeping in view the vast potential of microbial dynamics that too in relation to physico-chemical properties of casing, the objectives of present study were undertaken. The spawn of Calocybe indica was prepared on wheat grains using standard methodology. After spawn run, bags were cased with FYM+SC+SS (2:1:1) at different thickness to see the effect of thickness on yield. Different casing mixtures viz. FYM, FYM+SC (1:2), FYM+SC (2:1), SC, SC and FYM+SC+SS (2:1:1) were sterilized, with 4% formalin, autoclaved at 10, 15 and 20 psi and untreated was kept as check, to evaluate their effect on sporophore development and yield of Calocybe indica. These casing mixtures were collected at different time intervals and evaluated for the physico-chemical properties and casing microflora. Out of six casing thickness, 2.5 cm thickness resulted in significantly higher biological efficiency of Calocybe indica (39.4%). However, casing mixture FYM+SC+SS (2:1:1) gave significantly higher yield (368.06g/kg dry substrate). All the casing mixtures treated with 4% formalin resulted in significantly higher yield over other treatment. Among all the casing mixtures, bacterial populations were found to be maximum followed by pseudomonas and fungi and their pattern in different casing mixtures varied. In general, the microbial population increased upto 30 days of casing and thereafter it decreased. The casing mixture FYM+SC+SS (2:1:1) producing maximum yield was having pH 6.31, EC 196.07 deci-simen-1, 2.74% nitrogen, 0.62% phosphorus and 0.60% potassium. The physico-chemical properties (pH, EC, N, P and K) of different casing mixtures showed decline pattern with the advancement of the crop cycle. .
Open Access
Studies on post harvest diseases of mango: etiology and biological control
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2007-07) Gupta, Sonal; Singh, U.S.
India is the largest producer of mangoes and accounts for more than half of the world's production but it ranks third in mango export. Constraints like suitability of few varieties, short storage life, post-harvest pests and diseases etc. restrict the expansion of exports from India. Management of post harvest diseases has been mainly achieved by use of chemicals but due to public's growing health concern and limitation of use of chemicals for export purposes, we have been forced to look for alternative and safe measures for their control. The present work tries to identify the common post harvest diseases, their incidence, severity, varietal susceptibility, management with bioagents, in vitro antagonism studies and effect of bioagents on TSS and TA of fruits. Stem end rot, anthracnose, Rhizopus rot and black mold rot were the four commonly observed diseases. Gulab Khas, Alphonso and Bombay Yellow showed more susceptibility to post harvest while Dushehri, Lucknow Scrfeda and Malihabadi Safeda were relatively less susceptible. Significant in vitro inhibition of Rhizopus species was achieved by Trichoderma spp. and Pseudomonas fluorescens. Yet successful management of these diseases with post harvest fruit dips in bioagent suspensions could not be achieved when fruits were stored at ambient conditions. Langra fruits subjected to high R.H (95%, 30°C) for 12h just after dipping in suspension of biocontrol agents and then stored between 30-35°C, experienced significant reduction in post harvest rotting. In the same treatment significant difference in TSS values was recorded, maximum for P. fluorescens PBAP-28 and minimum for T harzianum PBAT-43. Thus it can be concluded that efficacy of bioagents can be increased under controlled conditions and probably their pre harvest spray will be more effective in managing post harvest diseases as compared to post harvest dips as it can allow their early colonization. In case of post-harvest dip in suspension of Trichoderma and Pseudomonas, storing of the treated fruits for 12 hours at high moisture might help biocontrol agents to multiply and colonize the fruit surface. This will enhance the efficacy of bioagents against post harvest rotting of mangoes. U.
Open Access
Screening of chemicals, botanicals and bioagents against Fusarium oxysporum, the cause of seed rot of soybean
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2007-07) Mehta, Priyanka; Vishunavat, Karuna
Soybean (Glycine max (L.) Merrill), a native of eastern Asia or China is an important pulse crop causing anthracnose, purple stain disease of soybean is one of the cause of lowered seed quality. Assessment of seed quality losses due to purple stain disease, detection of pathogen using different incubation methods, seed transmission and effects of different seed treatments with chemicals, botanicals and bioagents were studied. F. oxysporum was repeatedly isolated from purple stained seeds when subjected to different incubation methods. Czapek‟s Dox Agar medium yielded highest incidence of F. oxysporum followed by blotter method. The germination per cent and vigour index was decreased in infected seeds. These fungi resulted in more abnormal seedlings and seed rot. Germinating seedlings showed chlorosis on cotyledonary leaves followed by necrosis. Bavistin showed good germination per cent, more normal seedling and high vigour index at 500 ppm concentration. Amongst the botanicals, garlic extract reduced the fungal infection and decreased seed rot. However, these botanicals were significantly inferior to all chemical treatment used for seed treatment.
Open Access
Cultural studies and efficacy of fungicides and botanicals against Colletotrichum gloeosporioides Penz. the causal organism of guava anthracnose
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2007-06) Yadav, Manoj Kumar; Pradeep Kumar
Guava anthracnose caused by C. gloeosporioides is one of the most important disease of guava. Tarai and Bhabhar region of Uttrakhand and other parts of India. The disease appears on leaves, twigs and fruits and causes sever damage to the fruits during transportation and storage. Keeping in view the seriousness of the disease the present investigation was under taken on cultural character of the test pathogen evaluation of fungicides, botanicals and bio-agent against C. gloeosporioides in- vitro. The pathogen was able to grow in a wide range of synthetic, semi synthetic and natural medium, temperature and pH. Richard‘s medium supported best growth of test pathogen at a temperature of 250C and pH 6.5, respectively. Among the six fungicides evaluated against C. gloeosporioides, Topsin-M, Thiabendazole and Tilt @ 10ppm completely inhibited the growth. In-vitro efficacy of botanicals against the test pathogen, cold water extract of garlic @ 10 per cent was found most effective for complete growth inhibition followed by onion. Amongst the fungal bio-agent tested, Trichoderma viride was found effective inhibiting the growth (42.37per cent) while the bacterial antagonist, Pseudomonas fluorescens was found highly effective as it completely over lapped the growth of test pathogen by 6th day of incubation. The use of botanicals and bio-agent were found cheaper and would be environmentally safer alternative to the fungicides against guava anthracnose and they can explored commercially in Integrated Pest Management stetragy.
Open Access
Morphological and biochemical variability amongst parents and hybrids of oyster mushroom
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2008-06) Prasad, Meenakshi; Singh, R.P.
Oyster Mushroom (Pleurotus species) is one of the choice edible mushrooms grown in India as well as in World having high nutritive value and manifold uses. This mushroom contributes about 14.2 per cent of the total world mushroom production (6.16 million tonnes). However, share of this mushroom in mushroom production of India is hardly 6 per cent. Besides other factors, the strains play a most valuable role on yield and quality at diverse environmental conditions. Genetic manipulation of fungi is vital to meet the demand of the industrial world for fast growing and high yielding strains. The introduction of new strains through hybridization is thus required to maintain the production of quality mushroom. Considering the importance of strains in mushroom production, the present investigations were undertaken to identify and evaluate the parents and hybrids of Oyster mushroom in terms of qualitative (morphological and bio-chemical) and quantitative (yield) variability. A total of available species of ten parents and thirteen Pleurotus hybrids, finally five parents viz. P. sajor-caju (Fries) Singer, P. djamor (Fr.) Boedjin var. roseus, P. florida (Eger), P. flabellatus (Berk & Br.) Sacc, and H. ulmarius (Singer) and their four hybrids A1B5 (P. sajor-caju × P. djamor), A1C2 (P. sajor-caju × P. florida), A11D6 (P. sajor-caju × P. flabellatus) and F4H4 (P. florida × H. ulmarius) were selected on the basis of their yield and quality parameters. The selected parents and hybrids were studied for cultural variability on solid MEA medium. Mycelial growth rate of Pleurotus hybrids were recorded significantly higher or at par with their respective parents. Maximum growth (64.33 mm) and growth rate (8.04 mm/day) was recorded for the hybrid A1C2. Comparative colony characters were studied also on MEA medium viz. colony appearance, colour, shape, zonation, margin, exudates produced or not. The selected parents and hybrids varied significantly among themselves in terms of their colony characters. Macro-morphological & qualitative differences among the fruiting bodies of selected parents and hybrids were studied selecting ten fruit bodies randomly starting from first flush. Stipe length was found minimum in hybrid A1C2 (3.10 cm), Pileus length was found maximum in hybrid A11D6 (7.77cm) while Pileus width was found maximum in hybrid A1C2 (8.20 cm). On the basis of yield performance, the hybrid of P. sajor-caju × P. florida i.e. A1C2 found to be best by producing maximum yield (1536.90g/kg dry substrate) and fruit bodies (140.60 in number) followed by A11D6 hybrid of P. sajor-caju × P. flabellatus yield (1150.84 g/kg dry substrate) and fruit bodies (113.51 in number). The data of bio chemical constituents of the fruiting body of Pleurotus spp. (parents and hybrids) revealed that all the Pleurotus spp. contained low total soluble sugars (15.25-17.81 per cent on dry weight basis) and high protein content (23.42-28.75 per cent on dry weight basis). Amongst all, the hybrid of P. sajor-caju × P. florida i.e. A1C2 has lower total soluble sugars (15.25 per cent) and higher protein content (28.75 per cent).
Open Access
In vitro studies on Sclerotinia sclerotiorum (Lib.) de Bary cause of Sclerotinia rot of mustard
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2008-06) Goswami, Kiran; Tewari, A.K.
The oil seed crops especially rapeseed and mustard play a pivotal role in Agriculture economy of the world. Diseases and insects are among the most important factors in bringing down the acreage, production and productivity of the crop. Among diseases Sclerotinia rot of mustard caused by Sclerotinia sclerotiorum (Lib.) de Bary causes heavy losses and has become a serious problem since last few successive years. The pathogen produces creamy white to light brown colony with uniform and sparse mycelial growth which later becomes fluffy and compact with irregular margin. Brown to black, semi spherical sclerotia measured 4.35 × 3.25 mm in size were formed at the periphery of the Petriplates on PDA. Sterilized moist sand was found best for apothecia production at 20±10C. The plants inoculated with cut pieces of naturally infected plants showed significantly higher degree of infection under field condition. Slight variations in cultural and morphological characteristics were observed in S. sclerotiorum isolates collected from different Brassica species, pea, brinjal and Parthenium. Among eleven fungicides evaluated in vitro, thiophenate methyl and SAAF (carbendazim + mancozeb) were found best as they completely inhibited the mycelia growth of the pathogen at 250 μg a.i./ml; however, benomyl and carbendazim were found most effective in inhibiting sclerotia germination (100%) at 100 μg a.i./ml and 250 μg a. i./ml ,respectively in 15 minutes dip treatment. Complete parasitization of the fungus as well as sclerotial inhibition was observed with T.harzianum-T23, T-27 (Jammu) and T. viride 5-2 (IARI) after 8, 11 and 14 days of incubation, respectively. T. harzianum-T23 (Jammu) completely inhibited sclerotia germination by mycoparsitization. The culture filtrate of T. harzianum- T23 (Jammu) showed maximum mycelial growth inhibition (90%) and sclerotia germination (65%) at 50 and 100 per cent, respectively. T. harzianum-T23 (Jammu) released maximum quantity of secondary metabolites (liquid released during solid fermentation) and found effective in inhibiting mycelial growth (84.4%) and sclerotia germination (75%) at 50 and 100 per cent, respectively. The 4:1 ratio of CaSo4 and CaCo3 was found significantly superior in producing secondary metabolites (26 ml/150 g wet bajara grains).
Open Access
Studies on factors affecting the growth and multiplication of Colletotrichum musae (Berk and Curtis) Arx, the cause of banana anthracnose and its post harvest management
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2008-06) Geeta Devi; Pradeep Kumar
Banana anthracnose caused by Colletotrichum musae is one of the most important diseases of banana in Tarai region of Uttarakhand and other parts of India where bananas are grown. The disease appears on leaves and fruits and causes severe damage to the fruits during transit and storage. Keeping in view the seriousness of the disease the present investigation was under taken on cultural and physiological characters of test pathogen and evaluation of fungicides, botanicals and bio- agents against C. musae in- vitro. The pathogen was able to grow on a wide range of synthetic, semi-synthetic and natural medium, temperature and pH. Banana ripe agar medium and PDA supported best growth of test pathogen at 25°C and pH 6.0, respectively. Among the five fungicides Tilt @ 50ppm, Benomyl and Carbendazim @100ppm completely inhibited the radial growth, respectively. In- vitro efficacy of botanicals against test pathogen, extracts of Thuja @ 20 per cent was found most effective followed by Tulsi. Among the bio- agents tested, Trichoderma harzianum was found most effective inhibiting the growth (43.5 per cent). In the post harvest dip treatment among fungicides Tilt and Benomyl showed maximum increase in shelf life (11 days) of banana. Among the botanicals and bio- agents maximum increase in shelf life of banana was recorded when they were treated with Thuja @ 100 per cent (11days) and T. harzianum (10 days) for three minutes dip, respectively. The use of botanicals and bio- agents were found cheaper and would be environmentally safer alternative to the fungicides against banana anthracnose and they can be explored commercially in Integrated Pest Management Strategy.
Open Access
Studies on some aspects of maydis leaf blight of maize caused by Helminthosporium maydis Nisikado & Miyake
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2008-06) Abdul Nasir; Singh, Akhilesh
Maize (Zea mays L.) is one of the important cereal crops in the world agricultural economy as food for man and feed for animal. Maize does possess tremendous potential in terms of food as bread, pops and gruel, feed for dairy, poultry and piggery agro-industries. Maize is vulnerable to numerous diseases at various growth stages in the field as well as during storage. Among them, maydis leaf blight of maize (MLB) caused by Helminthosporium maydis is an important disease particularly in warmer maize growing areas and causes significant yield losses. Some chemical control measures against the disease are there but a global voice of integrated management has created a strong need to work upon other avenues of disease management along with chemical management. The experiments were conducted on study of morphological characters of the pathogen, in vitro screening of antifungal activities of plant extracts and fungicides against H. maydis, evaluation of various fertilizers doses on the severity of the disease, testing the efficacy of fungicides for management of maydis leaf blight and screening of germplasm against maydis leaf blight of maize to find out the source of resistance against the disease. Microscopic study of the test pathogen (H. maydis) was done for the morphological characters of the pathogen. Hyphae were branched, septate and sub hyaline. Olive brown to olivaceous conidiophores arose from these hyphae and emerged through the stomata singly or in groups of 2-3. The condiphores were simple, septate, erect and geniculate and measured 110-1796 μ in length and 6.2-10.8 μ in width. Conidia were light to olivaceous in colour and measured 30-112 x 10-16.5 μ. The dose of fertilizers i.e. NPK @ 100, 40, 40 kg/ha recorded minimum disease severity and maximum yield as compared to other combinations of NPK. Nine fungicides were tested for their fungicidal potential in vitro. Out of which propiconazole, chlorothalonil, triadimefon, mancozeb, saaf and thiram were found to be highly effective in reducing the radial growth of the pathogen. Seed treatment @ 4 g/kg of seed and one foliar spray with propiconazole or chlorothalonil significantly reduced the disease severity and increased the yield. Two foliar sprays at 10 days interval with propiconazole @ 0.1% or chlorothalonil @ 0.2% also significantly reduced the disease severity and increased the yield. Plant extracts of garlic (Allium sativum), onion (Allium cepa) and datura (Datura alba) were found to be highly effective in reducing the colony diameter of H. maydis at the concentration of 20%. Out of 256 genotypes evaluated under artificial inoculation conditions, only one germplasm (POB.33 C3 142-1-6-1-1-4) showed highly resistant reaction and 54 entries/varieties indicated moderately resistant to resistant reactions against maydis leaf blight of maize.
Open Access
Evaluation of certain biopesticides and fluorescent pseudomonads for their inclusion in ipm programme
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2008) Bhandari, Chandra Prabha; Kumar, J.
The sharp increase in the use of chemical pesticides in India in recent years has resulted in severe implications in the development of pesticidal resistance in key pest species, pesticidal residues in food chain and degradation in the quality of eco system and human health. It is therefore, important to identify alternatives to chemical pesticide in plant protection without sacrificing the productivity and profitability of agriculture. Among various non chemical options (host plant resistance, cultural, biological and integrated pest management), biopesticides which are target specific, eco friendly and biodegradable are potential alternatives to chemical pesticides and are known to exhibit antifungal activities against certain plant pathogenic fungi. In the present investigation studies were conducted to evaluate Azadirachtin formulations viz., Soluneem and Mycostat, Sodium bicarbonate, vermiwash and two fluorescent pseudomnads [ch-12 and ch- 18] obtained from mid gut of earthworm against nine potential test pathogens under in vitro conditions. The biopesticides were evaluated for their compatibility with bioagents in order to increase their action spectrum. The putative biopesticides were field evaluated against capsicum at six farmers’ fields in the Garampani vegetable belt in Distt. Nainital under natural infection conditions. In this belt, capsicum faces recurrent crop losses due to impact of diseases like root rot, collar rot and dieback. Under in vitro conditions, Mycostat (2000 ppm) resulted into complete inhibition of the radial growth of Sclerotium rolfsii and Sclerotinia sclerotiorum and recorded significantly higher inhibition against Rhizoctonia solani, Fusarium oxysporum and Fusarium solani. While Soluneem (600 ppm) recorded significantly higher inhibition against Helminthosporium oryzae and Fusarium oxysporum. Sodium bicarbonate (500 ppm) recorded complete inhibition of Sclerotinia sclerotiorum but at higher concentration (2000 ppm) Sodium bicarbonate recorded statistically significant inhibition against Rhizoctonia solani followed by Fusarium solani and Sclerotium rolfsii. It was found that Mycostat and Sodium bi carbonate both were fungistatic in their action. Trichoderma harzianum (th-43) showed some degree of compatibility with Mycostat at lower concentrations (1000-4000 ppm) but was incompatible at higher concentrations (6000 ppm). The bioagent showed relatively less sensitivity with Soluneem and Sodium bicarbonate thus could be considered compatible with Soluneem and Sodium bi carbonate. Combination of Sodium bicarbonate and th-43 completely inhibited the mycelial growth of Sclerotinia sclerotiorum, Sclerotium rolfsii, and Rhizoctonia solani however th-43 alone found was found to give lesser inhibition. Combination of Soluneem (600 ppm) and th-43 was highly significant in inhibiting the mycelial growth of Helminthosporium oryza and Fusarium oxysporum while th-43 alone inhibited less growth. Pseudomonas fluorescence (strain ch-18) was found to be highly significant in inhibiting the radial growth of Helminthosporium oryza and Pyricularia grisea and was also significantly effective against Colletotrichum capsici, Fusarium solani , Sclerotinia sclerotiorum, Sclerotium rolfsii, Fusarium oxysporum, Rhizoctonia solani and Colletotrichum graminicola. Pseudomonas fluorescence (strain ch-12) was highly significant in inhibiting the radial growth of Helminthosporium oryzae, Colletotrichum capsici and Pyricularia grisea and was also significantly effective against Rhizoctonia solani, Sclerotinia sclerotiorum, Fusarium solani, Fusarium oxysporum, Sclerotium rolfsii and Colletotrichum graminicola In vitro testing of vermiwash (1kg vermicompost extracted in 1 lit water) against different plant pathogens gave max reduction in dry weight of mycelium against Sclerotium rolfsii but was not much effective against other pathogens. In the field trials, five treatments viz. root dipping in Bavistin (0.05%) + Dithane M-45 (0.25%), root dipping in Soluneem (0.05%), root dipping in Mycostat (0.5%), root dipping in PBAT-3 (Trichoderma harzianum + Pseudomonas fluorescens (0.8%), and root dipping in Sodium bicarbonate (0.8%) were evaluated against capsicum. After 30 days of transplanting, maximum plant stand and minimum per cent disease was recorded in Soluneem (0.05%) followed by Mycostat (0.5%). After 45 days of transplanting maximum no. of plants in branching stage and maximum average plant length was also recorded in Soluneem (0.05%) and Mycostat (0.5%) as compared to other treatments. At 60 days of transplanting minimum % loss due to diseases was recorded in Mycostat (0.5%) followed by Soluneem (0.0.5%) proving the supremacy of the two biopesticides i.e., Soluneem and Mycostat in disease management and giving better plant growth. The study revealed that the two Azadiractin based biopesticides, Soluneem and Mycostat, hold promise in reducing field losses in capsicum but need further evaluation in other vegetables before inclusion in the biointenssive IPM programme.

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