Influence of bee pollination on quality and quantity of onion (Allium cepa L.) seed

The activity of bees pollination in onion was observed throughout the day. Numerically maximum activity was observed during afternoon hours (12.00 to 2.00 PM) with 7.00 numbers in rock bee, 5.40 in Indian bees, 11.60 in little bees and 7.80 in case of dammer be, respectively. Among the four species of bees, little bees were more in entire day with highest of 111.60 bees/10 inflorescence/ minute followed by dammer bee with 9.40 bees/10 inflorescence/ minute, Among the bees major contributor was little bee, this may be due to more colonies of little bees in that area and destruction of rock bee colonies. Also, the bee acitivty was observed maximum number at 100 per cent flowering stage. The observations on number of seeds per umbel, 1000 seed weight and per cent germination under the laboratory conditions. The results clearly indicated that, maximum number of seeds per umbel was observed in open pollinated flowers with 339.30 ± 60.27 seeds per umber where all the four species of bees were made visits regularly followed by in case of pollination in mesh cloth cage with bees with 330.00±35.80 and very least number of seed set was observed in case of pollination in mesh cloth cage without bees with only 60.70 seeds/umbel. Similarly, 1000 seed weight also differed significantly in case of pollination with bees and without bees. In case of with bees it weighed around 3.37 g/1000 seeds followed by 3.10 g/1000 seeds in onion with bee cage and least in case of control with only 1.97 g/1000 seeds.

Management of purple blotch of onion caused by Alternaria porri by using some novel fungicides under field condition in western Odisha

A field experiment was conducted at Regional Research and Technology Transfer Station, OUAT, Chiplima, Sambalpur, Odisha, India for the management of purple blotch of onion. From the experiment it was found that all the treatments were effective to reduce the severity of the disease as compared to untreated control. Among the treatments, seed treated with Carboxin 37.5%+Thiram 37.5%@ 2g/kg and three foliar sprays of Trifloxystrobin + Tebuconazole @0.4g/l of water at 10 days interval starting from initiation of the disease was most effective in reducing the purple blotch disease of onion (69.5% disease control) and was closely followed by seed treated with Carboxin 37.5%+Thiram 37.5% @ 2 g/kg and three foliar sprays of Tebuconazole @ 1.0ml/l of water (62.3% disease control). A maximum increase of yield (83.4%) with highest cost benefit ratio (1.97) was also achieved with the same treatment.

Screening of sesame genotypes against powdery mildew disease caused by Erysiphe cichorecearum

Powdery mildew disease of sesame occurs on epidemic scale in areas of high rainfall and humidity coupled with low night temperature causing considerable yield losses. Use of host plant resistance is the practical approach to manage this disease, but proper resistance sources with combining ability for the trait are unknown. Hence, an experiment was conducted to determine resistance in sesame genotypes against powdery mildew disease. Among the twenty four genotypes screened, none was found resistant while, nine genotypes exhibited moderately resistant to tolerant reaction and 15 genotypes exhibited susceptible reaction. Apparent rate of infection value varied and at times they did not remain consistent for given genotype and also did not show a particular trend which is attributed to genetic character of the genotype. The AUDPC values differed considerably for different genotypes. The values of AUDPC and apparent rate of infection of susceptible varieties were high as compared to moderately susceptible varieties. Genotype ‘JLS-302-11’ and ‘JLT-7’ having minimum AUDPC and apparent rate of infection value showed lowest intensity of powdery mildew while, genotype ‘JLT-408’ having maximum AUDPC and apparent rate of infection value showed highest intensity of powdery mildew.

Growth and yield of oyster mushrooms (Pleurotus spp.) on organically amended agro wastes

The present experiment was conducted to identify the best organic amendment on the growth and yield of five species of oyster mushrooms viz.,Pleurotus florida, P. sajor-caju, P. eous, P. tuber-regium and Hypsizygus ulmarius by using organic amendments like rice bran, dry azolla, Neem cake, vermiwash and dry biogas slurry at three different concentrations. The effect of organic amendments on the number of days for sporophore formation, number and weight of sporophores varied according to the mushroom species. Results revealed that except dry biogas slurry, all organic amendments had superior effect in reducing number of days for sporophore formation, increasing the number of sporophores and yield. Effect of organic amendments on the yield of oyster mushrooms showed that all organic amendments except dry biogas slurry performed well with more number and weight of sporophores. The number of days for sporophore formation varied between 16.5 to 20.8 days in P. eous, 19.5 to 39 days in P. tuber-regium and 17.5 to 36.8 days in H. ulmarius. In P. florida and P. eous highest yield of 350.3g and 379g, respectively obtained from paddy straw amended with 1 per cent Neem cake. P. sajor-caju gave the maximum yield of 405.3g in 5 per cent rice bran. The maximum yield of 134.8g was recorded in P. tuber-regium when treated with 4 per cent rice bran whereas paddy straw amended with 6 per cent dry azolla gave highest yield of 218.3g in H. ulmarius.

Evaluation of bio-efficacy of new fungicide molecule- Ametoctradin 300 g/l + dimethomorph 225 g/l sc against downy mildew of grapes in Northern Karnataka

A field experiment was conducted to evaluate the efficacy of ametoctradin 300 g/l + Dimethomorph 225 g/l sc against downy mildew disease of grapes for 2 seasons at Agricultural Research Station Bagalkot district. It was found that Ametoctradin 300 g/ l + Dimethomorph 225 g/l sc is highly effective in reducing the downy mildew disease in grapes. Further the phytotoxicity was not observed in the chemical Ametoctradin 300 g/l + Dimethomorph 225 g/l sc to the treated plots of grapevine even at high doses and also exhibiting an appreciable increase in grape berry yield.

Isolation and evaluation of rhizobacteria against Ralstonia solanacearum the incitant of bacterial wilt of tomato

Bacterial wilt caused by Ralstonia solanacearum is the world’s most economically important destructive disease of crop plants. In the current study, we aimed to evaluate the novel bacterial isolates from tomato rhizosphere for biocontrol of Ralstonia solanacearum. One eighty bacterial strains were isolated from the tomato rhizosperic soils collected from different regions of Uttarakhand state and evaluated for their biocontrol activity against R. solanacearum under in vitro conditions. Among them, six isolates were found to be highly effective in inhibiting the growth of R. solanacearum. The isolate GP2NA8 produced the highest inhibition zone followed by that of GP1NA2 and GP3NA6.

Management of powdery mildew of cluster bean through fungi toxicants

Leveillula taurica causes severe powdery mildew on all aerial parts of cluster bean plant. The objective of the present work was to identify potential methods for managing cluster bean powdery mildew through fungicides. Field trials were conducted during Kharif 2019 and 2020 to evaluate the efficacy fungicides. Nine systemic fungicides were tested both under in-vitro and in-vivo conditions against cluster bean powdery mildew disease. In vitro evaluation of fungicides revealed that complete inhibition of conidial germination was observed in all systemic fungicides at 0.1 per cent concentration. However, under field conditions, penconazole at 0.05 per cent was found to be best fungicide which recorded least incidence 3.66 per cent followed by hexaconazole (5.83%) and propiconazole (6.83%).

Pathophysiology of Fusarium oxysporum f. Sp. Dianthi in carnation (Dianthus caryophyllus L.)

The bio-chemical changes occurred in the carnation after inoculation with F. oxysporum f.sp. dianthi was studied under in vitro. Carnation plants inoculated with fourteen isolates of F.oxysporum f.sp.dianthi and monitored for their ability to production of fungal pectin-degrading enzymes viz., Pectin Methyl Esterase (PME), Polygalacturonase (PG) and Pectin Trans Eliminase (PTE) involved in development of disease symptoms. Production of pectinolytic enzymes in carnation plants were assessed from 2 days up to 8 days after inoculation at 48h intervals. The accumulation of these enzymes increased in two days after inoculation and attained a peak at six days after inoculation and slowly declined thereafter in all the inoculated plants. Among the fourteen isolates, YRPFOD2 had maximum ability to increase the activity of pectinolytic enzymes viz., Pectin Methyl Esterase (0.49 μ mole hydrogen ion / min / ml), Polygalacturonase (16.11% reduction in viscosity) and Pectin Trans Eliminase (57.59 % reduction in viscosity) after six days of inoculation in infected plants.

Stem borer incidence in maize

Field experiment was conducted at Maize Research Centre, Rajendranagar by undertaking sowings at monthly intervals from January to December during two years 2013 and 2014. Observations on stemborer incidence was recorded at 45 DAG and subjected to analysis after angular transformation. June sown crop had lowest infestation of 2.83 per cent followed by December (3.35%) and May (3.69%) sown crops and all were significantly on par. Dead hearts were low in April, May and December sown crops i.e., 0.11 per cent, 0.15 per cent and 0.55 per cent, respectively and all were on par with each other. Highest per cent dead hearts were in Sep. sown crop (7.67%).

Diseases, moulds, insect-pests and mites of mushroom

Mushroom is defined as macro-fungus with distinctive edible fruiting body which can be either epigeous or hypogeous. Cultivation of edible mushrooms carries great relevance in todays’ world in the context of a burgeoning population growth and extreme pressure on the environment. Mushrooms are highly nutritious and environment friendly crops that carry numerous medicinal benefits. The intensive cultivations of edible mushrooms can often be affected by several insect-pests and diseases caused by fungi, bacteria, viruses, nematodes etc. that rather frequently cause dramatic production loss. The market price of edible mushrooms is also reduced due mould’s contaminations. These infestations, infections and contaminations are facilitated by the particular environmental conditions under which mushroom cultivation is commonly carried out. There is not much bibliographic information related to such stresses of mushrooms and their management. The updated review presents a practical checklist of diseases and pests of the mushroom, providing useful information that may help different users.