Munmi Borah | Asssam Agricultural University (original) (raw)

Papers by Munmi Borah

The objective of this study was to identify pathogenic diseases of economically important floricu... more The objective of this study was to identify pathogenic diseases of economically important floricultural crops based on visual inspection and microscopic observation carried out during 2017-18 in and around Jorhat district of Assam. During the investigation, 3 diseases of chrysanthemum (2 fungal, 1 viral); 3 diseases of gladiolus (all fungal); 5 diseases of gerbera (all fungal), 2 diseases of rose (all fungal) and a fungal disease of marigold was identified. The diseases identified in chrysanthemum were alternaria leaf spot, sooty mould and mosaic disease. The diseases identified in Gladiolus were fusarium infection, alternaria leaf spot, curvularia leaf spot and corm rot. The diseases identified in gerbera were alternaria leaf spot, cercospora leaf spot, damping off, stemphylium infection and coniothyrium infection. Diseases identified in rose were alternaria leaf spot and cercospora leaf spot. In marigold, alternaria leaf spot was indentified causing infection to the crop. Overall pathogenic disease incidence of flower crops recorded as 60.41% in Chrysanthemum, 45.83% in Gladiolus, 55.55% in gerbera, 47.22% in rose and 45.83% in marigold. Area wise maximum disease incidence (61.11%) was observed in Borbheta area followed by Bahona(58.33%). Lowest disease incidence was recorded in Sungi (27.77%) in Jorhat district.

Field surveys were carried out in 8 citrus growing districts of Assam (Tinsukia, Lakhimpur, Jorha... more Field surveys were carried out in 8 citrus growing districts of Assam (Tinsukia, Lakhimpur, Jorhat, Kokrajhar, North Cachar Hills, Karbi Anglong, Golaghat and Kamrup). Altogether 411 samples were collected from three different citrus species, viz., Assam lemon (Citrus limon), Gul nemu (Citrus jambhiri) and Khasi mandarin (Citrus reticulata). Typical symptoms of CTV (Citrus tristeza virus), namely, leaf yellowing and vein clearing were prominent. Incidence of CTV was more in matured and older plants. Survey results indicated prevalence of the vector Toxoptera citricida and Toxoptera aurantii in this region. The samples were tested for the presence of CTV by double antibody sandwich-enzyme linked immuno-sorbent assay (DAS-ELISA). The results showed 261 trees infected with CTV indicating 63.50 per cent diseases incidence in Assam. Results revealed presence of CTV in all the surveyed districts of Assam showing a high incidence of 78.04 per cent CTV infection in Karbi Anglong districts followed by 76.92 per cent in Golaghat district. Among the different citrus species Assam lemon showed a significantly high CTV infestation of 76.47 per cent followed Khasi mandarin (61.18%) and Gul nemu (52.03%). The results of DAS-ELISA revealed that in all the three different citrus species Assam lemon, Gul nemu and Khasi mandarin the percentage of positivity is more in the higher age group viz. > 15 years and 10-15 years followed by lower age group (<10 year old plants). This indicated prevalence of CTV was more in older plants.

Infection of Citrus tristeza virus (CTV) in Assam was detected by double antibody sandwich-enzym... more Infection of Citrus tristeza virus (CTV) in Assam was detected by double
antibody sandwich-enzyme-linked immuno-sorbent assay (DAS-ELISA). Field surveys were
carried out in 8 citrus growing districts of Assam (Tinsukia, Lakhimpur, Jorhat, Kokrajhar,
North Cachar Hills, Karbi Anglong, Golaghat and Kamrup). Altogether, 411 samples were
collected from three different citrus species, viz., Assam lemon (Citrus limon), Gul nemu
(Citrus jambhiri) and Khasi mandarin (Citrus reticulata) to test against CTV. Results of ..............

Field surveys were carried out in 8 citrus growing districts of Assam. Altogether 411 samples wer... more Field surveys were carried out in 8 citrus growing districts of Assam. Altogether 411 samples were collected from three different citrus species, viz., Assam lemon (Citrus limon), Gul nemu (Citrus jambhiri) and Khasi mandarin (Citrus reticulata). The symptom expression on the indicator host was observed from 5th week to 9th week after inoculation. The DAS-ELISA results showed 261 trees infected with CTV indicating 63.50 per cent diseases incidence in Assam. Results revealed presence of CTV in all the surveyed districts of Assam showing a high incidence of 78.04 per cent in Karbi Anglong followed by 76.92 per cent in Golaghat district. Lowest incidence of CTV was recorded from Kamrup (38.63%). Among the different citrus species Assam lemon showed a significantly high CTV infestation of 76.47 per cent followed Khasi mandarin (61.18%) and Gul nemu (52.03%). The results of DAS-ELISA revealed that in all the three different citrus species Assam lemon, Gul nemu and Khasi mandarin the percentage of positivity is more in the higher age group viz. < 15 years and 10-15 years followed by lower age group (>10 year old plants). This indicated prevalence of CTV was more in older plants