Directorate of Plant Protection, Quarantine and Storage Department of Agriculture and Cooperation Ministry of Agriculture Government of India
amamk@rediffmail.com
Dr. Mohd. Mahmud Khan was born on 19th March 1980 in Imphal, Manipur, India and the second son of Aashiya Bibi and Late Mohd. Abdul Rahim Khan. He received his B.Sc. Degree in Botany Honours from the Department of Botany, Faculty of Life Sciences, Aligarh Muslim University in 2001. He completed M.Sc. (Ag.) Plant Protection in 2003 and obtained Ph.D. (Ag.) in Plant Protection from the Department of Plant Protection, Faculty of Agricultural Sciences, Aligarh Muslim University, India in the year 2011. He had worked with Dr. M R Khan as Junior Research Fellow (JRF) in DST Research Project and R&D Scientist (Product Development and Regulatory Affairs) in United Phosphorus limited. Recently, he has been appointed as PPO (Plant Pathologist) in the Directorate of Plant Protection, Quarantine and Storage, Department of Agriculture and Cooperation, Ministry of Agriculture, Govt. of India. Dr. Khan has published about 20 research paper and 2 review articles on various aspects of Plant Pathology and Nematology. His area of research is effect of environmental pollutants on the development of diseases on plant and Integrated Disease Management in crop protection.
Abstract: The study demonstrate morphological and physiological variations in isolates of Alternaria brassicae and to evaluate the efficacy of fungicide (in vitro) on radial growth of the fungus and foliar sprays (field) against the disease severity on rapeseed-mustard. Morphological variations of A. brassicae obtained from various places were differed in their conidial size and septation. Physiological response of A. brassicae at varying temperatures, the fungus showed its maximum growth at 25°C followed 20°C and on different culture medium, maximum radial growth is on PDA. However, the fungus exhibited a descending trend in its growth at lower and higher regimes of temperature. Among the non systemic and systemic fungicides evaluated in vitro on radial growth inhibition of A. brassicae were found significantly most effective and reduced maximum radial growth at higher concentration. All fungicidal sprays applied under field conditions to manage the incidence of blight reduced significantly the severity of the disease and increased yield in comparison to untreated control. Ridomil-MZ proved to be most effective. Highest net profit as well as cost : benefit ratio was Bavistin + Indofil-Z 78.
Abstract: Trichoderma harzianum, T. viride, T. virens and Aspergillus niger were isolated from mustard leaf
surface. Efficacy of their conidial suspension and culture filtrates was evaluated. In dual culture test, T. viride
caused maximum inhibition of radial growth of A. brassicae (74%) and A. brassicicola (77%). Highest
concentration (3:1) of T. viride culture filtrates caused 60 and 54% inhibition of radial growth of A. brassicae
and A. brassicicola, respectively. The culture filtrates of T. viride at their highest concentration (3:1) caused
71 and 69% inhibition of conidial germination of A. brassicae and A. brassicicola, respectively. In field trial
foliar spray of 1×107 conidia mLG1 of biological control agents was done on mustard plants 24 h after artificial
inoculation by A. brassicae conidial suspension (1×105 conidia mLG1. Viability of BCAs was recorded upto 30
days in phylloplane of mustard at relative humidity between 80-90% and temperatures between 20-25°C.
T. viride proved to be most effective as its conidial suspension caused upto 76 and 68% reduction in disease
intensity on leaves and pods, respectively. Whereas, its culture filtrate caused 45 and 36% reduction in disease
severity on leaves and pods, respectively. These results suggested that T. viride can be used to control
Alternaria blight disease of mustard.
Abstract: A pot experiment was conducted to evaluate the sensitivity of chickpea, Cicer arietinum
cv. T-3 to nickel and cobalt at 0, 10, 50, 100, 200 and 400 ppm concentrations. The bacterized seeds
of chickpea were sown in 15 cm clay pots containing 1.5 kg steam sterilized soil. Before the sowing
550 ml metal solution of different concentrations was added per pot. Nickel and cobalt at the higher
concentrations (100-400 ppm) were found injurious to chickpea. Seed germination, plant growth and
biomass production were adversely affected. Root nodulation was suppressed and number of functional
nodules appreciably decreased. Leaf chlorophyll contents were greatly reduced. These adverse impacts
reflected in reduced yield of the plants. Nickel was apparently more harmful than cobalt to chickpea.
The study suggests that cultivation of crops like chickpea in metal polluted soils should be avoided
or appropriate control measures be adopted to maintain the heavy metal content of the soil below the
damage threshold levels, which was found to be 10 ppm Ni and 50 ppm Co for chickpea.
Abstract: The common Indian mustard cultivars, Mahyco Bold, Rohini, Alankar, Swarna, Varuna, Pusa Karishma, Pusa Bold, BS-2, Kalamoti and Kranti procured from authorized dealer in Aligarh were found infected with Alternaria brassicicola and A. brassicae, former being highly dominant occurring singly and concomitantly while A. brassicae was found mostly in concomitant infestation. Due to dominant occurrence of the species, germplasm was screened against A. brassicicola using artificial inoculation by spraying foliage with pure spore suspension of the fungus. The fungus inoculation resulted to necrotic lesions on 15-70% leaves, stem and/or pods of all the cultivars tested. Development and progress of the blight was slower in Alankar (15-23%) followed by Kalamoti (16-25%) and Kranti (18-28%). All cultivars screened were found susceptible to A. brassicicola as inoculation with the fungus resulted to significant decline in the yield of all cultivars being greatest in cv Pusa Karishma (50%) followed by Kalamoti (46%) and lowest in Kranti (14%) in comparison to uninoculated control. Highest population of the fungus was recorded on leaves (20.0-37.0 x 105spores/cm2) followed by stem (8.0-15.0 x 103 spores/cm2) and pods (4.0-14.0 x 103 spores/cm2) and lowest on seeds (1.0-3.0 x 102 spores/seeds). Two cultivars viz., Kranti and Alankar were found less susceptible to A. brassicicola and can be cultivated in a situation of non availability of resistant/tolerant cultivars.
Abstract: Three systemic fungicides: Topsin-M (Thiophanate methyl, 70%WP), Ridomil MZ (Mancozeb, 64% +
Metalaxyl, 8%WP), and Bavistin (Carbendazim, 50%WP) alone and in combination with four non-systemic fungicides
Captaf (Captan, 50%WP), Indofil M-45 (Mancozeb, 75%WP), Indofil Z-78 (Zineb, 75%WP), and Thiram (Thiram,
75%WP) were evaluated both in vitro and in vivo for their effectiveness to manage Alternaria blight of rapeseedmustard
caused by Alternaria brassicae. A pure culture of the pathogenic fungus was applied in the field at 2 g
colonized sorghum seeds kg-1 soil. All the fungicides were evaluated for their efficacy at various concentrations, 50,
100, 150, 200 and 500 ppm, and were sprayed in the field at 0.2% a.i. l-1. All fungicides significantly reduced the
severity of the disease but Ridomil MZ was most effective. Topsin-M at a concentration of 500 ppm was the most
effective in reducing radial growth of the pathogenic fungi (74.2%). Ridomil MZ reduced disease severity by 32% and was followed in effectiveness by the combination Bavistin+Captaf (26.5%). Maximum yield was obtained in plots
sprayed with Bavistin+Captaf (1198 kg ha-1) followed by Bavistin+Indofil Z-78 (1172 kg ha-1). It was worth noting
that the highest net profit as well as the highest cost-benefit ratio was obtained with Bavistin+Indofil Z-78 (1:3.2),
followed by Bavistin+Captaf (1:1.3).
