Papers by Salik Nawaz Khan
Wuhan University Journal of Natural Sciences
Rice exhibits a significant share as a part of human food globally as well as in Pakistan. So, it... more Rice exhibits a significant share as a part of human food globally as well as in Pakistan. So, it is necessarily important to cope with the ever increasing food requirements through high yield of quality rice by cultivating improved varieties. In conventional conditions where farmers by themselves also prepare there seed from the best lot of standing crop for the upcoming season. In spite of the awareness of the importance of quality seed undesired biological and inert material contamination is experienced. Therefore sample drawn from commercial lots was evaluated against microbial and inert matter contaminants. Test material comprising on five commercial fine and course varieties exhibited wide range of variation in their susceptibility response. The seeds of IR-06 had considerable less inert matter (0.57%), followed by Basmati Super (0.67%), Basmati-2000 (0.85%), KS-282 (2.14%) and KSK-133 (3.28%). Basmati Super possessed highest germination potential of 96% in comparison with Basmati-2000 (92%), IR-06 (86%), KSK-133 (82%) and KS-282 (80%). The 1000 seeds weight of KS-282 was 24 g; while, the KSK-133, IR-06, Basmati Super and Basmati-2000 had 23, 23, 22.5 and 22.5 g; respectively. The comparative study of root and shoot length showed homogenized results, as 4 out of 5 varieties recorded average shoot length up to 15 cm. The remaining one variety (IR-06) was with quite dwarf seedlings. In case of root length again IR-06 was least in its length comparitively; while, the rest having average root length not less then 6.5 cm. KSK-133 atained the maximum average root length of 10 cm. Keen analysis of seed associated mycoflora was resulted in the isolation of Aspergillus flavus, A. niger, Penicillium sp., Alternaria spp., Fusarium spp. and A. fumigatus. Moreover study would help the producers for selection of suitable variety in their fields.
Pakistan Journal of …, 2009
Grain discoloration disease of rice is becoming a serious threat to rice crop in Pakistan. Rice p... more Grain discoloration disease of rice is becoming a serious threat to rice crop in Pakistan. Rice panicles infested with grain discoloration disease were collected from rice areas of NIAB, Faisalabad, Sheikhupura, Samundri, PirMahal and Vehari. Eight pathogens namely ...
African Journal of Biotechnology, Jul 31, 2010
Two pot experiments were conducted to investigate the potential of different plant materials to m... more Two pot experiments were conducted to investigate the potential of different plant materials to manage the corm rot disease of gladiolus (Gladiolus grandiflorus sect. Blandus cv. Aarti) caused by Fusarium oxysporum f.sp. gladioli (Massey) Snyd. & Hans. In the first experiment, leaves of five allelopathic plant species viz. Eucalyptus citriodora Hook, Syzygium cumini (L.) Skeels, Coronopus didymus (L.) Smith, Chenopodium album L. and Cyperus rotundus L. were incorporated in the soil at 2, 4 and 6 g 100 g-1 of soil. In the second experiment, leaves of five plant species namely Azadirachta indica A. Juss., Alstonia scholaris (L.) R. Br., Parthenium hysterophorus L., Ageratum conyzoides L. and Allium cepa L. were spread on the surface of the pot soil at 4 g 100 g-1 of soil. All the leaf incorporation and spreading treatments significantly reduced the disease incidence and number of infection lesions on corms. Incorporation of all the dosages of 2-4% of C. rotundus significantly enhanced shoot biomass. Similarly 2% E. citriodora and 4-6% C. album incorporation also enhance shoot biomass significantly over Fusarium control. All the leaf spreading treatments significantly enhanced shoot length and biomass. The present study concludes that corm rot disease of gladiolus can be effectively managed by using allelopathic plants.
AFRICAN JOURNAL OF BIOTECHNOLOGY, 2012
Field trials were conducted at a farmer's field in Talagang (Chakwal) in 2009 to evaluate the eff... more Field trials were conducted at a farmer's field in Talagang (Chakwal) in 2009 to evaluate the effect of manuring on root rot disease caused by Fusarium solani and agronomic characters of groundnut (Arachis hypogeae L.). The experiment was comprised seven treatments viz. (i) Control (no amendment and no inoculation); (ii) F. solani (FS)-inoculated control; (iii) poultry manure + FS; (iv) farmyard manure + FS; (v) cattle manure + FS; (vi) Brassica campestris straw + FS; (vii) Cicer ariantum straw + FS. In the Fusarium inoculated control, disease incidence and plant mortality was 85 and 22.2%, respectively whereas, disease incidence and plant mortality were both 0% in non inoculated control. All the manuring treatments managed the disease to variable extent and influenced agronomic characters of groundnut. Poultry manure was the most effective in disease management followed by cattle manure.
Weeds act as alternative host of many plant pathogens as they serve source of over-wintering for ... more Weeds act as alternative host of many plant pathogens as they serve source of over-wintering for a wide range of pathogens and effects on all aboveground parts of the plant. Perennials weeds play important role in the spreading of obligate pathogens. Among the prevalent diseases caused by obligate fungal pathogens, powdery mildew is counted in most common diseases especially for vegetables and ornamental plants in Pakistan. The pathogens Erysiphe cichoracearum, Sphaerotheca fuliginia, and Leveillulata urica have been reported on Convolvulus arvensis, Argemone mexicana, Rumex obtusifolious and Rumex dantatus, Euphorbia hirta, Conyza ambigua, Cucumis melo var. Agrestis and Chenopodium murale in Lahore, Faisalabad, Gujranwala and Sheikhupura districts of Central Punjab. Distribution assessment on a visual 0-5 visual rating scale was recorded at 4 severity rating on C. arvensis, while other weeds showed intermediate reaction except C. melo proved highly resistant against powdery mildew.
Indian Journal of Pharmaceutical Sciences, 2008
Prabhakar, et al.: Anticandida activity of some plant extracts Seventy fi ve patients with oral l... more Prabhakar, et al.: Anticandida activity of some plant extracts Seventy fi ve patients with oral lesions attending the different departments of Rajah Muthiah Medical College and Hospital, Annamalai University were screened for Candida. Forty six (61.3%) Candida strains were isolated from the oral lesions. Of the 46 Candida strains, Candida albicans accounted for 35 (76.08%), Candida glabrata for 5 (10.86%), Candida tropicalis and Candida krusei for 2 (4.34%) each and Candida parapsilosis and Candida guilliermondii for one (2.17%) each. Antifungal activity of ethanol extracts of fi ve plant species that included Syzygium jambolanum, Cassia siamea, Odina wodier, Momordica charantia and Melia azedarach and two algal species, Sargassum wightii and Caulerpa scalpelliformis were tested against 25 isolated strains by disc diffusion method. Antifungal activity was observed at 100 mg/ml for Syzygium jambolanum, Cassia siamea and Caulerpa scalpelliformis and at 10 mg/ml for Sargassum wightii.
Macrophomina phaseolina has a wide host range and is responsible for causing losses on m cultivat... more Macrophomina phaseolina has a wide host range and is responsible for causing losses on m cultivated and wild plant species. So far in Pakistan it has been reported to cause disease on hosts including field crops, pulses, flowers and vegetable have been reported. Infection on s first reported from Sri Lanka in 1927 and in 1982 it was reported from sunflower field in fungus is reported to be soil, seed and stubble borne. The fungus can survive for more th under dry soil conditions. The severity of the disease is directly related to the population of v in the soil. The pathogen generally affects the fibrovascular system of the roots and basal in parasitic fitness of a facultative soilborne pathogen before invading the host is linked with compete for its survival, utilization of organic sources and colonization in the host root r competing other microorganism in the vicinity.
District Kasur is the hub of Gladiolus cultivation in Punjab, Pakistan. Field surveys from 12 loc... more District Kasur is the hub of Gladiolus cultivation in Punjab, Pakistan. Field surveys from 12 localities of the district were undertaken during 2005-06 and 2006-07 to study the distribution of various weed species in Gladiolus fields. Sixty weed species belonging to 24 angiospermic families were found growing in the fields of Gladiolus. Ageratum conyzoides L., Amaranthus viridis L., Coronopus didymus (L.) Sm., Chenopodium album L., Chenopodium murale L., Convolvulus arvensis L., Cypreus rotundus L., Cynodon dactylon Pers., Poa annua L., Oxalis corniculata L., Rumex dentatus L., Melilotus parviflora, L. Cenchrus pennisetiformis Hochest and Eragrostis poaeoides Beauv. were found to be the most prevalent weed species occurring in 90% or more studied areas during one or the other growing season. Frequently occurring weeds with absolute frequency above 40% were C. didymus, C. arvensis, R. dentatus, C. pennisetiformis and C. dactylon. R. dentatus was found to be the most frequently occurr...
Six commercial and 20 candidate line of sesame were screened during 2012-2013 against M. phaseoli... more Six commercial and 20 candidate line of sesame were screened during 2012-2013 against M. phaseolina. Resistance response of Sesame germplasms was determined in pots and field under natural conditions. Sick field was prepared by mixing test pathogen at the rate of 0.4% on the upper soil layer. Observation regarding resistance reaction of test germplasms was recorded by observing charcoal rot incidence at maturity using 0-9 visual rating scale. Results demonstrated variation in response of test germplasms to charcoal rot and none of the variety or line was found immune. In pot experiment seventeen varieties/lines were highly susceptible, three were moderately resistant while six varieties/lines showed susceptible reaction. On the basis of varietal response in pot experiment nine varieties were selected for screening in field experiment against M. phaseolina. The only line that exhibited 1-10% mortality in field was 87008, lines 87502 and 95002 were moderately resistant while 20011, blacktill, TS3 and 98002 showed susceptible response. The variety TH6 and candidate line 40009 exhibited more than 50% infection and were highly susceptible in their response against M. phaseolina
Elsevier, 2020
Leaf tip burn in onion is a symptom of a number of biotic and abiotic stresses. It may appear in ... more Leaf tip burn in onion is a symptom of a number of biotic and abiotic stresses. It may appear in densely cultivated nursery transplants owing to one or the other simple or complex reasons. The present research work was planned to know the impact of rate and form of nitrogen (N) on post-transplantation recovery of tip burnt transplants, and signifcance of the disorder. Tip burn transplants were cultivated on sand culture hydroponic system at 0, 4, 6 and 8 mM N. In second trial 4 mM N was maintained in nutrient solution as 4:0, 3:1, 2:2 and 0:4 mM NO3-N:
NH4-N ratios. N supply linearly increased total leaf length (TLL). Both high and low N levels and replacement of NO3-N with NH4-N in solution signifcantly increased burnt leaf length (BTL). Lowest BTL and highest bulb yield was noted at 4 mM N and at 4:0 mM NO3-N : NH4-N ratio. N induced increase in TLL signifcantly reduced BTL by 42% at 60 and 75 days after transplanting (DAT). In both the trials BTL, particularly at early growth stages, was linearly and negatively linked to bulb yield of onion. Depending upon the DAT, the suggested linear regression models described about 50% variation in bulb yield counted for BTL. It is concluded from the results that leaf tip burning in onion is of great importance regarding bulb yield and a reasonable recovery is possible through appropriate dose of nitrate nitrogen.
A field survey was conducted in district Okara to determine existing plant pathogenic fungal coun... more A field survey was conducted in district Okara to determine existing plant pathogenic fungal count in various land use types. The target sites were classified as orchard, barren land, fallow land, cultivated land and forest land use types. Field soil samples were collected from these land use types at different depths of 15, 30 and 45 cm respectively. Dilution of soil samples was made in sterilized distilled water and 1ml was poured on to the malt extract agar (MEA) medium in 90 mm diameter Petri plates incubated at 25±2°C for 5-7 days. Purified fungal colonies of Mucor spp., Fusarium solani, Aspergillus niger, Penicillium spp., Alternaria alternata, Curvularia spp., Rhizopus spp., and Helminthosporium spp. on potato dextrose agar (PDA) medium were identified based on their morphological descriptions. These fungal counts were recovered from the soil at 30 cm depth which indicates an alarming situation for deep-rooted crops to soilborne fungal pathogens infestation in future.
Pakistan journal of pharmacuetical sciences, 2018
Acanthamoeba castellanii is member of free living amoeba that may cause painful sight-threatening... more Acanthamoeba castellanii is member of free living amoeba that may cause painful sight-threatening keratitis and life threatening encephalitis which involves central nervous system. Treatments for both infections are problematic because of the amoebic cysts resistance to therapeutic agents. Here we evaluated in vitro strength of methanolic seed extract of Peganum harmala on Acanthamoeba cysts and its encystment mechanism. Our results revealed seed extracts (1 to 30mg/ml) exhibited amoebicidal effects against Acanthamoeba cysts. Furthermore Acanthamoeba encystment was also inhibited in concentration dependent manner with maximum inhibition at 2µg/ml after 48h incubation. In conclusion, we demonstrated for the first time that methanolic extracts exhibit remarkable inhibition of Acanthamoeba cysts and encystment in vitro which could serve a potential new natural agent against Acanthamoeba.
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Papers by Salik Nawaz Khan
NH4-N ratios. N supply linearly increased total leaf length (TLL). Both high and low N levels and replacement of NO3-N with NH4-N in solution signifcantly increased burnt leaf length (BTL). Lowest BTL and highest bulb yield was noted at 4 mM N and at 4:0 mM NO3-N : NH4-N ratio. N induced increase in TLL signifcantly reduced BTL by 42% at 60 and 75 days after transplanting (DAT). In both the trials BTL, particularly at early growth stages, was linearly and negatively linked to bulb yield of onion. Depending upon the DAT, the suggested linear regression models described about 50% variation in bulb yield counted for BTL. It is concluded from the results that leaf tip burning in onion is of great importance regarding bulb yield and a reasonable recovery is possible through appropriate dose of nitrate nitrogen.
NH4-N ratios. N supply linearly increased total leaf length (TLL). Both high and low N levels and replacement of NO3-N with NH4-N in solution signifcantly increased burnt leaf length (BTL). Lowest BTL and highest bulb yield was noted at 4 mM N and at 4:0 mM NO3-N : NH4-N ratio. N induced increase in TLL signifcantly reduced BTL by 42% at 60 and 75 days after transplanting (DAT). In both the trials BTL, particularly at early growth stages, was linearly and negatively linked to bulb yield of onion. Depending upon the DAT, the suggested linear regression models described about 50% variation in bulb yield counted for BTL. It is concluded from the results that leaf tip burning in onion is of great importance regarding bulb yield and a reasonable recovery is possible through appropriate dose of nitrate nitrogen.