Tuesday, June 14, 2011
Rice Diseases
Sunday, June 12, 2011
Rice Crop
Friday, May 27, 2011
Landscape Design; Make Your Garden Beautiful
Friday, May 13, 2011
Irrigation
Sources of Irrigation: Mainly three sources are known as a source of Irrigation Water.
1. Surface Water: It includes all river, lakes, steams and any running water. Water coming from the mountains due to the snow melting is the source of this type of Irrigation.
2. Ground Water: Water present inside the earth is a major source of irrigation water which can be pumped through tube wells.
3. Rainfall: Rainfall is not a reliable source of water as it may increase or decrease. It is also not sufficient in some areas as the rainfall in arid and semiarid regions of world is not sufficient to meet the needs.
Monday, May 9, 2011
Management of Wheat Diseases
Saturday, May 7, 2011
Major Diseases of Wheat Crop
Most common disease of wheat all over the world is rust of wheat which is cause by a fungal pathogen Puccinia graminis and cause rust colored patches on stem and leaves of the plants. Other than stem rust, loose smut of wheat is also very common. This disease is also caused by a fungal pathogen Ustilago tritici. In this disease , the heads become black due to the presence of spores of fungi. Entire seeds are filled with loose, powdery black colored spores. Other fungal diseases are Common Bunt (Tilletia caries, T. foetida) which is also known as Stinking Smut, Septoria Glume Blotch and Scab also known as Head blight(Fusarium graminearum).
Viral diseases include Barley Yellow Dwarf, Soilborne Wheat Mosaic and Wheat Yellow Mosaic (Wheat spindle streak mosaic).
In Pakistan, many kind of smut and rusts had been reported from different regions of Pakistan by the Govetment of Pakistan. These include:
1. Black Stem Rust of Wheat (Puccinia graminis tritici)
2. Orange or Leaf Rust of Wheat (Puccinia recondite)
3. Yellow or stripe rust of wheat(Puccinia striiformis)
4. Loose smut of wheat(Ustilago tritici)
5. Flag smut or Leaf smut of wheat(Urocystic tritici)
6. Bunt of wheat(Tilletta foetida or T. caries or T. tritici)
7. Karnal Bunk(Tilletia indica)
8. Ear Cockle or Tundo of Wheat(Anguillulina tritici -a nematode.)
9. Foot rot, Leaf spot & Black Complex( Helminthosporium sativum)
10. Septoria leaf Spots(Septoria tritici)
Wednesday, May 4, 2011
Wheat Crop
Monday, May 2, 2011
how you can grow vegetables in your own garden?
Saturday, April 30, 2011
Macrophomina phaseolina
Macrophomina phaseolina is a very destructive gungi belongs to family Botryosphariaceae. It has been recorded up till now that this fungi can infect more than 500 plants causing rottning of plant especially charcoal rot in many plants.
Macrophomina phaseolina is a non host specific fungi. This is a soil born fungi which can resist unfavorable environmental condition with the help of its resting bodies known as sclerotia. (Short et al., 1980) In PDA, pycnidia are not produced except under some specific incubation conditions (Gaetán et al., 2006) and only sometimes in host crops (Mihail and Taylor, 1995), and their importance in the epidemiology of the fungus likely depends on the host involved as well as the fungal isolate (Ahmed and Ahmed, 1969).
Sclerotia are minute, black, round to oblong or irregular in shape with mycelial attachment. Kamalakannan A, et al 2005). Microsclerotia in soil, infected seeds or host tissues serve as primary inoculum (Abawi and Pastor-Corrales, 1990). Root exudates induce germination of microsclerotia and root infection of hosts. Increase in sclerotial population of M. phaseolina in soil resulted in great root infection by M. phaseolina (Dawar & Ghaffar,1998).
The sclerotia float freely on soil surface when field is flooded for irrigation and become primary inoculum for emerging seedlings. (Abawi and Pastor-Corrales, 1990) Additional sclerotia become dislodged and rise to the water surface in the flooded seed bed or any other factor, such as water wave action due to wind that disturbs the surface layer during growing season (Keim and Webster, 1974; Webster et al., 1976). However, mycelium of M. phaseolina in the soil is not considered as a major source of inoculum (Norton, 1953; Smith, 1969; Meyer et al., 1974).
Reference
(image) J. B. Sinclair and P. A Backman, eds. APS Press. St. Paul, MN
Short GE, Wyllie TD, Bristow PR (1980) survival of Macrophomina phaseolina in soil and residue of soybea. Phytopathol 70-13
Gaetan SA, Fernandez L, Madia M (2006) Occurence of charcoal rot caused by Macrophomina phaseolina on canola in Argentina. Plant Dis 90-524
Mihail JD, Taylor SJ ()1995) Interpreting vairibility among isolates of Macrophomina phaseolina in pathogenicity, pycnidium production and chlorate utilization. Cab J Bot 73. 1596-1603
Ahmed N, Ahmed QA (1969) Physiologic specialization in Macrophomina phaseolina. Ashby causing stem rot of jute, Chorcorus species. Mycopath39. 129-138
Kamalakannan A, Mohan L, Valluvaparidasan V, Mareeswari L, Karuppiah R (2005) First report of Macrophomina root rot (Macrophomina phaseolina) on medicinal coleus (Coleus forskohlii) in India. New Disease Reports 11, 48
Abawi GS, Pastor-Corrales MA (1990) Seed transmission and effect of fungicide seed treatments against Macrophomina phaseolina in dry edible beans. Turrialba 40: 304–339
Dawar S, Ghaffar A (1998) Effect of sclerotium inoculum density of Macrophomina phaseolina on charcoal rot of sunflower. Pak J Bot 30: 287-290
Webster RK, Bolstad J, Wick CM, Hall DH (1976) Vertical distribution and survival of Sclerotium oryzae under various tillage conditions. Phytopathol 66: 97-101
Smith WH (1969) Germination of Macrophomina phaseolina sclerotia as affected by Pinus lamberitina root exudes. Canadian J Microbiol 15:1387-1391
Meyer WA, Sinclair JB, Khare MM (1974) Factors affecting charcoal rot of soybean seedlings. Phytopathol 64: 845-849