Production of food and fibre are basic issues. Along with food security and environmental concerns, adoption of biotechnology too, needs special attention.
People are constantly trying to resolve issues which directly impact their lives, but fail to find ways and means due to agriculture illiteracy.
In Pakistan, the number of public and private institutions at primary level is 156,100, at middle level 28,716, and at high school level 16,059. The literacy rate for both sexes is estimated at 54 per cent with 66.25 and 41.75 per cent for male and female, respectively.
Agriculture has a low share in taught course syllabi up to high school level, which may be considered for calculating literacy rate. Agriculture is the backbone of economy as it the largest income generating sector contributing 23-25 per cent to the GDP.
It employs 42-49 per cent of the total labour force and supports directly or indirectly about 70 per cent of the population for their sustenance. There still is a possibility to increase its contribution to the GDP with getting more people engaged in this field.
The need is to educate people and give agriculture sector top priority. According to the agriculture ministry small or medium-sized farmers own 90 per cent of the total cultivable land with ownership ranging from one acre to 150 acres.
Only 10 per cent of the cultivable land is with 4.7 per cent of farmers, whose per capita holdings are more than 150 acres. About 38 per cent of the total cultivable land is owned by 35 per cent of the farmers, whose per capita holdings range between 12.5 and 50 acres.
No doubt, the majority of farmers (including small and medium) are working since their adolescent as per their tradition without the knowledge of modern farm principles.
They face problems, as devoted and concerted efforts associated with scientific approach are required to make the country self-sufficient in food and fibre, along with producing export surplus.
Agriculture is the largest source of foreign exchange earnings by serving as a base sector for textile and sugar industries. It provides raw materials as well as industrial products.
The sector is functioning without the basic facilities like education, health, and transport. The sector faces many bottlenecks. Crop diseases cause considerable growth loss, development and production by damaging the plants.
Farmers, landlords, self-cultivating persons, shareholders and contractors feel the disturbance and deviation in normal structures, function and growth of plants but are unable to get to the actual problem.
Many insect types are visible in crops making the grower think that these are the only insects causing trouble. Rather, not all insects are responsible for damage to crop plants. Many such insects are useful while few damage plants.
Growers kill all visible ones without the consideration of useful insects serving for pollination, and also as biological control agents. Nor do they comprehend on the creation of critical situation.
For-example, nutritional deficiencies, sudden change in climatic conditions or presence and multiplication of disease inciting micro organisms, which are all invisible, may be the actual cause of damaging crop plants.
Economic importance of plant diseases: Plant diseases were present on earth long before man established himself. Protection of neighbouring crops from diseases began since the advent of agriculture, as for man and insect same resources are needed for food and shelter for the survival.
Plant disease damages crops, reduces yields, lowers quantity and quality, increases production cost and requires cash outlays for material and equipment for controlling measures. However, chemicals used for disease control are poisonous for human health and can cause environmental pollution.
Importance of plant diseases in relation to crop production can be realized from the fact that in several crops, the yields achieved are not of desired level. Among other factors, plant diseases are prominent for causing loss in world crop production amounting to millions in cash.
Although, losses caused by the diseases are variable but their cumulative effect is considerable, and in certain cases field have been found to show as much as 100 per cent damage.
Record shows severe attack of diseases on various crops in the world. The black stem rust of wheat, Phyllody of sesame, whip smut of sugarcane, wilt and storage or tuber rot of potato, wilt of gram, early blight of potato, long smut of sorghum, ring rot, tip burn and early blight of potato, grain smut of sorghum, red rot of sugarcane, wilt or root rot and boll rot of cotton, blight of rice, grain smut of sorghum are the examples from 1906 to 1930 at different locations in Sindh.
While, wilt and viral diseases of chillies and tomatoes, powdery mildew of cucurbits, mango and jujube, downy mildew of different crops, banana bunchy top virus (BBTV) and cotton leaf curl virus (CLCV) also take a heavy toll and total losses in production.
However, it is quite difficult to present accurate estimates of the losses due to diseases, because it varies from year to year and from one region to another. Study of plant diseases: Plant pathology is a science dealing with the studies of nature, causes, prevention and other aspects of plant disease.
A new term 'Phytopathology' is being used instead of plant pathology. The word Phytopathology is the combination of three Greek words: Phyton meaning plant, pathos meaning suffering, and logos meaning discourse (reason).
Therefore, plant pathology and Phytopathology have the same meaning i.e., the science of plant diseases. In other words, this field comprises both the sciences of understanding the nature of diseased plant, as well as causes, and treatment of plants.
On the whole, many different areas of biological sciences, including different areas of agriculture are involved in the study of plant diseases, but Mycology deals with the study of fungi, Phytobacteriology deals with the study of bacteria in relation to plants, Nematology deals with the study of parasitic nematodes and Virology deals with the study of viruses causing plant diseases.
It is a need of the time that we should know something about the science which deals with the study of plant diseases, their possible causes, symptoms, classification, identification and safe, low cost and least toxic management by discussing basic facts.
