Wheat Stem Rust Disease In
Wheat is one of the commodities cereals became staple food in Indonesia. This commodity is an important source of protein and the second most important source of calories after rice for the community.
As with other major food commodities, efforts to increase wheat production is also faced with various challenges, both technical and social aspects economical. Globally, plant diseases is one of the major challenges in the production of wheat.
The emergence of epidemics of plant disease caused by a combination of inoculum, a favorable environment for the development of the disease (climate, soil and cropping systems), and the susceptibility of plants.
Climate change will also pose challenges associated with changes in temperature and cropping patterns.
Among the various types of diseases that destroy crops of wheat, rust disease is the most costly and the most widely spread, covering tropical and subtropical regions. Disease stem rust (Puccinia graminis f. Sp. Tritici) one of the important diseases of wheat crop.
Potential yield losses due to rust disease depends on the level of resistance of varieties, weather conditions, and the age of the plant at the time of contracting. The yield loss due to disease transmission occurs when rust appears before panicle formation phase.
Symptoms of infection. Pustules containing urediospora mass dark reddish brown and are found on both sides of the surface of the leaves, stems and panicles (Prescott et al. 2012). On the stem, uredinia elongated and reddish brown. Terkupasnya epidermal tissue is very clear, visible on the sides uredinia, so that the surface feels rough trunk. In severe infections, uredinia united that cover the plant tissue. Telia phase occurs on the same network in phase teliospore uredinia and more robust than urediospora. In the phase of Telia, no spores are released.
Development. P. graminis are macrocyclic five different spore phase, namely the phase of uredinia, Telia, basidiospora, spermatia, and aecia. The initial infection is usually mild and developed from urediospora carried on the wind. The disease can progress rapidly if the temperature and humidity favor.
Control. How to control stem rust disease, namely the use of resistant varieties, chemical, and cultivation. The use of resistant varieties is the most effective way to control and environmentally friendly. If it has been found to stem rust resistant varieties, the other control means relatively unnecessary.
Some reported to be effective fungicides to control rust diseases on cereals. However, fungicides are not widely used because it is expensive, rust epidemics are difficult to predict, may damage the environment, and the possibility of pathogens to build resistance to fungicides.
Control by means of cultivation can be done to reduce the intensity of the epidemic. Planted as early as possible and to plant early maturity varieties help suppress pathogens to infect. Other control by way of cultivation is crop eradication carrier inoculum source and eradication of alternative hosts.