Health of wheat and barley seeds: Key link in disease management
The sowing of the winter crops is approaching (in Uruguay) and it is a good moment to remember the importance of the use of healthy seeds or with minimal pathogen load. Before harvest, various pathogens can infect wheat and barley seeds and remain with their host until the next planting, when they will begin a new cycle of infection. With the germination of the seeds, the growth of the pathogen is restarted, it colonizes the tissues of the developing seedling, reproduces and finally disperses. The success of the process of transmission of the pathogen from seed to seedling depends on the occurrence of favorable temperature and humidity conditions for the infection. The blurry spot of wheat and barley caused by Bipolaris sorokiniana needs a temperature of 24 to 28ºC to be transmitted from seed to seedling, so, in small farms, it is rare to see early infections that come from seed. On the other hand, Drechslera teres f teres, cause of network-type net blotch on barley and Drechslera tritici-repentis causal of yellow spot on wheat, can infect the first growing leaves at low temperatures, of the order of 15 to 25ºC and 19 to 22 ° C, respectively. However, there are management factors that prevent and / or reduce the chances of this event occurring, such as: Plant healthy seeds of good germination and vigor, use cultivars of good sanitary behavior, avoid management that stress the seedling (ex. inadequate fertilization, deep sowing).
Revista INIA Uruguay 56 (2019):57-61.
Document author:Silvana González, Carlos Rossi, Silvia Pereyra