Agriculture Reference
In-Depth Information
some areas of Corrientes, it is important to obtain tolerance of straight-
head disease. Likewise, some areas require tolerance of iron toxicity.
Since Argentina is a rice importer, it must maintain competitiveness
globally. Although in the last decade there was an important increase
in grain yield due to improved agronomic practices, an important yield
gap in relation to the potential of the genetic material being used
remains and this gap must be closed. Thus, it is very important to
obtain cultivars with high yield potential. Two ways are being used for
this purpose. In conventional breeding, the objective is to obtain more
“
with fewer tillers per plant, but larger panicles,
which means more grains per panicle. The other way is to develop
hybrid rice cultivars. This second way is being followed by some
private companies, and more recently by INTA in association with
the HIAAL consortium.
The objective for grain quality is to obtain cultivars with uniform
slender long grain that are very low in chalkiness (as low as possible) and
high in amylose content (higher than 25%). It is also very important to
obtain a high whole-grain percentage (minimum 56%). Lately, we have
considered a very important characteristic to developmaterial with good
tolerance of delayed harvest.
Tolerance of lodging is another important objective. There was much
improvement in this area with the use of semidwarf germplasm com-
pared with traditional cultivars. However, the heavier load of grain that
must be supported by every tiller requires stronger stems. Also, seedlings
with good vigor are very important in the Argentine breeding program.
Host plant resistance to rice blast disease remains an important objec-
tive. Recently, changes in agronomic practices (basically earlier planting
date and more balanced nitrogen application) have helped decrease blast
incidence. However, in 2012, the diffusion of some very susceptible
cultivars allowed the blast fungus to appear on some farms with much
damage for some farmers in the southern region. Research is under way to
gaina better understanding of theblast lineages present in theArgentinean
rice region.
The physiological disease
compact plants
”
associated with arsenic
toxicity is important in some areas of the province of Corrientes, so at
the Corrientes Experimental Station a speci
“
straighthead
”
c program to obtain genetic
tolerance of straighthead is being conducted. Some advances have been
made in getting lines with good tolerance. The transferral of that toler-
ance to commercial cultivars is in progress. Iron toxicity is also impor-
tant in some areas of Corrientes; so, during the selection process, this
malady is taken into consideration. Cultivars currently being grown have
good tolerance.
