Anuário Brasileiro do Arroz 2011 - Unemat

Strangers
in the nest
Lack of technological
novelties to fight red
rice infestations have
led specialists to create
greater awareness
of appropriate
management practices
In one of the rooms in
the Agronomy Building at
the Rio Grande do Sul Rice
Institute’s Experiment Station,
in Cachoeirinha (RS), images
of red rice infested fields, projected
on a screen, are cause
for concern. The feeling, nevertheless,
is not exclusive to
the team of the institution. All
over Rio Grande do Sul, where
the weed marks its presence in
about 60% of the plantations,
farmers, technicians, specialists
and sales people are also very
preoccupied.
The absence of new technologies
to fight the infestation
has led agronomic engineer
Valmir Gaedke Menezes, of
Irga, to predict: “do not expect
miracles”. He maintains that
the main manner to render the
problem less difficult is to invest
in grower awareness regarding
correct management practices.
This is justified, since non-recommended
practices, like the
use of non-certified seed, the
application of less than needed
herbicides and same area plantings
for several years in a row,
might trigger intensive red rice
outbreaks.
According to agronomic engineer
Augusto Kalsing, of the
same institution, a great number
of growers have already got
aware and have adhered to the
recommended practices. The demand
for Irga certified seed, for
example, soared over the past
year. He adds that the information
spreading service never
stops. During the 2010/11 crop,
the institute attracted 5 thousand
producers to lectures, field
days and technical itineraries, at
which directives were given on
how to fight the scourge.
DREADED Herbalist and
crop management specialist,
Valmir Gaedke Menezes, of Irga,
considers red rice the number
one problem for the crop, followed
by weed infestations,
pests and diseases. Besides interfering
with the quality of the
kernels and with the field’s potential
productivity rate, it could
ruin the entire crop, depending
on the degree of infestation.
Damages in Rio Grande do Sul,
for example, amounted to 1.2
million tons in the past crop,
representing a loss of about R$
200 million, says Menezes.
The use of the Clearfield
system, not in compliance with
the recommended patterns, provides
evidence to what extent
the lack of awareness might
jeopardize the rice growing business.
Now, some 600 hundred
thousand hectares are planted
in line with this system, nonetheless,
Menezes notes, a great
part of these areas are infested
with red rice resistant to herbicides
recommended for this
technology. The researcher also
maintains that in the past crop,
about 70% of the plant and
seed samples, which had evaded
the control within this system,
showed resistance traits.
The use of more than one
tool, with the intention to slow
down red rice infestations, is essential,
says Menezes. He says
that nowadays the weed is no
longer uniform. As time goes
by, new genetic variations make
their appearance, which make
it necessary to go in search of
new fighting methods. Within
this context, Augusto Kalsing, of
Irga, mentions that “if the potential
yield of the kernels is to
be achieved, all rice plants must
be free from weed interferences,
from seeding to harvest”. A reality
that might add quality and
ease of management to every
different crop.
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