Winter sowing begins in the Southern Region

In the South Region, the area with winter grain crops should reach 3,4 million hectares in crops such as wheat, oats, barley, triticale, rye and canola (Conab). Wheat accounts for more than 80% of the winter area. Although agricultural zoning allows wheat sowing to begin in April, operations must be concentrated in the months of May and June, due to the delay in the soybean harvest in RS and SC, and the lack of rain in PR.

According to the agricultural climate risk zoning (ZARC), the indication for sowing wheat in the South Region (aiming at grain production in a rainfed system) started on April 1st in the north of PR, but according to the Deral, only 1 % of the area was sown until 20/04 due to lack of moisture in the soil. In RS and SC, the sowing season began on May 11, but in mid-April there were still approximately 46% of soybean crops left to be harvested in RS (Emater/RS) and 37% in SC (Epagri ) . The wheat sowing window indicated by ZARC extends until July 31 in the three southern states.

Farm preparation

Winter crop preparation requires weed control, especially ryegrass, which can steal up to 40% of wheat productivity. Ryegrass control may require up to two pre-sowing applications of herbicides, aiming to reduce the seed bank in the plots, as it is a weed that has the characteristic of emerging throughout the wheat cycle. Recently, the crop has gained new options for ryegrass management with the registration of herbicides for pre-sowing application, to control the seed bank, or post-emergence, when the target is to control ryegrass in the seedling phase.

In fertilization, the best strategy is to fertilize the system, which consists of applying the entire dose of Phosphorus (P) and Potassium (K) that goes into the field during the year, when wheat is sown. This practice enhances wheat yield and distributes nutrients in the soil in a more balanced way.

Seed treatment (TS) is essential before implementing the crop, preferably in industrial mode (TSI), a practice that guarantees protection of plants against fungi and pests for approximately 30 days after sowing. TS is a technology with low financial cost, reduced environmental impact and very efficient.

Cultivar

When choosing a cultivar, the producer must consider the productive potential in the region, the most adapted cultivars, the history of the property and the climate. The cultivar will determine crop management and the investment required, especially in plant protection. Given the prospect of a wetter winter and spring under the impact of the El Niño phenomenon, cultivars with better resistance to fungal diseases can be alternatives to save on cultural treatments.

The quantity of seeds to be used is a criterion that deserves attention when sowing. The cultivar breeder's recommendation must be respected to avoid the use of quantities far below the ideal or excesses that imply increased costs and could result in lodging of plants. A generic recommendation from most breeders is a population of 300 plants/m².

Another essential precaution is to stagger sowing, opting for cultivars with different cycles, a strategy that can reduce the risk of losses due to diseases and adverse weather conditions, in addition to making the establishment of the subsequent summer harvest more flexible. The guideline is to sow cultivars with a longer cycle first, while early cultivars go into cultivation later, at the end of the sowing window, to avoid damage from frost during heading and flowering.