Summer crops show variable damage in RS

The occurrence of irregular rains, concentrated in the South and East regions of Rio Grande do Sul, momentarily alleviated the stress on benefited crops. However, in most of the state's territory there was either no rainfall or insufficient rainfall.

According to Emater/RS, the last week was marked by heat. Dry days with a lot of solar radiation caused high rates of evapotranspiration. This negatively impacted soybean crops developing (48%), flowering (35%) and grain filling (17%). Planting is almost complete (99%).

In the most affected crops, it is possible to observe wilted leaves in the early hours of the morning, as well as a sharp drop in flowers. Defoliation can be seen concentrated in the lower third. And little emission of new leaves.

There was sampling in 412 municipalities in RS. Technicians estimate a reduction in productivity of just over 20% (most affected areas: Santa Maria and Santa Rosa). The decrease is estimated at around 10% in the areas of Bagé, Frederico Westphalen, Ijuí, Lajeado and Pelotas; between 2% and 3% in Erechim and Soledade. There is no reduction in Caxias do Sul, Passo Fundo and Porto Alegre.

The projected soybean area for the 2022/2023 harvest is 6.568.607 hectares, with an initial productivity of 3.131 kg/ha.

Corn

The corn harvest continues. Reached 35% of the planted area. The drought caused the stems of the plants to etiolate, which cannot remain standing. This situation contributed to the anticipation of harvest, even in grains with moisture above ideal.

Last week, an assessment was carried out of the effects of the drought in relation to productivity in 463 municipalities in the State.

The initial productivity estimate remained in the Emater/RS administrative region of Caxias do Sul; in Porto Alegre, the reduction is close to 10%; in the regions of Lajeado, Passo Fundo and Soledade, 20%; in Erechim, Ijuí, Pelotas and Santa Rosa, between 35% and 40%; and in Bagé, Frederico Westphalen and Santa Maria, just over 50%.

The estimated cultivation area for the 2022/2023 harvest is 831.786 hectares, with productivity of 7.337 kg/ha.

Rice

Approximately 48% of crops are between the panicle emission and flowering phases and there is concern about the possible impact of the combination of temperatures close to 40°C and low relative air humidity, recorded during the period.

Temperature spikes above 35°C can cause spikelet sterilization. The optimum temperature range for flowering crops varies from 30 to 33°C and, for maturation, between 20 and 25°C. Temperatures below 15°C during flowering can also cause spikelet sterilization.

Among the regions with the highest production, productivity expectations are still maintained in the Emater/RS-Ascar administrative region of Porto Alegre. There is a prospect of a reduction of between 2% and 4% in Lajeado, Santa Maria and Soledade. The greatest damage occurs in Bagé and Pelotas, with a prospect of a reduction of 7% and 8%.

Planting has already been completed, with 52% in the germination and vegetative development phase, 36% in flowering and 12% in grain filling. The estimated rice area by IRGA is 862.498 hectares. The projected productivity is 8.226 kg/ha.