Soybean crops in Rio Grande do Sul show signs of water stress

With 23% of soybean crops in Rio Grande do Sul in the grain filling phase, localized and uneven rainfall, associated with high temperatures, has negative consequences for the crop's water balance and creates disparities in crop conditions. According to the Conjunctural Information, released today by Emater/RS, linked to the State Secretariat for Rural Development (SDR), in regions where it has not rained enough, such as in the Northwest of the State, there are signs of water stress, which could affect the potential productive. 

Plants exhibit symptoms of wilting, exposing the underside of the leaves to the sun's rays, causing burns to these parts. The beginning of the detachment process of the lower leaves is also observed in crops most affected by water deficit, which show rapid yellowing and senescence.

However, in areas that received more significant or intermediate rainfall volumes, the situation of soybean crops is satisfactory, with the plants issuing shoots, with a height in accordance with the phenological phase they are in, which suggests productive results in line with established projections initially.

Regarding phytosanitary management, the main attention has been directed to Asian rust. High rainfall at the beginning of the crop cycle benefited the development of the disease. Despite the low humidity in recent weeks, which slows the progression of the disease, monitoring and application of the preventive control protocol continues.

Corn – The harvest of corn crops was intensified, favored by atmospheric stability, the significant presence of sun and the rise in temperatures throughout the day. The decrease in relative air humidity led to the harvesting of grains, whose moisture content varies between 18% and 22%. This range is considered adequate and has resulted in less grain breakage and more efficient threshing on the cob. The harvested area increased by 11% and reached 52% of the cultivated area.

The productivity of harvested corn is variable, and there are reports of high-tech crops with results exceeding 10 thousand kg/ha. On the other hand, some crops in adverse situations, such as the presence of leafhoppers, diseases and with more limited technology, have productivity of 3 to 5 thousand kg/ha. In general terms, there is a consensus that the harvest will be satisfactory, but lower than the initial projected estimate of 7.414 kg/ha. In addition to the reduction in productivity, the drop in product prices is identified as one of the main challenges, in some cases not covering production costs, even in the face of high productivity.

No new corn plantings were carried out during the period, due to the low moisture content in the soil. Crops sown in intermediate and late periods continue to develop, showing good production levels, depending on the technology used. However, moisture replacements are still expected at regular intervals.

Corn silage – new plantings were suspended due to insufficient moisture levels in the soil, with 97% of the projected area remaining planted. However, the whole plant harvesting and ensiling process continued, aiming to use the vegetable mass at the ideal point for making preserved food and to avoid any possible loss of quality. The harvested area exceeds 60% of the cultivated area. The estimated productivity is approximately 39 thousand kg/ha, and there may be a reduction in some regions, where crops were affected by excessive rain, winds, pests and diseases.

Beans 1st harvest - crop management and cultivation activities continue in the South and Northeast regions of the State, as well as harvesting in other productive regions. The yield projection is established at 1.775 kg/ha. In the administrative region of Emater/RS de Ijuí, the harvest reached 99%, and the yield is close to 1.600 kg/ha. Due to the low humidity in the soil, sowing of the 2nd crop only occurs in plots with irrigation. In rainfed crops, already sown, uneven germination is observed due to the lack of moisture in the soil.

Rice - the week was one of favorable conditions for plant development, especially due to days of full solar radiation, low relative air humidity and absence of rain, in addition to moderately high temperatures. The crop presents satisfactory development, and the predominant stages are flowering and grain filling. Projections point to productivity considered normal. However, there is concern regarding the possible incidence of extremely high temperatures, since values ​​above 35 °C can cause the sterilization of pollen grains, resulting in a potential decrease in productivity.

The plots are fully irrigated. The availability of water in the reservoirs is satisfactory and higher than that observed in the last three harvests. Rice farmers also continued with top dressing and possible disease control.

In the administrative region of Emater/RS de Bagé, in Campanha, in Dom Pedrito, there was a 10% increase in the planted area compared to the previous year, totaling 33 thousand hectares cultivated, 55% in the reproductive phase and 45% in the vegetative phase. In Barra do Quaraí and Uruguaiana, the harvest is expected to begin at the end of February.

Vegetable and fruit crops

Garlic - in the administrative region of Emater/RS of Caxias do Sul, weather conditions are favorable for the product stored in warehouses for curing. Some producers have been practicing bulb toileting in a moderate way, aiming for future sales. The quality and yield of crops have worried producers due to the lower-than-expected caliber, open bulbs, high rate of tillered bulbils (transformed into leaves) and low specific weight. Given this scenario, producers are having difficulty finding adequate stocks of bulbs to purchase and guarantee seed bulbs for the future harvest.

Grapes - in the administrative region of Emater/RS of Frederico Westphalen, the harvest is practically over, and the table grape productivity obtained was 10.900 kg/ha, which represents a reduction of 38% in relation to the initial expectation. For grapes destined for industry, productivity was around 17.400 kg/ha, a reduction of 29%. In addition to the significant decrease in productivity, excessive rainfall considerably compromised the quality of the grapes produced. At this time, producers carry out post-harvest management with phytosanitary treatments to maintain the leaf area in order to produce reserves for the next harvest. They also carry out replacement fertilization.