Anomalia em grãos de soja : efeito sobre a massa específica aparente

Abstract

Despite large investments in technology and adaptation of management, diseases continue to be a major challenge for soy production, as they can cause significant damage to productivity and grain quality. Besides the already known diseases, a problem called "soybean anomaly" has been reported in the last crops. This anomaly is shown by the darkening inside the pod and the grains of the lower middle third of the plant, which after opening the pod, one or more rotten grains are found. Thus, the objective was to evaluate the effect of the anomaly on the bulk density of soybean and percentage of anomalous grains as a function of plant protection treatments. Different fungicide protocols were performed during the soybean crop of the 2022/23 harvest in a farm located in the municipality of Sinop - MT. These were: Multisite Fungicides; Season of application; Fungicides; Active ingredient alone; Seed treatmentand absolute Witness. After harvest, the plants were threshed mechanically and the samples cleaned manually. The humidity of the grains was determined by the standard oven method and dried at low temperature (40 ºC) for standardization at 13 %b.u. For qualitative analysis the bulk density was determined using a 1-liter capacity cylinder in 4 repetitions and the percentage of grains visibly damaged by the anomaly was quantified in 4 repetitions of 50 g. The data was submitted to variance analysis, where it was found that only for the variable anomalous grains in function of the protocols Seed treatment and Absolute Control had no significant effect. Then the dispersion of the data was evaluated by means of box diagrams. According to the results the best protocols and their respective treatments were Multisite, Seed treatment and Application season, with values above 700 kg m-3. The lowest percentage and least dispersion in the percentage of anomalous grains was verified for the application Season protocol. The absolute witness demonstrated greater problems during grain filling and greater sensitivity to anomaly.