Background: Weeds reduce water use efficiency in crops due to water used by the weed and to the reduction in crop yield. In addition to the usual presence of weeds in the interrow of different crops, the management of these plants has moved away from the idea of total control. Thus, the amount of water lost through the evapotranspiration of weeds (ETW) must be understood. Objective: Determine the water use and crop coefficient (Kc) of the weed species Commelina [...] Abstract Background: Weeds reduce water use efficiency in crops due to water used by the weed and to the reduction in crop yield. In addition to the usual presence of weeds in the interrow of different crops, the management of these plants has moved away from the idea of total control. Thus, the amount of water lost through the evapotranspiration of weeds (ETW) must be understood. Objective: Determine the water use and crop coefficient (Kc) of the weed species Commelina

The descriptors used to differentiate new soybean cultivars which ensure their protection, has become insufficient. This makes evident the need to expand the list of that already used. The morphological traits that may be used as descriptors can be quantitative or qualitative; however, in the evaluation of their efficiency, they are not always analyzed simultaneously. Thus, this study aimed to identify new morphological characteristics for purposes of discrimination of soybean cultivars with the aid of Gower algorithm, which allows evaluation of quantitative and qualitative characters simultaneously. Ten soybean cultivars were used in two experiments, one in the summer and another in the winter. They were conducted in a greenhouse. The experiments were carried out in an experimental randomized complete block design with four replications. Each experimental unit consisted of one pot with two plants. Five quantitative and seventeen qualitative characteristics were evaluated and the discrimination analysis was performed by Gower algorithm. It was concluded that there are differences among cultivars for all traits analyzed in both sowing dates, except for the opening of the petioles of the unifoliolate leaves. The use of Gower algorithm was efficient in the evaluation of discriminatory capacity of quantitative and qualitative characteristics simultaneously, demonstrating that they are useful as soybean descriptors. Key words: Glycine max (L.), law on plant variety protection, productivity, qualitative variables.

Creation, adjustments and adoption of tests and tools that help in the prediction of seed storability have been highly demanded. Therefore, this work aimed to analyze the efficiency of different artificial aging times in predicting the performance of soybean seeds after storage, using the GGE biplot method. Seeds of six genotypes were subjected to storage, under refrigerated and non-refrigerated conditions, and artificial aging, being artificially aged for periods of 0, 48, 96 and 144 hours. Seeds freshly harvested and after natural and artificial aging were subjected to germination and vigor tests. The experiments were analyzed separately, using means test, regression analysis and model identity test, and together, using the GGE biplot method. Artificial aging at a temperature of 41 °C for 96 hours has the potential to be used to predict the performance of soybean seeds after eight months of storage. The GGE biplot is a method that can be used as a tool to analyze the relationships between aging environments and visualize the ranking of genotypes regarding the performance of seeds subjected to natural and artificial aging.

Irrigation frequency and vermiculite proportion in substrate for Eucalyptus grandis seedling