The plant management used in potato crop is usually similar across the main producing regions in Brazil. Same plant spacing are commonly used, despite the differences in climate and soil of the various potato planting areas. The objective of this work was to evaluate the yield of potato cultivars in response to different plant spacing. Experiments were conducted in the field, and the treatments consisted of three cultivars (Agata, BRS Clara and BRS F63 Camila) and three plant spacing (20, 25 and 30 cm) in randomized blocks with three repetitions in two years. The total, marketable and non-marketable tuber yield, total and marketable number of tubers per area and size class, mean total and marketable tuber weight and percentage of tuber dry weight of the tubers were evaluated. Camila was the cultivar with highest yield when spaced 20 cm due to the greater number of tubers in the marketable class 100-200 g. In the 25 and 30 cm plant spacing, there was no difference in yield among cultivars. Depending on the cultivar and the destination of the harvested tubers, producers can choose the most appropriated plant spacing.

Grain yield of bean (Phaseolus vulgaris L.) is affected by biotic and abiotic conditions, as well as by farmers' management. In the Center-South region of Parana State, the successive cultivation of black bean cultivars is common. The objective of this study was to evaluate the growth and yield of six black bean cultivars after successive monocultivation. The experiment was conducted in the field with six black bean cultivars and four repetitions (blocks). The cultivar with the highest grain yield was BRS Esplendor, a cultivar with a high number of grains per area. IPR Tuiuiú had the second-best grain yield because of its high harvest index. The continuous monocultivation resulted in low grain yield because of the high incidence of Colletotrichum lindemuthianum. Although common, the practice of continuous monocultivation of black bean cultivars in the Center-South region of Parana results in low grain yield and should be avoided.