ABSTRACT The inoculation of sweet corn seeds with Azospirillum brasilense in association to nitrogen fertilizer may be an agronomic alternative for increasing the crop yield and net income of plant growers. Therefore, the aim of this study was to investigate the effect of the different doses of inoculant (Azospirillum brasilense) associated to the nitrogen fertilization management on the phenotypic traits of one sweet corn hybrid in summer growing periods, under supplemental irrigation, in the Northwestern Paraná state, Brazil. The experiment followed the complete randomized block design with four replications. The treatments were: i) five inoculant doses (0.0, 50, 100, 150 and200 mL∙ha–1) containing Azospirillum brasilense; ii) two N doses (0.0 and 30.0 kg∙ha–1) applied at sowing time; and iii) two topdressing doses of N (0.0 and 110.0 kg∙ha–1) applied at the V4 stage. The sweet corn hybrid RB 6324 was evaluated in 2012/2013, 2013/2014 and 2014/2015. The traits plant height (ranged from 2.11 to 2.26 m), leaf area index (3.33 to 4.32), crop yield (7.21 to 10.43 Mg.ha–1), and the sugar kernel contents (38.46 to 43.31%) and protein (12 to 12.81%) were positively influenced by the seed inoculation with A. brasilense, and the nitrogen fertilizer increased all the traits except the kernel total sugars. The dose of inoculant that provided the best agronomic result was 100 mL∙ha–1 in conjunction with the application of N either at sowing or topdressing.

O emprego de índices biometeorológicos para a previsão dos estádios fenológicos tem sido amplamente utilizado no planejamento dos tratos culturais na viticultura. O objetivo deste trabalho foi caracterizar e comparar entre dois ciclos consecutivos, a duração em dias e as exigências térmicas em graus-dia de doze estádios do ciclo fenológico da videira 'Benitaka'. O estudo foi conduzido num vinhedo comercial localizado no município de Janaúba, região semiárida de Minas Gerais. As plantas, enxertadas sobre o porta-enxerto IAC 572 'Jales', foram conduzidas no sistema de latada e irrigadas por microaspersão. O acúmulo em dias e a exigência térmica (graus-dia) foram determinados em duas safras consecutivas, da data da poda até a colheita, adotando-se a temperatura de 10°C como temperatura de base. O acúmulo em dias, da poda à colheita, foi de 120 para a poda realizada em janeiro e de 131 dias para a poda em julho. Na poda de janeiro, as plantas acumularam 1.914 graus-dias, enquanto na poda de julho o acúmulo foi de 1.930 graus- dia.

The use of biometeorological indices for the prediction of phenological stages has been widely used in the planning of cultural practices in tropical vines. The objective of this study was to characterize and compare the duration (in days) and thermal requirements in degree-day of twelve stages of the phenological cycle of the vine 'Benitaka'. The study was carried out in the vineyard Santa Catarina, in the city of Janaúba, north of the state of Minas Gerais - Brazil. Grapevines grafted on the rootstock IAC 572 'Jales' were irrigated by microaspersion. The accumulation of days and thermal requirement were determined in the same plants on two consecutive pruning dates. The base temperature used for the study was 10° C. The total length of the cycle ranged from 120 days for the vines pruned in January to 131 days for those pruned in July. The total amount of degree days for the grape pruning in January was 1914, whereas for the pruning in July was 1930.