Use of increasing rates of ammonia nitrogen in pot-grown blueberries and its effect on fruit yield and macronutrient concentration in leaves

Juan Hirzel1*, Violeta Muñoz1, Ernesto Moya-Elizondo2, Octavio Lagos3, Cristian Balbontín1, and Hamil Uribe1
Due to the smaller size of berries plants and some vegetables, their production in containers has grown worldwide. To understand the effect of increasing doses of ammoniacal N, we evaluated production, firmness and size of fruits and concentration of macronutrients in leaves of four blueberry (Vaccinium corymbosum L.) cultivars (Duke, Legacy, Cargo, and Suziblue) in south central Chile. All were grown in pots with substrate during their third growing season. The results showed an interaction of ammoniacal N dose with blueberry cultivar in most of the parameters evaluated, except for firmness and size of fruits. The increasing dose of ammoniacal N allowed higher production per plant in only two of the four cultivars without effects on the quality attributes firmness and size of fruits. Differences in production per plant and fruit firmness were obtained between cultivars, with production values per plant between 86-210, 142-219, 195-203, and 504-979 g in ?Duke?, ?Legacy?, ?Cargo?, and ?Suziblue?, respectively, and greater fruit firmness in ?Suziblue?. The concentrations of macronutrients in leaves showed interactions between cultivar and doses of ammoniacal N, which did not allow obtaining a single dose of ammoniacal N that generate nutritional concentration values in leaves associated with greater fruit production in the four blueberry cultivars.
Keywords: Fruit firmness, fruit quality, fruit yield, macronutrient, Vaccinium corymbosum.
1Instituto de Investigaciones Agropecuarias, INIA Quilamapu, 3800062, Chillán, Chile.2Universidad de Concepción, Facultad de Agronomía, 3812120, Chillán, Chile.3Universidad de Concepción, Facultad de Ingeniería Agrícola, 3812120, Chillán, Chile.*Corresponding author (jhirzel@inia.cl).