Growth and production of conilon coffee under fertilization of nitrogen and molybdenum (Mo)

Abstract

Nitrogen is the most applied nutrient in Coffea canephora crops, due to the high requirement of the crop and low availability in most soils. The efficiency of nitrogen fertilization can be maximized by applying molybdenum, due to the role of molybdenum in the nitrate’s metabolism. This study was conducted during two coffee production cycles under field conditions. It aimed to evaluate the effects of applying molybdenum on the growth and production of conilon coffee, subjected to different amounts of nitrogen. The experiment was conducted from June 2018 to May 2020. The experimental design used was in randomized blocks, in a 2 x 5 factorial scheme, the first factor being the absence and presence of molybdenum fertilization (4 kg ha -1 year -1 ) and the second factor, nitrogen doses (300, 500, 700, 900 and 1,100 kg ha -1 year -1 ) applied in five plots, during fruit development. We evaluated the conilon growth variables in each agricultural year, in addition to the yield of processed coffee and grain yield. The length of plagiotropic branches, number of nodes per side branch, number of rosettes and fruits per productive branch were closely related to the coffee yield and were influenced by the nitrogen fertilization. Increasing doses of nitrogen promoted quadratic increases in coffee yield, with addition of 35.3% and 88.9% for the 2019 and 2020 harvests, respectively, indicating that maximum coffee productivity is genetically defined and affected by environment conditions and management. For the harvest 2020, the application of molybdenum resulted in an increase in the length of the orthotropic stem and plagiotropic branches, in addition to providing increase of 3.7% in the yield of C. canephora. This suggested that there was a reduction in micronutrient availability in the soil, throughout the experimental period, limiting the growth and production of coffee in the second year.