PERTANIKA JOURNAL OF TROPICAL AGRICULTURAL SCIENCE

Nitrogen (N), phosphorus (P), and potassium are the most important macronutrients for plants, particularly for guava trees, which are in the flowering, fruiting stage, and fruit development. The objective of this research was to determine the impact of levels of NPK compound Fertiliser applied via irrigation system on guava fruit yield and quality. The experiment was set up in a randomised complete block design with seven treatments and three replications. The NPK compound Fertiliser (19-19-19 + 3CaO + Te) was applied through drip irrigation according to six levels of treatment (Fertiliser amounts of 400, 600, 800, 1000, 1200, and 1400 g/plant/year) and control. The number of flowers, yield components, and quality parameters were measured. The results demonstrated that fertigation with 1000 g/plant/year of NPK compound Fertiliser led to significant increases of the fruits set (168.5 fruits/plant), haverst fruits (91.8 fruits/plant), fruit weight (368.4 g), yield (22.5 tons/ha), pulp thickness (29.1 mm), core thickness (44.9 mm), fruit diameter (70.9 mm), fruit flesh weight ratio (76.6 %), and total soluble solids (9.8 %). The results can be used to develop technical standards to produce the best guava yield and quality under the ecological situation of Nghe An Province.