Macro and micronutrient accumulation in watermelon

Abstract

The expansion of crop productivity such as watermelon can be reached by providing adequate nutrition in quantity and when plants need it most. It is known that well-nourished plants better resist biotic and abiotic stresses, being determinants for more sustainable management. In this sense, the objective of the present study was to evaluate the plant growth, the rate of nutrient absorption, the proportion of absorption, and estimate the quantity of exported nutrients by watermelon fruits. The experiment was implemented in randomized block design with eight treatments (phenological phases) - 33 and 40 (growth), 47 and 54 (flowering), 61 and 68 (filling), 75 and 82 (maturation) days after planting (DAP). Each evaluation consisted of plant collection for dry mass, macro, and micronutrient analysis in the shoot (leaves and stems), fruits, and the entire plant. The period between 61 and 68 DAP was the one with the highest plant dry matter increment. The accumulation of macronutrients in the plant shoot showed the following decreasing order: Ca>N>K>Mg>P>S, in the fruits: K>N>P>Ca>Mg>S and in the whole plant: K>N>Ca>P>Mg>S. For micronutrients, the decreasing order of accumulation for the shoot and the entire plant were Fe>Mn>Zn>B>Cu, and for fruits were Fe>B>Zn>Mn>Cu.