Tensions threshold and potassium concentrations in soil solution in crop Lisianthus (Eustoma grandiflorum) fertigated in greenhouse conditions

Abstract

In recent years, brazilian exports have been emboding largest commercialized market values of fresh-cut flowers. Among them, lisianthus (Eustoma grandiflorum) is attracting great interest, by beauty of the colors of flowers, length and firmness of the stems, as well as its postharvest longevity. However, this species is little studied in Brazil, especially regarding ideal culture conditions, irrigation, nutrition and fertigation management. This research aims to evaluate the effect of tensions threshold the soil water associated with different potassium concentrations in soil solution on the growth characteristics, nutrient uptake, yield and quality of stems and flower buds lisianthus (var . Echo), fertigated under greenhouse conditions. The treatments shall consist of five tensions threshold the soil water (T1 = 12, T2 = 24, T3 = 36, T4 = T5 = 48 and 60 kPa) and five concentrations of potassium in the soil solution (K1 = 50, K2 = 100, 150 = K3, K4 and K5 = 200 = 250 mg dm-3) managed by fertigation in two crop cycles, for a period of 120 days each. The plots are willing in randomized complete blocks, in factorial outline 5 x 5 (five tensions threshold and five concentrations of potassium in the soil solution), with four replications, totaling 100 experimental plots. Will be evaluated qualitative parameters of the stems and flower buds, productivity, electrical conductivity and concentrations of potassium (K+) in soil solution, with the aid of Time Domain Reflectometry (TDR), well as the concentrations of macronutrients in the tissue vegetable. (AU)