Spray nozzles performance on wheat diseases control

Abstract

Fungal diseases in wheat crops (Triticum aestivum) cause significant yield and quality grain losses worldwide. Field trials were carried out at the beginning of anthesis on wheat crop (state Z61), to evaluate different spray nozzles performance. The test was arranged in a 4x2 factorial design with ten repetitions. Factors consisted in four nozzles: flat-fan (XR 11002), air induction asimetrical dual flat fan (AI3070-02), air induction simetrical dual flat fan (GAT11002), hollow cone (TXA8002), and two artificial targets, one vertical and another horizontal related to head and flag leaf location, respectively. Water-sensitive cards and CIR 1.5® software were used for their evaluation, determining droplet density (DD, drop cm-2), coverage (%) and deposition (%), being the latter contrasted with the use of Brilliant Blue tracer. Data were subjected to ANOVA and means were compared by Tukey test (p≤0,05). The TXA8002 reached the best performance in DD, coverage, and deposition. AI3070 achieved similar deposition than TXA8002 in head, 51% and 45% respectively, despite having the lowest DD (44 drop cm-2), while TXA8002 had the higher deposition on flag leaf (40%). Air induction nozzles had the lowest DD but greater uniformity between head sides. The evaluation methodologies used are complementary when a complete analysis of application parameters is looking for.