Quimigação à base de ácido fosfórico e hipoclorito de cálcio na irrigação por gotejamento

Abstract

The use of fresh water available in the world needs to be more efficient, and localized irrigation systems such as drip irrigation show high efficiency for water use in crop irrigation. In the city of Salto do Lontra, state of Paraná, Brazil, several producers use drip irrigation in fruit growing and horticulture, accompanied by a family farming project developed in the region.One major problem of this system is the clogging in drip emitters, which can be caused by chemical, physical or biological agents, reducing the uniformity of water and fertilizer application, diminishing the system s effectiveness and usability. Reviews of uniformity were made to monitor the clogging over the treatments, whereas, according to the change of flow, with little variation in pressure, clogged emitters were found. Each system received a treatment for unclogging the emitters, composed of phosphoric acid and of calcium hypochlorite, which were subsequently analyzed by Tukey's comparison test and statistical control charts. The filters used (disc filter and screen filter) were analyzed by weighing the impurities contained therein, in an interval of six reviews. The uniformity was better assessed by CUD and CV, as the CUC presented data above 90% even with high variation in flow and pressure. With the help of control charts, it can be seen that the calcium hypochlorite showed better performance than the phosphoric acid to clean the system for returning the initial flow rating. The disc filter was more efficient for waste retention when compared to the screen filter, which showed blockage in the system where it was installed