ADAPTATION OF PH OF WATERS USED IN THE APPLICATION OF DEFENSIVES IN THE GOIANESIA REGION - GO

Abstract

THE AGRICULTURAL PESTICIDES ARE SUBJECT TO SEVERAL INTERFERENCES UNTIL REACHING THE TARGET, AND ONE OF THE MOST IMPORTANT FACTORS IN THIS PROCESS IS THE ADEQUACY OF THE PH OF THE WATER USED IN THE SPRAYING, IN ORDER TO STUDY THE PH RESPONSE OF WATER USED IN THE PREPARATION OF IN GOIAN�SIA-GO REGION TO THE ADDITION OF TWO AGRICULTURAL ADJUVANTS IN DIFFERENT DOSES. THE EXPERIMENTAL DESIGN WAS A RANDOMIZED BLOCK DESIGN WITH FOUR REPLICATES. WATER SAMPLES WERE TESTED FROM SEVEN SOURCES, USING TWO ADJUVANTS AND FOUR DOSES FOR EACH, MAKING 56 DIFFERENT CONDITIONS. EACH CONDITION TESTED WAS EVALUATED AT 2 HOURS AND 74 HOURS AFTER ADDITION OF THE REDUCTANT TO EVALUATE THE BUFFERING POWER (ON THE FIRST AND FOURTH DAY AFTER ADDITION OF THE PRODUCT). DATES WERE COMPARED FOR EACH CONDITION TESTED USING ANALYSIS OF VARIANCE. THE INITIAL PH AND EC OF ALL SAMPLES ON DAYS ONE AND FOUR WERE COMPARED USING THE X�² TEST. THE REGRESSION ANALYSIS WAS CARRIED OUT USING THE QUASI-NEWTON METHOD, IN ORDER TO FIND AND ADJUST AN EXPONENTIAL DECREASING MODEL THAT EXPLAINS THE RELATION BETWEEN THE DOSE OF THE ADJUVANT AND THE RESPONSE OF EACH WATER COLLECTED. IT WAS OBSERVED THAT EACH WATER SOURCE HAS DIFFERENT CHARACTERISTICS. AND IN THE EXTREMES ONE COULD OBSERVE ARTESIAN (MORE ALKALINE) AND DISTILLED (MORE ACIDIC) WELL WATER. MORE ALKALINE WATERS TEND TO BE MORE RESISTANT TO THE ACTION OF GEARBOXES. IN GENERAL, THE HIGHER THE DOSE OF THE REDUCER, THE LOWER THE PH OF THE WATER. THE MOST APPROPRIATE MODEL TO EXPLAIN THE RELATIONSHIP BETWEEN ADJUVANT DOSE AND WATER PH WAS Y = A + BE ^ ((- KX)), ABSORBING MORE THAN 92% OF THE VARIANCE IN ALL TESTED WATERS. THIS MODEL CAN BE USED TO PREDICT THE DOSES OF THE GEAR UNITS TESTED FOR DIFFERENT TYPES OF PLANT PROTECTION PRODUCTS. THE COMMERCIAL DOSE OF BOTH ADJUVANTS LEFT THE PH OF MOST SAMPLES BELOW 3.5, EXCEPT IN WELL 1. THIS PH RANGE IS INADEQUATE FOR MOST PHYTOSANITARIES. IT IS NECESSARY TO RE-EVALUATE THE USE OF PH REDUCERS UNDER FIELD CONDITIONS IN ORDER TO AVOID RECOMMENDATIONS THAT CAUSE LOSSES IN THE APPLICATIONS OF PESTICIDES.