Different types of sprayers are used in farm practice. In small farms it is getting more economical to couple spraying booms and manual spraying lances to large volume tanks. In large farms the trend is to replace the traditional system by the ready diluted mix system. In both cases a prolonged storing time of the mix in tanks or refilling vehicle, especially in rainy periods of the year is required. So, it is important to determine how long the storage time may be without causing the effectiveness of the diluted mix to decrease. That is what this paper is related to. A random block design trial was carried out during the 1991/92 crop season, at the Experimental Station of the Agronomy College of UNESP, in Jaboticabal, São Paulo, Brazil. Diluted mixes of commercial formulation of glyphosate, MSMA and paraquat beyond a ready-for-use glyphosate + 2,4-D amine mix were evaluted at 00, 05, 10, 15, 20, 25 and 30 days of storage. A testimony plot was not spraied. Visual control evaluations, both general and by species were perfomed at 15, 31 and 46 days after spraying. The results showed no influence of storage periods on herbicides efficiencies (Tukey, 5%) no matter independent of the commercial product and time of evaluation. One concluded that the diluted mixes can be normally used provided the storage time doesn't exceed 30 days.
glyphosate; 2,4-D; paraquat; MSMA