Efficient application of fungicides and insecticides in soybeans

Spray conditioner adjuvant combined with the correct spray tip helps improve the deposit and coverage of drops of the fungicide and insecticide mixture on the lower third of plants in soybean crops.

A tank mixing of curative and protective fungicides with insecticides and adjuvants is a common and essential practice in soybean cultivation due to the reduction costs and increased efficiency in pest and disease management. For improve the control carried out by defensive players, it is necessary that they are distributed evenly and in adequate quantity throughout the canopy of the plant. The addition of Nutrol Max to the spray solution promotes changes in quality of application (deposition and coverage) by changing the properties physical-chemical properties of the mixture and, consequently, increase spreading and interaction that the pesticides will have with the leaf surface. Nutrol Max is an oil multifunctional premium methylated with no breakthrough time, composed of methyl ester of vegetable oils associated with insect repellent. It is a concentrate emulsifiable biodegradable refined oils, which can replace other oils emulsifiable in water, such as vegetables and minerals. Has high solubility and compatibility with pesticides and their mixtures, such as new biotechnologies (Dicamba). Does not cause phytotoxicity or magnifying effect, being efficient at low dose. In this context, the objective of the work was to evaluate the deposit and coverage of the drops of the fungicide and insecticide mixture with and without the addition of Nutrol Max applied with single, cone, flat jet spray tips full and empty cone.

METHODOLOGY

A The research was conducted by the team at the Research Center laboratory in Application Technology and Agricultural Machines (Nitec) at the State University of Northern Paraná (Uenp), in Bandeirantes, Paraná. The test was carried out at field, consisting of six plots measuring 10m wide x 10m long, spaced 5m apart. The treatments followed the 2 x 3 factorial scheme, two mixtures sprayed by three models of spray tips. The syrups used were composed of a mixture of the fungicide trifloxystrobin, 150g/L + prothioconazole, 175g/L at a dose of 0,4L/ha with the insecticide thiamethoxam, 141g/L + lambda-cyhalothrin, 106g/L at a dose of 0,35L/ha with and without addition of Nutrol Max to 0,1%, v/v. When preparing the mixtures, a bright blue marker was added to the concentration of 6g/L. The tips used were simple flat jet AXI 11002 (400kPa), full cone jet JFC 8002 (700kPa), both generating fine droplets, and empty cone jet ATR 2.0 (700kPa), very fine drops. The spacing between tips used was 0,5m. For the AXI11002 tip, spraying was performed on the speed of 11km/h with bar height 0,5m from the highest point of the crop. For the JFC 8002 and ATR 2.0 tips, the application speed was 14,5km/h, while the height of the bar was 0,75m. The application rate was 100L/ha, for all sprays. During the test, the temperature was 27oC±1,0, relative humidity of 32±2% and wind speed of 9,45km/h±1,2 with a predominance of wind in the SW direction. Leaflets were collected from 20 points samples for each treatment. For the deposit analysis, the spectrophotometry technique and for coverage analysis, we used image analysis software (WinDias).

RESULTS

At Figure 1 shows the results of deposit (a) and coverage (b) in lower stratum of plants, and in Figure 2 the spatial distribution of drops on target depending on the spray tip models without and with Nutrol Max.

CONSIDERATIONS

A Application efficiency, among other things, depends on the spray solution and the tip used. The increase in syrup quality provided by Nutrol Max combined with the ATR 2.0 tip (very fine drops) was the combination that most increased deposition and coverage in the lower third of plants, compared with the isolated mixture of pesticides.

Antônio A. C. Tavares, João V. Oliveira, José G. C. Theodoro, Waldyr A. B. Cunha, Adenilson S. Silva, Matheus P. Ronqui and Rone B. Oliveira, Univ. State of Northern Paraná (Uenp)