Altitude and pesticide residu in tomatoes: study in Batu and TulungagungPurposeThis research aimed to determine the correlation between altitude and chlorothalonil residue in tomato from Batu and Tulungagung.MethodsThis study used a cross sectional design, and was conducted in two places at different altitudes, Batu (>700 m asl) and Tulungagung (<500 m asl). Tomatoes that were ready to be harvested from field that used chlorothalonil were taken as samples. Independent variables were altitude, dosage and time of application, and also frequency of spraying. Dependent variable was chlorothalonil residue in tomato.ResultsChlorothalonil residue levels in all samples did not exceed MRL (5 mg/kg). The differences between chlorothalonil residue in high and lowlands were not significant (p=0.06). There were differences in dosage application in high and lowland (p=0.004). The result of simple linear regression tests on dosage application obtained p=0.002 which has effect on chlorothalonil residue. The result of simple linear regression test on frequency of spraying obtained p=0.08 which was no effect on chlorothalonil residue. The result of Kruskal Wallis tests on time of application obtained p=0.189 which has no effect on chlorothalonil residueConclusionsChlorothalonil residue on tomatoes from lowlands (Tulungagung) is two times higher than from highland (Batu), but the differences were not significant. There were no effect between dosage application on chlorothalonil residue in tomato.