Revista Brasileira De Herbicidas 2019; 18(4): 1-8

ISSUE Cover

INTERFERENCE OF SOIL COMPACTION ON DICLOSULAM RESIDUAL

DOI: 10.7824/rbh.v18i4.687

The residual herbicides in the soil can be influenced by several factors, including soil compaction. The objective of this study was to evaluate the influence of soil compaction on selectivity of diclosulam to soybean, as well as the carryover effect on the corn in succession. The experiment was carried out in clay and sandy soil. The experimental design was in a randomized block with four replicates. The treatments were arranged in a 3×3 factorial scheme, where A factor was level of compaction (0 – no compaction, 10 and 20%) and the B factor doses of diclosulam (0, 25.2 and 50.4 g ai ha-1) applied in pre-emergence of soybean. After soybean harvested, the columns were opened and corn and cucumber were seeding. The analyzes carried out on soybean were chlorophyll a fluorescence, shoot dry matter (SDM) and NPK content at 90 days after germination (DAG). For corn: chlorophyll a fluorescence transient was performed at 15, 30 and 45 DAG. For corn and cucumber: plant height, root length, SDM and root dry mass at 45 DAG. The herbicide residue quantification was performed by LC-MS/MS at 94 days after application. Data were submitted to ANOVA (p ≤ 0.05) and the means were compared by Tukey at 5%. Soybeans plants in both soils showed no difference in growth parameters and NPK content but photosynthesis parameters was impaired. There was no corn crop carryover regardless of soil compaction. There was a reduction of cucumber plants being aggravated in soils with compaction. No diclosulam residue was detected in solutions evaluated by LC-MS/MS.