Weed control in a desert vineyard

    The following photos were taken at Santa Ana Pueblo vineyard June 23, 2020. All rows in the block were treated with the pre-emergence herbicide Chateau (flumioxazin), that has some post application activity on very small weeds (< 2 inches). This application occurred in early spring, timed to coincide just prior to some predicted rainfall. Rain is required to move the material into the soil where germinating weed seeds are located. The applications, at the labelled rate of 2-6 qts/acre were tank mixed with the adjuvant: "GROUNDED" that is available from Gemplers. After some timely rains...predicted prior to the application, the weed control was excellent. Again, the rainfall within a couple days of application are crucial for the material to be effective. Notice the difference in weed control evident in the side by side rows. The row on the left, with tumbleweeds Russian thistle (Kali tragus) present, was 'missed' by the applicator and thus received no herbicide treatment. The adjacent row on the right, was treated with the flumioxazin herbicide. The weed control is visually evident and obvious...as you can see by the lack of the Russian thistle in the treated rows...on the right hand side in the photos. 

Lack of weed control evident in left hand row, Russian thistle present. This photo was taken about two months after the herbicide flumioxazin was applied in the vine rows...with the row on the left having been skipped or 'missed'. The treated row, on the right, is relatively free of weeds including Russian thistle.

Same two rows shown from a slightly different perspective. One can see some weeds in the right hand row (treated row)...but few to no Russian thistle.