The University of Kentucky Extension and Iowa State University's Armstrong Research and Development Farm recommend the use of Curbit 3E for pumpkin crops. The product is a pre-emergent herbicide effective for annual grasses and a number of broadleaved weeds. The product can cause injury to pumpkin crop when used on wet, clod-filled ground or prior to heavy rain. Avoid using over or under hot caps, plastic mulch or row covers in pumpkin field and do not incorporate into soil.
Command 3ME is cited as among the "good" pumpkin herbicides by the University of Kentucky Extension. The pre-emergent herbicide effectively controls the growth of small seeded broadleaves and annual grasses. Read product label carefully to determine exact rates of application and precautions. Use Command 3ME in the middle areas of the rows between the plastic. Avoid getting the chemical under the plastic.
Sandea 75DF controls the growth of broadleaved weeds and nut sedge in pumpkin crops as recommended by University of Kentucky Extension. The pre-emergent herbicide is best used on pumpkin fields after planting is complete but before the plants start to emerge. If it is late for this then it is suggested to wait until crop reaches a two- to five-leaf stage. Read label carefully for specific information regarding transplanted crops.
Aim 1.9 EW is another good post-emergent herbicides for the control of broadleaved and perennial broadleaved weeds in pumpkins. The product may be used as a pre-transplant, preplant or before pumpkin plants start to emerge. Aim 1.9 EW is very effectively on weeds up to 4 inches tall in their active state of growth. The herbicide may also be used between the row crops, as cited by the University of Kentucky Extension.