The invention relates to a method and apparatus for applying liquids to plants. While the apparatus according to the present invention may be utilized to apply a wide variety of chemicals to plants, the apparatus and method are particularly suited for the application of liquid contact herbicides, such as ROUNDUP manufactured by Monsanto Company, to weeds.
Weed control in growing crops is a continuing problem in agriculture, and a great deal of research has been done in that area and there have been many prior art proposals and procedures for the chemical treatment of weeds. Often times one particular structure is utilized for spraying herbicides in the crop rows between plants, and then another structure is utilized for contacting weeds taller than the crop plants.
Conventional overhead herbicide applicators include recirculating sprayers and rope wick applicators. Both structures can be successful if properly utilized, however recirculating sprayers are quite complex with a tendency to clog, and conventional rope wick applicators can apply less than the desired amount of herbicide to plants unless operating parameters are entirely appropriate. Further, neither system is readily adaptable to between row usage.
According to the method and apparatus of the present invention, a rotating roller is utilized as a primary herbicide-applying component. While the utilization of rotating rollers per se has previously been proposed, such proposed structures conventionally have dripped herbicide onto rollers directly in contact with the ground and have been adapted to be rolled over the ground. Such structures therefore have limited utility for the application of herbicide to weeds adjacent crop rows. According to the present invention, a rotating liquid applicator roller is readily utilizable for applying herbicide simply and effectively to weeds between crop rows and to weeds growing above crop rows with equal efficiency. The apparatus according to the invention is readily adapted for mounting to a tractor tool bar, or to be pushed by hand.
According to the method of the present invention, a liquid applicator roller is mounted for rotation about a generally horizontal axis and in operative communication with a reservoir of liquid herbicide. The method includes the steps of: Mounting the applicator roller above the ground and in a position for the peripheral surface thereof to be brought into contact with plants. Effecting movement of the applicator roller in a direction generally perpendicular to the axis of rotation of the roller. And, effecting powered rotation of the applicator roller so that it rotates into contact with plants and continuously transfers liquid from the surface thereof onto the plants, the surface being continuously replenished with liquid from the reservoir. Preferably rotation of the roller is effected in a direction of rotation so that it rotates into plants with which it comes into contact, providing a thorough wiping effect of herbicide onto the plants. The method may be practiced by moving the roller just above ground level between rows of crops, while positively preventing the roller from contacting crops in the rows on either side thereof; or by moving the roller above the tops of the crop plants to contact any plants extending upwardly above the tops of the crop plants.
The apparatus according to the invention includes a liquid applicator roller and a liquid reservoir and means for transferring liquid from the reservoir to the applicator roller surface. The applicator roller preferably comprises a tube of hard plastic having the ends thereof capped with spindles extending outwardly therefrom to define the axis of rotation of the roller. A housing mounts the roller for rotation about a given axis while covering the roller at the top and sides but being open at the bottom to allow the peripheral surface of the roller to rotate out of the housing. The housing also mounts the liquid transferring means. Means are provided for mounting the housing and the roller applicator above the ground, with the axis of rotation of the applicator roller generally horizontal. Preferably a drive wheel is provided, and means are provided for mounting the drive wheel to the housing so that it is rotatable about an axis parallel to the axis of rotation of the applicator roller, with surface means formed on the applicator roller and drive wheel effecting rotation of the applicator roller in response to the rotation of the drive wheel. Preferably the direction of rotation of the applicator roller is opposite to the direction of rotation of the drive wheel.
When the drive wheel is utilized, it is mounted to one side of the housing while the other side of the housing is either mounted to the tractor tool bar or to a pair of ground engaging wheels. Horizontally spaced and elongated plates mounted to the housing adapt the housing for mounting either to a tool bar or to ground engaging wheels. Where a drive wheel is not utilized, the applicator roller may be powered by a motor mounted on a tractor.
A liquid pool is defined within the housing substantially the entire width thereof, corresponding to the applicator roller length. The level of liquid in the pool is substantially even with the axis of rotation of the applicator roller. Transfer of liquid from the pool to the roller may be effected utilizing a sponge, or a pair of transfer rollers. Where the apparatus is utilized between crop rows, preferably a wiper is provided mounted to the housing to wipe any liquid off the roller periphery after plant contact and before a given portion of the roller rotates back into the housing through the housing open bottom. A more remote liquid reservoir may be provided, with a conduit leading from the liquid reservoir to the pool and with a level-responsive valve located in association with the conduit.
It is the primary object of the present invention to provide a method and apparatus for simply, efficiently, and effectively applying a liquid to plants, and particularly for applying a liquid herbicide. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.