This invention relates to irrigation devices for delivering water and pesticides to agricultural crops and the like, and more particularly, to an up-spray deflector cup primarily intended for use in permitting the water discharged from a downwardly directed nozzle near the ground to be deflected upwardly to spray the underside of the plant foliage.
In co-pending application Ser. No. 901,012 filed Sep. 22, 1986, entitled "Low Energy Irrigation Device" commonly owned by the Assignee of this application, there is disclosed an irrigation device for delivering a relatively low pressure water flow in the form of a thin, substantially bubble-like film or curtain of water for close range delivery. The irrigation device of the aforementioned co-pending application, Ser. No. 901,012 the disclosure of which is hereby incorporated by reference into this application, is primarily intended to be used for the irrigation of row crops from an overhead traveling irrigation system such as the well known center pivot and linear wheel line type system, and is specifically designed for close range release of a low pressure flow of water into diked furrows to reduce evaporation losses and undesirable windage effects, and to prevent erosion.
In its most basic form, the irrigation device of the aforementioned co-pending application is attached to the lower end of a drop tube extending downwardly from an overhead water supply conduit of the traveling irrigation system, and includes a body supporting a nozzle through which a stream of water is discharged downwardly into a pressure regulated chamber. The water discharged into the chamber, which includes a bottom, substantially horizontally disposed base, and a regulator cover relatively freely and slideably supported about the body, is collected within the chamber to produce a pressure head sufficient to float the regulator cover above the base and form a narrow substantially annular gap through which the thin bubble-like film of water is emitted. An energy absorbing element may also be provided within the chamber to dissipate the energy of the water stream emitted by the nozzle.
Typically, the irrigation device of the aforementioned co-pending application is positioned to emit its bubble-like film from a height of about four inches above the bottom of the furrow, a height well below the foliage of the crop being irrigated. As discussed in the aforementioned co-pending application, in some instances such as during the germination phase of plant irrigation, it is desirable to spray water from a height well above the ground and the crop, and in such situations, the irrigation device therein disclosed is raised to a position near the overhead supply pipe, and the regulator cover is lifted out of the way or removed such that water from the nozzle is sprayed radially outwardly in a generally annular pattern by the base, thereafter to fall as droplets onto the ground.
Thus, the irrigation device of the aforementioned co-pending application is usable for both providing an overhead spray during the germination phase of crop irrigation, and during the growth period, for providing a bubble-like, low pressure irrigation stream needed for crop growth. There is, however, a third irrigation phase for which the irrigation device of the aforementioned co-pending application has not proved totally satisfactory. That phase is the chemigation phase where various chemical pesticides are added to the irrigation water to control pest infestation.
In the chemigation phase, it is desirable to spray pesticide added irrigation water onto the foliage of the crop, and preferably to the underside of the crop foliage. For example, with a row crop such as corn, pests tend to infest the underside of the plant leaves and it typically is necessary to apply chemical pesticides to the corn crop about four times during the growth cycle. To be most effective, the pesticide added irrigation water should be applied to the underside of the foliage, rather than from above the crop, thereby to insure spraying onto the crop leaves where pests are most likely to be found.
While it is possible to use the irrigation device of the aforementioned co-pending application in the chemigation mode, such use is generally restricted to turning the irrigation device upside down and looping the drop tube back upon itself so that the irrigation device may be clipped or otherwise detached in an elevated and inverted position to the downwardly extending portion of the drop tube level with the crop to be irrigated. With this positioning of the irrigation device, the regulator cover can be removed so that the nozzle sprays upwardly onto the base, and the base in turn deflects the water radially outwardly in an annular pattern onto the crop. When used this manner, however, only a small percentage of the crop foliage is irrigated on the underside as the majority of the pesticide added water falls onto the crop from above. Further it has been found that the drop tube loop formed below the irrigation device tends to become snagged by the crop as the irrigation system moves down the rows, thereby pulling the irrigation device away from the drop tube and possibly even separating the device from the drop tube itself.
There exists, therefore, a significant need for a device that can be used to divert the water discharged from the nozzle of an irrigation device of the type disclosed in the aforementioned co-pending application in an upwardly direction for spraying pesticide added water to the underside of the crop foliage, and which permits the irrigation device to be so operated without having to invert or move the irrigation device relative to the downwardly extending drop tube. The up-spray deflector cup of the present invention fulfills this need in a novel and unobvious manner.