Abstract:
The method for planting potatoes at high speed includes the steps of providing a press wheel behind the seed release mechanism; opening a furrow in a soil; dropping potato seed pieces at spaced intervals in the furrow such that each seed piece or a portion thereof intersects a forward shadow of the press wheel, and catching and decelerating each seed piece against the soil in the furrow thereby reducing set roll in each seed piece. In an alternate embodiment a pair of spaced-apart press wheels are used. These alternate press wheels are mounted astride the furrow in a positive-camber alignment for moving the soil of the furrow against the seed piece.

Description:
This is a divisional application of application Ser. No. 13/986,700, filed May 28, 2013. 
    
    
     FIELD OF THE INVENTION 
     This invention pertains to potato planting machines and more particularly it pertains to a method for planting potatoes. 
     BACKGROUND OF THE INVENTION 
     Potato planters from the prior art have not addressed the difficulties created by the momentum of the seed pieces when planting potatoes at high speed. For example, the following documents describe potato planters that are handling seed pieces one-by-one using a series of buckets mounted along a chain. The chain rotates at a same speed as the ground speed of the planter. As the chain rotates, the buckets drop seed pieces in a furrow at spaced intervals. These documents are: 
     U.S. Pat. No. 3,570,424 issued to J. H. Wigham on Mar. 16, 1971; 
     U.S. Pat. No. 3,690,511 issued to J. H. Wigham on Sep. 12, 1972; 
     U.S. Pat. No. 6,244,201 issued to W. Mauch et al., on Jun. 12, 2001. 
     Similarly, other types of agricultural planters are not addressing the momentum of seed pieces. The following documents describe seed planters having a press wheel mounted thereto for pressing the soil of the furrow against the seeds. The press wheels are mounted far behind the seed-drop chute and have no effect on the momentum of the seeds. These agricultural planters are described in the following documents: 
     U.S. Pat. No. 4,493,272 issued to L. M. Rouhotas, on Jan. 15, 1985; 
     U.S. Pat. No. 4,579,071 issued to D. J. Johnson on Apr. 1, 1986. 
     The documents found in the prior art comprise fixed-speed potato planters and agricultural planters that are designed to handle small seeds such as corn, wheat and other grains and soybeans, wherein the mass of these seeds is very low as compared to seed potatoes. Therefore, a search of the prior art has not given any suggestion for planting potatoes at higher speed than those used at the present time. 
     Different from cereals, corn, and bean crops, potatoes are not grown from seeds per se, which are relatively small in size and have little mass. Potatoes are grown commercially by farmers from cutting tubers or seed potatoes from the previous year&#39;s crop. When seed potatoes are cut into “seed pieces” or “sets” they can weigh from 1 oz., or less to 3-½ oz., or more. The seed run can also contain small round uncut seed potatoes mixed in with these larger irregular-shaped cut seed pieces. 
     “Seed potato”; “seed piece”; “set” and “potato seed piece” are used interchangeably in this document, to designate a whole tuber or a portion thereof that is used to germinate a potato plant. 
     Potato planters in general are used to separate and release seed pieces at a predetermine spacing in a row. Common spacings are 10, 12, 14, 18 and up to 24 inch. Most potato planters in the industry can achieve very good results at slow ground speeds. However, the seed spacing becomes inconsistent when these planters are pulled at ground speeds exceeding 2.5 to 2.8 mph. After the seed is released at high speed, it falls into the furrow and rolls until it loses all of its forward momentum. This is called “set roll”. A certain amount of set roll would be acceptable if all the seed pieces had the same amount of set roll. That is not the case, however. In North America, growers usually cut their seed potatoes in parts which means that the seed pieces do not have an uniform shape, sizea and weight, and therefore, not the same ability to roll. 
     It is well known that when planting speeds exceed 2.5 mph, set roll begins to greatly affect the seed spacings. Despite of this, most potato growers don&#39;t go that slow during planting. Most growers want to take advantage of a sunny and dry period in mid-May usually, to plant their fields as early and as quickly as possible to maximize the number of growing days before harvest. Therefore, a majority of potato growers in Eastern Canada plant their fields at high speeds such as 4, 5 and even 6 mph when planting Russet-Burbanks™ or Gems™ varieties, for examples. These varieties are planted at 14 inches to 18 inches apart. Although the mechanisms of common planters work well at high speeds, these planters cannot release the right amount of seeds per acre, at the right spacing when planting speed exceeds 2.5 to 2.8 mph. 
     Seed piece spacing is critical to achieve an ideal yield per acre from a field. When the plants are too close to each other, the crop potatoes are small. When the plants are too far apart, the yield per acre is low and the crop potatoes may be larger than the ideal market size. 
     Therefore there is a need in the potato growing industry for a method of reducing set roll when planting seed pieces at higher speeds than the present limitations. 
     SUMMARY OF THE INVENTION 
     In the method for planting potatoes at high speed, according to the present invention, seed pieces are dropped in the forward shadow of a press wheel. The press wheel catches and decelerate each seed piece against the soft harrowed soil of the furrow for reducing set roll. More specifically, this method includes the steps of: opening a furrow in a soil; dropping seed pieces at spaced intervals in the furrow such that each seed piece or a portion thereof intersects a forward shadow of the press wheel, and rolling a soft portion of the press wheel over each seed piece for decelerating and reducing set roll in each seed piece. 
     In another aspect of the present invention, the method includes the step of tucking each seed piece in the furrow before closing the furrow over the seed piece. 
     In yet another aspect of the present invention, the press wheel has firm sides and a soft and flexible center. The firm sides prevent the wheels from sinking strongly into the furrow. The soft and flexible center of the press wheel softly catches each seed piece and lightly presses the seed piece against the soft harrowed soil of the furrow for decelerating the seed piece into the soft soil of the furrow. The soft center of the press wheel has flexibility to catches seed pieces of all sizes and shapes and to impart a consistent deceleration to all these seed pieces. 
     In a further aspect of the present invention, there is provided an arrangement of equipment for planting seed pieces at high speed. This equipment includes a potato planter having in series; a plow or a furrow-opening shoe, a seed drop chute and a pair of closing discs. More particularly, this equipment includes a press wheel mounted between the seed drop chute and the closing discs. In that arrangement, the seed drop chute has a deflector therein for deflecting seed pieces toward the forward shadow of the press wheel. 
     The words “plow”; “plough” or “plough-share” were used in the prior art to designate a pair of V-shaped plates that were mounted to a planter to open a furrow in the soil. Modern potato planters refer to that element as a “shoe”, and therefore, the words “furrow-opening shoe” is used herein to designate this element, the function of which is to open a furrow in a harrowed soil. 
     Testing of the present method with a variety that was planted at 10 inches apart, has given consistent seed spacings, with very little set roll, at planting speeds of up to 4 mph. It is believed that better results can still be obtained after adjustment of the downward force on the press wheel and adjustment of the dimensions and relative position of the furrow-opening shoe. 
     This brief summary has been provided so that the nature of the invention may be understood quickly. A more complete understanding of the invention can be obtained by reference to the following detailed description of the preferred embodiment thereof in connection with the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A preferred embodiment of the method according to the present invention is described with the aid of the accompanying drawings, in which like numerals denote like parts throughout the several views, and in which: 
         FIG. 1  is a plan view of the preferred equipment for planting potato seed pieces at high speed; 
         FIG. 2  is a side elevation view of the preferred equipment shown in  FIG. 1 ; 
         FIG. 3  is a cross section view of a planting groove or a furrow made by the preferred equipment at location  3  along the furrow as indicated in  FIG. 2 ; 
         FIG. 4  is a cross section view of a planting groove or furrow made by the,preferred equipment at location  4  along the furrow as indicated in  FIG. 2 ; 
         FIG. 5  is a cross section view of a planting groove or furrow made by the preferred equipment at location  5  along the furrow as indicated in  FIG. 2 ; 
         FIG. 6  is a cross section view of a planting groove or furrow made by the preferred equipment at location  6  along the furrow as indicated in  FIG. 2 ; 
         FIG. 7  is an enlarged view of the press wheel portion of  FIG. 2 ; 
         FIG. 8  shows a rear view of an alternate embodiment of the press wheel included in the preferred equipment; 
         FIG. 9  is a cross-section view of one of the press wheels in the alternate embodiment, as seen along line  9  in  FIG. 8 . 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to  FIGS. 1 and 2 , the preferred equipment required to carry out the method according to the present invention will be described. The preferred equipment comprises in series, a furrow-opening shoe  20 , a seed drop chute  22 , a press wheel  24  and a pair of closing discs  26 . The preferred furrow-opening shoe  20  has a one-inch diameter cutting bar  30  thereunder for opening a furrow  32  in the soil. The preferred furrow-opening shoe  20  has a slender shape with a total width “A” of about 3 inches and an effective soil-contacting length of about 12 inches. These dimensions are not essential as a slightly more obtuse shoe shape has also given satisfactory results. 
     The preferred seed drop chute  22  has a deflector  34  mounted therein to cause the seed piece to be diverted toward the press wheel  24 . The press wheel is mounted in such a way as to press down against both sides of a furrow  34 . The press wheel  24  has a preferred diameter of about 10 inches and a preferred width “B” of about 7 inches. It is made of two relatively narrow hard-rubber casters covered by a flexible membrane  36  extending the full width thereof. The membrane  36  covers a void between the casters such has to form a soft region around the central circular portion of the press wheel  24 . The soft circular region preferably extends over a width of about one third of the total width of the wheel. Each of the harder side circular regions covers a width of about one third of the total width of the wheel  24 . 
     The press wheel  24  is supported on bearings (not shown) in a pair of arms  38  and can be forced against the soil by the movement of these arms  38 . The preferred distance “C” between the center of the press wheel  24  and the effective tip of the furrow-opening shoe  20  is about 24 inches. 
     The structure and function of the closing discs  26  are well known in the art and therefore do not need any explanation. 
     Referring now to  FIGS. 3, 4, 5, and 6 , the operation of the preferred equipment will be explained. Firstly, the furrow-opening shoe  20  opens a furrow or groove  32  in the soil. That groove has a width of 2 to 3 inches and a dept which is about twice or slightly more than the size of an average seed piece. In  FIG. 4 , a seed piece  40  is planted in the furrow  32  immediately ahead of the press wheel  24 , such as to be immediately pressed by the wheel  24  against the bottom of the furrow  32  to prevent set roll. 
     In operation, each seed piece  40  is deflected to fall within the shadow of the press wheel  24 . The seed piece  40  is captured against the soil by the soft region of the press wheel  24 , while the harder sides of the press wheel  24  push the soil from the sides of the furrow into the furrow  32  closing the furrow against the seed piece  40  and partly covering the seed piece  40 , as illustrated in  FIG. 5 . This action of the press wheel  24  against the seed piece is referred to as tucking the seed piece  40  into the furrow  32 . Then, the closing discs  26  bring more soil over the seed piece  40 , forming a row  42  of potato plants as shown in  FIG. 6 . 
     Referring now to  FIG. 7 , the best placement of seed pieces relative to the press wheel  24  will be explained. A vertical projection “D” of the forward half of the press wheel  24  is illustrated by a shaded area  50  in  FIG. 7 . The region defined by the shaded area  50  is referred to as the forward shadow  50  of the press wheel  24 . During planting seed pieces at high speed, it is preferable to deflect each seed piece  40  such that it will fall within the forward shadow  50  of the press wheel, but without hitting the press wheel  24 . High speed planting is also possible with minimum set roll when the seed piece falls slightly ahead of the press wheel  24  with only a portion thereof intersecting the forward shadow  50  such as illustrated by seed position  40 ′. 
     Although a wide press wheel  24  with a soft middle portion has been described in the preferred equipment, it will be appreciated that good results can also be obtained using equivalents. Such equivalents include a belt on two rollers, a caterpillar track, a skid plate and a flexible trailing flap, or other devices from which a moving shadow  50  and its association with a catching action can be defined. 
     Referring now to  FIGS. 8 and 9 , a rear elevation view and a cross-section view of an alternate embodiment of the press wheel  24  respectively, are illustrated. In this alternate embodiment, a pair of press wheels  54  are mounted in a spaced-apart relationship, astride the furrow  32 . The plans of the press wheels  54  are tilted in a positive-camber-like alignment of about 25° to 35° from a vertical line, with their bottom regions being closer to each other. The press wheels  54  are mounted that way for pressing simultaneously on both sides of the furrow  32 , for closing the furrow on the seed piece  40  and for more effectively tucking the seed piece  40  into the furrow for reducing set roll. 
     The press wheels  54  are preferably larger in diameter than the previously-mentioned press wheel  24 , and the spacing there between reduces the possibility of a seed piece  40  hitting one of them. The preferred diameter of the press wheels  54  is about 14 to 18 inches. This arrangement increases the length D′ of the forward shadow  50 ′ in which a seed piece  40  can fall and be captured by the closing soil of the furrow, for preventing set roll. It will be appreciated that the method mentioned before in relation with the press wheel  24  also applies to the use of the pair of tilted press wheels  54 . The pair of tilted and spaced-apart press wheels  54  eliminates the step of rolling over the seed pieces and improves the tucking step mentioned before. The step of dropping seed pieces at spaced intervals in a furrow such that each seed or a portion thereof intersects the forward shadow of a press wheel, still applies whether the wider press wheel  24  or the pair of narrower press wheels  54  are used. 
     The pair of press wheels  54  are mounted on movable arms  38 ′ substantially the same way as explained before, with the ability to adjust the downward force on the wheels  54  against the soil. Another advantage of the press wheels  54  of the alternate embodiment, it that a seed piece  40  can be dropped between the wheels  54  and still benefit from the tucking effect of the wheels  54  to prevent set roll. It will be appreciated that the effective span in which a seed piece  40  can be dropped relative to the pair of press wheels  54 , extends forward and back where the seed piece or a portion thereof intersects the forward shadow of the press wheel, whether it is the forward boundary of the shadow  50 ′ as shown by position  40 ′ or the rearward boundary of that shadow  50 ′, as shown by position  40 ″ in  FIG. 9 . 
     Because a press wheel has an inherent amount of slip against the soil, it is also contemplated to provide a drive system to rotate the press wheels  54  or the previously mentioned wider wheel  24  to match ground speed and to reduce the friction of the wheels against the soil. 
     As to other details and manner of operation of the preferred equipment, for planting seed pieces at high speed according to the present invention, the same should be apparent from the above description and drawings, and accordingly further discussion related to these aspects is deemed unnecessary.