an exemplary vine training system according to the disclosure is shown in fig2 shows a plurality of vineyard stakes 10 positioned in a grid pattern throughout a vineyard . training wires 12 are engaged with openings 14 formed in the stakes 10 to hold the wires at a desired position above the ground . as can be seen , the stake / wire engagement does not require the use of clips . fig3 a - 3c show an exemplary vineyard stake 10 , which may be an elongated tubular ( i . e ., hollow ) member having a length “ l ,” and first and second ends 16 , 18 disposed at opposing ends thereof . a plurality of openings 14 may be formed through the wall of the member at spaced apart intervals along the length “ l .” the first end 16 may be configured for receiving a driving force by , for example , a sledgehammer , to enable the stake 10 to be driven into soil at a desired location . in one embodiment , the second end 16 is simply a flat end . the second end 18 may include one or more points 20 to facilitate penetration of the soil during the driving operation . in one embodiment these points 20 can be formed by laser cutting , though other cutting / forming techniques could also be used . in one embodiment , the stake 10 is a steel tube having a square shape in cross - section ( see fig3 c ), with side lengths “ sl ” of about 1 . 5 inches . the tube may be formed from 16 gage material ( 0 . 065 - inch nominal wall thickness “ t ”). the length “ l ” may be about 96 - inches . making the stake 10 from such a square tubular member provides a desired high stiffness for the stake which will not buckle or bend when the stake is hammered into hard soil . as noted , the stake 10 can include a plurality of openings 14 formed in the stake wall . as more clearly seen in fig3 b , pairs of openings 14 a , 14 b are positioned in direct opposition on the sides of the stake 10 . this arrangement enables a training wire 12 to be engaged with either side of the stake 10 . it also could enable a pair of training wires 12 to be engaged a single stake . it will be appreciated , however , that providing opposing openings is not critical , and that only a single opening ( 14 a or 14 b ) could be used . fig3 b shows the geometry of the openings 14 which , in the illustrated embodiment , appear as t - shapes that have been rotated by 90 - degrees . each opening 14 includes a central horizontal leg 22 , a vertical leg 24 and upper and lower horizontal legs 26 a , b . the upper and lower horizontal legs 26 a , b may be configured to form a protruding nub 28 that resists movement of the wire 12 back toward the vertical leg 24 once the wire has been received in the associated leg 26 a , b . fig4 a shows a side view of the stake 10 of fig3 a . as can be seen , the plurality of openings ( in this case openings 14 a ) are disposed on the observable side of the stake 10 at spaced apart intervals “ cs .” in one embodiment the interval “ cs ” is about 6 - inches , which provides about eight individual openings 14 a along the length “ l ” of the stake 10 while retaining a desired column strength and stiffness of the stake . as previously noted , the first end 18 of the stake 10 may be configured to receive a driving force by , for example , a sledgehammer , to enable the stake 10 to be driven into soil at a desired location . thus , the opening 14 adjacent to the first end 18 may be offset from that end by an offset distance “ os ” to the end retains sufficient strength to withstand the driving force without being damaged . in one embodiment , the offset distance “ os ” can be about 1 - inch . fig4 b shows a rotated view of one of the openings 14 a as compared to the view of fig3 b . as can be seen , the opening 14 a appears as a linked pair of rotated “ t ” shapes having central horizontal leg 22 , vertical legs 24 and upper and lower horizontal legs 26 a , b . importantly , the openings 14 are positioned so as to span the corners of the stake 10 . with reference to fig4 b , opening 14 a is shown spanning an associated apex 30 of the square tubular stake 10 so that one half of the opening 14 a the resides on one side of the stake 10 while the other half of the opening resides on the adjacent side of the stake 10 . such an arrangement enables easy engagement of a training wire 12 with the openings 14 a , b , and also ensures that the stake 10 retains substantial strength and stiffness . the openings 14 a , b can be laser cut into the tubular stake 10 to form the arrangement shown in fig3 a - 4b . alternatively , the openings can be punched into strip material that is used to form the tubular stake 10 . the openings could also be roll - punched after the tubular member has been formed . fig5 a - 6c illustrate a second embodiment of a vineyard stake 100 in which the openings 114 have a rotated “ c ” shape in lieu of the “ t ” shape of the previous embodiment . as compared to the embodiment of fig3 a - 4b , stake 100 may be stiffer and stronger because the openings 114 require the removal of less material from the walls of the stake . as with the previous embodiment , the openings 114 are formed so as to span an associated apex 130 of the stake 100 to enhance the strength and rigidity of the stake while facilitating easy engagement of a training wire 12 with the openings 114 . fig5 b and 6b show the details of one of the openings 114 of the stake 110 . as noted , the openings 114 of this embodiment have a rotated “ c ” shape that includes an upper horizontal portion 116 that crosses the apex 130 of the stake 110 , and a pair of descending legs 118 that run downward and slightly inward toward the apex 130 of the stake . as such , the opening 114 forms an included protrusion 120 having first and second side tab portions 122 a , b . the protrusion 120 and side tab portion s 122 a , b serve to retain a training wire 12 in the opening 114 . the stake 110 may be made from similar materials , and may have a similar overall geometry ( i . e ., length “ l ,” spacings between openings “ cs ,” offset distance “ os ,” tubular profile with side lengths “ sl ” and nominal thickness “ t ”) as compared to the stake 10 described in relation to fig3 a - 4b . in addition , the stake 110 may have an end include one or more points 20 to enable the stake to penetrate the soil . further , the openings 114 may be cut , punched or otherwise formed in the same manner as that described in relation to fig3 a - 4b . it will be appreciated that although two particular designs have been described in relation to the disclosed openings 14 , 140 , other designs can also be used . in addition , it is contemplated that different opening designs may be used on a single stake 10 , 100 . fig7 and 8 show a plurality of different positionings of training wires 12 in openings 14 of the stake 10 of fig3 a - 4b . fig7 shows that a training wire can be engaged either with the upper horizontal legs 26 a of the opening 14 , or with the lower horizontal legs 26 b of the opening . this arrangement provides a fine level of vertical adjustment of training wire 12 in cases in which moving the training wire 12 to the adjacent opening 14 would result in too great a vertical distance increase for accommodating a particular increment of new vine growth . fig8 shows the positioning of a training wire for application in which the stakes 10 are installed on a hill or slope . thus , the linked pair of rotated “ t ” shapes of the opening 14 enable the wire 12 to be run at an angle . as can be seen , the training wire 12 is received in the upper horizontal leg 26 a of one linked t - shape , and in the lower horizontal leg 26 b of the other linked t - shape . as previously noted , the disclosed stakes 10 , 110 may be driven into the ground by applying force to the first end 16 using , for example , a sledge hammer . fig9 shows a detail view of the second end 18 of the stakes 10 , 110 which , as previously described , includes a plurality of points 20 to facilitate penetration of hard soil . in one embodiment , the first end 16 may be a closed section to provide an impact surface for the sledge when driving the stake 10 into the ground . a cap ( now shown ) can also be used to further protect the first end 16 of the stake 10 from hammering damage during installation . such a cap may be a closed - end pipe section that can fit down over the first end 16 of the stake 10 to ensure that force is applied even to the first end as the sledge strikes . the stake 10 , 100 can be formed from a steel roll - form shape , preferably a square tubular roll form shape . the steel stake 10 , 100 can also include a galvanized coating to minimize corrosion during extended exposure to the outdoor environment . referring now to fig1 a - c , and 11 a - d an exemplary end post 200 is shown for use in maintaining one or more training wires 12 at a desired tension in use . as can be seen from fig2 , the vine training system can include a large number of vineyard stakes 10 positioned in a grid pattern throughout a vineyard . for even moderately sized vineyards , the training wires 12 can be strung across substantial distances . although the disclosed vineyard stakes 10 , 110 will be positioned across the vineyard to hold the training wires 12 at a desired distance above the ground , the wires 12 must still be held at the ends . thus , the training wires 12 can be engaged with a pair of end posts 200 positioned at opposite ends of each wire . in the illustrated embodiment , the end post 200 includes a plurality of openings positioned in spaced apart relation along the length of the post to enable a training wire 12 to be coupled to the end post 200 at a variety of distances above the ground . a first set of openings 210 facilitate attachment of one or more ratchet tensioning devices 212 shown in fig1 a and 11b . a plurality of ratchet tensioning devices 212 may be installed at spaced apart intervals along the length of the end post 200 . in one embodiment , a first ratchet tensioning device 212 is positioned about six inches from a top end 214 of the end post 200 . additional ratchet tensioning devices 212 can be spaced at twelve inch intervals along the length of the end post . in use , a ratchet tensioning device 212 is coupled to a first end post 200 and connects to one end of the wire 4 . in one embodiment , the end post 200 includes one or more threaded inserts 213 , received in openings 210 , which enables the tensioning devices 212 to be bolted directly to the post . the opposite end of the wire 4 may connect to an opposing end post 200 by feeding through an attachment element 216 fitted within an attachment opening 218 . on an inside surface of the end post 200 , the wire 4 may wrap around and back through another opening 220 so that the wire exits the post on the same side that it enters ( see fig1 b ). this arrangement reduces the chance for user injury from contact with wires extending from a back side of the post . the attachment element 216 may include first and second portions 216 a , 216 b , where the first portion 216 a is a tubular element that fits within the attachment opening 218 and the second portion 216 b abuts a surface of the end post 200 to prevent the tubular element 216 from being pulled through the opening under tension from the wire 4 . the first and second portions 216 a , b may each have an opening sized to receive the wire 4 to enable the wire . in one embodiment , the opening in the first and / or second portion 216 a , b includes features that enable the wire 4 to be fed through in a first direction , but prevents the wire 4 to travel in the reverse direction . thus , in one embodiment , directionally oriented teeth are provided in the opening of the first and / or second portion 216 . alternatively , the first portion 216 a may be crimped down on the wire once the wire is positioned within the attachment element 216 . once the wire 4 is fixed between an attachment element 216 of a first end post 200 and a ratchet tensioning device 212 of an opposite end post 200 , the ratchet tensioning device can be actuated to draw the wire 4 tight between the end posts 200 . the end posts 200 can be any of a variety of roll form shapes . in one embodiment , the end posts 200 are square tubular members having three inch sides , and are made from 11 gauge steel . the end posts 200 may also have a protective coating to prevent corrosion . in one embodiment , the end posts 200 are galvanized . the end posts 200 may have a bottom end 216 that can be flat , or it may have a pointed profile similar to that described in relation to fig9 to facilitate driving of the end post 200 into hard soil . as shown in fig1 d , the end posts 200 may be installed at an angle with respect to the ground . this angled installation can reduce the chance for sagging of the wires in use by providing a desired counter - tensioning of the end posts . it will be appreciated that the disclosed design is not limited to use in vine training applications . thus , the disclosed stake can also find use in other applications , such as fence or barrier systems . the stake could also be used as part of a highway cable barrier system . while the invention has been disclosed with reference to certain embodiments , numerous modifications , alterations and changes to the described embodiments are possible without departing from the spirit and scope of the invention , as defined in the appended claims . accordingly , it is intended that the present invention not be limited to the described embodiments , but that it has the full scope defined by the language of the following claims , and equivalents thereof .