The goal of our project was to determine if row placement would help minimize the risk of bloom drop on pole lima beans during days with sustained high air temperatures. We planted (8) 100’ rows of pole limas in an East/West direction and (8) 100’ rows in a North/South direction. We kept all growing techniques the same for both plots (plant date, fertilizer, pH, pesticide usage, irrigation, etc). We found that although we did have hurricane damage 2 weeks before first scheduled harvest the row that were run in east/west direction had approximately 60 percent better yield than rows run in a North/South direction. Because of wind damage from the hurricane, especially in North/South rows, this percentage could be higher than should be expected. East/West rows did grow better and mature earlier than North/South rows although interior row temperatures averaged 3 degrees F warmer in East/West rows. Because of the damage sustained from hurricane we would like to do this research for another year so that we can solidify this research for other pole lima growers.
We have a 200 acre farm on which we farm 7 acres of fruit and vegetables and rent 90 acres to a local crop farmer. The other 100 acres are in forest. We grow pole lima beans, sweet potatoes, strawberries, blueberries, blackberries, tomatoes, pumpkins, gourds, cut flowers, peaches and melons. We also raise about 100 layer hens.
My technical advisor is Mike Wasylkowski who is a small farm extension educator with Delaware State University. Mike has a lot of experience with pole lima bean trials and research. We use Helena Chemical to do soil testing, leaf analysis, and IPM.
We grew (8) 100’ rows of pole lima beans (Dr. Martin variety) in East/West row placement and (8) 100’ rows in North/South row placement. We space 4”x4” poles 20’ apart per row and run high tensile wire across the top of the poles. Plastic trellis netting is attached to high tensile wire using plastic zip ties. We weave 17 gauge soft wire through the bottom of trellis netting to keep it from blowing in the wind while plants are still small. We use 36” black plastic mulch and drip irrigation which is gravity fed from a 1000 gallon poly water tank. Transplants were set on June 24th and 25th at 4’ plant spacing. We spread a pre-plant 10-20-20 fertilizer at 400 pounds/acre along with necessary lime to get our soil pH to 6.0. We supply ¼” of water every 5 days and once pin pods show we raise that to ½” of water every 5 days. Between rows is tilled as needed. Once plants begin to grow well the runners are “trained” to the trellis netting daily. We had a total of (4) separate harvests and beans are hand picked into 5/8 bushel baskets.
The total unshelled harvest in East/West 800 row feet was 404.3 lbs (20.2 bushel).
The total unshelled harvest in North/South 800 row feet was 247.5 lbs (12.5 bushel).
East/West row placement looked better (fuller and greener), matured more quickly, and finished with better yield. It should be noted, however, that we had a once in a hundred year hurricane 2 weeks before our first scheduled harvest and the North/South rows were damaged much more than East/West rows. A good indicator of how much more sustained winds the North/South rows endured can be found when we look at the first 4 rows (West side) of North/South rows. The total harvest off of those 4 rows was 64.0 lbs (3.2 bushel). Total harvest off of the back 4 rows (East side) was 183.5 lbs (9.3 bushel). After taking daily air temperature recordings daily within rows we found that the East/West row placement averaged 3 degrees F warmer than North/South row placement. We also compared yield in outer rows versus inner rows. Outer rows in East/West row placement yielded 203.2 lbs (10.2 bushel) and inner rows yielded 201.1 lbs (10.0 bushel). So there was no discernible difference comparing inner to outer rows in East/West row placement. However, in North/South row placement outer rows yielded 90.6 lbs (4.5 bushel) and inner rows yielded 156.9 lbs (8.0 bushel). We must attribute this yield difference to plants being wind beaten on outer rows. We had a total of 4 pickings before plants were killed by frost.
The big issue this year that we encountered on our farm this year was Hurricane Irene. In this area (southern Delaware) we have not seen a hurricane like this in one hundred years. We had 2 days of extreme winds and received 9.5 inches of rain in those 2 days. Hurricane Irene hit our shores two weeks before our scheduled first harvest. One of our rows was knocked down during the storm so we worked for 5 hours during the midst of the storm to stabilize the rest of the rows. The rest of the rows held but were certainly wind damaged. As a side note, the row that was knocked over ended up with the highest final yield of 69.8 lbs! This is certainly proof that wind damage took its toll because although the row went down, it was shielded by the other rows once it did.
We sell pole lima beans unshelled for $50.00 per bushel. East/West row placement yielded a total of 20.2 bushel @ $50.00 per bushel = $1010.00. North/South row placement yielded a total of 12.5 bushel @ $50.00 per bushel = $625.00. So we made $385.00 more on 800 row feet running East/West than 800 row feet running North/South. We do, however, have to keep in mind that the 800 row feet of North/South pole lima beans sustained more wind damage during Hurricane Irene than did the East/West rows. There was no significant difference in pesticide cost/savings as we had to spray both plots twice for aphids and bean worms. Both plots were also sprayed for Downy Mildew late in the season.
Weather can be that one variable that cannot be controlled on the farm. While this research project showed a definite profit in pole lima beans in rows running East/West versus North/South, Hurricane Irene did alter the findings. We are going to put in electric poles on the ends of our rows for better stability in high wind/heavy rain situations. We currently use 4”x4” post on the ends with 2’ buried and 6’ above ground. Our electric poles will be buried 3’ with 6’ above ground. They will also be attached to ground augers using high tensile wire and crimps. While early research showed east/west row placement to be more profitable we feel as though one more year of research should be conducted due to hurricane wind damage sustained in north/south rows.
I would like to do this project again in 2012 to determine how much yield was affected by Hurricane Irene. When I speak at seminars and field days, growers always want to know which row placement direction is best. I let them know my findings but always follow that up by letting them know that another year of data (without a Hurricane) would really solidify the numbers. By using only the data from 2011, running pole lima row placement in East/West direction was clearly the most profitable.
Our outreach started on the farm with SARE signage. We designed and purchase two signs explaining our research and crediting Northeast SARE with partial funding of the project. This was very important with this particular crop because most of our pole lima sales are here on the farm. I was a speaker at Delaware State University on August 13, 2011 and discussed my pole lima project as well as the procedure for acquiring a SARE grant. I was a speaker at DSU Research Center on October 5, 2011 for a pole lima field day for growers. I discussed our methodology for growing pole limas and explained early results from our project. We have had tremendous interest on this topic at all of the events we have been a part of. We held an on-farm field day on November 12, 2011 to let growers tour our pole lima production fields and answer any questions that they had. This was a huge success and farmers were able to gain knowledge of not only pole lima production techniques but also of the role that SARE plays to allow us to conduct this research.
I will be putting in 8 more 100′ rows of pole limas in a North/South row direction. This process starts by putting in (10) treated 4×4 posts every 10′. Parallel to those posts at a distance of 6′ we put in (10) more treated 4×4 posts. We connect the post with a post parallel to it with treated 2×4’s. This adds to the stability of the "double row". Next we add 4×4 braces at each of the 4 end posts at a 45 degree angle. Again, adding to the stability of the "double row". The next stage is attaching netting to the posts 12" up from the ground to the top of the posts which are 6′ tall (4′ underground and 6′ above). Finally we add a cable to the top of each side of "double row" running the entire 100′ and attach them to ground augers. We do all this 4 times for a total of 800 row feet. We run plastic and drip fertigation for each row. Transplants are set around June 1 at 3-4′ spacing. As you can see, putting in the necessary equipment used for growing Pole Limas is both labor intensive and costly. We find it necessary due to both windy conditions and the weight of the plants themselves.