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Worthmore |
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Live in Forsyth, Missouri Farm in N, MO | Trying to figure out what population to plant this year. Here is some background info. About 30 acres no till and 30 acres conventional till. Using 30" rows with JD 7000 and Kinze brush meters with keeton firmers. Only planted soybeans for 3 years now and have always used the JD cups; THis is first year for Kinze meters, usually plant about 140000 per acre. Everything i have read says i need about 100000 plants per acre emergence for a good stand. It seems like in the past my beans have been to thick and without actually doing a count it would seem like every seed planted in the ground came up. With only a few acres, i usually have planting done pretty early (May 8th last year). I realize it may take a year or two to figure out exactly what population, but where should i start, or should i stay with 140,000 and assume the cups dropped way to many seeds. Planting on gently rolling hills in NW missouri. Also had a ittle frogeye last year, what would be a good variety to prevent this? (seems hard to get much help from seed dealers when you only plant a few acres). | ||
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| ernestf |
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| The subject of plant population in soybean is strongly debated, with (as you might expect) the seed companies tending toward the high end of the range. At 140,000, you have been doing what they want you to do. I normally suggest that growers plant around 90,000 to 100,000 per acre, without a lot of regard to row spacing since plants adjust (compensate) for the space available to them. There is good research showing that yields don't drop significantly until plant population falls below about 50,000 per acre; but we can't afford to plant to that level since a partial loss of viable plants could cause a yield loss. As with anything connected with a crop, stand can't be isolated from other issues like soil fertility, planting date, plant type, maturity group, and several other things; however if most other production issues are addressed properly the lower populations can yield just as well as the high populations. One thing I caution growers about when they plant for reduced population is to include a recommended insecticide with the first post glyphosate application to reduce any damage to the stems from three cornered alfalfa hoppers; and if you are planting no-till into debris you should have an insecticide on before plants emerge for cutworms and other pests that might reduce the stand. I feel you can justify the cost saving on seed in reduced populations; but you should take better care of the plants early to avoid stand loss. You will then likely see reduced incidence of fungal infection since you get better light penetration and airflow within the canopy; and lodging should be less of a problem. One complaint I have heard from growers is that stalks are larger and are harder on the sickle bar and tires during harvest. As for frogeye, I suggest you look for ratings done in your region since reaction can vary quite a bit. Your county should have an Extension Service office that can get you connected with the soybean specialists at the University of MO, who should be able to help you. I suggest that you use information from both Extension and industry rather than just from industry. | |||
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| earp |
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Manila, Ar | mississippi state has some good soybean pop recommendations...............i know they are a little south of you but am not so sure if location makes much difference soybean pops....................probably 100-120k is optimum for most locations and variety's | ||
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| Mizzou Tiger |
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| anyway........as for population in NWMO.....I would stick with a bare minimum of 140K drop......most run closer to 150-170K.......not saying that is right or wrong but a lot of things go into a good stand........remember that 100K final stand is assuming a perfectly even stand (not half of it missing or very thin).........that rarely happens in NWMO, you also mentioned no-till which adds another factor.......also seed treatment plays a role......you can probably fudge your planting rate lower if you use a good seed treatment as it will help develop a good even stand...... Also, narrow row soya typically do better than 30" in conditions typical of N and C MO...........so if there is anyway to get them to 15" you might also increase your yield........ Remember there are a lot of things that can happen to your stand potential from planting to 1st tri-foliate.........trying to ride that line of 100K is dicey in the best conditions and if you don't hit your mark you will likely have to spot in or replant which just defeated your purpose of balancing yield and seed cost......... I agree that overplanting is probably more common that underplanting..............just don't get too crazy.... As for frogeye.........most soya varieties have decent resistance.........most seed guides should give a rating.......if they don't find a variety that does...... Edited by Mizzou Tiger 2/6/2011 16:11 | |||
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| Gerald J. |
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| in recent years ISU's resident bean guru ( Who jumped ship to join Syngenta last year) has been pushing very early planting and no more than 120K hoping for at least an 85K stand being the most profitable. Last fall, Iowa Soybean Association's research guru put out a note that said he found more yield from 160K than from lower planting rates and indeed his raw data did show almost a bushel more than at lower planting rates. A $13 bushel of yield might almost pay for 1/3 sack of $40 seed, but not $60 seed. Palle Pedersen is talking profit, Tracy Blackmer is talking absolute yield and not much difference over the ranges of tests. Seed cups work more on volume than a seed count and are not precise in these relatively costly seed times. They are more attuned to the days of planting a bushel to the acre than a count. (140K of 2850 seed to the pound makes a 56 pound bushel). Best I can tell the penalty for planting the traditional 160K is seed cost and the benefit for cutting back to 120K or less is saved seed cost with little effect on the yield. As for planting in early May, I must presume the guru has some magic scheme to prevent frost burning off the first planting. Last year in central Iowa, corn suffered from cold on Mother's Day. Beans would have suffered more, I think. If you search this forum for "soybean population" you should find 40 or 50 discussions over the past couple years. Gerald J. | |||
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| JimmyP |
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Lancaster, OH | What you want are maximum nodes since that is where your blooms and pods are set. If population is heavy, you'll have less nodes/plant. Lighter populations will do some compensating by having more nodes/plant. With the photo-period determination with soybeans, there is point where no more nodes will be formed. Earlier planting allows more time for node development while later planting gives very little. With that said, planting date and conditions will influence what the population will be. Reams of data have suggested that a final, even stand planted in the early part of the season will achieve maximum yield. At the same time, higher populations achieved a similar yield. If you are planting later or with shorter season soybeans in your area, higher pops than that would be beneficial. Also, I have seen data from replicated third party sources that have shown that treatments and inoculants provided more nodes, blooms and pods/foot of row. This carried over to a 4 bushel yield advantage in 2010 over Ohio & Indiana where these counts were done. Rather than thinking populations, start by thinking of maximizing nodes and adjust populations from there accounting for soil productivity (clays can be tougher than looms), planting date and soybean maturity. | ||
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| cotncrzy |
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PROSPECT, TENNESSEE | To sum it up.... You have to find the right population. I used to plant 170,000 plus. I started cutting back as priced increased. I noticed no yield reduction. I have been in 7.5" rows all the way to 38" rows. I am now on 19" rows and I am not looking back. I seem to think the indeterminate soybeans need to be a tad thicker, than determinate. I plant group 4.0 to 6.9, so I look for a tall bushy plant type, drop around 115,000 seed hope for 90,000 bean producing plants. With the Kinze meter you can almost "picket fence" beans with a little care (I clean my brushes of splits very often). If you can get three or four beans per foot in the 19" row you wont have the lodging problems you would have at 6 beans per foot, the bean quickly bushes out to compensate for space. Usually a bean that is advertised as 40" tall will end up(on this farm at my population) 30" tall with more nodes than any 40" plant you can find. I am sure there is a fine line between enough and over population. Only you can answer the question. I would say 140,000 is the highest starting point you would want, it only takes a second to swap the chains around and stick a flag down. you can see a bunch of populations in a small field. Also every variety reacts different. I also bet the more north you go and the shorter the growing period is the more beans you will need to get the pods. Good Luck!!!!!! PLANT AS EARLY AS YOU CAN!!!!!!!!!!!!!!!! THIS WILL ALSO EXTEND THE PHOTO PERIOD AND ADD NODES. | ||
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| Ltfire |
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North Central Iowa | Your post is good and informative, but how about giving us some information as to what you are basing your opinion on (are you a producer, supplier, etc.)? What part of the country are you in? | ||
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| ernestf |
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| I am not going to take a defensive posture on the issue of soybean plant populations. If you want to plant 200K then go for it; and you will need a craper head to harvest them most years. I have tried various plant pops for the last 40 years; and there is no "correct" pop; however if you look at the published research you will see that yields in general do not decline until pop drops below 50K in good cultural situations. Of course, noone can plant to that level; but 100K is enough in most situations. Spend time looking at the published research; and you will find the same story. The high pops that perform well are rare; and require intensive IPM measures that are very expensive. We commonly harvest 50 to 70 bpa with one fungicide/insecticide app at R2 to R4 in populations of 90 to 100K (even in dryland culture). In the 70's and 80's we were happy to get 25 to 30 bpa; so this is working for us. It may not be as appropriate north of the M/D Line; but I expect it will be. | |||
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| Worthmore |
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Live in Forsyth, Missouri Farm in N, MO | Thanks for all the replys; I like the idea of putting different populations in the same field. Yes Forsyth is SW MO. I farm with my inlaws in N, MO... | ||
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