Late planted soybeans face several challenges. They stay shorter and form fewer branches, making podded node counts lower. Adding additional branches, supplying minerals, boosting energy supply (sugars) for the plant and for the rhizosphere microbes are key. Applying root growth promoting hormones (cytokines) and supplementing planter placed or residual fertilizer with foliars help as uptake by the plant is faster & more complete.
As an example Dave P farms about ten miles north of me. He used to harvest the first cutting of hay for his cattle, then disk the stubble and plant beans around June 15th. He was usually getting yields of 23 to 25 Bu/A and did not think higher yields were possible. After learning about the high yield techniques of the top bean growers we changed his management to where he was making two or three foliar applications beginning when the beans reached V3-4. He applied a three-way blend of half rates of MicroMix, Foliar Blend and Respire. Then when the beans began to flower he would apply a mixture of sugar, food grade P&K, and a host of other things. In time a product involving a mix of 17 different items called Seed Set (SS) was developed. It included foliar calcium to build strength into the added branches, sugar to initiate more flowering and shorten the internodes, P to transport energy, and B12 to stimulate the leaf and soil dwelling microbes…etc.
Once the Seed Set was available we would apply it twice about two to three weeks apart after R1. When the growing season was very short the three-way mix was added to the first 2 quarts of SS. Any needed fungicide or insecticide was applied prior to row closure by adding it to the second application of Seed Set.
After Dave began to use this program he saw a regular increase of about 25+ Bu/A. Narrowing to 15” helped him boost his bean yields another 5 Bu/A. So this program worked great for him and added one extra trip. Part of the success was likely the application of a hormone producing bacteria that typically adds 4 to 9 extra branches on each plant. Varieties vary as to how much they branch and breeders now select for branch number and raceme formation. This program can be used on beans planted on time. Keeping the plants shorter with closely spaced internodes allows late season applications to be made to increase seed size.
This program has worked well with other growers who desired to aim to higher bean yields. It allows growers to manipulate plant architecture and influence plant physiology. Keeping the plants short and well fed is key. The ‘bulking’ of seed typically involves mixtures of K, S, and Mg. Kips beans that yielded 154 Bu/A were at 1915 per lb. We are advising the use of Nutra Boost from AgriGuardian, formulated by Dave Sasseville at R4.
Spray Schedule
V3-V4: 8oz Foliar Blend, 8 oz MicroMix, 4 oz Respire, 2 oz Moly and 1 oz Hormonal bacteria.
R1 (usually June 21 st ): 2 qts of Seed Set. Add an additional 2 qts of food grade N-P-K if time is crucial.
R3 (typically July 20-25 th ): 2 qts of Seed Set. Add the extra .5 to 2 gals of N-P-K to speed development if time is crucial, as it supplies additional building material. Include a strobe fungicide or strobe/carboxamide mix of fungicides for Septoria control. This fungus causes yellowing and loss of lower leaves after rows closure.
R4 -4.5: If the plants stay short and a ground rig can get thru, apply 1 -2 gals of Nutra Boost to bulk the seed. This mix of K, S and Mg can be aerial applied as well. The Seed Set’s chelated Ca serves to add stem strength.
