Asco-Gro (Reg. no. K6714 of Act 36 of 1947) is a product from Miller™ Chemical and Fertilizer, LLC. It consists of kelp extracts and is combined with macro- (N, P and K) and several chelated secondary nutrients (Mn and Ca) along with molybdenum and iron.
Previous Forum articles ("Investigating the effect of Asco-Gro on soybean vegetative growth and yield" – Volume 1, 2019 and "The ASCO-GRO effect" – Volume 1, 2020) reported on investigations conducted with Asco-Gro during soybean production. The results indicate that the inclusion of Asco-Gro within a soybean spray program increases the yield. A recent independent study echoed these results, while another independent study confirmed that Asco-Gro (with Nu-Film P) in a tank mixture with a glyphosate containing herbicide does not have adverse effects on glyphosate tolerant soybeans. These trials were conducted in the Mpumalanga Province of South Africa during the 2021 production season. PAN1555R was the soybean variety of choice and were sown at 450 000 plants per hectare.
TRIAL 1: Effect on yield
The trial consisted of 7 replicates for each of the two treatments. Every replicate was a plot of 4 m x 10 m (40 m²) = 1800 plants. Asco-Gro was applied at 2 L/ha, 42 days after sowing, at the R1 phase (BBCH = 51; first flower buds visible) in 200 L water per hectare. At maturity the pods from each replicate were harvested and the average yield of seed per hectare was determined in tons per hectare. The latter was compared to the average seed yield from the untreated replicated (7) plots. The Asco-Gro treatment significantly increased the yield by almost 20% (Figure 1), when compared to the untreated control.
[Figure 1: The effect of various treatments on mean soybean yield in T/ha.]
In addition to yield, the average weight of 100 seeds was determined for the Asco-Gro treated plants and the untreated plants. Seed from the Asco-Gro treated plants had a significant increase in average weight (13.7%) when compared to the average seed weight of the untreated plants (Figure 2). The size of the seed from the Asco-Gro treated plants appeared visually bigger when compared to seed from the untreated plants (Figure 3).
[Figure 2: The effect of various treatments on mean soybean seed weight in g/100 seeds.]
[Figure 3: Visual appearance of 100 soybean seeds from different treatments. Note the larger seed from plants treated with 2 L Asco-Gro/ha (bottom photo) vs seed from untreated plants (top photo).]
TRIAL 2: Asco-Gro in a tank-mix
The application of Asco-Gro on soybean as described above and in previous Forum articles has become popular. Recently Miller was approached to illustrate the effect of a glyphosate (540 g/L) containing herbicide in a tank mixture with Asco-Gro and *Nu-Film P® (adjuvant to be applied with Asco-Gro) on glyphosate tolerant soybeans and weeds present.
The number of replicates, size of the replicated plots, timing of application and application volume were similar as described in Trial 1. However, instead of two treatments the trial had three:
1. Untreated control.
2. Glyphosate herbicide (540 g/L) at 2 L/ha.
3. Glyphosate herbicide (540 g/L) at 2 L/ha + Asco-Gro at 2 L/ha + Nu-Film P at 150 ml/ha.
Compatibility
No physical compatibility problems, i.e. separation, foaming or sedimentation etc., were observed with any of the compounds during preparation and application.
No phytotoxicity
No signs of phytotoxicity were observed in any of the treated plots of any treatment throughout the duration of the trial.
Efficacy
Grass weeds, large crabgrass (Digitaria sanguinalis) and Sabi grass (Urochloa mosambicensis), and broad leaf weeds, green pigweed (Amaranthus hybridus) and common purslane (Portulaca oleracea), were present in all plots when the trial started. Weed control was monitored for all three treatments at 21, 28 and 35 days after application. Although very much similar, the combination of the glyphosate herbicide in a tank-mix with Asco-Gro and Nu-Film P often managed to control the various weeds significantly better than the glyphosate herbicide by itself (Figure 4).
[Figure 4: Mean percentage control of different weeds after different Days After Treatment (DAA).]
Yield
The combination of glyphosate, Asco-Gro and Nu-Film P resulted in significantly the best yield average of the treatments (Figure 5).
[Figure 5: The effect of various treatments on mean soybean yield in T/ha.]
The results from this trial confirm that Asco-Gro (with Nu-Film P) in a tank-mix with a glyphosate herbicide does not have a negative effect on the efficacy of glyphosate nor the tolerance of glyphosate tolerant soybeans.
[Nu-Film P is a trademark of Miller Chemical & Fertilizer, LLC and contains 875 g/L Poly-1-Menthene. Reg. No. L2980 of Act 36 of 1947.]
By Johann van der Vyver (African Technical Sales Director: Miller Chemical & Fertilizer, LLC)
