R110 - AGRISPON GERMINATION STUDIES ... - Agrisciences.com

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Individual Variety Differences It is apparent from dry weight data of Tables 4 and 5, and from the genera evaluations in Table 8 (ryegrass), 10 (fescue), and 12 (bentgrass), that there were some differences between the different genera in response to Agrispon, and also within each genus. The response curves to Agrispon at the dilutions used took various shapes, from an abrupt rise at low concentrations and maintenance of the response at higher concentrations, to a rise and fall, to a gradual rise culminating in a greater rise at the highest concentrations. Some of these cases are displayed for each genus in Figures 8, 9, and 10. Dry matter mass, g 18 15 12 9 6 3 0 5.3 13.6 15.3 6.9 Ovation Perennial Ryegrass 10 0 0.01 0.1 1 10 Agrispon application, % 7 6 5 4 3 2 1 0 4.5 6 6.3 5.4 Advent Perennial Ryegrass 4.8 0 0.01 0.1 1 10 Agrispon application, % 7 6 5 4 3 2 1 0 4.8 5.5 5.9 5.9 APM Perennial Ryegrass 5.8 0 0.01 0.1 1 10 Agrispon application, % Figure 8. Response curves for perennial ryegrass varieties in a golf course grass study. Dry matter mass, g 20 15 10 5 0 8.3 9.2 14 19.8 Adobe Tall Fescue 19.4 0 0.01 0.1 1 10 Agrispon application, % 6 5 4 3 2 1 0 4.1 5.3 5 5 MX-86 Sheep Fescue 0 0.01 0.1 1 10 Agrispon application, % 5 8 6 4 2 0 4.3 4.2 4.7 6.1 Jamestown II Chewings Fescue 7.8 0 0.01 0.1 1 10 Agrispon application, % Figure 9. Response curves for fescue varieties in a golf course grass study. Dry matter mass, g 28 21 14 7 0 12.8 23.2 21.6 15.3 12.9 Penncross Creeping Bentgrass (Scott) 0 0.01 0.1 1 10 Agrispon application, % 25 20 15 10 5 0 10.3 22.2 13.6 15.1 ProCup Creeping Bentgrass 15.6 0 0.01 0.1 1 10 Agrispon application, % 16 12 8 4 0 9.1 15.5 12 12.5 Southshoure Creeping Bentrrass (REP IV) 11.2 0 0.01 0.1 1 10 Agrispon application, % Figure 10. Response curves for creeping bentgrass varieties in a golf course grass study. 13
Without replications there is some question as to whether these response curves are truly indicative of the grass variety under all conditions. By examining the variability within the replicated variety for each genus it is clear that different response curves do indeed occur for the different replicates, indicating that natural variability accounts for some of the differences observed between varieties. Thus, average responses for each entire genus are more meaningful as far as field application recommendations are concerned. However, the reality of Agrispon response variability among varieties and replications does exist, and may be explained by differences in rhizosphere microorganism populations among pots. It is possible that somewhat different bacterial, fungal, algal, actimomycete, and cyanobacterial populations existed in the original soil of different pots, even though an attempt was made to mix the soil and eliminate differences. With different microbial communities populating different pots, more favorable species and combinations of species which respond to Agrispon better might inhabit some pots and give greater growth increases. In addition, some grass species may be more compatible with certain microorganism species; this is especially true of the mycorrhizae, 18 which Agrispon is known to markedly stimulate. 19 Thus, a pot containing more spores of a particular vesiculararbuscular mycorrhizae fungi species that is effective, and is compatible to live symbiotically with that grass, would stimulate growth more with Agrispon addition than for an adjoining pot. Perhaps the same scenario could be theorized for other microbial species as well. According to Abbott and Robson, 20 "Species and strains of VAM fungi have been shown to differ in the extent to which they increase nutrient uptake and plant growth." Powell and Bagyaraj went on to say that the species of mycorrhizae that were most effective at increasing plant growth were the ones that resulted in the most rapid and extensive infection rates. They further stated, "Frequently, at a final harvest, there is no difference in the percentage of roots infected by different species of fungi although they may have produced differences in plant growth. This could arise if fungi differed in the rate at which they formed mycorrhizae." 21 Although some authors feel that most VAM fungal species can infest virtually all plant roots that are potentially susceptible to infection, 22 others have understood the reality of host-VAM preferences, such as Kropp and Anderson: 23 "The endomycorrhizal fungi are unable to colonize certain hosts although the majority of plants are compatible. In the field, preferences between endomycorrhizal fungi are seen for a host and differences in functional efficiency are measured for various host-fungal combinations." To explain differences in different grass genera responses at different Agrispon levels -- for instance, bentgrass responding best at 0.01%, but ryegrass at 0.1% -- it is possible that the certain microorganism species responsible for the symbiotic growth stimulus of one genera, but not the other, are more sensitive to the porphyrins, zeatin, triacontanol, and salicylic acid present in Agrispon. If the growth rate is accelerated for one species, such as a VAM, more than for another VAM species or a beneficial bacteria or algae, then growth differences would logically appear between pots. Summary and Conclusions This germination and early growth study of 37 golf course grass varieties proved that Agrispon significantly improves the germination and early growth of the varieties studied. All six of the Kentucky bluegrass varieties, the three bermudagrass varieties, the two Poa trivialis varieties, and the Zoysia Japonica variety had to be terminated because of a severe fungus outbreak that destroyed up to 80% of the leaves and roots of some pots of these finebladed grasses. The coarser-leafed grasses such as ryegrass and fescue were not affected very much by the fungus. Although the fine-leafed bentgrass varieties were quite severely stricken, it was possible to harvest them and obtain usable data by using adjustment factors. 14
Page 1 and 2: AGRISPON GERMINATION STUDIES WITH G
Page 3 and 4: 1. In all cases, Agrispon at all di
Page 5 and 6: Table 2. Agrispon treatments for an
Page 7 and 8: The initial dry weights of each sam
Page 9 and 10: Perennial Ryegrass Table 6. ANOVA o
Page 11 and 12: Table 9. ANOVA of Reliant Hard Fesc
Page 13: Dry plant mass, g 20 15 10 5 12.48
Page 17 and 18: The variability in response of diff
Page 19 and 20: A PHOTOGRAPHIC SUMMARY OF AN AGRISP
Page 21 and 22: By October 17, Arid Tall Fescue had
Page 23 and 24: At harvest on November 4, note how
Page 25 and 26: Ovation Perennial Ryegrass produced

R110 - AGRISPON GERMINATION STUDIES ... - Agrisciences.com

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