Endophytic Treatment of Soybeans against Pathogen R. solani: A Possible Alternative to Pesticides?
Pesticides not only kill harmful organisms to crops, but also vital ones like bees, and they pose health hazards to people. Scientists have been exploring a more natural alternative to pesticides. One hopeful but largely unexplored solution is the use of endophytic treatments. Previous studies have shown that endophytes, micro-bacteria or fungi living within plants’ cells, provide beneficial effects for hosts, such as support growth, prevent disease development, and increase their resistance to environmental stresses. Endophytic treatment consists of coating seeds with pre-selected, helpful endophytes, which in theory should promote plant growth and decease disease in plants.
Since endophytic treatments vary widely according to species of plant and the type of immunity needed, many experiments are required to test the treatment’s range of abilities. Dalal and Kulkarni’s research paper specifically studies the different endophytic treatments needed to protect soybean Glycine max (L.) Merril, a soybean species commonly grown in India, against the soil pathogen R. solani. His research also further explores Cultivar JS-335, the indigenous endophytic microbes for soybean crop cultivar. The researchers hypothesize that endophytic treatments on soybeans will aid plant growth and decrease disease incidences.
The experiment took place in an experimental agricultural research facility in India that has suitable climate and soil for soybean production. The researchers constructed a microsystem grid of 33 1plots and randomly assigned spots for the control and experimental seeds. The researchers infected the all soil with R. Solani; however, the experimental plots were fortified with the pathogen manually, while the control plots were not. There were 3 control seeds, which did not receive endophytic treatment, and 30 experimental seeds, which consisted of 10 different endophytic treatments (3 seeds per treatment.) The seeds grew and were harvested 3 months later. The data collected included: Root Nodulation Count, Yield, and Disease Incidences (%). The researchers gathered the data for each category, and then found the mean values.
Before analyzing the results of the experiment, inconsistencies with the method must be addressed. Out of the 33 plants, there were only 3 controls plants. To have truly reliable data, the control numbers should equal the treatment numbers. This disproportionate ratio of control and experimental variables shows bias towards the experimental variable and skews data, making it unreliable. Also, the control treatment plots were not treated with the same 10% more R. solani fortified soil, unlike the experimental treatment. This variable between control group and the experimental group should have been standardized. Once again the data appears biased and the relationship between the experimental treatment and the result comes into doubt.
The researchers concluded that endophytic treatments do increase plant growth and build resistance against R. solani. The data do show in most critical tests, such as disease incidence and seed yield, the experimental variable did consistently outperform the control. However, the researchers’ methods did not produce reliable data, so the conclusion must also be unreliable. This research does not effectively support that endophytic treatment increases plant growth and defenses against R. solani in soybeans.
Literature Cited
Dalal, J., &Kulkarni, N. (2014). Effect of Endophytic Treatments on Plant Growth Performance and Disease incidences on Soybean (Glycine max (L.) Merril) Cultivar JS-335 Against Challenge Inoculation with R. solani. American Journal of Agricultural and Biological Sciences, 10(2), 99-110. doi:10.3844/ajabssp.2015.99.110
