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A P R I L 2 0 1 6 POTATO GROWER 13 ple stems from a single eye it is likely that another herbicide or other issue besides glyphosate is causing the problem. Problems that may cause similar symptoms as glyphosate can be biotic abiotic or from other pes- ticide residues. Uneven emer- gence can be caused by many factors including diseases such as Fusarium dry rot soft rot or phytoplasmas in seed tubers CIPC residues in seed tuber physiologically young seed or various herbicides to name a few. The epinastic symptoms some- times observed from glyphosate can be caused by other herbi- cides especially plant growth regulators such as dicamba clopyralid or others Figure 2. The candelabra formations of stems have been observed when the tip of the main stem dies or when the apical dominance of the stem is lost. This may be caused by Rhizoctonia or physio- logically old seed. Candelabra formations are also frequently seen as a result of hot and sunny days in the early growing season when the soil temperatures are cool. This creates a heat layer in the hill and as the stem grows into this heat layer the apical meristem growing point is shocked causing the tip of the stem to die or lose dominance Figure 2. When this occurs axillary buds nodes further down the stem will grow caus- ing the multiple stems known as the candelabra effect. As you can see there are many ways that funky things can hap- pen to emerging potato stems and not all are related to the same cause. Thus careful diag- nostics will need to be taken to ensure the proper conclusion is made. This article is a small primer and there are many other situations that may result in similar symp- toms. If you need help in diag- nosing your problem you can submit it to me from your smart- phone tablet or computer at z.umn.edud. I look forward to another great potato production year in 2016. Figure 1. Glyphosate symptoms expressed from seed tubers with glyphosate residues. Figure 2. Epinasty of leaves caused from a plant growth reg- ulator in the seed tuber A B. Heat damage causing leaf crinkling and candelabra of Russet Burbank potato C D.