Why are my corn plant's leaves turning yellow?

Question

Backstory:

I picked up my Corn Plant about a month ago (January 21st) from a local nursery. The plant had just been watered and the lady told me that I will likely have to water it once a week. After a week passed the surface of the soil was still damp to the touch so I let it go a few more days before I gave it a thorough watering.

Please note that this is my first house plant so I am learning as I go. When checking for moisture content in the soil I was mostly looking at the surface or slightly below (half and inch or so). I have since read that waiting until the soil is drier a little deeper would be better. The other thing I did (that I have since read wasn't a great idea) was to use tap water instead of purified water. The water in my area comes mostly from the ground and has a high mineral content. Worried this might have had an affect on the plant.

A few days ago I noticed some of the leaves turning yellow on the small stalk. They have since started to turn brown at the base. The centre of the sprout is also brown where new leaves should be coming out. The other sprout on the same stalk seems to be doing just fine.

I have yet to water the plant again as the soil is still damp below the surface. All of the rest of the sprouts are looking really healthy and green.

Questions

Any ideas why the leaves are turning yellow and brown at the base?

Is this a result of overwatering, mineral content in the water or something else?

Should I be trimming this sprout before it affects the rest of the plant?

Any advice will be greatly appreciated.

Thanks!

Answer 1

The black sealant seems to have been over applied on the shorter trunk - I asked if the area was soft because it appears to glisten a little in the image you've provided. The black area is also at the base of the sprout you're worried about, and that is likely why the leaves are turning yellow. If the base of the sprout where it joins the trunk isn't soft and soggy, it might just be a result of whatever they used as a sealant, but I'd be inclined, if possible, to return the plant to wherever you got it and ask for a replacement. If that's not an option, cut off the blackened sprout where it joins the main trunk - if its soggy inside and especially if it doesn't smell good, you may need to reduce the height of that whole trunk by cutting off the top inch or two. If the remainder seems healthy inside, it should, with luck, produce new growth later on.