Brown Pseudobulb. Rot or not?

[OrchidMan101]

I just got a new Oncidium and it’s oldest bulb has brown coloration. I would guess that it’s rot but I thought that rotted bulbs were soft and squishy but this one is still firm. So is it rot or not?

Also what’s up with the leaf coloration?

[SouthPark]

Don't worry about it if it remains firm. Just maintain comfortable growing temperature ..... not too cold. And not too soggy or saturated for the media. And avoid long periods of cold and wet media.

As for the leaves ------ does that layer scrape off when you use finger nails to scrape? If it does .... then check for 'scale' attack.

[estación seca]

Agree. Pseudobulbs can get some brownish coloring from time to time. This is OK.

In addition to scale, look for mealy bugs or spider mites. Do you have a magnifying glass to look at the dots?

[OrchidMan101]

Originally Posted by SouthPark

As for the leaves ------ does that layer scrape off when you use finger nails to scrape? If it does .... then check for 'scale' attack.

The layer doesn't scrape off.

[SouthPark]

Originally Posted by OrchidMan101

The layer doesn't scrape off.

That sounds good. A lot of growers - including me - have spots on the leaves ----- some common feature that most of us see in this sort of plant. Mine don't get as much or dense spotting like that ------ but as long as your plant just keeps growing new leaves and simply keeps growing well, then that's ok.

Just maintain nice temperature etc, and allow for some gentle air-flow around leaves/pot etc. And also - every once in a while - apply some relatively weak fertiliser and also weak magnesium-calcium treatment ---- once in a while only, such as every month, or maybe every couple of weeks.

[OrchidMan101]

Originally Posted by estación seca

In addition to scale, look for mealy bugs or spider mites. Do you have a magnifying glass to look at the dots?

I looked for scale and mealybugs and didnt spot any. I dont think theres any spider mites because I dont see any webs and I wiped the leaves with some white paper and didnt find any mites on the paper.

I did use a magnifying glass(although its pretty bad) and I didnt see anything moving on the leaves.

---------- Post added at 05:57 PM ---------- Previous post was at 05:38 PM ----------

Originally Posted by SouthPark

And also - every once in a while - apply some relatively weak fertiliser and also weak magnesium-calcium treatment ---- once in a while only, such as every month, or maybe every couple of weeks.

For the magnesium-calcium treatment is their any products you'd recommend using? I found one product, "General Hydroponics CALiMAGic", with 5% calcium and 1.5% magnesium and I was wondering if that was a good product. I don't know what ratios of calcium and magnesium are good for orchids so I'm unsure.

Heres the link to the product: https://www.amazon.com/General-Hydro...ct_top?ie=UTF8

[estación seca]

Check the annual water quality report published online by your water utility. Many people in the US have enough magnesium and calcium in their tap water for orchids to do just fine.

These nutrients are not included in adequate amounts for most plants in fertilizers because they can interfere with solubility of nutrients. I often mix tap water with rain because the dissolved solids in my tap water - mostly magnesium and calcium carbonates - are higher than most orchids prefer, but I can avoid buying cal/mag supplements this way.

[Shadeflower]

Ca should be roughly the same as the Nitrogen you feed. If your fertilzier or water already contains enough you will not need to supplement.

Lets say you add 1 gram of a 7-7-7 fertilizer that doesn't contain any calcium and the water deoesn't either. You should add 1.5ml of Calmag in that case (1.5 x 5% = 7.5)

Of just feed it in one large dose once a month. So something like 6ml Calmag per gallon once a month.