Every 3 days?! Are you growing this tree in a container? Was it newly planted? The reason I ask is because that sounds like you're watering much more frequently than necessary. Aside from that, it's really impossible to say with the information given.

Is this a nut-producing almond tree (Prunus dulcis) or instead one of the flowering almond ornamental shrubs (P. glandulosa or P. sinensis)?

In either case twig dieback due to pathogenic infestations is common in moist climates. If you have any of that going on individual pieces will look blighted or fired while others will remain intact. All the leaves going yellow and dropping at this time of the year, without shriveling of leaves or stems would be expected to be the normal fall shedding.

Unless the frequent watering has rotted the roots, with the resulting defoliation of the top not occurring until late in the season.

most likely a flowering shrub almond ...

yes.. its mid october.. leaves are getting ready to fall off ...

shrubs tend to like a good drink.. and then to nearly dry ... so depending on how your soil drains.. perhaps you are on the verge of loving it to death thru drowning ... insert finger and water.. when the plant needs water.. not on some schedule... in late fall .. with cold nights .. soil can stay damp for a month ...

personally i would not have wasted spray in sept on a deciduous shrub ....

if anything negative happens to this shrub.. it might be from excessive love ... a 4.5 foot almond has probably been there for a decade at least... most likely with little or no care... because that is what you do with shrubs ...

good luck

ken

Thank you for the tips -- too much watering seems to have been the culprit. I guess my nuturing instincts went into overdrive. I stopped watering & the yellow leaves fell off and no more have appeared! She looks nice and healthy again.