I have witness damage on my plums that look like bruises. The browning is all on the inside of the fruit. I have seen this in a lot of my plums and assumed it was the beings of brown rot formation. This year I had some shiro plums (second year tree) and the bruising was even more apparent in them. I had very large and beautiful shiro plums but about 2-3 weeks before ripening, the bruising started. My assumption was that the bruising was being caused by heat. I put a shade tarp over the tree and the bruising was less but still evident. I’ve seen this on my Methley, Morris and AU Cherry plums in previous years but assumed it was brown rot. But, I’m not seeing the typical rotting and molding of the skin of the fruit that I thought brown rot caused. I wish I had pictures but I can’t locate my photos. Basically, it is a enter browning and souring of the fruit starting from the seed. What is this and how can I prevent this? I still have a young plum orchard but my Methley and AU Cherry (six years old now) seem to be having this problem less with age. I’m hoping the Shiro will also improve with the age of the tree. I’ll add that I planted Satsuma, Mariposa, Emerald Drop, Elephant Heart and Starks Delicious in Spring 2014. I’m suspecting they will fruit in 2016 and will have same issue. Thanks in advance for any advice.
I sometimes get brown spots just under the flesh on my Shiro. For me it only happens on that one variety of plum. I don’t think it is brown rot, and it seems to happen more in strong heat and on fruit that are (over)ripe. What exactly is going on I don’t know, but its not a major problem for me.
FascistNation, Where are you located? I sprayed my Shiro with Copper in spring and followed up with a few fungal sprays during growing season. Also, I fertilize in dec with phosphus then 2 months later (once I see swell) with fertilome fruit tree fertilizer (19-10-5). During growing season I add nitrogen. I have seen the bruising in all my large California plums so I was thinking it was the humidity/heat. Do you all think I could be over fertilizing? I doubt its a low nutrient lssue since every tree gets at least 2 cups during my three fertilizing cycles. The only thing I can think of is the heat is doing it and a older/larger canopy might help in future. Because if this, I’m consider very little pruning on my fancy plums.
Hoping someone will have a suggestion on my plums. @alan, i noticed from previous post that you grow Ozark Premier. Have you seen spots like this appear on yours? Regardless, does anyone have any idea what this issue is? As the fruit ripens, the hard dry spots appear. I see this on other plums but it is prevalent on the OP. Once the spot is cut out, the rest of the plum is good and eats well. About 60% have this spots. Like the issue above, I assumed this is related to heat but this year I put shade cloth over most of the limbs. I also have been spraying Montery Fungi Fighter and Triz + permethrin insecticide (for stink bugs). No help so far. Really looking for some suggestions on my plum issues. I’m about to give up on the Cali plums.
I can’t be sure from the photo- spots don’t appear black enough, but the only on fruit issue I ever get with J.plums beyond cracking is some bacterial spot- especially when springs are particularly wet. What you have looks like something else- almost like freeze spots.
Were these spots usually on the tops, or were they all over? Sun/heat would be worse on the upper sides.
Also, did the fruits on the bottom start out looking like the Shiro in your earlier post? In other words, did the skin first get the darkened look and then shrivel? The damage in the lower picture looks like it could be a bug of some sort, but if it started out as a bruise thing I doubt it.
My best guess at this point is you have some form of plum scab in those Ozark plums. Next best possibilities are heat damage and bug damage.
Seems I have my own personal issues with Jap. Plums - which is surprising and frustrating. I have a lot of issues with brown rot and I have been spraying MFF for that. But the issues with Shiro and Orazk are different and I have not figure them out yet. The spots on the shiro are not just on top. I think that this is related to heat because it’s as if the fruit has spoiled (simulaur to if the fruit fell to the ground and spoiled. The spots smell and taste like warm spoiled fruit or rotting fruit. The Ozark issue could be insect, heat or disease. I have sprayed some but I would like to id the issue so I can target spray for whatever is causing this. Below are two pictures of the same plum I picked today. One side is perfect, the other side has the spot. the spots appear just as the fruit starts to color and grow rapidly. I would say that the fruit in the picture was green and spot free just 3 or 4 days ago.
This was an unusual spring - no frost or freezes. The trees are somewhat shaded in the very early morning. Late morning they start to get full sun (around 8am).
Today, I bagged all the remaining plums that are totally green and not showing any signs of coloring up. I bagged them similar to how I would bag an apple (OP’s are large as apples…lol). Anyway, I will like to see if the quality improves. Also, I have shaded the tree with a shade cloth to lessen the effect that heat might cause. Not sure what I expect to learn from this exercise but I can’t wait to see the results.
seems later plums don’t have same issues as ones picked at beginning of ripening stage. I think I might need to spray the plums more throughout growing season (at least after rains). Typically, I rarely spray stone fruits after spring. not sure, but the spots must be related to some fungus or some insect. Right know, I’m leaning towards an insect. lately, I have harvested spot free Ozark and santa rosa plums. the bagged and unbagged look same. Given credit to recent sprays of Immunox, triazicide, MFF and permetrin.
Just wondered if you ever figured out anything more about what was causing your problems. I have something almost exactly like that happening to my Bruce plums. If I allow them to completely ripen on the tree, they almost always have a soft spot somewhere (not the kind of soft a ripe plum has, I mean a basically liquefied area, and it does act like a bruise. The only slight difference is that on your photos your spots are wrinkled and very visible. But then again mine might look that way after a few days…I’ve picked them all when fully ripe, then throw them away if they have the soft spot. SO I don’t know if they’d develop the discolored, wrinkled look in your photos. When picked, you can only feel these liquefied spots but not see them. But the big problem is that these spots are usually soured (which you mentioned) and so the whole plum in many cases, or least half of it, is soured.
Again, not sure if this is same thing you had, but if so I wondered if you ever resolved your problem? thanks
cityman, I had two different spot problems. Seems the major problem that I saw on Ozark and Santa Rosa went away after several sprays of Immunox, triazicide, MFF and permetrin (with sticker). The issue on my Shiro was a totally different problem and I never figured it out. Due to the souring, I’m almost certain it was related to heat/humidity. Next year I will put a shade cloth over the tree. Also, maturity solves some issues from what I can tell from my years of growing fruit. Perhaps a larger canopy will shade the fruit next year. For this reason, I will not prune the shiro this year or next.
I have the same problem with my Shiro. Methley plums in same tree seem to not be affected (and it’s more ripe; see small branch in the background near the ground). It was in the 90F for a couple days last week and humid! So is this rot because the skin is still smooth and shiny and not shriveled like typical brown rot?