I wish I was a member of ACTA so I could see the whole study. The research indicates that the red staining in Hippeastrums can actually deter fungi. Sounds as if the plants produces it in response to injury for that purpose.
You just have to scroll way down the page and the article will be present to read.
I don't have amembership either, but I do know of somebody who does. If I happen to se e them tommorrow, I will ask them if they will download it and email it to me. Looks like some interesting reading.
To be real honest--I've seen red coloring/staining on lots of bulbs that have been damaged by digging. Including Zephyranthus and Habranthes. I think its some sort of defense mechanism until it can "heal" its wound. I've dug them back up a month or two later and its gone. I've also seen it on crinums and Isthemes (I'm sure my spelling is wrong on this one but I really don't want to look it up). =)
I have too especially when moving bulbs growing in pots around the yard and when repoting them. Not so much on the bulbs , but on the foliage especially from the handling. Kind a like Poinsettias leaking a milky sap when touched or handled during flowering or temp changes. They just bleed white.
I could be wrong , but to me if it was red rot then the bulb would not be firm, you would possibly se e other physical signs of damage from bacteria and fungi.
I have taken bulbs and cut them up for divisin by using part of the plate and had the outsid e be red a bit for awhile til the new roots grew and the bulbs dried and healed over with new tissues at the cut.
dmj and star, I hear you and I agree with what you've said regarding red staining on bulbs from mechanical damage.
I have so many questions about red-blotch and few answers.
If "red-blotch" is present on the foliage, it will be growing, right? So if any red spots aren't getting any larger, it might be some other sort of damage reaction or perhaps red-blotch that started and died out? Does that happen?
I have seen some sort of disease rot a hole in the side of a scape causing it to collapse and it might well have been red-blotch. I see red spots on foliage from time to time, but they don't grow beyond a smallish size. Is it red-blotch?
Can red-blotch just stop soon after starting on foliage, never reaching maturity and producing it's black spores? Say if the temperature goes into a certain range it dies or ceases growth? How can you tell it's red-blotch and not fusarium or bacterial infection?
The only identifier I know of for red-blotch, is that the lesion has a darker red border to it. But there are so few pictures to learn from...
If red-blotch can just halt its spread after making a small spot, does that mean it has died? Or is it waiting some certain condition before starting up again in that spot?
There needs to be more common language layman-friendly instruction on identifying red-blotch and other diseases in Amaryllids and Narcissi. Now!
Diseases are usually not a serious problem in growing amaryllis. There are a few diseases that may occur, however. One disease occurs commonly on amaryllis in Florida. This disease is referred to as "red-blotch" or leaf scorch. It appears worse in areas of morning shade or where sprinklers hit amaryllis plants on a reoccuring basis. It is caused by the fungus Stagonospora curtisii. Red spots form on leaves, flower stems, and on the flower petals. On the foliage the spots are bright red to purplish, small at first but often increasing to form large longitudinal blotches with definite margins. Leaves and flower stems attacked by this fungus are characteristically deformed or bent at the point of attack. The flower stalks of heavily infested plants may break over at an infected area or wither and dry up before the flowers are produced. Dark reddish brown spots occur on the bulbs. The spots may develop into large rotted areas.
The fungus and spores of red blotch are carried on the bulbs. Consequently, the leaves and flower stalks which push up from infected bulbs may become infected. Badly infected bulbs should be destroyed. It is helpful to dig lesser infected bulbs in late fall and remove leaves. Soak the bulbs in hot water (temperature not to exceed 104 degrees Fahrenheit) for 30 minutes. Following the water treatment, dip the bulbs in a fungicidal dip containing thiabendazole (Mertect-340-F) or thiophanate methyl (Cleary's 336, Fungo 50, Domain or Systex). Let the bulbs air dry and then replant them. The severity of the disease on the foliage can be lessened by periodic spraying of thiophanate methyl. Watering at the roots (rather than into the crown of the plant) and growing the plant in full sun also help reduce this disease.
Amaryllis are subject to red spotting from various physiological causes, from injury and from mite and insect damage. This is not to be confused with the red blotch disease. Reddening from these causes appears as streaks, specks, or irregular patterns lacking definite margins or outlines.
"Mosaic" is a virus disease of amaryllis. The leaves at first have an indefinite yellow mottling which later becomes more pronounced, showing small angular spots or streaks of yellow and dark green color. Red streaks may appear on infected plants from secondary causes. The plants become more stunted each year. If the plants bloom, the leaves, flower stalks, and flowers are greatly reduced in size. The flowers that open are normally deformed. Since this is a systemic disease and there is no known control, it is advisable to destroy all infected bulbs and plants.
Seedling plants of amaryllis may be attacked by one or more fungi, such as Pythium spp. or Sclerotium rolfsii, that cause root and bulb rots. Although S. rolfsii may attack large bulbs and plants of amaryllis, this is not common in Florida. The attacks of this and other root-rotting fungi are confined primarily to seedlings in which they cause rotting of the bulbs or sloughing of the plant roots. Plants that have been attacked become pale, grow poorly, wilt, and eventually die. Succulent stems may have a black, sunken lesion at the ground line and the plants may rot off and fall over.
These diseases cannot be cured once they have become established, but they can be largely prevented by starting the seed, small bulbs, or bulb sections in soil where disease problems have not occurred or in soil that has been sterilized. Wetting pots, flats, or seedbeds with a solution of a good fungicide will help keep these diseases in check.
Granted there are bulbs that get infected, but I thik alot of bulbs are unneccsarly destroye d becaus e of lack of proper care for them.
People buy the bulbs especially durign the holiday season, thos e bulbs are crammed into boxes and back of trucks and then tosed out on store floors til soem stock clerk gets a chance to put them up. They take one heck of a beating and get bruised and bange d up pretty bad. IMOP to see some red streaks developing during this time would be normal.
Now people take these poor battered bulbs home and most folks will pot them up in a nic e potting soil they have gotten that has fertilizer in it. These bulbs can't handle a high pH and nutrient level. it blocks their ability to take up the essential macro and micro nutients they specifically need for growth and blooming. They think they are helping thei r bulbs and in actualilty they are setting them up for rot.
The nutrients the bulbs need are locked up and the roots die and then they keep watering their plants and adding more fertilizer which just speeds up the rot process and develops fungal bacterial problems.
Another major problem I find is the overwatering problem. Folks take alook at the top of soil and think " Oh it needs a drink" and out comes the watering can. What alot of folks don't realiz e is that that the root s are way at the bottom of pot and whiel the top inch may look dry the bottomis soaked and the bulbs can't sit in all that water constantly without havign some adverse reactions.
If you noticed, alot of bulbs do really great in during the drought periods. They wil green up and look the picture of health. Then if you get alot of rain for days on end especially in the early spring or late fall, you wil notice the foliage starting to have some of the red hues and streaking. If the bulbs are left alone, and let dry out completely the problem goes away. But people forget that water goe s down in the ground and the bulbs are usually 6 to 8 inches down under where it damp and cool. They get a couple of days of sunshine and their annuals and perennials which need the water get hose d down and so do the Amaryliss who definately don't need it.
Anothe r way I notice d people infect their bulbs is after cutting the stalks when the bloom is done. On some plants especially like Gerbers you need to cut the stalks all the way down to the bottom to prvent fungal diseases. On the Amarylis s you need to leave several inches of that stalk still showing and let it dry out naturally then remove the dea d foliage. Cutting the stalk down removes essential nutrients that the Amaylis s need to replac e in their storage orangs for next years growth and blooming. Removign to much of it weakens the bulbs and that promotes not onlt nutrient lose but allow s for bacteria and fungi to find a ne w home.
Robert most fungi has spores, you probably know that. if you have a microscope or a friend that ha s one you can take a q-tip so as not to the damage the bulb or foliage and look to se e if you se e any hyphea growing. You can also take the q tip and spread it on a small paper plate and put ina seale d baggy and sometimes if it a fungus it wil start growing and devloping on the plate and you can see it.
You can also take the q-tip cultures to yoru county or local extension offic e and have then send it over to the pathology lab. The goign rate right now is about 10 bucks, but it worth it soemtimes to fidn out before you start pitchign a bunch of bulbs. Plus it also a good way to find out for sure that if it is a rot that you don't coem back and replant in that area with some other plant or bulbs that woudl be infecte d withotu sterilizing the soil in that area first.
One thing too I have notice d and maybe somebody else has, that as the temps change and the bulbs start to go dormant her e in the late fall begining of winter that just as the leave s on the trees change so do the leave s on the bulbs. As the days start getting shorter, and the bulbs are starting the proces s of storing sugars instead of photsynthesizing, they develop a reddish color and streaking. You can rub your fingers over the streaks or use a white tissue and no spores are present on the tissuse. Thsi make s me think that as the chlorophyll pigments are dying and the anthocyanin piments are making there presence known. Also I notice d that soon after thes e streaks appear in the colder temps the leave s then go from a red streakign to the brown and die back naturally if left alone.
it coudl alo be that the storage orans is pulling out the sugars and carbs it need from the chylorophyll pigment s and the anthocyanin pigments are by products of what the plant doesn't nee d at the time and then they just go through a later period of senencing.
Maybe at some point I can find the time to do a leaf peel on one of them and see exactly what is goping on with the pigments, but I have so many projects going right now that I don't have the time to run up to the pathology labs and experiment.
Maybe somebody else here who know s how to do do the peels would be good enough to try and see.
I think oen of the reasons ther e is not mroe of an indepth study of te Amarylis s is becaus e most folks who buy them , over water them, over fetilize them, don't store then properly, don't giv e them the required rest peiod they need and the bulbs rot on them so they just go buy ne w ones each year or never try to grow them again which is a shame.
Thank-you Starlight for the informative and thought-provoking post!!
I hope you didn't think my cry of "Now" was aimed at you or anyone here, personally. I was decrying (to those that have information) the fact that while there are scientific studies of plant diseases on the web to be read, I find them all too frequently above my head, and lacking in practical down-to-earth measures in knowing and dealing with them. And a lot of "plant care" information doesn't go into enough detail for me. I hope that there will be more published articles made available to the home gardener in understandable language so that we can activley work with our plants to help them grow well and not just have to watch them perish.
You have shed some light that helps me look after my plants in several ways and I will use your information as I observe what's going on with my Hippis. Again, thanks!
LOL... You don't know how many times I cry the word " Now" myself especially when I trying an experiment. Naw I just procrasting form havign to study for a final tommorrow and this is much more fun than straining my poor old brain any further than I have too.
That is one of the reasons that even while I twice as old as my classmates I decided to go to school. I am a hort major, with a minor in plant patholgy, plus I grow and sell plants, do fund raisers, and am working on several research projects and theories of my own. Actually I am a pain in the rump going up and down the halls picking professors brains like crazy to get answers to questions and techniques that I want. I am gonna be one of them 60 year olds ya see graduating on tv at the rate I am going. There just too much to learn and too many exciting things going on .LOL I look at it this way. Plants are just like human, they have to be nutturied, they have to grow through lot s of differnt developmental stages and get sick like we do. We take 18 to 19 years to raise our children before setting them out to face the world on their own, our plants are just like those children and since we take them out of their natural habitats, manipulate them to our asthestically pleasing qualities then we need all the information we can get to help them thrive.
My biggest problem is I read and do resreach on alot of the plants I grow and those I am thinking about growing and then I find something interesting and have to find the reason why, how come and if it to do with disease or problems find the cure or at least preventive measures. I guess I will finally decide to graduate when I have taken every hort, pathology, forest and plant biology class I can. Don't feel bad so much is still over and above my head and I am always grateful when somebody brings it down to what I call " dirt" terms as that is where my hands and body are always playing. LOL
I use copper to reduce fungal problems, and I plant my bulbs in extremely free draining soil or Bonsai mix. Rule of thumb - water when the pot is light. Always wait until the pot is completely dry (not parched) before watering again.
I'd like to resurface this post because I need to know what to do about my crinums and amaryllis. Does this look like "red blotch"???
I don't remember my crinums or amaryllis having these red spots until I started trading bulbs a couple of times and now I've got spots! I wasn't wise enough to "quarantine" new bulbs/plants prior to putting them in with mine. :-(
What should I do? My original crinums were from my grandmother and she has passed away. I'd hate to lose them or my amaryllis (from her)!
It looks like "red blotch" to me and I would spray them with a systemic fungicide.
I use a combination insecticide/fungicide called "Orthenex" but I'm sure there are others that are systemic fungicides without the insecticide. Check your garden center for suggested product. Maybe another DGer knows a good one.
When you water, try not to wet the foliage. I know that you can't control the rain and heat in the humid south, but keeping water from splashing around can help avoid spreading the spores.
Your plants won't die from stag unless it goes on *rampantly* under the worst conditions for a long time, but do treat for it as it can spread to other plants.
Raydio - Thanks for the reply. I think I have some of the orthonex... will check and make sure its the systemic fungicide. I have those little spray heads on sticks that connect to black tubing. I guess I could stick them in the ground as far as they will go so that less foliage gets sprayed and/or change to some sort of drip system. Sand is my enemy though LOL... clogs up everything!
Some absolutely incredible/informative data in this thread. Why don't you guys work at the nurseries where you buy plants/bulbs and want advice. I usually get some knucklehead that says put them in the ground and give plenty of aqua. I especially love it when they tell you to drown your new plant for the first two weeks. To echo raydio, I love the fact that its in laymans terms. Great thread, great info, Thanks!