For details, kindly go through my article in Aroideana
vol.26 on Field and Storage diseases of
Amorphophallus.
Sincerely
RSMisra
--- Peter Matthews wrote:
>
> Dear Adam,
>
> Did your garden recenty import Amorphophallus
> specimens from SE Asia or
> other places where the genus is native? If you could
> identify possible
> geographical sources, this might help narrow down
> the search for a cause.
>
> Also, I wonder if there are any insects that lay
> their eggs in the lower
> petiole area? In theory, a newly spreading insect
> might spread a new or
> existing fungus. I do not know of such happening in
> Araceae, but it is
> conceivable. Taro has taro-specific planthoppers
> (Delphacidae) that lay
> eggs in the lower petiole, and they are spread with
> planting materials
> when the petioles are kept attached to the corm.
> There might be
> planthoppers that are specific to Amorphophallus
> (this is speculation).
>
> If you want, I could try to contacting konyakku
> researchers here in
> Japan. There would certainly be interested in the
> outbreak you describe,
> even if it is something new for them. Or they might
> immediately
> recognise what is happening to your plants. There is
> a lot of experience
> with intensive production of Amorphophallus here in
> Japan.
>
> Good luck...
>
> Peter Matthews
>
>
>
> On 8/7/2006, "Adam Black"
> wrote:
>
> >
> >We are suddenly having a severe problem with the
> Amorphophallus species
> >at the botanical gardens where I work. We are
> seeing a localized rotting
> >of the base of the petiole an inch or two above the
> soil line that turns
> >the petiole base to jelly and topples the leaf. It
> is affecting all
> >three species we have - A. konjac, A. bulbifer, and
> A. paeoniifolius,
> >and is occurring in various areas of the gardens
> that are seperated by a
> >considerable distance and have been otherwise
> healthy in thier locations
> >in the ground for years. I started noticing it in
> the konjacs and the
> >bulbifers a month or so ago shortly after they put
> up thier leaves, and
> >the rate of loss has escalated from there. I just
> now noticed on the
> >late emerging paeoniifolius that most of them have
> early signs of this
> >infection. I am by no means an expert on fungi, but
> there are several
> >different colors of fungus on the affected areas,
> but I am not sure if
> >this is secondary or not. The infection starts out
> as a brown patch on
> >the base of the petiole a few inches above the
> soil/leaf litter line,
> >and this progresses around the petiole and inward,
> but does not spread
> >up or down the petiole from that point. I dug up
> one corm from an
> >infected A. bulbifer and it appeared shrunken in
> and clearly unhealthy,
> >felt softer than a healthy corm but no external
> evidence of rot was
> >evident. I did not cut it open to see what it
> looked like inside, but
> >plan to on another specimen this week.The base of
> the petiole below
> >where the leaf had rotted off was still healthy in
> appearance and firmly
> >connected to the corm.
> >
> >Curiously, I have yet to see it affect any similar
> aroids growing
> >side-by-side with affected Amorphs in the gardens
> including Typhonium
> >venosum (of which we have many plants), Gonatopus
> bovinii, Remusatia
> >vivipera, and our native Arisaema triphyllum and
> jillions of Arisaema
> >dracontium. The Amorphs affected include both
> potted specimens and those
> >situated in the ground for years, and among the
> potted specimens some
> >affected plants are in a greenhouse with controlled
> watering, while
> >other potted plants are exposed to the weather in
> addition to
> >supplemental irrigation. I am keeping a closer eye
> on it now, but the
> >infection appears to spread and rot through the
> petiole relatively
> >quickly, so that the leaf itself still looks
> unstressed and perfectly
> >healthy after it has rotted off. I have only worked
> here since this past
> >winter, but the gardens director remembers a few
> Amorphs having this
> >problem last year but didn't think much of it, as
> the hundreds of others
> >in our mass plantings looked fine. If I had to
> guess now, I would say we
> >have lost about 60 or so plants with about as many
> showing the early
> >stages of the infection. It also seems to affect
> our mid to largest size
> >specimens rather than the smaller plants.
> >
> >Has anybody seen this before? Any recommendations?
> I am going to try a
> >fungicide this week, but with the huge number of
> plants we have spread
> >out all over our 60+ acre gardens, I am worried
> about how effective any
> >methods will be in controlling this. If anyone is
> interested I can email
> >photos of affected plants in various stages of
> infection.
> >
> >Thanks
> >
> >Adam
> >
> >
> >_______________________________________________
> >Aroid-l mailing list
> >Aroid-l@gizmoworks.com
> >http://www.gizmoworks.com/mailman/listinfo/aroid-l
> >
>
>
> _______________________________________________
> Aroid-l mailing list
> Aroid-l@gizmoworks.com
> http://www.gizmoworks.com/mailman/listinfo/aroid-l
>
Dr.Raj Shekhar Misra
Principal Scientist & Head
Crop Protection Division
Central Tuber Crops Research Institute
Sreekariyam, Trivandrum-695017(India)
Mobile Phone No. 91-9446557657
Fax-0471-2590063
Phone-0471-2598551 to 2598554
__________________________________________________
Do You Yahoo!?
Tired of spam? Yahoo! Mail has the best spam protection around
http://mail.yahoo.com
_______________________________________________
Aroid-l mailing list
Aroid-l@gizmoworks.com
http://www.gizmoworks.com/mailman/listinfo/aroid-l
|
IAS on Facebook
IAS on Instagram
