This document discusses several important post-harvest diseases that affect ornamentals and spices. It describes the symptoms, causal organisms, and management strategies for diseases like botrytis blight, soft rot, green mould rot, coriander wilt, storage rots, and anthracnose in ginger. Botrytis blight causes decay in cut flowers and is caused by the fungus Botrytis cinerea. Soft rot and green mould rot symptoms include browning, rotting, and discoloration caused by fungi like Aspergillus and Colletotrichum. Coriander wilt is caused by the fungus Fusarium oxysporum and leads to wilting, yellowing, and

1. Academic Program: Bsc.(Hons.)Horticulture
Semester: Fifth Semester
Course : PLPT-516, Diseases of vegetables, Tubers & spices Crops
Assignment - Important Post Harvest
Diseases of Ornamentals and Spices.

2. Introduction:
Not only quantity and quality, but even appearance of spices and ornamentals
may be affectedand their market value is reduced. In addition to losses in terms
of foodvalue, post-harvest loss also be apportioned into looses at various stages,
viz. storage loss, transportation loss and loss at the level of wholesaler, retailer or
consumer. Losses at the wholesaler or retailer are sometimes referred to as
‘shrink’. Such data would provide a post-harvest crop loss profile.
Among the different perishable commodities, flowers and spices are of prime
importance due to their large size, soft texture, high water content and
respiration, which make them very prone to deterioration after harvest. In
addition to various non-parasite causes (disorders), fungi, and bacteria and in
some cases viruses are responsible for post-harvest rots.
Important Post Harvest Diseases of Ornamentals
Major diseases Only a few bacteria (eg, Xanthomonas and Erwinia) are major
pathogens of ornamental crops . However, ornamentals are afflicted, both pre-
and postharvest, by many diseasecausing fungi. Pot and field grown plants are
attacked by both necrotrophic fungi(eg, Botrytis, Alternaria, Colletotrichum)
and biotrophic fungi that cause diseases such as downy (eg, Peronospora) and
powdery (eg, Erysiphe) mildew. Fungal pathogens causeroot rot (eg,
Phytophthora, Pythium and Rhizoctonia ,wilt (eg, Fusarium ,and leaf and petal
spot(specking) and flower blight (eg, Alternaria, Botrytis . The most
problematical postharvestpathogen to the cut-flower industry is B. cinerea
.Alternaria alternata is another pathogen that infects harvested cut-flowers.

3. A) BOTRYTIS BLIGHT OR ROT:
Symptoms:
This disease is considered most serious as post –harvest disease particularly in
roses, geraniums. Floweres and flowering stems are generally attackedafter
harvest if proper storage facilities are not provided. Cut flowers becoming an
increasingly troublesome problem. Cut flowers may be damaged by Bortytis
fungus during storage and shipment. Healthy, symptomless flowers become
badly decayed during transit and /or subsequent storage.
Mycelium:
Grey to greyish brown mycelium .
Asexual reproduction: Asexual reproduction occur through conidiophores and
conidia. Conidiophores and conidia appear as bunch of grapes.
Causal organism:
Botrytis cinereal

4. B) SOFTROT:
Symptoms:Generally infect the plants after harvest and infection usually
resulted due to mechanical injury. The infection originates in the field as
latent infection in inflorescence. Black and white to creamish growth
covers the harvested plant parts in dual infection which causes browning
and rotting of the infected parts.
Cuasal organisms:AspergillusandColletotrichumspp
C) GREEN MOULDROT:
Symptoms:Thisdisease appearsinpackinghouses,transit,storage andmarket.The
pathogeninvolvedisawoundparasite butwell spreadbycontactalso.It requireslow
temperature duringstorage andisan efficientproducerof ethylene.Itformsspongy,watery
and decolourizedspotsoninfectedportions.
Causal organisms:Penicilliumspp

5. 1. CORIANDERWILT
The occurrence of the disease in India has been reported from Madhya Bharat as early
as 1952. In favourable weather, the disease causes significant yield reductions.
Symptoms
Initial infection occurs on radicles causing brown lesions, rotting of tissues and
finally pre-emergencemortality.
In post-emergence, underground portion of hypocotyls initially develops
lesions, which slowly coalesced and girdled the region leading to death of
theplants.
Adult stage symptoms are typical and characteristic ofFusariumwilt.
The wilt symptoms are initiated by yellowing and curling of lowerleaves.
Gradually these symptoms get extended up to the apical portion, and during
this period lower leaves become dry and plantsdroop.
Affected plants generally remain stunted and bear less flowers andfruits.
Pathogen:
The fungus responsible for this disease
isFusariumoxysporumf.sp.coriandriNarula &Joshi.
The mycelium is abundant, fluffy and cottony white to light pink, both micro- and
macro conidia areproduced.

6. Later in theseason
chlamydospores are also produced.
Management
i) Follow long croprotations.
ii) Collect and burn the infected plantdebris
iii) Addition of oil cakes in the soil and raising of soil pH to 8.2 is also found
effective in reducing the diseaseincidence.
iv) Coriander varieties/ lines like MP 5365 and UD 373 showed least infection to the
disease and can be used in breeding programme for developing resistantvarieties.
v) Treat the seed with carbendazim (0.2%) followed by sprays withcarbendazim
(0.1%) reduce thedisease.
vi) Seed treatment withTrichoderma viride(4g/kg seed) was also found effective in
reducing the diseaseincidence.

7. STORAGE ROTS
Post-harvestlossesingingerareaseriousconcern.Thepost-harvest
lossesareaffectedbyvariousbioticandabioticcauses.Rhizomesare stored for seed and
commercial purpose. During storage, rhizomes softareaffectedbyfungiandbacteria.
Symptoms
Fungal mycelia
discolored the surface of rhizome accompanied with dry rotting and
decaying
Rotting of rhizome due to the infestation of F. Oxysporum
ANTHRACNOSE
Thediseaseisalsoknownas“Pollu‟.Spikesheddingduetothisdiseasecangoupto
10percent.Inearlyinfection,thereisupto77percentweightlossofberrieswhile
lateinfectioncauses56percentinfection.
Symptoms:
Thesymptomsonyoungleavesandspikesappearassmallbrownspeckswhich
aresurroundedbyyellowhalo(Plate-3a).
In severe form, defoliation and spike shedding may also occur.

8. Smallcracksdevelopontheberriesaftertheinfectionhasbeenestablished,thus
reducingthequalityoftheproduce.
Theinfectionontenderberriescausesdarkeningofthepericarpandaffectstheir subsequent
development(Plate-3b).
With time, these dry up resulting in chaffey berries, hence the name „pollu‟ which
means the hollow berry.
Pathogen:
Three species of genus Colletotrichum like C. gloeosporioides (Penz.) Penz. &Sacc.,
C. necatorMasse and C.capsici (Syd.) Butler&Bisbyhave beenreportedtobe associatedwith
thisdisease.
The myceliumof C.capsici is septate,intercellularaswell asintra-cellularandaerial mycelium
appearslightto darkgrey incolour.
Acervuli are roundandelongatedinshape (Plate-4),setaeare scattered,brown,1-5septate,
rigidand swollenatbase andacute at apex.
Conidiophoresare short,hyalinetofaintlybrown,cylindrical,septateoraseptate.
Conidiaare falcate,fusiformwithacute apicesandnarrow truncate base,one celledhyaline
and uninucleate.
Acervulusof C.capsica