Seeds, corms, cuttings and cut flower treatments for pest control

1. Techniques to check the spread of pest by
seeds, corms, cuttings and cut flowers
By :
JAYANT YADAV, CCSHAU, HISAR, HARYANA

2. INTRODUCTION
• Most plants reproduce sexually from seeds, but
some can be reproduced (or multiplied) by
vegetative parts such as stems, roots, and leaves.
• some plants produce modified stems and/or
roots, referred to here as specialized structures
that accumulate food reserves and therefore have
built-in regeneration potential and are valuable as
vegetative propagules. Plants with specialized
structures are well-suited for asexual
propagation.eg. corms, cuttings, rhizomes, tubers,
bulbs.

3. • Examples of vegetative propagated crops.
• Corms-Banana, Gladiolus, Crocus
spp.(saffron),Taro(Colocasia spp.).
• Rhizomes-banana, ginger, turmeric.
• Cuttings-rose, hibiscus, lavender, geranium,
chrysanthemum, aster, stevia.
• Bulbs- daffodil, dahlia, onion, garlic.
• Stolon-sweet potato.
• Tubers-potato.
• Runners-Strawberry.

4. Importance
• Knowledge about modes by which pathogens are
dispersed are helpful to devise suitable and effective
disease management practices.
• Knowledge about modes by which pathogens are
dispersed helps to reduce further spread of disease
inoculum.
• Prior knowledge of disease spread can help the
farmer to devise situational management practices
i.e. prophylactic and curative practices.

5. Continued…….
• Better knowledge of disease spread by vegetative
propagules can help to prevent entry of disease into
the country i.e. better quarantine regulations.
• As over 40% of bacterial pathogens are transmitted
over by veg. propagating materials, control in initial
stages can help ensure better growth of the crop. Eg.
X.compestris (c.canker)(c stocks),cuttings-
A.tumefaciens(crown gall),potato tubers.
• Viruses and other related agents are invariably
transmitted by vegetative propagules hence, viral
diseases are particularly serious in horticultural crops.

6. Diseases spread through corms, cuttings
and cut flowers
Disease
causing agents
Insects/Mites Bacteria Fungi Virus Nematodes
crops
Banana Banana weevil Rhizome soft
rot
Panama wilt,
leaf spot,
sigatoka
Banana
bunchy top,
Banana bract
mosaic
-
Cassava - Erwinia soft rot Shot hole leaf
disease
- -
Gladiolus Bulb mites scab Botrytis blight,
curvularia leaf
spot, fusarium
yellows
Bean yellow
mosaic,cucu
mber
mosaic,tomat
o ring spot
Bulb
nematode(Mel
oidogyne spp.)
Saffron Bulb mites - Root rot - -
turmeric Rhizome scale - - - -

7. cuttings
Disease
causing agents
Insects/Mites Bacteria Fungi Virus Nematodes
crops
Rose - Crown gall Stem canker,
Botrytis blight
Mosaic virus -
chrysanthemu
m
- - Leaf spot, wilt - Foliar
nematode

8. Seed borne pests and diseases
Seed transmitted insect pests
• Pulse beetle(Callosobruchus chiiensis)
• Pink boll worm(diapause in third instar).
• Coffee seed borer
Seed transmitted diseases of nematodes
• Ear cockle of wheat
• Potato cyst nematode.
• Rice white tip nematode.

9. Seed transmitted diseases
Internally seed borne diseases
• Loose smut of wheat and barley
• Ascochyta blight of chickpea
• Phomopsis blight of brinjal
Externally seed borne
 Covered smut of barley, oats.
 Grain smut of sorghum
 Bunts of cereals

10. Management practices for control of
pests and diseases of seeds, corms,
cuttings and cut flowers
Cultural control
• Proper field sanitation.
• Healthy plant material ,seeds free from pest and disease inoculum
should be selected.
• Deep ploughing in summer with the help of a disc plough helps to
expose the planting material exposes hibernating stages to
sunlight.

11. Physical control
• Hot water or hot air treatment at 50 -55 degrees celsius of plant
propagating materials like corms, rhizomes, bulbs etc. help to
control pest like bulb fly, rhizome weevil , nematodes etc.
• Steam sterilization of soil is done to kill soil insects and
nematodes.
• Exposure of cotton seeds to sun heat in thin layers for 2-3 days
during April helps to kill diapausing larvae of pink boll worm.
• Storage of seeds to low temperature of <4 degrees helps to
prevent damage.

12. Mechanical control
• Manual removal of infested plant parts such as pink boll worm
attacked rosetted flowers, adults of rhizome weevil, help to reduce
pest infestation.
• pruning and destruction of infested corms, flowers,
cuttings etc to check the multiplication of scales, mealy
bug, etc.
•Pheromone traps can be used to control the pests eg. Cosmolure for
rhizome weevil , gossyplure for pink boll worm.

13. Chemical control
• Application of Carbofuran 3G or Phorate 10 G @ 10-15 kg/ha, for
soil incorporation at the time of sowing.
• Treatment of Chlorpyriphos 20 EC @0.1% in soil before planting
affords control.
• Seed treatment with Imidacloprid 17.8 SL(Gaucho),70 WS @5-10
g/kg to control pests.
• Application of 500 ml of Dimethoate 30EC in 500lt of water/ha to
control pests of flower bud, cut flowers.

14. Continued
• Application of dicofol(kelthane) at 0.04%,propargite(O
mite)@1ml in 4litre of water for control of mite pests.
• Application of EDB(Ethyl dibromide) @60 ltr/ha, DBCP(di
bromo chloro propane) @20-50 ltr/ha for control of
nematodes.
• Seed treatment with systamic fungicide vitavax in protection
with thiram, kerathane@0.04%,sulfex @0.35% for controlling
fungal pathogens.

15. Continued
• Soaking seeds in Agrimycin(0.025%) for 8hrs,spray of copper
fungicides alternatively with copper fungicides gives effective
control to bacterial diseases.

16. Sources……
• Crop diseases and their management-Dr. H.S.
Chaube and Dr. V.S. Pundhir.
• Agricultural pests of south asia and their
management-A.S. Atwal and G.S. Dhaliwal.
• Introductory plant nematology- Dr. H. K. Bajaj
and Dr. R. K. Walia.
• Internet

17. Thank you