Nematode Pests of Horticultural Crops and their Management (1+1)

Carnation and Tuberose

V. Carnation
Carnations are the important cut flowers that suffer about 5% loss due to nematodes alone in developed countries. Various plant parasitic nematodes have been found to be associated with carnation in India and elsewhere. Of these, the damage potential of Meloidogyne spp., Criconemella xenoplax and Paratylenchus spp. is well known.
Symptoms:

• Stunted and patchy plant growth.
• Reduced stem sturdiness i.e., weak stalks, leaf yellowing and delayed flowering occur due to infestation of these nematodes.
• In addition, roots bear numerous small galls in case of infestation with root knot nematode.

Management:

• Application of organic amendments like neem cake or mustard cake @ 25q/ha
• Application of phorate or cabofuran @ 2 kg a.i./ha reduced the nematode population and improved the plant status.
• Steam sterilization in the glass house is still the preferred method abroad as the crop is highly sensitive to the bromine present in most of the soil sterilants.

VI. Tuberose
Tuberose is grown in the states of Karnataka, Tamil Nadu, Maharashtra and West Bengal. The crop is highly sensitive to the infestation of Meloidogyne spp. and Rotylenchulus reniformis. Three species of root-knot nematode namely M. incognita, M. javanica and M. arenaria damage the crop in various states. Aphelenchoides besseyi has been found to infest tuberose in West Bengal and Orissa
Symptoms:

• Retardation in plant growth and yellowing of leaves which eventually dry
• Suppression of spike emergence and losses in yield.

Management:
Use of organic amendments and nematicides like carbofuran or phorate @ 2 g a.i./plant is effective against the nematodes.

List of some important nematodes and their ornamental hosts:

Sr.No.	Nematode	Ornamental Host
1	Meloidogyne spp.	Rose, Crossandra, Jasmine, Antirrrhinum, Phlox, Poppy, Naustertium, Carnation, Celosia, Begonia, Pyrogustia, Hedichium, Acalypha, Geranium, China aster, Cacti etc.
2	Ditylenchus dipsaci	Narcissus, Carnation, Phlox, Begonia, bulb crops
3	Tylenchorhynchus claytoni	Azalea, Ilex, Sedum
4	Aphelenchoides ritzemabosi and A. besseyi	Tuberose, Zinnia, Chrysanthemum
5	Scutellonema brachyurum	Begonia, Camellia, cCarnation African violet
6	Radopholus similis	Anthurium, Canna, Celosia, Shoe flower, Ixora, Jasmine
7	Pratylenchus penetrans	Rose