Pests
Slugs and grass hoppers, which feed on the leaves, and thrips which damage and cause distortion of the spikes are the major pests. Malathion and carbaryl are effective against these pests. No major disease is noticed. Sclerotium fungus, which attacks the leaves and flower stalks at ground level causes defoliation and toppling of spikes. This can be controlled by drenching of soil around the plant with fungicides.
Bud borer (Helicoverpa armigera)
This pest mainly damages flowers. Eggs are deposited singly on growing spikes. Larvae bore into buds and flowers and feed on them by making holes.
Control: Collection and destruction of damaged buds reduces the damage. Setting up of light traps helps to control population by attracting them. Sprays of carbaryl 0.2 % taken up at appearance of eggs on buds and tender foliage controls borer damage. Neem oil 1% also gives considerable protection by repelling various stages of pest.
Aphids
These are tiny insects, soft bodied, green, deep purple or black in colour. These usually occur in clusters and feed on flower buds and young leaves.
Control: Spraying the infected plants with malathion @0.1% at an interval of 15 days is effective.
Grasshoppers
These feed on young leaves and flower buds. Affected plants with damaged foliage and flowers lose their elegance, especially during rainy season.
Control: Dusting the plants with 5% Cythion dust may prevent the damage. Scraping of buds exposes egg masses to natural enemies. Netting prevents damage from hoppers to nurseries. Spraying of quinalphos @0.05% or malathion 0.1% or carbaryl @0.2% protects foliage of newly transplanted crop.
Red spider mites
Mites thrive well under hot and dry conditions, usually on the undersides of the leaves, where these make webs, if allowed to continue. These are usually red or brown in colour and multiply fast. Mites suck sap, which results in the formation of yellow strips and streaks on the foliage. In due course of time, leaves become yellow, silvery or bronze and distorted.
Control: Spraying with Kelthane @ 1.2% concentration is effective to control the mites.
Rodents
Rodents do considerable damage to tuberose plants in the field by making burrows.
Control: Poison bait is quite helpful in checking rodent menace in the field. Commercial bait by the name, 'Roban' is available in the market and the same may be used effectively.
Thrips
Thrips feed on leaves, flower stalk and flowers. These suck the sap and damage the whole plant. Sometimes, these are associated with a contagious disease known as 'bunchy top', where the inflorescence is malformed.
Control: Thrips can be controlled by spraying the plant with 0.1% malathion.
Weevils (Myllocerus sp)
The weevils are nocturnal in habit and damage shoots and leaves. Usually, they feed the edge of the leaves, producing a characteristic notched effect. Larvae feed on roots and tunnel into the bulbs.
Control: Applying BHC dust (10%) in the soil before planting controls larvae.
Source: http://www.ficciagroindia.com/production-guidelines/flowers/tuberose/pest.htm
Diseases
Stem Rot
The disease symptoms are preceded by the appearance of prominent spots of loose green colour due to rotting which extend and cover the entire leaf. The infected leaves get detached from the plant. More or less round sclerotic, brown spots are formed on and around the infected leaf. As a result, the infected plant becomes weak and unproductive.
Control: The disease can be controlled by soil application of Brassicol (20%) @ 30kg/ hectare.
Botrytis spot and blight (Botrytis elliptic)
The disease appears during the rainy season. Infected flowers show dark brown spots and ultimately the entire inflorescence dries up. The infection also occurs on the leaves and stalks.
Control: Spraying the plants with carbendazim @2g/litre of water effectively controls the disease. The treatment should be repeated at 15 days interval.
Sclerotial wilt (Sclerotium rolfsii)
The initial symptom of this disease is flaccidity and drooping of leaves. The leaves become yellow and dry up. The fungus mainly affects the roots and the infection gradually spreads upward through the tuber and collar portion of the stem. Both tubers and roots show rotting symptoms. Thick cottony growth of the fungus is visible on the rotten stem and on petioles at the soil level.
Control: Drenching the soil with 0.3% zineb is effective in controlling the disease.
Source: http://www.ficciagroindia.com/production-guidelines/flowers/tuberose/diseases.htm