Pests and Diseases


Pests and diseases
    Pests
    Shoot borer (Conogethes punctiferalis)
    • attacks the ginger crop. The larvae bore into the shoots, and the plants wilt and eventually die.
    • One or two prophylactic sprayings with Monochrotophos (0.1%) or Rogor (0.01%) or Dipel (0.3%) should be given as a precautionary measure and also the seed rhizomes may be dipped in 0.1% Quinalphos for 5 minutes before planting.
    • The usual practice is a bio monthly spray of either of these chemicals. Hexamermis sp. and
    • hymenopteran parasitoids could be used for bio-control of this pest.
    Rhizome scale
    • Another important pest of ginger is the rhizome scale. (Aspidiella hartii) which can be controlled by the application of Quinolphos or Fenthion (0.025%) before storage of rhizomes.
    Leaf roller (Udaspes folus)
    • The larvae cut and fold the leaves, remain within and feed on them.
    • The adult larvae are medium-sized and have brownish-black wings with large white spots.
    • Spraying with Carbaryl (0.1%), Dimethoate or Phosphomidon (0.05% each) checks the pest infestation.

    Nematodes
    • Nematode damage has also been reported. The control measure recommended is application of Thimet @ 10-15 kg/ha or Phorate 10 kg/ha at the time of land preparation.
    • Denematisation of ginger rhizomes at 45°C for 3 hours plus summer ploughing and covering of soil with polythene in May (15-30) is reported to reduce the population of root-knot nematode (Meloidogyne incognita).
    • In addition, stored ginger is attacked by the common storage pests like dung store beetle, the tobacco borer beetle, etc. Fumigation of the store houses should be carried out regularly to control these pests. The rhizome maggot, Mimegralla coerulifrous, is reported to cause rotting of the rhizomes.

    Diseases
    Soft-rot or rhiozme-rot
    • It is caused by (Phythium apanidermatum, Phythium myriotylum and Fusarium solani) is the most serious disease of ginger.
    • The bases of the aerial shoots become soft, watery and they rot.
    • The affected plants become pale. Their leaf tips turn yellow, followed by complete yellowing and drying. The shoots fall and cease to produce rhizomes.
    • The infection also spreads to the rhizomes and the inner tissues are reduced to a soft, black, putrefying mass.
    • The disease is favoured by high soil moisture content of the soil with insufficient drainage.
    • In order to control this disease, the first and foremost measure is the eradication of the infected plants and avoiding the monocropping of ginger.
    • For fresh planting, only sound, disease-free and healthy seed rhizomes should be selected.
    • They are treated with 0.25% organo¬mercuric compounds for 10-30 min. before planting or with Indofil M-45 (0.25%) plus Bavistin (0.1%) for 60 min. and drying in shade for 24 hours before sowing or storage, or the rhizomes may also be dipped in Blitox 50 (0.3%) before storage.
    • Trichoderma harzianum, T. hamatum or T. viridae @ 50 g (2 x 10 cfu) may be used for biological control of the disease pathogen. The cuitivars resistant to soft-rot are 76.1, OCP-855 and OCP-822.
    Leaf spot
    • The leaf-spot disease is caused by Taphrina sp., Colletotrichum sp. and Phyllosticta zingiberi. This disease is controlled by spraying Dithane M-45 (0.2%) or Bordeaux mixture (1%) at 15-day intervals.
    Bacterial wilt
    • The bacterial wilt disease is caused by Ralstonia solanacearum, for which the control measure is spray of streptocycline (200 ppm) during the month of June.

    The fungus Khuskia oryzae is also reported to cause leaf-spot disease.

    Yellows
    • 'Yellows' disease is caused by Fusarium oxysporum f.sp.zingiberi. The disease is characterised by foliar yellowing, starting from the base.
    • The rotting of the pseudostem, stunting of the plant, poor rhizome development and rotting of the rhizomes are the other symptoms.
    • The control measures besides phytosanitation are application of compost/FYM @ 2 t/ha and seed treatment with Mancozeb (0.25%) plus Bavistin (0.1%).
    • The nematode (Aphelenchus sp.) and the fungus (Fusarium sp.) together are reported to cause basal sheath rot.

Last modified: Sunday, 11 March 2012, 4:59 AM