অসমীয়া   বাংলা   बोड़ो   डोगरी   ગુજરાતી   ಕನ್ನಡ   كأشُر   कोंकणी   संथाली   মনিপুরি   नेपाली   ଓରିୟା   ਪੰਜਾਬੀ   संस्कृत   தமிழ்  తెలుగు   ردو

Cabbage and Cauliflower diseases

Damping Off

Pythium aphinidermatum (Eds.) Fitz.; Rhizoctonia sonali Kuhn

Symptoms:

  • Damping off of Cabbage occurs in two stages, i.e. the pre-emergence and the post-emergence phase.
  • In the pre-emergence the phase the seedlings are killed just before they reach the soil surface.
  • The young radical and the plumule are killed and there is complete rotting of the seedlings.
  • The post-emergence phase is characterized by the infection of the young, juvenile tissues of the collar at the ground level.
  • The infected tissues become soft and water soaked. The seedlings topple over or  collapse.

Damping Off  Symptoms

Favourable Conditions:

  • High humidity, high soil moisture, cloudiness and low temperatures below 24° C for few days are ideal for infection and development of disease.
  • Crowded seedlings, dampness due to high rainfall, poor drainage and excess of soil solutes hamper plant growth and increase the pathogenic damping-off.

Survival and spread:

  • Primary: Soil, Seed, Water
  • Secondary: Conidia through rain splash or wind

Survival and spread

Club root of crucifers

Also known as Finger and toe disease: Plasmodiophora brassicae Woronin

Symptoms:

  • Stunting and yellowing of plants
  • Leaves become yellowish and wilt on hot days.
  • Club like swelling of root and root lets
  • Club root is particularly prevalent on soils with a pH below 7, whereas it has been observed that the disease is often less serious on heavy soils and on soils containing little organic matter

Club root of crucifers Symptoms

Survival and spread:

  • Primary: Soil borne resting spores, which survive for longer periods in soil (10yrs.) Collateral hosts: Broccoli, Brussels sprout, cabbage, cauliflower, Chinese cabbage, mustard, raddish, turnip
  • Secondary: Resting spores or zoospores carried through irrigation water or by root contact.

Favourable conditions:

  • It occur at a temp range of 12 - 270C (250C)
  • High soil moisture
  • Neutral to acidic soils 5-7.0 pH

Alternaria leaf spot

Alternaria brassicae (Berk.) Sacc; A. brassicicola (Schw.) Wiltshire

Common on cabbage, cauliflower and mustard.

Symptoms:

  • Spots are small, dark colouredCommon on cabbage Symptoms
  • They enlarge, soon become circular & 1mm. in diameter
  • Under humid conditions groups of conidiophores will be formed in the spot
  • Spots develop concentric rings
  • Finally the spots coalesce leading to blighting of leaves.
  • The fungus is seed borne and cause shriveling of seeds and poor germination
  • Linear spots also appear on petioles, stems, pods & seeds

Survival and spread:

  • Primary: Mycelium persisting in the seed or as spores on seed or from debris
  • Secondary: Wind or insect borne conidia

Favourable conditions:

  • Soil temperature of around 280 C
  • High humidity or persistent dew
  • Moist weather with intermittent showers>

Black rot

Xanthomonas campestris pv. campestris (Dowson) Dye, et al.

Serious on cabbage, cauliflower, knol-khol and raddish

Symptoms:

  • First appear as chlorotic or yellow (angular) areas near the leaf margins
  • Yellow area extends to veins and midrib forming characteristic ‘v’ shaped chlorotic spots which later turn black
  • Veins and veinlets turn brown and finally black
  • Vascular blackening extend beyond affected veins to midrib, petiole and stem
  • In advanced stages, infection may reach the roots system and blackening of vascular bundles occurs. Bacterial ooze can also be seen on affected parts
  • If the infection is early, the plants wilt and die
  • If the infection is late plants succumb to soft rot and die.

Black rot Xanthomonas Symptoms

Survival and spread:

  • Primary :Bacterial cells internally seed borne and soil borne
  • Secondary: Bacterial cells dispersed through irrigation water and rain splashes.

Favourable conditions:

  • Relative humidity > 90%
  • High soil moisture
  • Frequent rains

Downy Mildew

Peronospora parasitica (Pers.) Fr. Syno. (Hyaloperonospora parasitica (Pers.) Constant., 2002

Severe in raddish, cabbage, cauliflower, mustard, and knol-khol.

Symptoms:

  • Small purplish brown spots on under surface of leaves
  • Small, pale yellow angular spots on upper surface of leaves, with downy growth on the under surface. The spots coalesce and the leaves shrivel and dries up prematurely
  • In cabbage, these spots expose the heads to soft rot
  • Cauliflower curds look brownish at the t
  • Stems show dark brown and depressed lesions or streaks which later develop downy growth of fungus.

Downy Mildew Peronospora parasitica Symptoms

Survival and spread:

  • Primary: Oospores in infected plant debris or in soil
  • Secondary: Wind borne and rain splashed sporangia

Favourable conditions:

  • It occur at a moderate temperature range of 12-270 C
  • High soil moisture
  • Neutral to acidic soils 5-7.0 pH

Powdery mildew

Erysiphe cruciferarum Opiz.ex Junnell

Infects mostly cabbage and cauliflower

Symptoms:

  • White powdery spots on the upper surface of leaves, stems,Powdery mildew Symptoms
  • flower parts etc.
  • Finally the mildew may cover the entire surface
  • Infected plants may show rotting and do not have normal growth

Survival and spread:

  • Primary: Dormant mycelium in infected plant debris
  • Secondary: Wind borne conidia.

Favourable conditions:

  • It occur at a moderate temperature range of 12-270 C
  • Dry conditions with morning relative humidity of 80%

White rust

Albugo candida (Pers. ex Lév.) Ktze

Symptoms:

  • White, shiny raised blisters (pustules) on the lower surfaces of leaves, stems and flowers
  • Pustules coalesce to form irregular patches
  • The epidermis ruptures exposing white spore mass which gives the pustule a powdery appearance
  • Distortion of the floral parts including petals, pistils and anthers due to hypertrophy and Hyperplasia
  • Plants malformed beyond recognition

White rust Symptoms

Survival and spread:

  • Primary: Oospores in soil and sporangia from perennial weed hosts in the vicinity
  • Secondary: Wind borne and rain splashed conidia (sporangia) or autonomous zoospores

Favourable conditions:

  • Relative humidity > 90%
  • High soil moisture
  • Frequent rains

IPM for Cabbage and Cauliflower

To know the IPM practices for Cabbage & Cauliflower, click here.

Source: NIPHM, Directorate of Plant Protection, Quarantine & Storage



© 2006–2019 C–DAC.All content appearing on the vikaspedia portal is through collaborative effort of vikaspedia and its partners.We encourage you to use and share the content in a respectful and fair manner. Please leave all source links intact and adhere to applicable copyright and intellectual property guidelines and laws.
English to Hindi Transliterate