Nemoci

Phytophthora nicotianae

• Zamioculcas zamiifolia (Lodd.) Engl.
• Monocotyledonous plant in the Araceae
• 2003, basal petiole rot and death of ZZ plants in two nurseries in southern Taiwan
• 18% of the plants diseased at one nursery [14]

Symptoms

• water soaking of the petiole base
• Slight yellowing of the leaflets
• Followed by browning of leaflets
• Petiole base became dark brown
• Shriveled, collapsed, and eventually rotted
• Surface of the roots and rhizomes
• Initially blackish brown
• Followed by root rots and mortality of plants [14]

A Phytophthora species

• Consistently isolated from diseased petioles, rhizomes, and roots
• Phytophthora nicotianae Breda de Haar. (synonym P. parasitica Dastur) was identified
• Chlamydospores with walls 1 to 4 µm thick
• Terminal or intercalary
• Spherical
• Averaged 30.6 µm in diameter
• Ranged from 18 to 46 µm [14]

• Disease-free ZZ plants were propagated by rhizomes in 242-cm3 round pots with 500 g of sterilized potting medium (vermiculite/peat moss/perlite = 1:2:1).

Inoculated with suspension:

• After 10 days of cultivation
• Aerial mycelia with sporangia were scraped off the plates
• Placed in 10 ml of sterile distilled water at 8°C for 15 min to release zoospores
• A zoospore suspension was adjusted to 104 zoospores/ml
• And 200 ml of the suspension was added to each pot, or rhizomes and roots were dipped in 400 ml of the suspension for 60 min and planted immediately
• Ten plants were inoculated with either method
• water was added to inoculated control plants
• Water soaking of the petiole bases developed in 7 days
• Mortality occurred in 10 days
• Control plants remained healthy [14]

P. nicotianae

• Was isolated from the advancing lesions of the inoculated plants
• First report of basal petiole rot and plant kill of Zamioculcas zamiifolia caused by P. nicotianae [14]

Root rot

• If the leaves turn yellow
• The stalks lean downwards
• An unpleasant odor rises from the soil
• Cause is usually a root rot
• Occurs when the plant is kept permanently wet or waterlogging has formed
• Remedy if you recognize the root rot at an early stage
• Lift the ZZ plant from the ground
• Free the roots from soil
• Where the mould has already formed, you must cut off the entire root part
• Roots, which are strongly soaked
• Should be shortened about one third
• Allow the root ball to dry out for about 24 hours at room temperature
• Replace the soaked, old soil with fresh, dry soil
• Put the dried ZZ plant back in
• Keep the soil only slightly but evenly damp for the first two to three days
• Keep the soil much drier
• Fertilizing is not necessary in the first four to six months [8]

Pests

• Limitedly protected against pests
• Many parasites show no interest in the poisonous plant

Spider mite

• Occurs predominantly in the winter months
• When heating air ensures a dry room climate
• White spider-net-like structures form below the leaves
• Suggests a spider mite infestation
• You have to immediately take the ZZ plant away from other plants
• Numerous insecticides available against spider mites – for spraying, casting or as ground sticks.
• Old home remedy
• Equally effective but less detrimental.
• Shower the ZZ plant vigorously
• Place it into a transparent garbage or plastic bag
• Close airtight
• Place the plant in a bright place for two or three days
• Then free it from the plastic wrapping
• Spider mites should now be dead [8]