Wear chemical-resistant gloves when working with fungicide. Irum Sarfaraz is a freelance writer with over 20 years of nonfiction writing experience in newspaper op-eds and magazine writing, book editing, translating and research writing. Avoid allowing the fungicide to come in contact with skin and eyes. Some begonias offer not only delicate, colorful blossoms but also decorative foliage. These include darkened foliage, blackened and rotting roots, rotting stems just above ground level, and collapsing crown. Pythium: Plant in pasteurized potting media. Begonia Maculata Care . For example, Pythium fungus spores thrive in water and spread in excessively wet soil. are annual or perennial bedding plants that are also widely grown in pots. The base of stems develops a soft rot with sunken lesions. Begonia stem and root rot is a fungal disease which may affect your plant. Prepare the soil by covering it with plastic when the weather will be hot for several weeks and weighing down the edges with rocks. This problem is often severe when cuttings are placed in beds for rooting. Use disease-free seeds and healthy transplants from reliable sources. She holds a Bachelor of Arts in English literature, and diplomas in nonfiction writing. Always read and follow the warnings and instructions printed on a fungicide's label. This disease is spread through moisture and can be activated by damp ground and cool weather. If you think starting begonias from seeds is too meticulous, you can use cuttings […] Water the begonia when the top few inches of soil are dry, and avoid overwatering the plant. Depending on the brand and type of fungicide, a second treatment may be required. Ward; 1999. These fungicides are available in various forms, such as granules, powder and liquid, and combat the various types of rot that affect begonias. Those who need to learn how to root begonia can choose from two methods. How to Treat Tuberous Begonia Rot. The begonia, with over 1,000 different species, originated in the tropics. The diseases also spread with contaminated tools or by propagation of sick plants with seed or cuttings. An infection from Phythium fungi leads to root and stem rot in begonias. Use disease-free seeds and healthy transplants from reliable sources. If contact occurs, flush eyes and skin immediately with cool water. Create raised beds in areas that have poorly draining soils. Avoid overwatering plants and grow in well-drained soil. For me, a more sure fire way of propagating begonias is to plant those four inch (10 cm.) Plant the begonia in disease-free soil to help protect against all types of rot. Start use of fungicide at the first sign of disease. Improve soil drainage by incorporating organic mulch into the original soil before planting. Both fungi affect a host of other flowers besides begonia and are characterised by similar symptoms. The stems sometimes rot, especially if the sunlight is too direct, leaving a mushy goo in the glass; and tap water contains traces of chlorine, which can poison the young shoots. The problem is fairly easy to address, however, by ensuring that your soil drains well and never becomes waterlogged. The leaves may die and drop prematurely, leaving the begonia susceptible to sunburning. Both fungi are soil-borne and survive in contaminated soil for extended periods of time in the form of fruiting bodies or spores. Improve soil drainage by incorporating organic mulch into the original soil before planting. Botanists have classified begonias (_Begonia_ spp.) Stem rot is among the pathogenic disorders of begonias. The waxy, herbaceous flower clusters bloom from summer to fall in a range of colour including orange, red, salmon, yellow or white. The best defense against any of the various tuberous begonia rots is prevention. The most common reason begonia leaves rot is too frequent watering. Apply of fungicide that contains fosetyl-aluminum or mefenoxam to the begonia on a day when the temperature will not exceed 90 degrees Fahrenheit, there is no rain in the forecast and the wind is calm. and others): Affected plants wilt and break over at the soil line due to decayed spots being formed on stems. Cut away diseased, damaged or dying plant parts from the begonia using pruning shears, and place these pieces inside a garbage bag. Shiny blackened areas develop on the stems and petioles of established on the stems and petioles of established plants at and just above the soil line as plants collapse and die. Early symptoms of Rhizoctonia infection include wilting and yellowing foliage that are stunted in growth. Flanigan completed two writing courses at Pierpont Community and Technical College. This is possible by cutting a large enough stem, with possibly some buds in it, at a 45 degree angle and plant it potting soil. Fungi responsible for this condition may be introduced on cuttings or be present in soil. A tuberous begonia (Begonia spp. The Phythium fungus causes water soaked discolouration to appear on the stems. Affected roots become discoloured and plants become stunted in growth. Tan spots and sometimes water-soaked lesions appear on the foliage and stems of the plant. Eventually, those leaves rot and then fall off. An infection from Phythium fungi leads to root and stem rot in begonias. Begonias are succulent plants with stems that are mostly water, which makes them very sensitive to moisture and fungus. Stem and Root Rot (fungi – Pythium spp., Rhizoctonia spp. "A Contemplation Upon Flowers"; Bobby J. Remove any plant parts that have fallen to the ground, placing these inside the bag as well. Root and stem rot: If your tubers begin to look discolored or your stems start turning black, your begonias may be suffering from rot caused by fungi. This problem is often severe when cuttings are placed in beds for rooting. Chemical control options include the use of iprodione and thiophanate methyl. Apply the granules or powder fungicide to the soil and lightly dampen it with water. Stem rot. As you can see above I still have a small part of the plant to the right which is not infected. Avoid overwatering plants and grow in well-drained soil. Both fungi affect a host of other flowers besides begonia and are characterised by similar symptoms. Taking preventive measures is one of the best control strategies. Begonia-Stem Rot. Sarfaraz is originally from Pakistan and has been published in both American and Pakistani newspapers and magazines. Excessive water leads to rot and increases the possibility of future problems. Leave the plastic in place for four to six weeks. Diseased plants are highly prone to sunburn. Rhizoctonia Crown Rot "Stems rot at the soil line. Established begonia plants rot as well, starting in the crown. The temperature of the soil should reach up to 140 degrees Fahrenheit, which kills pathogens, insects and weeds living in the top 12 to 18 inches of soil.