What Is Belly Rot: Tips On Avoiding Rotting Vegetable Fruit

What Is Belly Rot: Tips On Avoiding Rotting Vegetable Fruit

By: Kristi Waterworth

An over-eager cucurbit producing bushels of cucumbers, melons, or squash feels like a plague in the garden by midsummer, but there are worse things that can happen. Rotting vegetable fruit, caused by rhizoctonia belly rot, is one of those things. As difficult as disposing of healthy vegetables can be when your zucchini explodes into life, it’s a much bigger task dealing with bad fruits.

What is Belly Rot?

Belly rot in fruit is caused by the fungus Rhizoctonia solani, which survives in the soil from year to year. The fungus becomes active when humidity is high and temperatures warm, causing obvious signs of infection within 24 hours and entirely rotting fruits in as little as 72. Temperatures below 50 degrees F. (10 C.) can slow or prevent infection. This is primarily a disease of cucumbers, but may cause belly rot in fruit of squash and melons as well.

Fruits that are in direct contact with the soil develop small, tan to brown water-soaked spots on the ground spot. As the disease spreads, the spots expand and become crusty and irregularly shaped. An advanced case of rhizoctonia belly rot causes these spots to sink, crack, or appear crater-like. Flesh near the lesions is brown and firm, sometimes extending into the seed cavity.

Preventing Rotting Vegetable Fruit

Crop rotation is one of the best ways to prevent rhizoctonia belly rot, especially if you rotate with grain crops. If your garden is small, though, crop rotation may be difficult. In that case, you must do what you can to minimize contact between fruits and fungal structures. Start by tilling your garden deeply, or even double-digging when possible. The deeper you can bury the fungus in the soil, the less likely you’ll be bothered by it.

Once plants are growing, a thick, black plastic mulch can prevent fruit from contacting the soil directly, but you must still water carefully to avoid over saturating the fruits or the soil. Some gardeners put their young fruits onto small mounds made from wood, shingles, wire, or mulch but this can be labor intensive.

Another way to get your fruits off the ground is to train them to a trellis. Not only does trellising save space, it can prevent many different problems caused when fruits are in contact with the soil. Trellises keep your beds tidy and fruits within easy reach for harvesting. Just remember to support growing fruits with stretchy hammocks made from material such as pantyhose.

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Rhizoctonia is a genus of anamorphic fungi in the order Cantharellales. Species do not produce spores, but are composed of hyphae and sclerotia (hyphal propagules) and are asexual states of fungi in the genus Thanatephorus. Rhizoctonia species are saprotrophic, but are also facultative plant pathogens, causing commercially important crop diseases. They are also endomycorrhizal associates of orchids. [1] The genus name was formerly used to accommodate many superficially similar, but unrelated fungi.

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Fruit surface in contact with the soil becomes watersoaked and whole fruit eventually becomes soft and mushy.

Cultural practices that reduce fruit contact with soil, or splashing of infected soil onto fruit are beneficial. Fungicide sprays may be required.

The information given herein is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Texas AgriLife Extension Service is implied.

Educational programs of the Texas AgriLife Extension Service are open to all people without regard to race, color, sex, disability, religion, age, or national origin.

Practice a three-year or longer crop rotation between cucurbit crops. The belly rot pathogen can attack many weeds thorough weed control is essential for crop rotation to be most effective. Crop debris should be promptly and thoroughly incorporated after harvest to hasten the breakdown of the pathogen’s dormant resting structures. Belly rot can be controlled effectively by not letting fruit touch the soil. Plastic mulches are often effective in preventing belly rot in semi-arid and arid production regions.

Soil-applied fungicides provide inconsistent disease control. Soil fumigation can be effective but is generally not economical in the High Plains.

Product List for Belly Rot:

Pesticide Product per acre Application Frequency (days) Remarks
Quadris 11.0-15.4 fl oz 5-14 days Maximum of 4 applications or 2.88 quarts per season Alternate Quadris with fungicides with different modes of action 1 day PHI
Bravo 720, Ensign 1.5-2 pt 7 days Do not graze or feed debris to livestock 7 day PHI
Bravo Ultrex 1.4-1.8 lb 7-10 days Maximum of 16.5 pounds per season 0 day PHI
Bravo WeatherStik 1.5-2.0 pt 7-10 days Maximum of 20 pints per season 0 day PHI
Echo 720 1.5-2.0 pt 7-10 days Maximum of 2.5 gallons per season 7 day PHI
Echo 90DF 1.2-1.6 lb 7-10 days Maximum of 16.67 pounds per season 7 day PHI
Echo Zn 2.2 to 2.8 pt 7-10 days Maximum of 3.6 gallons per season 7 day PHI
Thiophanate Methyl
Topsin M 70WP 0.5 lb 7-14 days Maximum of 3 lb per season Alternate fungicide sprays or tank-mix with fungicides with a different mode of action 1 day PHI
Topsin 4.5 FL 10 fl oz 7 days Maximum of 60 fl oz per season Alternate fungicide sprays or tank-mix with fungicides with a different mode of action 1 day PHI
Topsin WSB 0.5 lb 7-14 days Maximum of 3 lb per season Alternate fungicide sprays or tank-mix with fungicides with a different mode of action 1 day PHI

The information herein is supplied with the understanding that no discrimination is intended and that listing of commercial products, necessary to this guide, implies no endorsement by the authors or the Extension Services of Nebraska, Colorado, Wyoming or Montana. Criticism of products or equipment not listed is neither implied nor intended. Due to constantly changing labels, laws and regulations, the Extension Services can assume no liability for the suggested use of chemicals contained herein. Pesticides must be applied legally complying with all label directions and precautions on the pesticide container and any supplemental labeling and rules of state and federal pesticide regulatory agencies. State rules and regulations and special pesticide use allowances may vary from state to state: contact your State Department of Agriculture for the rules, regulations and allowances applicable in your state and locality.

Resistance to Belly Rot in Cucumber Identified through Field and Detached-fruit Evaluations

Belly rot, caused by the fungal pathogen Rhizoctonia solani Kühn., is a severe disease in many regions that produce cucumber (Cucumis sativus L.). Annual crop loss to belly rot is commonly 5% to 10%, but losses as high as 80% can occur in individual fields. There are no resistant cultivars, so fungicides are used to provide partial control. Genetic resistance in an acceptable cultivar would be more desirable and economical. Studies were conducted in Summers 1991 and 1992 to screen promising germplasm for belly rot resistance using field and detached-fruit screening methods. In 1991, 105 cultigens (cultivars, breeding lines, and plant introduction accessions) were evaluated for belly rot resistance. The tests were repeated in 1992 with 63 cultigens, including the most resistant cultigens identified in 1991 and appropriate controls. Several cultigens were identified as potential sources of resistance genes. Pickling cucumbers showing resistance included PI 197085, PI 271328, and an F4 selection of PI 197087 × PI 280096. Slicing cucumbers with resistance included `Marketmore 76' and the F1 of Gy 14 × PI 197087. Belly rot resistance was not correlated with other horticultural traits measured, including fruit type, skin type, spine color, and firmness. The resistant cultigens identified should be useful for developing cucumber cultivars with enhanced resistance to Rhizoctonia solani.

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Rhizoctonia Primer

Andrew K. Gonsalves, Educational Specialist

Stephen A. Ferreira, Extension Plant Pathologist

Department of Plant Pathology, College of Tropical Agriculture and Human Resources

University of Hawaii at Manoa

Numerous Rhizoctonia species have been reported to occur in Hawaii on many hosts (Raabe, et al., 1981). The following is a list of the reported pathogens from this genus (Rhizoctonia) and the hosts they infect. The list is organized by the scientific name of the pathogen species (CAPITAL LETTERS), followed by the various susceptible plant hosts. Words in blue indicate what symptom or disease a given pathogen causes on the listed hosts.

head lettuce (Lactuca sativa var. capitata)

taro (Colocasia esculenta)

potato (Solanum tubersoum)

ginger (Zingiber officinale)

peanut (Arachis hypogaea)

narrow-leaved carpet grass (Axonopus affinis)

broad-leaved carpet grass (Axonopus compressus)

field mustard (Brassica campestris)

turnip (Brassica rapa)

Bermuda grass (Cynodon dactylon)

carnation (Dianthus caryophyllus)

yellow passion fruit (Passiflora edulis f.sp. flavicarpa)

parsley (Petroselinum crispum)

garden bean (Phaseolus vulgaris)

panax (Polyscias guilfoylei)

Douglas fir (Pseudotsuga menziesii)

rutabaga (Brassica campestris var. napobrassica)

cabbage (Brassica oleracea var. capitata)

Chinese or celery cabbage (Brassica pekinensis)

tomato (Lycopersicon esculentum)

rhubarb (Rheum rhaponticum)

bread vine or black-eyed susan (Abrus precatorius)

St. Augustine grass (Stenotaphrum secundatum)

aechmea (Aechmea fasciata)

cultivated asparagus (Asparagus officinalis var. altilis)

coriander (Coriandrum sativum)

hydrangea (Hydrangea macrophylla)

Christmas cactus (Schlumbergera bridgesii)

spinach (Spinacia oleracea)

pathos (Scindapsus aureus)

stephanotis (Stephanotis floribunda)

African marigold (Tagetes erecta)

cape honeysuckle (Tecomaria capensis)

garden beet (Beta vulgaris)

Formosan kow (Acacia koa)

koa (Acacia koa var. koa)

Chinese evergreen (Aglaonema commutatum)

seaside bentgrass (Agrostis palustris)

shallot (Allium ascalonicum)

Chinese chives (Allium tuberosum)

red ginger (Alpinia purpurata)

joy weed (Alternanthera amoena)

slender amaranth, pakai (Amaranthus gracilis)

pineapple (Ananas comosus)

dill (Anethum graveolens)

anthurium (Anthurium andraeanum)

Mexican creeper (Antigonon leptopus)

celery (Apium graveolens var. dulce)

aster (Aster sp.)

snow bush (Breynia nivosa)

pigeon pea (Cajanus cajan)

China aster (Callistephus chinensis)

sweet pepper (Capsicum frutescens)

papaya (Carica papaya)

Natal plum (Carissa grandiflora)

cockscomb (Celosia argentea var. cristata)

golden-fruited palm (Chrysalidocarpus lutescens)

florist's chrysanthemum (Chrysanthemum morifolium)

watermelon (Citrullus vulgaris)

croton (Codiaeum variegatum)

tickwood (Coreopsis lanceolata)

crown vetch (Coronilla varia)

ctenanthe (Ctenanthe oppenheimiana)

cantaloupe (Cucumis melo var. cantalupensis)

cucumber (Cucumis sativus)

pumpkin (Cucurbita pepo)

Italian cypress (Cupressus sempervirens)

carrot (Daucus carota var. sativa)

sweet william (Dianthus barbatus)

carnation (Dianthus caryophyllus)

lawn leaf (Dichondra repens)

centipede grass (Eremochloa ophiuroides)

poinsettia (Euphorbia pulcherrima)

Chinese banyan (Ficus retusa)

fern tree (Filicium decipiens)

strawberry (Fragaria chiloensis var. ananasa)

galinsoga (Galinsoga parviflora)

gazania (Gazania rigens)

globe amaranth (Gomphrena globosa)

baby's breath (Gypsophila paniculata)

white ginger (Hedychium coronarium)

kahili ginger (Hedychium garderianum)

sunflower (Helianthus annuus)

garden balsam (Impatiens balsamina)

sweet potato (Ipomoea batatas)

Arabian jasmine (Jasminum sambae)

head lettuce (Lactuca sativa var. capitata)

'akulikuli' (Lampranthus glomeratus)

lantana (Lantana camara)

Hawaiian holly (Leea coccinea)

pincushion protea (Leucospermum cordifolium)

farfugium (Ligularia kaemperi)

statice (Limonium sinuatum)

birds-foot trefoil (Lotus corniculatus)

European blue lupine (Lupinus angustifolius)

macadamia (Macadamia integrifolia)

alfalfa (Medicago sativa)

tree heliotrope (Messerschmidia argentea)

crested fern (Microsorum punctatum)

naio (Myoporum lacteum)

oleander (Nerium oleander)

lily turf or mondo grass (Ophiopogon japonicus)

yam bean (Pachyrrhizus erosus)

tree peony (Paeonia suffruticosa)

hilo grass (Paspalum conjugatum)

passion fruit (Passiflora edulis)

Peperomia obtusifolia

avocado (Persea americana)

Philodendron hastatum

baby's tears (Pilea depressa)

creeping charlie (Pilea nummularifolia)

edible-podded pea (Pisum sativum var. macrocarpon)

cats claw, black bead (Pithecellobium unguis-cati)

Japanese pittosporum (Pittosporum tobera)

Podocarpus macrophyllus

tuberose (Polianthes tuberosa)

panax (Polyscias guilfoylei)

leather holly fern (Polystichum adiantiforme)

purslane (Portulaca oleracea)

jade tree (Portulacaria afra)

self-heal (Prunella vulgaris)

guava (Psidium guajava)

Macarthur palm (Ptychosperma macarthurii)

castor bean (Ricinus communis)

rosemary (Rosmarinus officinalis)

African violet (Saintpaulia ionantha)

weeping willow (Salix babylonica)

common sage (Salvia officinalis)

beach naupaka (Scaevola sericea)

Dwarf Schefflera (Schefflera arboricola)

stonecrop (Sedum lineare var. variegatum)

gloxinia (Sinningia speciosa)

eggplant (Solanum melongena)

black nightshade (Solanum nigrum)

potato (Solanum tuberosum)

sorghum (Sorghum bicolor)

Jamaica vervain (Stachytarpheta jamaicensis)

common comfrey (Symphytum officinale)

strawberry clover (Trifolium fragiferum)

manila palm (Veitchia merrellii)

cowpea (Vigna sinensis)

pansy (Viola tricolor)

cultivated zinnia (Zinnia elegans)

Indian jujube (Ziziphus mauritiana)

Japanese lawn grass (Zoysia japonica)

mascarene grass (Zoysia tenuifolia)

Seedling Blight and Root Rot:

silkwood (Flindersia brayleyana)

Sheath, Basal Stem, and Root Rot:

sugar cane (Saccharum officinarum)

papala, kepau (Bougainvillea umbellifera)

dasheen (Colocasia esculenta var. globulifera)

Bermuda grass (Cynodon dactylon)

petunia (Petunia hybrida)

double-flowering pomegranate (Punica granatum var. nana)

SUBDIVISION: Deuteromycotina (The imperfect fungi)

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Below is a list of graphics that are available for this Genus:

This may be caused by Rhizoctonia solani.

This may be caused by Rhizoctonia solani.

Agrios, G.N. 1988. Plant Pathology, 3rd edition. Academic Press, Inc: San Diego. 803 pp.

Farr, , D.F., G.F. Bills, G.P. Chamuris, and A.Y. Rossman. 1989. Fungi on Plants and Plant Products in the United States. APS PRESS: St. Paul, Minnesota. 1252 pp.

Raabe, Robert D., Ibra L. Conners, and Albert P. Martinez. 1981. Checklist of Plant Diseases in Hawaii. Hawaii Institute of Agriculture and Human Resources, College of Tropical Agriculture and Human Resources, University of Hawaii (Information Text Series 022).

Streets, R.B. 1982. The Diagnosis of Plant Diseases: a field and laboratory manual emphasizing the most practical methods for rapid identification. The University of Arizona Press: Tucson, Arizona.

Watch the video: TREATING SCALE ROT