|Anthracnose and chocolate spot||Colletotrichum gloeosporioides||fruits, petioles|
|Phytophthora||Phytophthora palmivora||fruit, stem, roots|
|Powdery mildew||Oidium caricae||leaves|
|Black spot||Cercospora papayae||fruit|
|Damping off||Pythium, Phytophthora, Rhizoctonia||seedlings|
|Wet rot||Phomopsis sp.||fruit|
|Dry rot||Mycosphaerella sp.||fruit|
|Watery fruit rot||Rhizopus stolonifer||/|
|Stem-end rot||Botryodiplodia theobromae, Rhizopus stolonifer, Phomopsis sp. , Mycosphaerella sp.||mature fruit|
|nematode disease||Reniform nematodes, Rotylenchulus reniformis，Root-knot nematodes, Meloidogyne spp.||root|
Papaya ringspot virus (PRSV) is an aphid-transmitted plant virus belonging to the genus Potyvirus, family Potyviridae, with a positive sense RNA genome.There are two main types of this virus that are serologically indistinguishable and are so closely genetically related that they are now considered the same virus species. Type P isolates (PRSV-P) infects papaya and several members of the melon family (Cucurbitaceae). The other type, Type W isolates (PRSV-W) infects only cucurbits such as watermelon, cucumber, and squash and were originally known as Watermelon mosaic virus (Tripathi et al. 2008).
Both pathotypes are distributed worldwide. PRSV-P is found in places where papaya mainly grow (Tripathi et al. 2008).
Virions are filamentous, non-enveloped and flexuous with the length of 760-800nm and the width of 12 nm. Virus particles comprise of 94.5% protein, containing the virus coat protein (CP) with a molecular weight of about 36kDa and 5.5% nucleic acid (Tripathi et al. 2008).
The virus is usually transmitted through aphids in a non-persistent way. But the virus can also be not seed-transmitted (Tripathi et al. 2008).
PRSV has a limited number of hosts which belong to the families Caricaceae, Chenopodiaceae and Cucurbitaceae. Propagation hosts are: Carica papaya, Cucurbita pepo and Cucumis metuliferus cv. accession 2459. Local lesion assay hosts are: Chenopodium quinoa and Chenopodium amaranticolor (Tripathi et al. 2008).
Two transgenic papaya varieties, Rainbow and SunUp, with engineered resistance to PRSV have been commercially planted in Hawaii since 1998. A lot of practices have implanted to manage the disease like transgenic resistance, tolerant cultivar, cross-protection and so on (Tripathi et al. 2008).
|Common name||Scientific name|
|Stevens leafhopper||Empoasca stevensi|
|Mediterranean fruit fly||Ceratitis capitata|
|Melon fly||Bactrocera cucurbitae|
|Oriental fruit fly||Bactrocera dorsalis|
|Common Name||Scientific name||Pathogenic part|
|Broad mite||Polyphagotarsonemus latus||seedlings, young plants, lower surface of young leaves|
|Red and black flat mite||Brevipalpus phoenicis||fruit|
|Tuckerellid mites||Tuckerella ornata, T. pavoniformis||trunks of old plants|
|Carmine spider mite||Tetranychus cinnabarinus||lower surface of mature leaves|
|Citrus red mite||Panonychus citri||upper surface of mature leaves|
|Texas citrus mite||Eutetranychus banksi||upper surface of mature leaves|