Plant Pathology - Guava Wilt
- 1. COLLEGE OF AGRICULTURAL TECHNOLOGY (Affiliated to Tamil Nadu Agricultural University, Coimbatore-3) Kullapuram (Po), ViaVaigai Dam, Theni - 625 562 GUAVA WILT COURSE TEACHER STUDENT Dr. PARTHASARTHY. S NAME : C. GOKILA Asst. Professor (Plant Pathology) ID.NO : 2015021038
- 2. GUAVA WILT • Fusarium oxysporum f.sp. psidii (Prasad et al 1952)
- 3. Occurrence History • The disease was first noticed in 1935 in Allahabad. • It spread to more than 20,000 sq. miles during 1952.
- 4. Geographical distribution World • Guava wilt has been reported in Taiwan (Hsieh et al), South Africa (Grech and Frean), Brazil (Tokeshi et al), Pakistan (Ansar et al) and Reunion island (Normand).
- 5. Geographical distribution India • Guava wilt reported in the different part of Uttar Pradesh, West Bengal, Haryana, Punjab, Bihar, Delhi, Andhra Pradesh, Gujarat, Maharashtra and Madhya Pradesh.
- 6. Significance Economical • Reported, 5-20 % trees killed in annually in Allahabad, Lucknow and Faridabad. • In West Bengal the wilt caused reduction of the yield upto 80%.
- 7. Significance • In Andhra Pradesh land value reduced to half due to wilt disease. • 150 acres of the wilt affected guava orchid in Punjab. • 300 acres in Haryana were uprooted in 1978-1981.
- 8. Symptoms • First external symptom of the guava wilt is the appearance of yellow colouration with slight curling of the leaves on terminal branches. ©http /www.agriverge.in
- 9. • Subsequently browning, drooping and pre-mature shedding of the leaves occur. • Generally the symptoms appears after the rains. ©http://www.forestyimage.org
- 10. • That is during October - November when the fruits are small. • The wilt affected branches fruits remain under developed, hard and stony.
- 11. • Usually fifteen days are required for the complete wilting. • Some trees take even up to one year. • Light brown discolouration is also noticed in the vascular tissues. ©http://www.invasine.org
- 12. Pathogen • Das Gupta and Rai reported the association of Fusarium sp with the wilt disease in U.P.
- 13. Systematic position Kingdom : Fungi Phylum : Ascomycotina Subphylum : Peziziomycotina Class : Sordariomycetes Subclass : Hypoceromycetidae Order : Hypocereales Family : Nectriaceae Genus : Fusarium Species : oxysporum
- 14. Pathogen characters • Mycelium is white or pink with a purple tinge. • Pathogen produces microconidia, macroconidia and chlamydospores. ©http://www.researchgate.net
- 15. • Microconidia are single celled, hyaline elliptical shape. • Macroconidia are sickle shaped, hyaline, 3-5 septate and tapering at both ends. • Chlamydospores are thick walled, spherical to oval, hyaline to slightly yellowish in colour. ©http://www.researchgate.net
- 17. Survival and spread • It is soil borne pathogen. Survives in soil as chlamydospores for longer periods. • The primary spread of the disease by the affected soil. • Secondary spread by water. • Root injury predisposes wilt disease.
- 18. Favourable conditions • High rainfall during August/ September. • Stagnation of water in guava field for long duration. • Maximum and minimum temperature ranges 23-32○C with 76% RH are conducive. • Lack of timely application of suitable control measures.
- 19. Integrated disease management • Cultivate the resistant varieties of Banarasi, Dholka a Sind, Nasik white guava, Supreme and Lucknow 96. • Pruning and burning the affected twigs. • Application of green manure and oil cake.
- 20. • Spread of the wilt could be checked by judicious amendments of N and Zn. • The wilt was reported to be controlled by soil treatment with 1.82 kg lime or gypsum / tree.
- 21. • Biocontrol agents Trichoderma sp and Streptomyces chibaensis have been suggested for the control of wilt pathogens. • Soil drenching with Carbendazim 0.2% at 4 times in a year.
- 22. References • Tripathi.D.P. 2009. Crop diseases. Kalyani publishers. New Delhi. Pg.No :164. • Saha.L.R. 2002. Hand book of plant diseases.Kalyani publishers. New Delhi. Pg.No : 299. • Thind.T.S. 2001. Diseases of fruit and vegetables and their management. Kalyani Publishers. New Delhi. Pg.No : 124. • www. agrivilage.in