Premature Yellowing And Bean Shedding In Vanilla

By Agropedia on 06 Apr 2016

Submitted by Spicepedia

This is a major disease of relatively recent origin, noticed in all vanilla plantations of Kerala and Karnataka during summer months. The disease incidence is favored by high temperature exceeding 32°C and very low relative humidity 

Symptoms:

The disease is initially manifested by the premature dropping off of dried corolla from the tip of immature beans. As the dried corolla drop off, exudates from the beans accumulate at the tip. This is followed by premature yellowing of the beans at the tip that extends towards the pedicel portions. Later, brown discoloration develops at the tip portion that spreads upwards. Fully affected beans fall off from the peduncle before reaching maturity. After fruits fall, or even before, rotting appears in the apical part and continues throughout the fruit.

Yellowing and shedding of immature beans 

Management:

Provide 50% shade in the plantation.  Provide mist irrigation for at least 4-6h during pollination till the onset of pre-monsoon showers in order to maintain a relative humidity of more than 70%. Restrict the pollination to 15-18 flowers/inflorescence. Spray dimethoate or quinalphos 0.05% during flowering period thrice at 15-20 days interval and fungicides such as thiophanate methyl 0.2% or carbendazim+mancozeb (0.25%) at 15-20 days interval thrice from February up to May. 

Reference:

Anandaraj, M., Rema, J., Sasikumar, B. and. Suseela Bhai, R. (2005) Vanilla (extension pamphlet). Rajeev P. and Dinesh, R. (eds), Indian Institute of Spices Research. Daphna Havkin-Frenkel and Faith C. Belanger. Handbook of Vanilla Science and Technology. Wiley-Blackwell 2011.

R Suseela Bhai & Jithya Dhanesh. Occurrence of fungal diseases in vanilla (Vanilla planifolia andrews) in Kerala. Journal of Spices and Aromatic Crops, Volume 17 (2) : 140-148 (2008). Vanilla. Indian Spices Database By DIC, KAU. kaubic.in/spicesdatabase/Vanilla/index.htm‎l. Eric Odoux and Michel Grisoni. Medicinal and Aromatic Plants- Industrial Profiles : Vanilla. CRC Press, 2011.