A rootstalk to revive guava cultivation

This plant is expected to help increase the longevity of guava orchards in north India,where wilt is more common.

“An inter-specific hybrid rootstalk of guava has been derived by crossing the normal variety of guava with its wild relative called Psidium molle,which has a wilt-resistant gene in it. Its field results were encouraging,” said Dr Shailendra Rajan,principal scientist,CISH,who brought the wild species from Saharanpur and got the hybrid plants screened for their susceptibility to wilt for 12 years before it was distributed to farmers.

“The disease,being soil-borne,hits the plant through the roots. Thus,we developed the rootstalk so that the wilt-resistant gene of the wild species of guava can protect the resultant inter-specific hybrid plant from the disease. But to retain the shape,colour and taste of the fruit,the rootstalk was grafted with the scion of commercial varieties of guava,” said Dr Rajan.

The hybrid plant has other advantages. “The wilt-resistant guava plants are dwarfs,making their cultivation and management easier. The variety also starts fruiting a few months earlier than the normal guava trees and the fruits are of better quality,” claimed Dr Rajan.

The project,‘Clonal multiplication of inter-specific wilt-resistant rootstalk for grafting of guava cultivars’, was sanctioned to CISH by Indian Council of Agriculture Research in 2007.

The resultant rootstalks were also clonally multiplied to avoid dilution of wilt-resistant characteristics and were grafted with commercial varieties to be distributed amongst

farmers. “We initially plan to distribute clonally multiplied hybrid rootstalk plant to the farmers. We have more than 500 saplings ready for the same. We are also trying to

develop low-cost techniques to multiply the saplings asexually so that even small farmers can put cheaper set-ups on their farmland and multiply the saplings themselves,” he said,adding: “We are planning to distribute the saplings for plantation in February-March 2010 in the guava producing belt of Uttar Pradesh.”

Dr A K Shukla,another principal scientist at CISH,said the wilt disease had forced farmers to shift to other crops. “This rootstalk will definitely help in reviving the cultivation of guava.”