Selection of cocoa progenies resistant to and tolerant of cocoa swollen shoot virus
The high incidence of cocoa swollen shoot virus in cocoa, its presence in alternate hosts and inapparent infection in some individuals of Amazon cocoa plantings make the control of swollen shoot disease by cutting out diseased cocoa in the Eastern Region a difficult and possibly impractical task. An alternative solution would be to plant resistant and/or tolerant trees. In field trials, we have demonstrated significant differences in resistance to natural infection between certain progenies. Such tests are slow and cumbersome and should be reserved for the ultimate tests of progenies known to possess good inherent resistance. For preliminary screening we have developed a manual inoculation technique which enables many progenies to be tested each year, gives a good estimate of resistance as well as providing data on tolerance. The inter-Nanay cross (Nanay 33 X Nanay 34) has given the most resistant progeny, but although resistance of this order would reduce the direct crop losses and the cutting out treatment losses, much higher levels of resistance are desirable. In the meanwhite, resistant progenies are usually tolerant and these combined properties offer a means of diminishing the effects of the disease until immune or highly resistant types become available. When sufficient tolerance combined with good agronomic features has been demonstrated in varieties, these will be considered for replanting in areas of mass infection after sensitive cocoa types, i.e. Amelonado, have been cut out because of infection
| Main Authors: | , , , |
|---|---|
| Format: | biblioteca |
| Published: |
Tafo (Ghana)
1971
|
| Subjects: | THEOBROMA CACAO, PROGENIE, VIROSIS, RESISTENCIA A LA ENFERMEDAD, COCOA SWOLLEN SHOOT VIRUS, CLONES AMAZONAS, CLONES AMELONADOS, HUESPEDES, GHANA, |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|