Articles
EVALUATION OF NEW APPLE VARIETIES IN THE HIGHLANDS OF GUATEMALA
In accordance with the US/Guatemala program "Diversification Systems for the Small Farmer in the Guatemalan Highlands", during 1985 and 1986 33 apple varieties were imported from USDA experiment stations in Washington, Texas and West Virginia.
These varieties were considered to be superior and hoped to be suitable for Guatemala.
Only certified disease-free budwood was introduced.
Prior to introduction, a 7-year evaluation and management plan was written to assist local horticulturalists in the long term evaluation of new varieties.
The budwwod was grafted in March onto Malling Merton 106 (MM 106) and Criollo rootstocks at the government nurseries of DIGESA (Tje National Agricultural Extension Agency), and ICTA (The Institute of Agricultural Science and Technology). Formal evaluations occurred in June-July and October.
At least 5 visits were made annually to inspect the stock for the presence of diseases and pests.
A rigorous pest control program was initiated on a routine basis.
Any abnormal plants were roqued.
All varieties were permanently labelled with aluminum taqs.
In July, 1986 (DIGESA) and March, 1987 (ICTA) the saplings were transplanted to permanent, mapped experimental orchards.
By 3 June, 1986 mean survivability of the more than 200 saplings was 92%. By the end of October, 1986, mean survivability was 89% on MM 106 and 74% on Criollo rootstocks.
All 33 varieties lived through year 2 (July, 1987). The growth rates of the scions in 1986 was excellent, forming good callus, and thick straight stems.
By the end of 1986, the mean primary leader length for all varieties tested on MM 106 was 91.6 cm and on Criollo was 92 cm.
By the end of 1986, 24 varieties were considered to be excellent in conformity, compatibility, vigor, disease resistance and stem length.
All varieties considered superior had at least 1 disease or plague present, although of minor intensity. 1986 superior varieties were Spuree Rome, Criterion, Red Free and Dorsett Gold.
However, by 27 June, 1987, the majority of saplings had not broken dormancy.
Therefore at the ICTA site, all dormant trees were sprayed with 500 ppm commercial grade Gibberellic Acid plus adherent.
By 29 July, 1987 at both ICTA and DIGESA there was no difference in percent of bud break (mean of 15%), nor in the number of buds breaking per sapling (3.4). The length of the longest stem per tree however was about twice as long on untreated saplings (9.6 cm) than for Gibberellic acid treated stems (4.5 cm). Of the 33 varieties introduced, 9 broke dormancy normally.
The rest were only starting to sprout by the end of July.
The variety Maayan