The date of full bloom for olive (Olea europaea L.) tree varieties planted in the World Collection in Córdoba, Spain, has been determined from 10 years of data. The full bloom dates were analyzed using three methods to develop a model predicting flowering time. The method of heat units accumulated before flowering was the most accurate. The heat accumulation periods were determined from phenological and temperature data. Prediction methods were evaluated for the earliest-flowering variety, a model variety representing the mean values for the collection, and the latest-flowering variety. The most appropriate threshold temperature for heat accumulation has been confirmed to be 12.5C; it can be used to predict the flowering time in olive.
A.R. Alcalá and D. Barranco
R. Fernández-Escobar, D. Barranco and M. Benlloch
Chlorotic `Manzanillo' olive (Olea europaea L.) trees and `Maycrest' peach [Prunus persica (L.) Batsch] trees were injected with Fe solutions using an apparatus that consisted of a plastic injector and a pressurized latex tube containing the solution to be injected. Injections were made on various dates from Sept. 1987 to July 1988. All treatments increased chlorophyll content compared to that of the control. Ferrous sulfate was the most effective Fe compound in alleviating chlorosis; its effect lasted for two seasons in peach and for at least three seasons in olive. Also, ferrous sulfate increased vegetative growth and affected cropping the year following injections. Ferrous sulfate at 0.5% to 1% is recommended to reduce the risk of foliar burning. The injection method effectively introduced Fe compounds into olive and peach trees.
A. Belaj, I. Trujillo, D. Barranco and L. Rallo
Thirteen randomly amplified polymorphic DNA (RAPD) primers were assayed in 82 Spanish olive cultivars of economical interest. A total of 82 bands were scored giving an average of 6.3 bands per primer. A total of 4 (OPA-01) to 10 bands (OPA-19) was amplified, while the number of polymorphic fragments ranged from 2 (OPK-07) to 9 (OPA-19) with a mean of 5.7 polymorphic bands per primer. A total of 89% of the amplification products (73 bands) were polymorphic. The 13 primers yielded 184 banding patterns (14.9 per primer). The number of banding patterns per primer ranged from 4 (OPK-07) to 39 (OPA-19). Fifty-three unique banding patterns were found, the majority of them resulted from different combinations of polymorphic bands. The combination of only five primers OPA-19, OPF-06, OPX-01, OPX-03, and OPI-12, allowed identification of all the cultivars. Seventy-four cultivars (90%) were identified only by the combination of the first four primers. The addition of the fifth primer (OPI-12) was necessary for the identification of the eight remaining cultivars (10%). The ordination of the primers according to their practical discriminating capacity in this study was: OPA-19 > OPF-06 > OPX-01 > OPX-03 > OPI-12. Hence RAPD markers are recommended for olive fingerprinting in order to generate a database for olive cultivar identification.
M. Benlloch, F. Arboleda, D. Barranco and R. Fernández-Escobar
The influence of sodium and boron excess in the irrigation water on shoot growth and on the distribution of these elements within various leaf types was studied on rooted olive cuttings (Olea europaea L.). `Lechín de Granada' was more tolerant than `Manzanillo' to sodium excess, as indicated by greater shoot growth and lower accumulation of sodium, especially in the young leaves. `Picual' was more tolerant to boron than `Manzanillo', with less accumulation in adult leaves. The results suggest the avoidance of toxicity by an ionic exclusion mechanism that is more effective in some cultivars than others. Also, the results reveal cultivar differences in the tolerance of olive to sodium and boron excess in the culture medium.