Showing papers by "Raphael A. Stern published in 1999"

`Jonathan' apple is a lower-potency pollenizer of `Topred' than `Golden Delicious' due to partial S-allele incompatibility

Abstract: Summary`Topred' is one of the main apple cultivars in Israel. Since `Topred' exhibits full self incompatibility, its fruit production is totally dependent on cross pollination. The two commercial pollenizers of `Topred' in Israel are `Golden Delicious' and `Jonathan'. In the study presented here, the potential of these two pollenizers was determined. In two consecutive seasons, it was found that the rate of fruit-set and fruit yield were significantly higher in the rows of `Topred' adjacent to the `Golden Delicious' as compared with the rows adjacent to the `Jonathan'. PCR analysis of the S-alleles, a polymorphic gene locus, determining the outcome of pollination, revealed that `Jonathan' and `Topred' share allele S9. PCR-S-allele analysis of progeny seedlings revealed that in `Jonathan' only S7, the unshared allele, took part in fertilization, whereas both alleles of `Golden Delicious' (S2,S3) participated at equal rates. Thus, the lower potency of `Jonathan' as a pollenizer of `Topred' is due, at least ...

The synthetic auxin 3,5,6-TPA reduces fruit drop and increases yield in `Kaimana' litchi

Abstract: SummaryThe effects of the synthetic auxin 3,5,6-TPA on fruit retention and yield of `Kaimana' litchi (Litchi chinensis Sonn.) was examined in Israel. This cultivar is characterized by a heavy initial set and then heavy fruit drop. 3,5,6-TPA decreased fruit drop and increased yield by 130 to 170% relative to untreated control trees. The best response occurred with an application of 25 or 50 mg l21 three weeks after full female bloom (FFB) (when fruit weighed ca. 0.5.g) compared with applications at 2, 4 or 5 weeks. Further commercial trials are warranted.