Search Results
A winter gibberellic acid (GA3) spray consistently reduced flower formation, but had a variable effect on the amount of first-grade fruit in the early harvest of `Clausellina' satsuma (Citrus unshiu Marc.), and in the long term these applications had no significant effect on the value of the crop. Auxin applications increased the amount of first grade-early harvested fruit, and increased crop value as compared to hand-thinned trees. No significant differences in yield or fruit grade could be found among the different auxin applications tried, namely an application of 20 mg·L-1 2,4-dichlorophenoxyacetic acid (2,4-D) at flowering, or applications of 25 mg·L-1 naphthaleneacetic acid (NAA), or 50 mg·L-1 2,4-dicholorophenoxypropionic acid (2,4-DP) at the end of fruitlet abscission. Apart from their effect on size, the auxin applications had only a marginal effect on fruit quality.
A putative polyploid seedling tree appeared among the polyembryonic mango (Mangifera indica L.) `Gomera-1', widely used as a rootstock in the Canary Islands. Initially detected because of its wider and more coriaceous leaves, further studies showed that fruit from this seedling are considerably larger than normal, although all other fruit characteristics (including polyembryony) were similar to those of standard `Gomera-1' (G-1) fruit. The progeny of this plant has, to date, proved to be morphologically identical to the mother plant. Studies of seedlings from normal G-1 trees growing in the same orchard showed that 10% of the plants had morphological characteristics similar to those of the putative polyploid seedling. Flow cytometry and chromosome count analyses confirmed that G-1 is diploid, whereas the putative polyploid is a stable tetraploid. The study also showed that the morphologically abnormal seedlings from diploid parent trees were spontaneous tetraploids.