Combined Effects of Fertilizer, Irrigation, and Paclobutrazol on Yield and Fruit Quality of Mango

Combinations of fertilizer rates, foliar N sprays, irrigation practices, and paclobutrazol were studied to determine how much they could alter and/or improve mango (Mangifera indica L.) growth, flowering, and yield. Two treatment combinations derived from several years of prior studies of individual practices were compared: one combination was comprised of the best (BT) individual practices from the prior studies and included three applications of fertilizer, a 4% KNO3 spray application before flowering, paclobutrazol at 7.5 g/L, and weekly irrigation, and the other combination was comprised of the next best (NB) individual practices including two applications of the same amount of fertilizer, a 4% urea spray before flowering, paclobutrazol at 10.0 g/L, and biweekly irrigation. Both combinations significantly reduced terminal shoot growth and leaves per terminal shoot, advanced the date of flowering and harvest, increased panicle number, length and secondary branching, increased fruit set, fruit number at harvest, fruit size, and yield, with BT producing larger fruit and a greater yield than NB. Although both combinations produced fruit with higher quality than the control, the BT combination produced fruit with the higher total soluble solids, reducing, non-reducing, and total sugar content, and vitamin C content than the NB combination. Both BT and NB combinations of the optimums identified in the prior studies were successful at advancing bloom and harvest and increasing yield more than any of the optimum individual components alone, by 14-fold more than untreated trees for the BT combination, suggesting there were additive, if not synergistic, effects on mango. Further studies are warranted to assess the sustainability of these effects over longer periods of time, and to ascertain if the effects occur across mango cultivars and production environments

Rapid In Vitro Multiplication of Non-Runnering \u3cem\u3eFragaria vesca\u3c/em\u3e Genotypes from Seedling Shoot Axillary Bud Explants

Fragaria vesca L. has become a model species for genomic studies relevant to important crop plant species in the Rosaceae family, but generating large numbers of plants from non-runner-producing genotypes is slow. To develop a protocol for the rapid generation of plants, leaf explants were compared to single axillary bud shoot explants, both from in vitro-grown Fragaria vesca seedlings, as sources of shoots for new plant production in response to benzyladenine (BA) or thidiazuron (TDZ) combined with indolebutyric acid (IBA) on Murashige and Skoog’s Basal Salt (MS) medium. BA at 2.0 and 4.0 mg L−1 and TDZ at 1.5 mg L−1 promoted the greatest number of shoots produced per shoot explant. There were no IBA effects or IBA interactions with BA or TDZ. Significant interactions between BA and IBA, but not TDZ and IBA, occurred in leaf explant callus formation and % explants with callus at 6 and 9 weeks of culture and on shoots per leaf explant at 9 weeks. TDZ treatments produced uniformly high levels of callus but low numbers of shoots. The treatment generating the most shoot production was BA at 4.0 mg L−1 plus IBA at 0.50 mg L−1. After 9 weeks of culture, leaf explants of the non-runner-producing genotype Baron Solemacher had generated 4.6 shoots per explant with the best treatment, while axillary bud explants had generated 30.8 shoots with the best treatment. Thus, in vitro culture of shoot axillary bud explants can generate high numbers of clonal shoots from a single seedling plant in vitro