ABSTRACT
Significance of preharvest salicylic acid (SA) treatments on maturity, quality and postharvest life of grape cv. Flame Seedless were studied during two years. The experiment was performed on 12-year old own rooted, grapevines planted at 3 m × 3 m spacing trained on overhead system. Vines were treated with aqueous solutions of SA (0.0, 1.0, 1.5 and 2.0 mM) at pea stage and at veraison. After harvesting, clusters were divided into two lots in which one was subjected to initial quality evaluation, while the other was stored in cold room (3-4 °C, 90-95 % RH) for evaluation of postharvest quality. SA at the dose of 1.5 and 2.0 mM hastened berry maturity by 3 to 5 days, produced less compact bunches alongside larger berries in contrast to control and the lowest dose. The same doses effectively maintained peel colour, higher firmness, lower pectin methyl esterase activity and electrolyte leakage alongside suppressing degradation of TSS and TA during cold storage. These two doses also exhibited higher efficacy on maintaining anthocyanins, phenols and organoleptic properties while reducing weight loss, rachis browning and decay incidence. Correlation analysis demonstrated that many quality parameters are interdependent. In conclusion, preharvest spray of 1.5 mM SA proved to be an effective means of improving quality and extending postharvest life of grape cv. Flame Seedless.
ABSTRACT
Fruits of banana (Musa spp) cultivar 'Grand Naine' were harvested at physiological green mature stage. The first lot of fruit was exposed to ethylene gas (100 ppm) for 24 h in ripening chamber. The second lot was treated with different concentrations of aqueous solution of ethephon (250, 500, 750, 1000 ppm) each for 5 min. The fruits were packed in plastic crates and stored in ripening chamber maintained at 16-18°C and 90-95% RH. Treatment with ethylene gas (100 ppm) or ethephon (500 ppm) resulted in adequate ripening of fruits after 4 days with uniform colour, pleasant flavour, desirable firmness and acceptable quality and better shelf-life. The untreated control fruits were hard textured and poor in colour and quality. The ripening with ethylene gas or ethephon treatment seems to hold promise in reducing postharvest losses and boosting the economy of banana growers and traders.
ABSTRACT
The effects have been studied in vitro of the non-ionic, co-polymer surfactant, Pluronic F-68, on shoot regeneration and bud induction in epicotyl and cotyledon explants of Citrus depressa, a potential alternative rootstock to C. jambhiri for commercial Citrus. Supplementation of Murashige and Skoog (1962)-based, agar-solidified shoot regeneration/bud induction (SRBI) medium with 1.0 mg l(-1) 6-benzylaminopurine and 0.5% (w/v) Pluronic F-68 significantly (P < 0.05) increased mean fresh weight by a maximum of 60%, the proportion of explants exhibiting shoot/bud regeneration by 25% and the mean number of shoots per epicotyl explant by 184%, compared to untreated controls. Similarly, 0.5% (w/v) Pluronic F-68 significantly (P < 0.05) enhanced the mean percentage bud induction (91%) and the number of buds regenerated (>4-fold) per cotyledon explant. Interestingly, the mean fresh weight gain for both explants was unaffected across the range of concentrations (0.001-0.1% w/v) of Pluronic F-68 evaluated. Regenerated plants from epicotyl explants were transferred and acclimatized to glasshouse conditions.
