Effect of pre-harvest spray of putrescine on shelflife and quality of tomato during storage

Putrescine (PUT) is a polyamine responsible for plant growth and development, fruit ripening, stress response, senescence and in higher quantities to maintain post-harvest quality in vegetables.Tomato (cv. Punjab Ratta) crop grown during 2012-13 and 2013-14 at Vegetable Research Farm, Punjab Agricultural University, Ludhiana, Punjab, India replicated thrice treated two times at 120 and 130 days after transplanting with putrescine at 1 mmol/L, 2 mmol/L and 3 mmol/L concentrations and water sprayed in control corresponding to T1, T2, T3 and T4 respectively. On following the day of second spray, fruits of uniform size and weight at mature green to breaker stage were picked, taken in plastic crates and stored at 13±2oC and relative humidity of 85-90% for further storage studies. To find out the effect of pre-harvest application of putrescine on tomato during storage, representative sample fruits from the treatments were analysed at 5 day interval i.e at 1st, 6th, 11th, 16th, 21st and 26th day of storage for various quality parameters and average of two year readings was presented. T1 (PUT at 1 mmol/L) treatment showed significant lowest cumulative physiological loss in weight % compared to other putrescine treatments at all the days of analysis except at 6th day after storage. However, at the end of the storage period, putrescine treatments T1 (0.58%) and T2 (0.58%) were significantly higher in titratable acidity than control. All the putrescine treatments able to maintain decay % below threshold level (10%) upto 16th day of storage while, in control it was upto 11th day of storage only.