Genetic diversity in chestnuts of Kashmir valley Despite the ample increase in peach growing area, improvement in quality and average yield is still negligible. The influence of foliar application of calcium chloride (CaCl 2 ), putrescine (PUT) and salicylic acid (SA) on fruit yield and physico- chemical characteristics of ‘Florida King’ peach cultivar was evaluated for two consecutive years (2011 and 2012). Results indicated that, application of CaCl 2 (1%) , PUT (1, 2 and 3 mM) and SA (2 and 3 mM) increased fruit weight, fruit diameter, pulp: stone ratio and yield compared to control. In addition, fruit harvested from these growth elicitors treated trees did not show significant difference in total soluble solids and total sugar contents. All treatments resulted in higher fruit firmness, acidity and ascorbic acid contents than control. Higher calcium treatments proved toxic and significantly increased the calcium level in leaves and fruit. From present work it can be referred that spraying of CaCl 2 , PUT and SA, significantly affected yield, and physico-chemical characteristics of peach cv. ‘Florida King’. These growth elicitors are considered safe chemicals and can be applied to enhance production and improve fruit quality of peach without compromising the food safety standards. Keywords: GRAS chemicals, physico-chemical characteristics, toxicity, safe food, fruit growth INTRODUCTION Peach (Prunus persica L.) is an important fruit crop of the world which was originated from China. It’s delicious taste and unique flavour with high nutritional value have popularized it across the world. It is one of the important stone fruit of Pakistan having total cultivated area about 14700 ha with annual production of 55800 tones (FAO, 2010). Over the last decade despite the ample increase in peach gro wing area, there has been a very small progress in average fruit yield. In recent years, the production and commercialization of stone fruits like peaches have increased briskly throughout the world including Pakistan, mainly because of introduction of improved, low-chilling cultivars and better handling of fruit. Northern areas and Baluchistan are the most prominent regions of Pakistan for production of peaches. Various pre- and postharvest factors are associated with yield and quality of fruit including growth conditions, harvest maturity and post-harvest factors (Serrano et al., 1996). Plenty of researchers have attempted to increase the productivity and quality of fruit crops. The use of growth elicitors and minerals in this respect had been reported on apricot, pear and apple (Nagwa et al., 2007; Eissa et al., 2008; Khalifa et al., 2009; Ali et al., 2010; Abd- El-Messeih et al., 2010). The effect of polyamines (PAs) in promoting fruit set and retention have been examined in apple, apricot, pear, litchi, olives and mangoes (Ali et al., 2010). Moreover, application of PAs had been an effective tool for improving embryo development in grapes. PAs have shown their functions for delaying maturity and ripening in apricot and grapes (Metha et al., 2002; Ponce et al., 2002) inhibiting abscission, reduced fruit drop, increased fruit firmness in peach, nectarine and pear (Bregoli et al., 2002; Torrigiani et al., 2004). Pre and post-harvest application of calcium for improvement of quality and minimizing the disorders have been reported in various fruits like strawberry, peaches, nectarines and apples (Dunn and Able, 2006; Hernandez-Munoz et al., 2006). Similarly, use of salicylic acid (SA) was very effective in improving yield as well as physical and chemical characters in apple, kiwi, banana, jujube (Al-Obeed, 2012). Peach exhibits a double–sigmoidal growth curve like other stone fruits (Kushad, 1998). The initial increase in the fruit growth has been attributed to cell division, followed by cessation of mesocarp growth due to lignification of the endocarp (stone) tissue and is referred as pit hardening or lag phase stage which is second stage of fruit growth and development (Romani and Jennings, 1971; Westwood, 1978) while, third phase of fruit growth has been attributed to cell enlargement (Romani and Jennings, 1971). Flurkey and Jen (1978) reported an increase in total soluble solids and protein concentration during pit hardening, suggesting that pit hardening is an active growing period. The application of growth elicitors at these critical stages of fruit growth and development may prove more effective. But, Pak. J. Agri. Sci., Vol. 51(1), 33-39; 2014 ISSN (Print) 0552-9034, ISSN (Online) 2076-0906 http://www.pakjas.com.pk PHYSIOLOGICAL RESPONSE AND QUALITY ATTRIBUTES OF PEACH FRUIT CV. FLORIDA KING AS AFFECTED BY DIFFERENT TREATMENTS OF CALCIUM CHLORIDE, PUTRESCINE AND SALICYLIC ACID Irfan Ali, Nadeem Akhtar Abbasi * and Ishfaq Ahmad Hafiz Department of Horticulture, PMAS-Arid Agriculture University Rawalpindi, Pakistan * Corresponding author’s email: nadeemabbasi65@yahoo.com