PERFORMANCE OF APRICOT VARIETIES / GENOTYPES IN NORTH WESTERN HIMALAYAN REGION OF INDIA

A long term experiment (2010-11 to 2014-15) was performed to evaluate the morphological and qualitative traits of apricot varieties/genotypes under north western Himalayan region of India. There were ten varieties/genotypes (CITH-Apricot-01, CITH-Apricot-02, CITH-Apricot-03, Communis, Erani, Afghani, Balcota, CITH-Apricot-09, Chinese apricot, Tokpopa Nimu ) were evaluated under RCBD with three replications. The results of five year pooled data indicated that maximum average Trunk Cross Sectional Area (TCSA) (168.03 cm 2 ) was recorded in the variety Communis. Maximum fruit weight (80.03 g) and yield (113.87 kg/tree) were recorded in CITH-Apricot-01. The productivity efficiency (1.21 kg cm -2 TCSA) was noted in CITH-Apricot-02. The fruit stone ratio 21.62 was recorded in Afghani variety. The highest TSS (25.07 0 Brix) was estimated in CITH-Apricot-09. Acidity was noticed maximum in the variety Chinese apricot. The total sugar and non reducing sugar were manifested maximum in the apricot genotype Tokpopa Nimu and reducing sugar (8.9%) was recorded in CITH-Apricot-09 under the north western Himalayan region of India.


INTRODUCTION
Apricot (Prunus armeniaca L.) belongs to the family Rosaceae, an important stone fruits widely grown in temperate region of the world.Major apricot producing countries in the world are Turkey, Italy, Greece, Spain, USA and France (Ghorpade et al., 1995).In India, it is commercially cultivated in the state of Jammu and Kashmir, Himachal Pradesh and Uttarakhand (Parmar and Kaushal 1982;Parmar and Sharma 1992;Sharma2000).The total area under apricot cultivation is 4886 ha with an annual production of 16739 tonnes and productivity only 3.43 t ha -1 (FAO 2011).The fruits of apricot are highly nutritious and rich in vitamin and minerals.Primarily, it is consumed as fresh and in smaller quantity, it is processed to juice, puree, jam, and dried fruit (Radi et al., 1997 andSchmitzer et al., 2011).The βcarotene and lycopene activity of apricots may prevent the heart disease in human.It is a good source of fibre, which has a health benefit such as prevents digestive conditions called as diverculosis.These fruits are antipyretic, antiseptic, emetic and ophthalmic (Pramar and Kaushal, 1982).The decoction of apricot bark is used to smooth inflamed and irritated skin conditions (Chevallier, 1996).Moreover, apricot kernel is used in production of oil, benzydehyde, cosmetic activity, carbon and aroma perfume (Yildiz, 1994).Due to low sugar and moderate high acidity, the apricot varieties grown in mid hills and valley areas are not suitable for drying (Sharma et al., 2004).
Fresh apricots fruit is a good source of fibres, minerals especially potassium and vitamins such as vitamin A, vitamin C, thiamin, riboflavin, niacin and pantothenic acid (Lichou et al., 2003).The chilling requirement of this crop ranges from 300 to 900 chill unit depending upon the variety and genotypes.The molecular studies have been integrated into the conventional germplasm characterization (Ali et al., 2008;Akpinar et al., 2010;Mratinic et al., 2011;Pinar et al., 2013 andKumar et al., 2016).The main reason for the low productivity of apricot is to identify the variety and technology best suited to particular agroecological condition.In order to improve the productivity, an experiment was under taken to evaluate the varieties/genotypes for specific traits under north western Himalayan region of India.

MATERIALS AND METHODS
An experiment was conducted at the ICAR-Central Institute of Temperate Horticulture, Srinagar during 2010-11 to 2014-15.The Research farm at Srinagar is situated at latitude of 34° 05'N, longitude of 74° 50'E and altitude of 1640 m above msl.The soils of this experimental field are sandy clay loam (45-55% sand, 10-20% Silt and 20-25 % clay; 6.5-7.5 soil pH, 0.50% organic carbon, 462.1 kg N ha -1 , 9.59 kg P ha -1 and 278.85 kg K ha -1 ) with poor drainage.The experiment was laid out in a randomized complete block design (RCBD) with three replications.The apricot varieties budded/grafted on seedling rootstocks and planted in 2003 at a spacing of 5 m × 5 m were used as study material.Ten varieties/genotypes of apricot (CITH-Apricot-01, CITH-Apricot-02, CITH-Apricot-03, Communis, Erani, Afghani, Balcota, CITH-Apricot-09, Chinese apricot, Tokpopa Nimu) were evaluated for growth, yield and quality.The plants were trained on modified central leader system and applied uniform recommended cultural practices to all the trees under study.The experimental farm falls under temperate region having cold conditions from November to February and total average annual rainfall received during the cropping season was 710 mm.Observations on growth, yield and quality were recorded.The trunk cross-sectional area was calculated by using formula TCA = Girth 2 /4 π (Westwood et al., 1963).Fruit was harvested at maturity and yield per tree was estimated in kilogram.Fruit, stone and kernel size were determined by observing the length and diameter and measured by Vernier callipers.Ten fruits were randomly selected from each tree and pooled as per replication in all treatments for quality analysis.The total soluble solids (TSS) of fruits were estimated by the hand refractometer (0 to 32 0 B) and the results were expressed as degree Brix ( 0 B).To estimate TSS, fruit pulp was crushed in a pestle and mortar and then squeezed through a muslin cloth for extraction of juice.The titratable acidity expressed in terms of percentage of citric acid was recorded by titrating 2 ml of juice against N/10 sodium hydroxide using phenolphthalein as an indicator.The total and reducing sugars of fruit were estimated by Lane and Eynon following volumetric method (AOAC, 1980) by titrating the sample against Fehlings solutions.The data of five years and pooled data for quality parameters were analyzed statistically as per Steel and Torrie (1984) for the interpretation of results and drawing conclusions.

Trunk Cross Sectional Area (TCSA)
Results on Trunk Cross Sectional Area (TCSA) of the tree is presented in table 1 indicted that the TCSA increased over the years from 2010-11 to 2014-15 in all the varieties/genotypes in apricot.Significantly maximum TCSA (140.34 cm 2 ) was recorded in Afghani variety closely followed by the genotype CITH-Apricot-09 (135.85 cm 2 ) and variety Communis (135.48 cm 2 ), respectively in 2010-11.In 2011-12, maximum TCSA (155.64 cm 2 ) was recorded in variety Afghani followed by Communis (154.96cm 2 ) and CITH-Apricot 09 (154.82cm 2 ), respectively.In 2012-13 and 2013-14, maximum TCSA (169.36 cm 2 and 182.45 cm 2 ) was recorded in Communis variety followed by CITH-Apricot-09 (168.25 cm 2 and 182.36 cm 2 ) and Afghani (162.58 cm 2 and 175.26 cm 2 ), respectively.In 2014-15, the highest TCSA (198.70 cm 2 ) was noticed in CITH-Apricot-09 followed by Communis (197.88 cm 2 ) and Afghani (191.24cm 2 ), respectively.An overall mean for five years data indicated that maximum TCSA (168.03 cm 2 ) was noted in Communis followed by CITH-Apricot -09 (168.0 cm 2 ) and Afghani (165.01cm 2 ) respectively in apricot.Maximum TCSA was observed in Communis variety of apricot might be due to heredity character of the variety, which increases the TCSA by increasing the uptake of nutrients from root to aerial part of the tree.Similar finding on apricot was reported by Kumar et al. (2013).

Fruit quality
Fruit quality parameters like fruit weight, fruit/stone weight ratio, TSS, acidity and total, reducing and non reducing sugar of apricot fruit were influenced by variety/genotype (Table 5).The fruit weight of apricot varied from 23.14 to 80.03 g, the significantly highest fruit weight (80.03 g) was noted in CITH-Apricot-01 followed by CITH-Apricot-02 (69.0 g) and Communis (51.44 g), respectively.The fruit /stone wt.ratio, an important character for quality of fruits, the highest ratio (21.62) was recorded in Afghani followed by Communis (20.41) and Erani (12.87), respectively.Total soluble solids of apricot fruits varied from 14.67 to 25.07 0 Brix, the highest TSS (25.30 0 Brix) was estimated in Tokpopa Nimu followed by CITH-Apricot-09 (25.07 0 Brix) and Afghani (22.4 0 Brix), respectively.Acidity was recorded the highest (0.65%) in Chinese Apricot and superior to other varieties/genotypes.Total sugar, reducing and non reducing sugar varied from 8.4 to 14.6 %, 5.3-8.9 % and 1.4-6.4%, maximum total and non reducing sugar (14.6% and 6.4 %) was estimated in Tokpopa Nimu variety and reducing sugar (9.7%) was registered maximum in Balcota variety of apricot.The better fruit quality of respective variety/genotype might be due to inherent character of the particular variety/genotype.Similar findings were reported by Kumar et al., 2015.

CONCLUSIONS
The experimental results revealed that the newly identified genotypes CITH-Apricot-01, CITH-Apricot-02 and CITH-Apricot-03 performed better in respect to fruit yield (113.87 kg tree -1 , 92.96 kg tree -1 and 73.73 kg tree -1 , respectively) and quality under north west Himalayan region of India.

Table 1 .
Trunk Cross Sectional Area of tree as influenced by apricot varieties/genotypes Flowering and fruit set in apricot was influenced by varieties/genotypes (Table 2).The time of bud burst ranged from 19.03.2014 to 22.03.2014(4 days), first flowering from 25.03.2014 to 29.03.2014(4 days) , 75% flowering from 29.03.2014 to 03.04.2014 (6 days), full bloom from 03.04.2014 to 07.04.2014 (5 days) and fruit set from 10.04.2014 to 13.04.2014(4 days) in apricot varieties/genotypes.Minimum 21 days taken from bud burst to fruit set in Erani variety and maximum 25 days taken in CITH-Apricot-02.There were less variations in terms of flowering and fruit set among the apricot varieties/genotypes.The variations in flowering/fruit set might be due to varietal characters.

Table 2 .
Bud burst, flowering and fruit set as influenced by apricot variety/genotype S.

Table 3 .
Fruit yield as influenced by apricot varieties/genotypes

Table 4 .
Productivity efficiency as influenced by apricot varieties/genotypes

Table 5 .
Fruit quality as influenced by apricot varieties/genotypes