Variability in Physico-Chemical Characteristics of Ber ( Zizyphus mauritiana Lamk) Varieties Under Rainfed Conditions of Shivalik Foothills of Himalayas

Five ber varieties were evaluated for various physico-chemical characteristics and fruit rot incidence during 2010 and 2011. Highest fruit weight (21.2 g) and fruit yield (99 kg tree -1 ) was recorded in cultivar Sanour 4 and the minimum 8.8 g and 63 kg tree -1 was observed in ZG 2. Fruit length, TSS, acidity and ascorbic acid varied from 2.4 to 5.0 cm, 12.95 to 25.45 per cent, 0.41 to 0.74 per cent and 77.9 to 123.3 mg 100 g -1 , respectively. Varieties viz . Ranjari Selection-1, Ranjari Selection-2, Raya Selection and ZG-2 showed highest per cent fruit rot (19.5-32.0), while it was minimum (10 %) in Sanour-4.

Ber (Zizyphus mauritiana Lamk.) is one of the most ancient and India ranks first amongst the ber growing countries of the world. Owing to its good potential for high yield and excellent economic returns, ber is grown as a commercial crop in Jammu, Punjab, Haryana and Rajasthan (Gupta and Kaul, 2011). The total area under major horticultural crops in Jammu and Kashmir State is 3.07 lakh ha, of which ber fruit crop occupies 7,820 ha with an annual production of 16,330 metric tons (Anonymous, 2009). Ber fruits are very nutritious and rich in vitamin C, A and B complex. Ber fruits can be within the reach of the poor people and hence known as poor man's fruit. Among the fruit trees, ber cultivation requires perhaps the least inputs and care. It is a crop of semi-arid and arid regions. There are quite a good number of cultivars which are liked by the different people. As yet no serious attempt has been made to classify these cultivars on the basis of physico-chemical characteristics and resistance to storage diseases (Pareek, 1983). In addition to this, a cultivar should possess good blend of TSS, acidity, hard flesh, good flavour and aroma besides resistance/tolerance to diseases especially storage (Kaushik et al., 2004). The present paper describes the fruit characters of five ber varieties so as to find the most suitable one for rainfed conditions of Jammu.

Materials and Methods
Eighteen years old ber trees of five cultivars planted at 5 m x 5 m spacing in the experimental orchard of Rainfed Research Sub-Station for Sub-Tropical Fruits, Raya, SKUAST-Jammu were undertaken for investigation. The five cultivars taken for this investigation were Ranjari Selection 1, Ranjari Selection 2, Raya Selection, Sanour 4 and ZG 2. More than 50 percent fruits changed colour was considered as the time of ripening. For other fruit characters fifty representative ripe fruits were picked at random from each tree at the time of harvesting during the months of March-April in the years 2010 and 2011 and different observations were recorded on physical (shape, colour of ripe fruit, fruit weight, fruit length, fruit diameter and yield) and quality (pulpstone ratio, total soluble solids, acidity and ascorbic acid) characteristics of ber. Completely randomized block design was used for chemical analysis purpose and fruit-rot incidence in storage with four replications. Fruit weight was measured by using digital balance (Indosaw-805CH). Fruit length and fruit diameter was determined by digital Vernier Calliper (Mitutoyo) whereas, fruit yield data were recorded at the time of each picking. Total Soluble Solids (TSS) was estimated with the help of hand refractrometer. Titratable acidity and ascorbic acid was determined by using the standard procedures of Ranganna (1986). The data obtained was statistically analysed (Gomez and Gomez, 1984). Fruit rot incidence was recorded at 0, 1, 2, 3 and 4 days after storage by counting the infected and healthy fruits of each cultivar and converted into percent fruit rot incidence by using the following formula:

Percent fruit rot
No. of infected fruits X 100 incidence = Total no. of fruits observed However, the fungus was identified through microscopic examination. *Corresponding author email: neeruguptapht@rediffmail.com

Physical characters
The fruits of all cultivars differed in their ripening time. Fruits of cv. ZG 2 experienced earliest maturity (1 st -3 rd week of March), while Ranjari Selection 1 was last to mature (4 th week of March-2 nd week of April), and fruits of cvs. Ranjari Selection 2, Raya Selection and Sanour 4 matured during 2 nd -3 rd week of March to 1 st week of April. The shape of fruit was oval in all the cultivars under study. The colour of fruits at maturity was golden yellow in Sanour 4 and yellowish green in Raya Selection. However, rest of the cultivars showed greenish yellow colour (Table 1). The statistically highest value of fruit length (4.75 cm and 5.25 cm) was observed in Ranjari Selection 2, followed by comparable values (4.15 and 4.53 cm) in cv. Sanour 4 during the years 2010 and 2011, respectively. The variety Raya Selection registered highest fruit diameter (4.72 cm and 4.98 cm), followed by (3.18 cm and 3.38 cm) in Ranjari Selection 2 during both the years. However, minimum fruit length (2.25 cm and 2.53 cm) and diameter (1.76 cm and 1.95 cm) was recorded in Raya Selection and Ranjari Selection 1, in years 2010 and 2011, respectively (Table 1).

Quality characters
Higher pulp to stone ratio is considered to be a desirable character for ber quality. Statistically highest pulp stone ratio (21.7) was observed in Ranjari Selection 2, followed by comparable value 19.3 recorded in Raya Selection whereas, minimum value of pulp stone ratio (10.0) was observed in ZG 2 (Table 2). Inconsistency in pulp stone ratio in ber varieties was also reported by Kaushik et al., (2004).
Total Soluble Solids (TSS) of all varieties varied between 12.9-25.5 percent however, highest mean value of TSS (25.5 %) was noticed in Ranjari Selection 1 and minimum mean value (12.9 %) in variety ZG 2 during both the years. However, values of TSS obtained with varieties Ranjari Selection 2, Raya Selection and Sanour 4 were statistically at par during both the years under study ( Table 2). The acidity in fruit pulp varied between 0.26-0.77 per cent in 2010 and 0.24-0.70 percent in 2011 with the mean minimum value (0.27 %) in Raya Selection and mean maximum value (0.74 %) being in Ranjari Selection. Dass et al., (1992) also reported a wide range of variability in TSS and acidity among different cultivars of ber.

Fruit Rot incidence
All the studied ber varieties viz., Ranjari Selection 1, Ranjari Selection 2, Raya Selection, Sanour 4 and ZG 2 were infected with fruit rot. Cladosporium tenussimum Coobe, Pythium aphanidermatum and Phoma nebulosa were fungal pathogens identified as a cause of fruit rot during storage under rainfed area of Jammu. The minimum fruit rot incidence was found in cv Sanour 4 at different storage days viz., 0.75, 3.3, 7.0, 10.0 and 10.0 percent at 0, 1, 2, 3 and 4 days of storage. It was immediately followed by Ranjari Selection 1 viz., 2.5, 7.0 and 19.5 percent at 0, 1 and 4 days of storage. However, maximum fruit rot incidence was recorded in cultivar ZG 2 at all the storage days under study. These findings are in line with Sharma et al., (1993). They also identified Tenussium coobe, Fusarium pallidoroseum (Coobe) Sacc., P. aphanidermatum, Phoma nebulosa and Rhizoctonia solani as a cause of fruit rot during storage.