Screening and Evaluation of Exotic and Indigenous Walnut Genotype and Varieties

A trail to investigate the “screening and evaluation of exotic and indigenous walnut genotype and varieties” was conduct at Agriculture Research Institute (ARI) Swat during 2015. Thirteen genotypes such as G-04, G-09, G-10, G-12, G-13, G-15, G-16, G-17, G-19, G-20, G-26, G-29, G-33 and varieties such as Paynee and Serr. The parameters studied were picking dates, nuts with husk weight, nuts fresh weight, dried nuts weight, kernel percentage, nuts size, kernel color, kernel test, fruit color, yield per plant, number of nuts per kg. Regarding genotypes (G-10, G-13, G-26 and G-33) were observed as early picking, (G-17, G-20, G-29) as mid picking and (G-04, G-09, G-12, G-15, G-16, G19) as late picking. (G-15, G-16) showed light, (G-17) Amber, while (G-04, G-09, G-12, G-13, G-19, G-20, G-26, G-29, G-33) showed light Amber, and (G-10) was dark Amber in color. Very good, good and fair, kernel taste was noted in (G-19, G-20), (G-10, G-12, G-13, G-15, G-16, G-26, G-29, G33) and (G-04, G-09, G-17) respectively. Maximum nut with husk weight (80.0g) fresh weight (29g) and dried weight (21.1g) was recorded in G-15. On the other hand maximum kernel percentage (55%), number of nuts [1-3] per kg were recorded for G-13, and nuts size (1840.4mm2) for G-12, while yield (15.200kg) per plant was noted for G-10, whereas the minimum nut size (937.9mm2), nut fresh weight (11.5g) and nut dried weight (8.1g) was noted in G-13. Minimum number of nuts (50) per kg was recorded in G-15, minimum nut with husk weight was noted in G-4 (29.0g) and minimum yield (10.250kg) was recorded in G-12, while minimum kernel percentage (38%) was noted in G-15. In case of varieties Paynee and Serr were noted as late picking varieties having good kernel test with light and extra light kernel color. Maximum nut with husk weight (22.9g) fresh weight (17.3g) dried weight (12.8g) kernel percentage (50%) nut size (1356.6mm2) was observed in Serr. On the other hand Paynee showed maximum kernel percentage (54%), yield (15kg) per tree and number of nuts (105) per kg, whereas minimum number of nuts (101) per kg was observed in Serr.


Introduction
Walnut belongs to the family Juglandaceae and genus Juglans.
The family consists of about 60 species, 21 of which are placed in the genus Juglans. However, the most important among them are Juglans regia L and Juglans nigra L. [4] that are famous for their delicious kernel and valuable wood. Persian walnut (Juglans regia L) is an ancient species [5] originated in Central Asia, the West Himalayan chain and 4 Kyrgystan [6]. Walnuts are the most widely distributed of all nut species and have been appreciated by human beings since ancient times. It has been cultivated in southern Europe since 1000 BC [7]. Walnuts are growing in the Northern Pakistan since time immemorial and are one of the most important nut crops grown in Malakand division. Malakand division contributes about 82% of the total walnut production of the country [8]. The walnut trees in Malakand division are mostly of seedling origin and exhibit considerable variability in nuts size, shape, shell thickness and color, quality and color of kernel and in other morphological attributes. There are no regular orchards of walnut in the area; however, significant numbers of trees are grown on marginal lands in diffused plantations and thus are a source of additional income of the farming community.
In Malakand division, due to the extensive local use of walnut bark and timber, the specie is being aggressively harvested. Swat valley is the best place for walnut production and account around 35 percent of the country's walnut population. In Swat walnut occupies 500ha out of the total 1,497ha. Mostly, Swat walnut is exported due to its high quality and demand. Kernels of good 002 Agricultural Research & Technology: Open Access Journal quality have good price and there is especially a high demand for thin-shelled walnut (Kaghzi akhrot) in market [9]. Walnut has a number of medicinal and non-food uses. Traditionally, since time immemorial, walnut bark has been used for teeth cleaning and curing gum diseases. Walnut consists of mostly omega-3 and omega-6 polyunsaturated fattyacids, which are essential dietary fatty acids and helps in the prevention of coronary heart diseases [10]. Nut consumption is associated with a protective effect against coronary heart disease, partly due to its high antioxidant content [11].
Walnut husk yields valuable oil and yellowish dye when pressed. The oil is used in soaps, paints, and making dye. Walnut has high nutritional value. It is rich in proteins (14-24%), fats (52-70%) and vitamins; especially vitamins B group and E, while in minerals; K and Mg are worth mentioning. Important amino acids are glutamic acid, arginine and leucine. Taurine (2-amino ethyl sulfonic acid), an organic acid and a derivative of the sulfur-containing amino acid cystine is found in variable quantities between 0.2 and 0.6mg %). It is an important compound and involved in many functions; homeostatic regulation, thermoregulation, nervous conduction, protection against oxidative stress [12]. Walnut tree is medium to large with spreading crown. The leaf is compound consisting of 7-11 leaflets. Walnut tree is perennial, monoecious and mostly cross-pollinated. It shows high variability in both pomological and phenological traits. Male (catkins) and female (pistillate) flowers are borne on the same tree. Catkins are borne laterally on one-year old shoots while pistillate flowers borne terminally or laterally on current season's growth in spikes of typically 2-3 flowers (some times more than three).
It is heterogamous, either protoandrous (male flowers mature first) or protogynous (female flowers mature first) depending upon the cultivars. This dichogamy encourages cross pollination and thus production mainly depends on wind pollination and bloom overlap [13]. Nuts are borne singly or in clusters and a green, fleshy husk surrounds it, which splits irregularly at maturity. Walnut is extremely sensitive to site conditions and should only be planted on the most suitable frost free, fertile, well drained and deeply root able sites [14]. The wood of walnut is regarded to be as one of the most valuable woods in the world for high grade furniture [15]. Common methods of propagation are tongue, cleft and hypocotyle grafting. However, chip and patch budding can also be used as propagation methods.
There are up to 50 different genotypes of Juglatis regia cultivated in different areas of Pakistan that is in the KPK province including Malakand division (districts of Swat, Dir, Bunir, Chitral, Shangla and Malakand Agency), Kaghan (district Mansehra), in Gilgit-Baltistan province have a number of walnut clusters, and Leepa in Neelum valley and Muffazarabad in Azad Jammu & Kashmir Ali et al. [9] while Murree Hills in Punjab have sparse plantations. Approximately, 35,000 families cultivate walnut for their livelihood. This production is consumed locally and also exported to some countries. Individual walnut trees are grown along boundaries of fields, channels, and backyards, etc. Mostly Pakistan seedlings are commercially grown, however some exotic cultivars have also been tried from time to time at research stations such as `Chandler', 'Hartley', 'Lam', `Germisara', lupanesti', `Valerie,'Odum', 'Sere and `Sulemani' [16] and many local selections like `MS-1′, `MS-2′, 'MS-18′ from Malakand, `SW-1′, `SW-3′ from Swat, `Dir-2′ and 'Chitral-I', `Chitral-2′, `Chitral-3′, (, `Kurram-1′,'Kurram-2′, 'Kurram-3′, 'Kurram-4′ [17]. Good research work has been going on with characterization of 226 genotypes collected from various locations of Malakand [18]. Genotypes present in Dir, Chitral, Swat and Leepa (Neelum, AJ & K) are superior in various qualitative and quantitative traits to the adopted exotic varieties i.e., 'Serr' and 'Paynee'. Pakistan has a tremendous population of indigenous walnut germplasm, but multiplication by seeds give variation in the orchards. Therefore nursery men need to use vegetative means of propagation to provide true types plants with better production capability. Keeping in view the best agro climatic conditions of Swat for walnut production this study was designed to screen and evaluate indigenous walnut varieties in Agriculture Research Institute Mingora Swat to determine the fruit size, quality and yield of walnut [19][20][21][22][23][24][25][26][27][28][29][30].

Materials and Methods
The study of Screening and evaluation of exotic and indigenous walnut germ plasm was conducted at Agriculture Research Institute Mingora Swat during 2015. The focal objective was to identify high yielding genotypes in Agriculture Research Institute Mingora Swat for better fruit size, fruit quality and yield of walnut.

Experimental design
There were thirteen different genotypes and two varieties of walnut and each having two trees, thus sixty trees were cultivated in the field. The distance between plant to plant and row to row was 20x20 feet. Experiment was based on the following genotypes and varieties

Result and Discussion
The research work on screening and evaluation of exotic and indigenous walnut germplasm was conducted at Agriculture research institute Mingora swat during 2015. Data recorded the following parameter are presented in Table 1-10, while the original replicated data is placed in Table 1a-10a. The result are briefly describe as under.

Picking date
Frequency distribution analysis of picking dates is presented in Table 1 while the original data is presented in Table 1a.

Number of nuts per kg
Number of nuts per kg frequency distribution analysis is presented in Table 10, while the original data is presented in  Table 10a.  Data for number of nuts per kg revealed that in thirteen genotypes and two varieties of walnut 53.3% (G-12, G-15, G-16, G-17, G-20, G-26, G-29, G-33) ranged between 50 -74.33 nuts per kg followed by 26.6% (G-04, G-09, G-10, G19) having 75-99.33 nuts per kg, while 20% (Paynee, Serr, G-13) had 100 -124.33 nuts per kg. The maximum nuts per kg was recorded in G-13 is 123 while the minimum nuts per kg was recorded in G-15 is 50.

Conclusion and Recommendations
Based on the above observation following conclusion are made. For G-04 gave maximum yield per tree, G-15 nut with husk weight, nut fresh weight and dried nut weight while G-16 have high kernel percentage, number of nuts per kg was recorded in G-13. In case of varieties maximum yield per tree, kernel percentage and number of nuts per kg was recorded in Paynee, while maximum nut size, nut with husk weight, nut fresh weight and dried nut weigh was noted in variety Serr. Based on the above conclusion, the following recommendations are made. For maximum yield per tree G-04, number of nuts per kg G-13 and maximum nuts size G-12 is recommended. For better yield, maximum number of nuts per kg Paynee variety is recommended, whereas for maximum nut size variety Serr is recommended.