Evaluation of Phenological Traits of Pear Varieties in Warm Temperate Region of Nepal Padma Nath Atreya*, Ramila Dhakal, Jiban Shrestha Page | 142 AGRICULTURAL SCIENCE Journal Of Agricultural Science And Agriculture Engineering ISSN : 2597-8713 (Online) - 2598-5167 (Print) Available on : http://agris cience.s cientific -wor k.org/inde x.php/agris cience This is Under CC BY SA Licence Evaluation of Phenological Traits of Pear Varieties in Warm Temperate Region of Nepal Padma Nath Atreya 1* , Ramila Dhakal 2 and Jiban Shrestha 3 1 Warm Temperate Horticulture Centre, Ministry of Agriculture and Livestock Development (MoALD), Kathmandu, Nepal 2 Institute of Agriculture and Animal Science (IAAS), Tribhuwan University, Kirtipur, Kathamndu, Nepal 3 Nepal Agricultural Research Council, National Plant Breeding and Genetics Research Centre, Khumaltar, Lalitpur, Nepal E-mail: atreyapadma@gmail.com, ramila.dhakal3@gmail.com, jibshrestha@gmail.com * Corresponding: atreyapadma@gmail.com ABSTRACT Phenological study of a fruit tree is important for timely and proper orchard management. This study was carried out in orchard located at Warm Temperate Horticulture Centre (WTHC), Kathmandu, Nepal from January to August, 2020 with the objective to identify the different timing of phenological stages in 18 different varieties of pear. Data on days from swollen bud to bud burst, swollen bud to green cluster, swollen bud to white bud, swollen bud to bloom, swollen bud to petal fall, swollen bud to fruit set, fruit length, and fruit diameter were recorded. The phenological and fruit traits were found highly significant. The shortest flowering period (days from swollen bud to petal fall) was observed in varieties Sinko and Yakumo (13.33 days) and the longest period was found in Pharping local (Green) (35.00 days) followed by Pharping local (Brown) (34.00 days). The longest fruit (58.80 mm) was recorded in Anjou followed by Bartlett (52.90 mm) and Yakumo (49.80 mm). Similarly, the highest fruit diameter (57.60 mm) was recorded in Anjou followed by Yakumo (55.80 mm) and Atago (51.60 mm). On the basis of total variability, pear varieties were grouped into five distinct clusters. Cluster 2 showed that Anjou had the highest fruit length and fruit diameter. Cluster 5 illustrated that the longest flowering period was observed in the Pharping local (Green) followed by Pharping local (Brown). Based on phenological traits Sinko and Yakumo and based on fruits traits Anjou were found potential varieties for cultivation under warm temperate region of Nepal. Keywords: Cultivar, Growth stages, Pear, Phenology 1. INTRODUCTION Pear (Pyrus spp.) is a temperate fruit, belongs to the family Rosaceae. Mainly two species of pear are commonly cultivated in the world, Pyrus communis (European type) and Pyrus pyrifolia L. (Asian type). European type of pear is mainly cultivated in Europe, South America, North America, and Australia and Asian type of pear are predominate in China, Japan and South- East Asia (Hancock, 2008). As pear fruit has its sweetness, crispness, characteristic fragrance and slight aroma, it is popular among the consumers (Chen, Wang, Wu, Wang, & Hu, 2007). The total area production of pear in the world are 1,381,923 ha and 23,733,772 tons respectively. Asia is the highest producer of pear (about 70%) in the world. In Nepal, the area under pear cultivation is 3,248 ha and total production is 30,827 tons (FAOSTAT, 2018). There is a great possibility of pear Evaluation of Phenological Traits of Pear Varieties in Warm Temperate Region of Nepal Padma Nath Atreya*, Ramila Dhakal, Jiban Shrestha Page | 143 AGRICULTURAL SCIENCE Journal Of Agricultural Science And Agriculture Engineering ISSN : 2597-8713 (Online) - 2598-5167 (Print) Available on : http://agris cience.s cientific -wor k.org/inde x.php/agris cience This is Under CC BY SA Licence cultivation from 1200 to 2200 masl throughout the mid hills of Nepal (Atreya, 2018). Hybrid pear varieties (obtained from crosses between Pyrus pyrifolia and Pyrus communis) can be cultivated in subtropical climate having mild winters (Tecchio, Bettiol Neto, Barbosa, & Tucci, 2011). The varieties as well as rootstock influence the evolution dynamic of tree and the fruit formation gets affected by the type of the fruit structure and its foliar area which are important parameters to the phenological evolution (Petri, Hawerroth, Leite, Couto, & Francescatto, 2012). In pear tree, fruiting structures arises from the buds located on the branches and these buds may give rise to structures as spurs (vegetative or reproductive), brindles (vegetative or reproductive) and bourses (de Alcântara Barbosa et al., 2018). Phenology of a deciduous fruit tree is the periodical biological events from the dormant stage to the fruit development and which are closely regulated by climate and seasonal changes (Chen et al., 2007). The study of phenology of fruit tree is important for timing proper management practices such as training and pruning, irrigation, fertilization, pest and weed control etc. At the end of winter or early spring, the period of vegetative growth begins and finishes in autumn (Martínez Valero et al., 2001). For the first time, Fleckinfer defined ‘phenological stages’ with the combination of letters and numbers in 1945 (Fleckinger, 1948). Later on, Bleiholder, Kirfel, Langeluddeke, and Stauss (1991) proposed a uniform decimal code, known as the BBCH- scale (Biologishe Bundesanstalt, Bundessortenamt, Chemische Industrie). The extended BBCH scale was later proposed by Hack et al. (1992) and Hess et al. (1997). This study was also conducted on the basis of extended BBCH scale but important growth stages were only recorded. Chapman and Catlin (1976) also suggested eight important growth stages of pear. These eight growth stages of pear are dormant, swollen bud, budburst, green bud, white bud, bloom, petal fall and fruit set. In dormant stage, fruit buds are relatively inactive. Fruit buds starts to swell separating scales and exposes areas of lighter colored tissue. Then budburst takes place showing tips of blossom buds. After few days of budburst, green blossom buds appear in the cluster with lengthened stem and later on turns into white blossom buds. Finally, the blossom buds get opened (bloom) which will later on followed by petal fall and fruit set stage respectively. In early varieties of pear tree, the cell division stage lasts for 25-30 days after blooming and 45 days in late varieties (Jackson, 2003). The fruit enlargement stage takes place at the last one month or two before harvest and at that time pear fruit grow quickly. The pear fruit enlarge slowly during the period between cell division and fruit enlargement (Marsal, Rapoport, Manrique, & Girona, 2000). Cluster analysis is frequently used to classify fruit genotypes and can be used by breeders and geneticists to identify subsets of accessions which have potential utility for specific breeding or genetic purposes (Rincon et al., 1996). The main aim of using a cluster technique in plant breeding Evaluation of Phenological Traits of Pear Varieties in Warm Temperate Region of Nepal Padma Nath Atreya*, Ramila Dhakal, Jiban Shrestha Page | 144 AGRICULTURAL SCIENCE Journal Of Agricultural Science And Agriculture Engineering ISSN : 2597-8713 (Online) - 2598-5167 (Print) Available on : http://agris cience.s cientific -wor k.org/inde x.php/agris cience This is Under CC BY SA Licence trials is to group the varieties into several homogeneous groups such that those varieties within a group have a similar response pattern across the locations (Shrestha, 2016). The objective of this study was to identify the different timing of phenological stages in 18 different varieties of pear (including both European and Asian type) in mid hills of Nepal. 2. MATERIALS AND METHODS Experimental site: The experiment was performed in the pear orchard located at Warm Temperate Horticulture Centre (WTHC), Kirtipur, Kathmandu. Warm temperate region in Nepal is the zone that covers the areas of upper part of mid hills running from east to west of the country and the mean annual temperature ranging from 15-17.5 0 C (MPHD, 1990). The experimental site is situated at 27°4’N latitude and an altitude of 1320 masl. The climatic condition of the research site is warm temperate. The maximum temperature reaches up to 31 0 C during summer and minimum temperature drops to 1 0 C during winter and average annual precipitation is 1025mm. The experiment was carried out from January 2020 to August 2020. Cultivar selection: Eighteen varieties of pear (fifteen Asian, two European and one unidentified cultivar named as Kirtipur-1) were selected to conduct the phenological observations. The list of varieties used in the experiment was given in Table 1. Japanese and European varieties were brought from Japan during JICA project period while Pharping Local (white and brown) were collected from our local pear production area i.e., Pharping. Two plants from each cultivar were selected. The different varieties were tagged with the white colored tagging ribbon. All the plants from different varieties belongs to similar age group, approximately 26 years old. All the varieties were grafted plants and were cultivated under similar management practices like training and pruning, weed management, fertilization, disease and insect management etc. Trees were trained in open center system and top working of the tree was done whenever necessary. The spacing between plant to plant was 5 m. Evaluation of Phenological Traits of Pear Varieties in Warm Temperate Region of Nepal Padma Nath Atreya*, Ramila Dhakal, Jiban Shrestha Page | 145 AGRICULTURAL SCIENCE Journal Of Agricultural Science And Agriculture Engineering ISSN : 2597-8713 (Online) - 2598-5167 (Print) Available on : http://agris cience.s cientific -wor k.org/inde x.php/agris cience This is Under CC BY SA Licence Table 1: The details of pear varieties used in the experiment S.N. Varieties Source of origin S. N. Varieties Source of origin 1 Hosui Japan 10 Pharping Local (Brown) Nepal 2 Kosui Japan 11 Pharping Local (Green) Nepal 3 Meigetsu Japan 12 Nittaka Japan 4 Yakumo Japan 13 Hawana Japan 5 Kikisui Japan 14 Aatago Japan 6 Waseka Japan 15 Chojuro Japan 7 Gold Nijisseiki Japan 16 Kirtipur-1 Nepal 8 Okisankichi Japan 17 Bartlett Europe 9 Sinko Japan 18 Anjou Europe Design of experiment: The experiment was carried out in randomized complete block design (RCBD) with two replications. The eighteen varieties of pear were selected as treatments and replicated two times with two trees per treatment. Data observations: In each tree, four branches were selected for phenological study. The selection of branches was done in such a manner that each branch faces one direction i.e., north, south, east and west so that errors can be minimized. The observations were started from the dormant stage and were done on 2-3 days interval until fruit set. Visual observations were taken from the tagged branches. Data on days from swollen bud to bud burst, swollen bud to green cluster, swollen bud to white bud, swollen bud to bloom, swollen bud to petal fall, swollen bud to fruit set, fruit length, and fruit diameter were recorded. Statistical analysis: The data were entered in Microsoft excel 2016 and analysis was done by using STAR 2.0.1 (Statistical Tool for Agricultural Research) and Cluster analysis by Minitab 17. 3. RESULTS AND DISCUSSION The phenology of pear was studied with reference to BBCH (Biologische Bundesanstalt, Bundessortenamt and CHemical industry) scale. Eight stages were recorded for 18 pear varieties. The major eight stages are dormant, swollen bud, bud burst, green cluster, white bud, bloom, petal fall and fruit set (Chapman & Catlin, 1976). Among 18 varieties, ‘Pharping Local (Green)’ showed earlier bud burst on 14 th February followed by ‘Pharping Local (Brown)’ which showed bud burst on 22 nd February and Waseaka showed bud burst at the last on 24 th March. Varieties; ‘Hawana’ and ‘Aatago’ showed earlier bud burst on 5 th March among Asian varieties. Anjou showed earlier bud burst on 27 th February among European varieties. The seasonal timing and duration of different Evaluation of Phenological Traits of Pear Varieties in Warm Temperate Region of Nepal Padma Nath Atreya*, Ramila Dhakal, Jiban Shrestha Page | 146 AGRICULTURAL SCIENCE Journal Of Agricultural Science And Agriculture Engineering ISSN : 2597-8713 (Online) - 2598-5167 (Print) Available on : http://agris cience.s cientific -wor k.org/inde x.php/agris cience This is Under CC BY SA Licence phenological stages of fruit trees depends on local climatic conditions and fluctuate from year to year (Cordero, Bocanegra, García-Galavís, Santamaría, & Camacho, 2013). The phenology mainly depends on the genetic characteristics of different varieties. Different varieties show same stage of growth in different time period. Most of the temperate deciduous fruit trees undergo dormancy and requires certain amount of chilling for release (Lang, 1996). The growth cycle that takes place between late summer and budburst is considered as dormancy period (Faust, Erez, Rowland, Wang, & Norman, 1997). The development of inflorescence is initiated in the summer and autumn of the previous season of the bloom and flower continues to develop in the spring after a month of pollen meiosis and anthesis starts at the end of April or the beginning of May (Staritsky, 1970). The mean number of days required from swollen bud to bud brust, green cluster, white bud, bloom, petal fall and fruit set were influenced by the varieties due to the variation in genetic makeup. The number of days required from swollen bud to bud burst was found highly significant different among the varieties (Table 2). The highest no of days required from swollen bud to bud burst in Hosui (7 days) followed by Aatago, Chojuro and Nittaka (6 days) while the lowest no of days recorded in Sinko (2 days). Similarly, swollen bud to green cluster, swollen bud to white bud, swollen bud to bloom, swollen bud to petal fall, swollen bud to fruit set were recorded and is shown in Table 2. Table 2: No of days require for different phenological stages of pear varieties Pear varieties No of days Swollen bud to bud burst Swollen bud to green cluster Swollen bud to white bud Swollen bud to bloom Swollen bud to petal fall Swollen bud to fruit set Aatago 6 b 10 a 16 a 19.33 a 25.33 b 30.67 abc Anjou 4 d 5.67 bcd 10.67 bc 11.67 bcd 20.67 bc 24.33 abcde Bartlett 3 e 6 bcd 7.67 cde 10.67 cd 17.33 cde 19.67 cde Chojuro 6 b 6 bcd 11.33 b 12.33 bcd 17.33 cde 24.33 abcde Gloden Nijisseiki 4 d 6.67 bcd 9.33 bcde 14 bc 20 bcd 25.33 abcde Hawana 4 d 7.67 abc 9 b cde 12 bcd 21.67 bc 25 abcde Hosui 7 a 7.67 abc 9.67 bcd 11.67 bcd 14.67 de 20.33 cde Kikisui 5 c 5.33 cd 11.67 b 16.33 ab 18 cde 20.67 cde Kirtipur 1 5 c 9.33 a 11.33 b 14 bc 20.67 bc 30 abc Kosui 5 c 5.33 cd 10.67 bc 13.67 bcd 16 cde 21.67 cde Meigetsu 2.33 ef 6 bcd 8.67 bcde 11.33 bcd 18 cde 23.33 bcde Nittaka 6 b 8 ab 11.67 b 15 abc 21.33 bc 28.67 abcd Okisankichi 3 e 5 d 7 de 11 cd 14.33 de 17.67 de Pharping Local (Brown) 4 d 6.67 bcd 7.33 de 8.67 d 34 a 34.33 ab Pharping Local (Green) 4 d 5.67 bcd 7.67 cde 11.67 bcd 35 a 34.67 a Evaluation of Phenological Traits of Pear Varieties in Warm Temperate Region of Nepal Padma Nath Atreya*, Ramila Dhakal, Jiban Shrestha Page | 147 AGRICULTURAL SCIENCE Journal Of Agricultural Science And Agriculture Engineering ISSN : 2597-8713 (Online) - 2598-5167 (Print) Available on : http://agris cience.s cientific -wor k.org/inde x.php/agris cience This is Under CC BY SA Licence HSD: Tukey's Honest Significant. Difference, SEM: Standard error of mean, CV: Coefficient of variation. For each parameter, different lowercase letters in the same column indicates significant differences (p < 0.05) among pear varieties according to Tukey's test. Pharping Local (Green), required the longest interval (34.67 days) between swollen bud to fruit set and is followed by Pharping Local (Brown) (34.33 days), Aatago (30.67 days) while the shortest interval was recorded in Sinko & Yakumo (16 days), followed by Okisankichi (17.67 days). An experiment conducted in Czech Republic, significant difference was not found in the flowering dates of different varieties of pear (Nicas et al., 2020), which is in contrast to our findings. Number of chilling hours and temperature required for breaking of dormancy vary from varieties to varieties. It was reported by Asano and Okuno (1990), cultivar ‘Kosui’ required temperature below 10 0 C and cumulative chilling hours required was 600 hours for breaking dormancy of bud. But in case of ‘Nijisseiki’ 10 0 C was effective to break bud (Tamura, Tanabe, & Ikeda, 1993). Varieties ‘Hosui’ and ‘Kosui’ were earlier than other varieties of both Asian and European type. Among these two varieties ‘Hosui’ and ‘Kosui’ breaking of dormancy takes place earlier in ‘Hosui’ as ‘Kosui’ requires more hours of chilling than ‘Hosui’ (Asano & Okuno, 1990). Flower differentiation occurs after the cessation of shoot elongation and formation of 12 bud scales in the early to mid-summer season due to increase in the cell division (Ito et al., 1999). Date of full bloom varies between varieties and some varieties in which bud burst took place earlier also showed full bloom date later than others. For example, in cultivar ‘Kikisui’, ‘Gold nijisseki’ and ‘Kosui’ bud burst took place on same date, 11 th march but the date of full bloom varies among them i.e., 27 th , 25 th and 19 th March respectively. Different hybrid varieties of pear required average of 41-69 days from first flower to full bloom and required about 99-120 days for harvesting (De Alcantara Barbosa et al., 2018). The Asian varieties ‘Hosui’ and ‘Kosui’ required 25 days and 30 days respectively from budburst until the onset of fruit growth (Lopes et al., 2013). Most of the Asian varieties of pear requires about 94-112 days from dormant bud to full bloom stage (Necas et al., 2020). Gotame, Subedi, Dhakal, and Khatiwada (2015) reported that cultivar ‘Pharping Local’ takes about 130 to 150 days from bud burst to full bloom whereas other Asian varieties ranges from 112 to 150 days. Petal fall stage was recorded after 1-2 weeks of full bloom in all Asian and Sinko 2 f 4.33 d 6.33 e 11.33 bcd 13.33 e 16 e Waseaka 4 d 5.67 bcd 8.67 bcde 12.33 bcd 17.67 cde 23.33 bcde Yakumo 3 e 5 d 8 cde 10.67 cd 13.33 e 16 e Mean 4.30 6.44 9.59 12.65 19.93 24.22 SEM 0.0741 0.5882 1.1329 2.6492 3.6002 13.3039 P value 0.0000 0.0000 0.0000 0.0000 0.0000 0.0000 CV (%) 6.33 11.90 11.10 12.87 9.52 15.06 HSD at 5% 0.8369 2.3584 3.2729 5.0049 5.8345 11.2157 Evaluation of Phenological Traits of Pear Varieties in Warm Temperate Region of Nepal Padma Nath Atreya*, Ramila Dhakal, Jiban Shrestha Page | 148 AGRICULTURAL SCIENCE Journal Of Agricultural Science And Agriculture Engineering ISSN : 2597-8713 (Online) - 2598-5167 (Print) Available on : http://agris cience.s cientific -wor k.org/inde x.php/agris cience This is Under CC BY SA Licence European varieties whereas it took about 1 month for petal fall from full bloom in varieties ‘Pharping Local (Brown)’ and ‘Pharping Local (Green)’. Fruit set stage occurred after about 1 weeks of petal fall in all varieties and harvesting was done about 4-5 months after fruit set in all varieties. First harvesting was done in cultivar ‘Kosui’ followed bycultivar ‘Hosui’ The mean fruit length and diameter of different varieties of pear was found highly significant (Table 3). The longest fruit was recorded in Anjou (58.80 mm), followed by Bartlett (52.90 mm) and Yakumo (49.80 mm), while the shortest fruit was recorded in Nittaka (32.50 mm) followed by Kirtipur 1 (35.0 mm) and Pharping Local (Brown) (37.50 mm). Similarly, the highest fruit diameter was recorded in Anjou (57.60 mm) followed by Yakumo (55.80 mm) and Waseaka (50.80 mm) while the lowest fruit diameter was found in Nittaka (32.50 mm) followed by Kirtipur- 1 (35.0 mm) and Sinko (40.10 mm). Table 3: Fruit length and diameter of different pear varieties Pear varieties Fruit length (mm) Fruit diameter (mm) Aatago 48 bcd 51.60 abc Anjou 58.80 a 57.60 a Bartlett 52.90 ab 45 cde Chojuro 41.50 defg 48.80 bcd Gloden Nijisseiki 44.50 cdef 46.70 cde Hawana 44 cdef 47.20 bcde Hosui 45.60 bcdef 49.30 abcd Kikisui 44.20 cdef 49.60 abcd Kirtipur 1 35 gh 35 fg Kosui 43.90 cdef 50.10 abcd Meigetsu 47 bcd 46.60 cde Nittaka 32.50 h 32.50 g Okisankichi 44.20 cdef 48.30 bcde Pharping Local (Brown) 37.50 fgh 42.40 efg Pharping Local (Green) 43.20 cdef 44.5 cde Sinko 37.90 efgh 40.10 efg Waseaka 46 bcde 50.80 abcd Yakumo 49.80 bc 55.80 ab Mean 44.25 46.77 SEM 26.7526 30.0072 P value 0.0000 0.0000 CV (%) 11.67 11.68 HSD at 5% 8.1381 8.6189 HSD: Tukey's Honest Significant. Difference, SEM: Standard error of mean, CV: Coefficient of variation. For each parameter, different lowercase letters in the same column indicates significant differences (p < 0.05) among pear varieties according to Tukey's test. Harvesting duration of all 18 varieties lasts for about two months (Table 4). Early harvesting was done in cultivar Kosui on 4 th week of July and late harvesting was done in cultivar Evaluation of Phenological Traits of Pear Varieties in Warm Temperate Region of Nepal Padma Nath Atreya*, Ramila Dhakal, Jiban Shrestha Page | 149 AGRICULTURAL SCIENCE Journal Of Agricultural Science And Agriculture Engineering ISSN : 2597-8713 (Online) - 2598-5167 (Print) Available on : http://agris cience.s cientific -wor k.org/inde x.php/agris cience This is Under CC BY SA Licence Okisankichi on 4 th week of September. The period of ripening and maturity is affected by some of the factors like flowering dates and temperature during the period from flowering to the ripening. Among different varieties of Asian pear, the period from dormant bud to maturity of the fruit varied from about 223 days to 276 days (Nicas et al., 2020). Table 4: Different timing of harvest of 18 varieties of pear. Varieties Date of harvest Varieties Date of harvest Hosui 1 st week of August Pharping Local (Brown) 2 nd week of September Kosui 4 th week of July Pharping Local (Green) 2 nd week of August Meigetsu 4 th week of August Nittaka 1 st week of September Yakumo 2 nd week of August Hawana 3 rd week of August Kikisui 2 nd week of August Aatago 3 rd week of September Waseka 3 rd week of August Chojuro 3 rd week of August Gold Nijiseiki 4 th week of August Kirtipur-1 4 th week of August Okisankichi 4 th week of September Bartlett 4 th week of August Sinko 3 rd week of August Anjou 3 rd week of August The 18 pear varieties were grouped into five clusters (Figure 1 and Table 5). The pear variety grouped into cluster 1 showed the highest value for swollen bud to bud burst (6.00 days), swollen bud to white bud (16.00 days) and swollen bud to bloom (19.33 days). The variety belonged to cluster 2 showed the highest value for fruit length (58.80 days) and fruit diameter (57.60 days). Similarly, the varieties belongs to cluster 4 showed the highest value for swollen bud to green cluster (8.67 days), and cluster 5 showed the highest value for swollen bud to petal fall (Table 6). Clustering into natural groups is represented by a dendrogram, which gradually divides interventions into smaller and smaller groups (KC, 2001). Evaluation of Phenological Traits of Pear Varieties in Warm Temperate Region of Nepal Padma Nath Atreya*, Ramila Dhakal, Jiban Shrestha Page | 150 AGRICULTURAL SCIENCE Journal Of Agricultural Science And Agriculture Engineering ISSN : 2597-8713 (Online) - 2598-5167 (Print) Available on : http://agris cience.s cientific -wor k.org/inde x.php/agris cience This is Under CC BY SA Licence Ph ar pi ng L oc al (G ) Ph ar pi ng L oc al (B ) N itt ak a K irt ip ur 1 Si nk o Y ak um o O ki s a nk ic hi H os ui W as ea ka M ei ge ts u H aw an a G lo de n N iji ss ei ki K os ui K ik is ui Ch oj ur o B ar tle tt A nj ou A at ag o 35.52 57.01 78.51 100.00 Pear varieties S im il a ri ty Dendrogram Average Linkage, Euclidean Dis tance Figure 1: Cluster analysis of 18 pear varieties evaluated for flowering traits under at Warm Temperate Horticulture Centre, Kirtipur, Kathmandu, 2020 [In Pharping Local 'B' indicate brown and 'G' indicate green] Table 5: Grouping of 18 pear varieties into five clusters based on flowering traits Cluster1 Cluster 2 Cluster3 Cluster4 Cluster5 Aatago Anjou Bartlett, Chojuro, Gloden Nijisseiki, Hawana, Hosui, Kikisui, Kosui, Meigetsu, Okisankichi, Sinko, Waseaka, Yakumo Kirtipur-1, Nittaka Pharping Local (Brown), Pharping Local (Green) Table 6: Flowering traits of 18 pear varieties within and among five clusters Variable Cluster1 Cluster2 Cluster3 Cluster4 Cluster5 centroid Fruit length (mm) 48.00 58.80 45.13 33.75 40.35 44.25 Fruit diameter (mm) 51.60 57.60 48.19 33.75 43.45 46.77 Swollen bud to bud burst (days) 6.00 4.00 3.47 5.50 4.00 3.92 Swollen bud to green cluster (days) 0.42 5.67 5.89 8.67 6.17 5.91 Swollen bud to white bud (days) 16.00 10.67 9.00 11.50 7.50 9.59 Swollen bud to bloom (days) 19.33 11.67 12.28 14.50 10.17 12.65 Swollen bud to petal fall (days) 25.33 20.67 16.81 21.00 34.50 19.93 Swollen bud to fruit set (days) 30.67 24.33 21.11 29.34 34.50 24.22 4. CONCLUSION In this study, 18 pear varieties have been evaluated with respect to the phenological and fruit traits. From the observation, significant variation for these traits was found in pear varieties. Evaluation of Phenological Traits of Pear Varieties in Warm Temperate Region of Nepal Padma Nath Atreya*, Ramila Dhakal, Jiban Shrestha Page | 151 AGRICULTURAL SCIENCE Journal Of Agricultural Science And Agriculture Engineering ISSN : 2597-8713 (Online) - 2598-5167 (Print) Available on : http://agris cience.s cientific -wor k.org/inde x.php/agris cience This is Under CC BY SA Licence The shortest flowering period was observed in Sinko and Yakumo. The longest fruit and the highest fruit diameter were found in Anjou. Based on fruits traits Anjou and based on phenological traits Sinko and Yakumo were found potential varieties for cultivation under warm temperate region of Nepal. Conflicts of Interest The authors declare no conflict of interest. REFERENCES Asano, S., & Okuno, T. (1990). Period of breaking the rest and the quantity of chilling requirement of 'Kosui' and 'Hosui' Japanese pear. Bulletin of the Saitama Horticultural Experiment Station (17), 41-47. Atreya, P.N. (2018). Improved cultivation practice of pear. Warm Temperate Horticulture Centre, Kirtipur, Kathmandu, Nepal. Bleiholder, H., Kirfel, H., Langeluddeke, P., & Stauss, R. (1991). Codificacao unificada dos estadios fenológicos de culturas e ervas daninhas. Pesquisa agropecuária brasileira, 26(9), 1423-1429. Chapman, P. J, & Catlin, G. A. (1976). Growth stages in fruit trees-from dormant to fruit set. New York's food and life sciences bulettin (No 58). New York state agricultural experiment statio, Geneva. Chen, J., Wang, Z., Wu, J., Wang, Q., & Hu, X. (2007). Chemical compositional characterization of eight pear cultivars grown in China. Food Chemistry, 104(1), 268-275. Cordero, F. T. A., Bocanegra, J. A. J., García-Galavís, P., Santamaría, C., & Camacho, M. (2013). Comparative tree growth, phenology and fruit yield of several Japanese plum cultivars in two newly established orchards, organic and conventionally managed. Spanish journal of agricultural research, 11(1), 155-163. De Alcantara Barbosa, C. M., Pio, R., de Souza, F. B. M., Bisi, R. B., Neto, J. E. B., & da Hora Farias, D. (2018). Phenological evaluation for determination of pruning strategies on pear trees in the tropics. Scientia Horticulturae, 240, 326-332. FAOSTAT, F. (2018). Crop statistics. http://scholar.google.com/scholar?q= FAOSTAT,+F.+(2018).+Crop+statistics.&hl=en&as_sdt=0&as_vis=1&oi=scholart. Faust, M., Erez, A., Rowland, L. J., Wang, S. Y., & Norman, H. A. (1997). Bud dormancy in perennial fruit trees: physiological basis for dormancy induction, maintenance, and release. HortScience, 32(4), 623-629. Fleckinger, J. (1948). Les stades végétatifs des arbres fruitiers en rapport avec les traitements. Pomologie Française, 1, 81-93. Gotame, T. P., Subedi, G. D., Dhakal, M., & Khatiwada, P. P. (2015). Postharvest Handling of Asian Pear in Nepal. Evaluation of Phenological Traits of Pear Varieties in Warm Temperate Region of Nepal Padma Nath Atreya*, Ramila Dhakal, Jiban Shrestha Page | 152 AGRICULTURAL SCIENCE Journal Of Agricultural Science And Agriculture Engineering ISSN : 2597-8713 (Online) - 2598-5167 (Print) Available on : http://agris cience.s cientific -wor k.org/inde x.php/agris cience This is Under CC BY SA Licence Hack, H., Bleiholder, H., Buhr, L., Meier, U., Schnock-Fricke, U., Weber, E., & Witzenberger, A. (1992). Einheitliche codierung der phänologischen entwicklungsstadien mono-und dikotyler pflanzen–erweiterte BBCH-Skala, Allgemein. Nachrichtenblatt des deutschen Pflanzenschutzdienstes, 44(12), 265-270. Hancock, J. F. (2008). Temperate fruit crop breeding: germplasm to genomics: Springer Science & Business Media. Hess, M., Barralis, G., Bleiholder, H., Buhr, L., Eggers, T., Hack, H., & Stauss, R. (1997). Use of the extended BBCH scale-general for the descriptions of the growth stages of mono; and dicotyledonous weed species. Weed Research, 37(6), 433-441. Ito, A., Yaegaki, H., Hayama, H., Kusaba, S., Yamaguchi, I., & Yoshioka, H. (1999). Bending shoots stimulates flowering and influences hormone levels in lateral buds of Japanese pear. HortScience, 34(7), 1224-1228. Jackson, J. E. (2003). The biology of apples and pears: Cambridge university press. KC, R.B., Sharma, M.D., Panthee D., & Gautam, D.M. (2001). Physio-morphological characterization of indigenous garlic germplasm of Nepal. Master Thesis. Institute of Agriculture and Animal Science Rampur, Nepal. Lang, G. (1996). Plant Dormancy: Physiology. Biochemistry and Molecular Biology, CAB International, Wallingford, UK. Lopes, P. R. C., Oliveira, I. D. M., da Silva-Matos, R. R. S., & Cavalcante, I. (2013). Phenological characterization of pear trees' Housui'and'Kousui'under semiarid conditions in the northeastern Brazil. Revista Brasileira de Fruticultura, 35(2), 670-675. Marsal, J., Rapoport, H., Manrique, T., & Girona, J. (2000). Pear fruit growth under regulated deficit irrigation in container-grown trees. Scientia Horticulturae, 85(4), 243-259. Martinez Valero, R., Melgarejo, P., Salazar, D., Martínez, R., Martínez, J., & Hernández, F. (2001). Phenological stages of the quince tree (Cydonia oblonga). Annals of applied biology, 139(2), 189-192. MPHD. (1990). Major agro climatic zones of Nepal. Master Plan of Horticulture Developemnt. Ministry of Agriculture Development, Nepal. Necas, T., Wolf, J., Kiss, T., Gottingerová, M., Ivo, O., & Bieniasz, M. (2020). Evaluation of certain pomological and phenological traits of selected asian pear varieties growing in Middle European conditions. Horticultural Science, 47(2), 81-92. Petri, J. L., Hawerroth, F. J., Leite, G. B., Couto, M., & Francescatto, P. (2012). Apple phenology in subtropical climate conditions. Embrapa Agroindústria Tropical-Capítulo em livro científico (ALICE). Shrestha, J. (2016). Cluster Analysis of Maize Inbred Lines. Journal of Nepal Agricultural Research Council, 2, 33-36. https://doi.org/10.3126/jnarc.v2i0.16119 Evaluation of Phenological Traits of Pear Varieties in Warm Temperate Region of Nepal Padma Nath Atreya*, Ramila Dhakal, Jiban Shrestha Page | 153 AGRICULTURAL SCIENCE Journal Of Agricultural Science And Agriculture Engineering ISSN : 2597-8713 (Online) - 2598-5167 (Print) Available on : http://agris cience.s cientific -wor k.org/inde x.php/agris cience This is Under CC BY SA Licence Staritsky, G. (1970). The morphogenesis of the inflorescence, flower and fruit of Pyrus nivalis Jacquin var. Orientalis terpo. https://www.amazon.com/morphogenesis-inflorescence- orientalis-Mededelingen-Landbouwhogeschool/dp/9027805776 Tamura, F., Tanabe, K., & Ikeda, T. (1993). Relationship between intensity of bud dormancy and level of ABA in Japanese pear'Nijisseiki'. Journal of the Japanese Society for Horticultural Science, 62(1), 75-91. Tecchio, M. A., Bettiol Neto, J. E., Barbosa, W., & Tucci, M. L. S. a. (2011). Evolution and perspective of the temperate fruit crops in São Paulo state, Brazil. Revista Brasileira de Fruticultura, 33(SPE1), 150-157.