Performance evaluation of tomato accessions across two locations of Khyber Pakhtunkhawa

Identification of adaptable and stable genotypes is an important aspect of applied crop breeding which can insure sustainable crop production. Adaptability studies in tomato is an essential part of breeding for adequate evaluation of genotypes accomplished through environments (years/locations). A set of forty tomato accessions of diverse origin were tested at Swabi and Haripur locations to assess their performance. The experiment was carried out in randomized complete block design with three replications. Data were recorded on 50% flowering, days to fruiting and yield per hectare. Genotype (G), environment (E) and GEI share in total sum of squares were also studied. Significant (p≤0.01) differences were observed among the accessions, environments (locations) and G × E interaction means for majority traits, which assured greater genetic variability among the accessions due to their divergent genetic make-up, as well as environments. On average, the accessions showed best performance in Swabi location than Haripur for yield and duration parameters. Overall, the promising accessions could be further explored for improvement in tomato fruit yield.


Introduction
Tomato (Solanum lycopersicum Mill.) is relatively a new addition to the world food crops, used in various forms both fresh and processed.Although tomato does not rank high in terms of caloric value, by virtue of volume consumed in its various forms such as cooked, salad, soup, preserves, pickles, ketchup sauces and many other products, it contributes substantially to dietary intake of vitamin A, B, C and essential minerals [1].Tomato being a tender perennial crop, it is susceptible to both frost as well as high temperature, and thus it is grown under varying environmental conditions.Since 1961, tomato production in the world has increased 291%, and during the year 2002 production reached 108 million metric tons.This expensive seed supply of tomato necessitates the vegetable breeders to breed varieties/hybrids having great yield potential under local environments.For this purpose, irrespective of the tools adopted during the breeding process, the breeder has to take two major steps: first to find and/or create genetic variation and secondly to select the best genotypes [4].In present study, small samples of 40 tomato accessions were evaluated for their performance across two locations of Khyber Pakhtunkhawa.

Material and methods
The present investigation was conducted to categorize native and foreign tomato germplasms from diverse genetic sources.For morphological characterization tomato germplasm, consisting of 40 tomato genotypes, were acquired from national agriculture research center (NARC), Islamabad and federal Seed certification and registration department (FSC and RD), Islamabad, Pakistan in January, 2013 (Table 1).

Nursery preparation
Sowing of the accessions was done at Agriculture Research Farm, University of Haripur, in February 2013 for raising nursery seedlings.For sowing different soils like sandy, light, well drained and high in organic matter were selected by keeping a row to row distance of 10 cm and plant-toplant distance of 5 cm.Transplantation Transplantation of the seedlings was carried out into well prepared field plots rich in organic matter after 4 weeks from the nursery at the evening time so to reduce the risk of transplant shock.Each field plot was composed of 4 rows of 1 meter with a row to row distance of 120 cm and a plant to plant space of 40 cm.

Field management
FYMs [(@ 15 tones per hectare) and NPK (@ 100:80:60 kg per hectare)] was applied at the time of seed bed preparation, followed by irrigation.Total amount of organic manure, P2O5, K2O and 1/3 N was applied at the time of seed bed preparation and the rest of nitrogen was side dressed in two splits i.e., 20 days after transplantation and at preflowering stage.Furadon granules were also applied to the soil before transplantation to aviod any insect attack on young plantlets.In order to keep the block weed free, mechanical weeding was done from transplantation till harvest.Earthing up and supporting and training with vertical strings was done after 15 th day of transplantations.

Traits measurement and statistical analysis
Data were recorded on days to 50% flowering, days to fruiting and yield per hactare.Data were subjected to analysis of variance (ANOVA) according to Steel & Dickey [6].After getting the significant variations among genotypes performance for various parameters, the means for each trait were further separated and compared by using the least significant difference (LSD) test at 5% level of probability.

Results and discussion
Pooled analysis of variance across two locations revealed significant (p<0.01)differences among genotypes, environment and genotype × environment interaction for days to 50% flowering and yield per hectare; however environment and genotype × environment interaction was non-significant for days to fruiting(

Table 2 . Mean square values of ANOVA for yield and yield related traits of 40 Accessions across two location of Khyber Pakhtunkhwa Parameters Mean
This scenario was manifested in Tropimech which has shorter days to flowering and performs better than the other genotypes in terms of yield.Similar results have been reported by Dhankhar & Dhankhar [10].Comparison between the environments showed that genotype EUR-312 revealed maximum (54.67 days) in Haripur environment followed by the same genotype in Swabi location; however, lowest (42.33 days) were observed in Swabi.