Performance Evaluation of Gladiolus Varieties under Diverse Climatic Conditions

Crop production is inherently sensitive to climatic variations. Flowers have been admired and used by human to beautify their environment, and also as objects of romance, ritual, religion, medicine and as a source of food. Gladiolus (Gladiolus grandiflorus Andrews; family Iridaceae) is an important bulbous cut flower grown all over the world. The present study was carried out to check the growth and development of three cultivars of Gladiolus under different ecological conditions. As far as vegetative results are concerned early germination was observed at Faisalabad plantation, maximum plant height was observed at Rawalakot. Floral characteristics such as number of florets, diameter of florets, fresh and dry weight of spike were the best at Rawalakot plantation. Parameters such as corm weight, corm diameter, number of cormels and their weight were also favoured by Rawalkot climatic conditions. The temperature remained a critical factor for growth and production, early germination was observed at 26.5 ̊C at Faisalabad whereas ideal average temperature for vegetative, flowering and corm growth was 23.18 ̊C at Rawalakot plantation.


Introduction
Floriculture is emerging as a profitable venture due to divergence of farmers towards high value floral crops and utilization of flowers in social and industrial level . International trade in cut flowers is growing at a rate of 25 per cent annual growth rate. It has been reported that Pakistan is earning 35 million rupees from cut flower export (Bashir, 2010). Comprehensive survey indicates gladiolus is next to roses in preference by the consumers in various cities of the Pakistan (Riaz et al., 2007). Gladiolus is one of the most beautiful bulbous cut flowers in the floriculture industry and occupies the fifth position in the international floriculture trade (Sharma and Sharma, 1988;Butt et al., 2015) It is native to South Africa and presently has been cultivated throughout the world due to its attractive characteristics, dazzling colors, varying sizes and long vase life (Farid et al., 2002). These ornamental plants exhibit great diversity in their morphology, physiological responses to en vironmental factors, growth and developmental biology. Pakistan has a possibility to produce gladiolus all the year around. The sowing time of gladiolus in plains of Pakistan is from late July to early October liable upon the climatic circumstances of the area and flowering starts from December to March. Where as in hilly areas April-May is the sowing time and flowering starts in July-November. Thus gladiolus is considered as winter crop in plain areas and summer crop in hilly areas (Aftab et al., 2007). Agro-ecological conditions such as: Light, temperature, rainfall, humidity and soil condition are important in flowering of this crop. In gladiolus temperature affects all aspects of plant growth including shoot emergence, leaf area and flower development (Smith and Langhans, 1962). The suitable agro-climatic conditions of the country clearly indicate that wide range of ornamental crops can be grown, which can improve the economic conditions of the growers. The present experiment was conducted to study the effect of two different agro-ecological conditions on for growth, yield and quality of three Gladiolus varieties of Gladiolus.

Result and Discussion
Ornamental plants show considerable diversity in their growth habits, colors, blooming structure, flower shape and size (Pasha et al., 2015) Hence the performance of a cultivar in respect of growth and yield is known to be greatly influenced by the environmental conditions particularly integrated temperature and light (White and Warrington, 1988;Hodges, 1991). Growth and development of bulbous plants are mainly affected by seasonal thermo periodicity, constituting the basis of the techniques used to control flowering during forcing (Rees, 1992). In some bulbous species daily thermoperiodic changes are required to induce flowering (Halevy, 1990). Analyses of variance showed highly significant results for all the studied traits of gladiolus plants. Corm diameter was the only trait which showed non-significant results. Variety×climate interaction was also found significant ( Table 1). The results regarding effect of different climatic conditions on all the studied traits of three gladiolus cultivars are given as treatment means (Figure 1 and Figure 2).

Effect of different Agro-ecological conditions on vegetative growth of Gladiolus
Plants have to face various environmental stresses simultaneously, which affect their growth and development severely . The response of three gladiolus varieties with respect to their vegetative growth under the environmental conditions of Faisalabad and Rawalakot are given (Table 2). From the data it is concluded that temperature is an important factor for the vegetative growth of this flowering plant. Therefore Days to germination (11.13) and germination percentage (93.31%) was best under Faisalabad climatic conditions while at Rawalakot due to low temperature more number of days (13.43) was taken for to sprouting (Table 2).
Early germination at high temperature is also reported by (Hartmann et al., 1981). Due to low temperature during germination, under Rawalakot climatic conditions germination percentage also remained low (85.8%). High sprouting percentage at Faisalabad might be due the fact that the environmental conditions were favorable for the sprouting at that time when the temperature was higher ( Figure 3). As the varieties are concerned at Faisalabad Plant Gene and Trait2016, Vol.7, No.4, 1-8 http://pgt.biopublisher.ca 3 conditions maximum germination percentage was observed in White prosperity while at Rawalakot maximum germination percentage was observed in rose supreme. Carpenter et al. (1995) also reported that temperature between 20˚C to 25˚C promoted germination to 97% in gladiolus. The traits Plant height and Number of leaves plant -1 were best under Rawalakot climatic conditions. At the Faisalabad plant height was recorded 90.2 cm whereas under Rawalakot climatic conditions it was 107 cm. Maximum plant height was recorded in the variety Rosesuoreme at Rawalakot, whereas minimum plant height was recorded in the variety Amsterdam at Faisalabad.  The increase in plant height of gladiolus at high temperature is also reported by Gursan (1993  climatic conditions might be due the fact that the environmental conditions were favorable for floral growth at that time when temperature at Rawalakot was higher than Faisalabad. At Faisalabad the temperature was lower due to which maximum number of days to spike initiation was obtained. The variety White prosperity took the minimum number of days to spike initiation at Rawalakot and at Faisalabad Amsterdam got maximum number of days to spike initiation. The early spiking of gladiolus was observed during high temperatures, which promoted quicker transition from the vegetative state to the reproductive state. Early spiking at high temperature is also reported by Halevy (1985) who stated that gladiolus flowered more rapidly under warm temperatures regardless of photoperiod. The results are in accordance with the finding of Piringer and Borthwick (1961) (Table 2, Table 3 and Table 4). Increase in floret diameter at high temperature is also reported by Gill et al. (2003) who reported increased diameter of the first floret during high temperature in early planting dates as compared to inflorescences obtained at low temperature during later dates of planting.
In Rawalakot climatic conditions 50.12 g fresh weight of the spike was found whereas at Faisalabad 39.36 g fresh weight of spike (g) was recorded. Rose supreme showed the best results regarding the fresh weight of spike at Rawalakot while minimum fresh weight of spike at Faisalabad was shown by Amsterdam ( Table 2, Table 3). The results are in accordance with Kamble (2001). The results are in line with the findings of (Ko et al., 2005) who reported increased fresh weight of chrysanthemum flower at 17˚C as compared to 21˚C in a winter greenhouse experiment. At Rawalakot climatic conditions 14.28 g dry weight of spike was found whereas at Faislabad 10.13 g dry weight of spike (g) was observed. Best results regarding the dry weight of spike at Rawalakot the variety Rosesupreme proved to have maximum dry weight while in Faisalabad Amsterdam has minimum spike dry weight. The results are in line with the findings of Bose and Tripathi (1996) who reported increased dry matter production at high temperature may be attributed to greater accumulation of photosynthates by vegetative parts in gladiolus.

Effect of climatic conditions on corms and cormels growth among three verities of Gladiolus
Corm size is a major factor to determine the capacity of bulbous plants to flower (Le Nard and De Hertog, 1993). Difference in corm size is responsible for the wide differences reported in the time of flower initiation and Plant Gene and Trait2016, Vol.7, No.4, 1-8 http://pgt.biopublisher.ca 6 flowering in different places (Koul and Farooq, 1984;Negbi, 1999). Flower formation is directly related to the corm size (Negbi et al., 1989;De Mastro and Ruta, 1993) and a quantitative relationship between these two parameters was found by (Negbi et al., 1989). It is observed that under Rawalakot climatic conditions corm and cormels growth was better as compare to growth under Faisalabad climatic conditions (Table 4).
During corm and cormels growth temperature was higher (24.95˚C) at Rawalakot as compare to Faisalabad where it was (10.02˚C). At Rawalakot 5.94 cm corm diameter was recorded whereas at Faisalabad 5.03 cm corm diameter was recorded .Rosesuprem obtained maximum corm diameter at Rawalakot while at Faisalabad revealed minimum diameter. The results are in line with the findings of Parker and Borthwick (1951) who reported an increase in corm diameter at high temperature in part to the production of more photosynthates. At Rawalakot climatic conditions 55.62 g corm weight was recorded whereas at Faisalabad 50.72 g corm weight was recorded. The minimum corm weight (g) at Faisalabad was observed during low temperatures (10.02˚C), while maximum corm weight at Rawalakot was observed during high temperature (24.95˚C). At Rawalakot maximum corm weight was found in Rose supreme while at the Faisalabad minimum weight of corm was observed in Rosesupreme. The results are in line with the findings of Shilo and Halevey (1981) who reported increase in corm weight at high temperature and long day lengths.
At Rawalakot, it took 28.76 number of cormels clump -1 while 26.17 number of cormels clump -1 were obtained at Faisalabad. Highest number of cormels was recorded in the variety White prosperity at Rawalakot, whereas lowest number of cormels was recorded in the variety Amsterdam at Faisalabad. The results are in line with the findings of Laskar and Jana (1994) who reported an increase in gladiolus cormels production at slightly high temperature.At Rawalakot 8.58 g cormels weight was recorded while at Faisalabad 6.84 g weight of cormels was recorded. Among the varieties at Rawalakot in White prosperity obtained the maximum weight of cormels while at Faisalabad Amsterdam obtained minimum number of cormels. The results are in line with the findings of Laskar and Jana (1994) who reported an increase in gladiolus cormels production at slightly high temperature.

Materials and Methods
The present study was conducted under the Agro-climatic conditions of Faisalabad and Rawalakot. Three Gladiolus cultivars namely, Rose supreme, Amsterdam and White prosperity were used for the present research.
The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. Uniform agronomic practices were applied to all three cultivars. Ten plants from each of the entry were selected randomly and data was recorded for morphological traits i.e. Days to Germination, Germination Percentage, Plant Height (cm), Number of Leaves, Days to Spiking, Length of Spike (cm), Diameter of Spike (cm), Diameter of Florets (mm), Number of Floret Spike -1 , Fresh Weight of Spike (g), Dry Weight of Spike (g), and corm indices i.e. Diameter of Corms (mm), Weight of Corms (g), Number of Cormels, Weight of Cormels (g). Complete data was analyzed statistically by using analysis of variance technique and treatment means were compared through LSD test at the 5% level of significance according to (Steel et al., 1997). Before startingto experiment, soil samples from various blocks of experimental field in Faisalabad and Rawalakot were collected randomly to assess physio-chemical properties (pH, EC, texture, organic matter contents and N, P, K and Zn contents) of the soil. Soil analysis was performed to examine physical and chemical properties of soil. The results regarding physio-chemical analyses of soil from both ecological conditions are given below (Table 5).