Effect of different dates on the growth and flower production of gladiolus ( Gladiolus hortulanus ) under the agro-climatic condition of Quetta, Balochistan

Effect of different dates on the growth and flower production of gladiolus ( Gladiolus hortulanus ) under the agro-climatic condition of


Introduction
Gladiolus (Gladiolus hortulanus) popularly known as "Sword Lily" is an Ornamental cormelous plant native to South Africa.It belongs to monocot family Iridaceae, having approximately one hundred and fifty known species [1].This plant is commercially used for cutting flowers and occasionally used for landscape designing purpose.Due to very attractive flowers gladiolus has great demand in market.To satisfy customer demand, it is important that gladiolus flower is available round the year.Gladiolus is one of the few plants which produce pleasant cut flowers with long spikes.These spikes are an integral part of almost every cut flower arrangement ranging from table decoration to bucket formation.Gladiolus is cultivated in most of the tropical and subtropical countries of the world.In plains of Pakistan, it blooms profusely during the spring and summer.Gladiolus spikes take 60 to 100 days after planting to be harvested depending upon the cultivars and time of year [2].It is native to South Africa and Asia Minor.British people introduced it to the Indo-Pak subcontinent during sixteenth and seventeenth century [3].The genus Gladiolus comprises about 250-300 species.Thousands of present-day cultivars belong to Gladiolus hortulanus and Gladiolus hybridus [4].Commercially, the gladioluses worldwide considered as most popular flower [5].Glorious inflorescence with multiple colors, make it attractive to use as cut flowers as well as in beddings, rockeries, herbaceous borders and pots [6].Mentioned that, internationally in cut flower trade, gladiolus ranks 4 th after rose, carnation and chrysanthemum [7].During 2017, 14.7 million Gladiolus, 16.8 million rose stems, while 292 tones Surkha roses were marketed from Patto kimandi (the biggest flower market in the country).The major share of total flower area of about 4,450 ha is in Punjab.Flower production is emerging sector in KP and area under various flower crops such as roses, gladiolus and lilium are fast increasing and have reached around 1,012 ha.In Sindh, mostly Surkha rose, Motia/ Jasmine, and marigold are being grown on an area of about 1,214 ha.While rest of area is in Baluchistan (only a few hundred ha), Kashmir (Rawlakot and Kotli) and recently emerging in Gilgit Baltistan, [8].
Since last decade, production of flowers in Pakistan has increased and similar trend is expected to be continued during the coming years Moreover, recently, new flower crops like stock, snapdragon, delphinium, sunflower and celosia have been introduced by the University of Agriculture, Faisalabad, and their commercial production has also been started which will further promote flower production in coming years in Pakistan [9].Currently, growers are getting on an average around 135,850 gladiolus stems from one ha of land and while average rose petal yield is around 13.59 tons of fresh petals per ha and 1.73 million stems of cut rose per ha; however, this may vary based on several production and handling factors [10].Cut flower business deals with the growing and marketing of flowers along with their specific length of stem and leaves.Upon various social functions whereas supply of cut flowers fluctuates due to seasonal effects of weather.Usually, the flowers are developed for esthetics, social functions as well as essential oil extraction and manufacture of perfumes [8].Pakistan has better scope to adopt the floriculture as a lucrative industry due to its diversified agro-climatic conditions and cheap labor force (Ahmed et al.2010).Unfortunately, the research work been done on its quality production is sporadic and inconclusive.There are many factors limiting its quality production and nutrition is the most important of these factors [3].The well fertilized flowers also perform better in the vase [4,11].Thus can meet with the demands of consumers.However, now-a-days particularly in the Punjab (Pakistan), floriculture has become potential trade due to farmers' trend to develop valued floral plants and utilize at high social and commercial scale.Thus, floriculture is emerging inside the country at commercial level.Pakistan cultivates rose, carnation, iris, gladiolus, tuberoses, narcissus, lilies, freesia, statice and gerbera etc. that are most important floriculture plants to utilize for cut flower trade [12,13].In past decade, along with production, tremendous increase in consumption of cut flowers has also been witnessed and such positive movement in this sector in Pakistan is probable [14].Planting time in gladiolus has crucial role to regulate growth and establish flower quality.Gladiolus development and flower quality is enhanced when proper sowing time is adopted and consumer's demand in relation to gladiolus flower is better fulfilled [15].Proper schedule of planting gladiolus not only supplies flower to the market steadily but also affix beauty for a longer period to the landscape.The grower is always predictable flowering time of gladiolus raised at different planting dates under normal ecological situation.The research [16] showed that growth and yield traits of gladiolus including florets number in a spike, length of spike, diameter of the floret, length of the floret are significantly (P<0.05)influenced by the planting time.

Materials and Methods
The effect of different sowing time on growth and flower production of gladiolus was evaluated in an experiment during 2018 to optimize time for cultivation of gladiolus under climatic condition of Quetta.The experiment was carried out in experimental and demonstration orchard of Directorate Agriculture Research Fruit ARI Sariab Quetta.The plot size was 7m × 5m (35m 2 ) with 30 cm × 45 cm plant to plant and row to row spacing respectively.The experiment was conducted in Randomized Complete Block Design (RCBD) with Four (4) replications.The soil of the experimental site was analyzed for basic physicochemical properties and texture.According to the soil analysis report, sand, silt, and clay ratios in the experimental soil were 16.34, 46.66 and 37.00 percent, respectively and recognized as silt clay loamy in texture.The soil pH was 7.83, Calcium carbonate 6.98 percent, Electric conductivity 1.09 dSm -1 , organic matter 0.576 percent, available Phosphorus 7.11 mg kg -1 , and total Potassium 832.12 ppm.Accordingly, the soil was deficient in organic matter and available Phosphorus while pH and Electric conductivity levels were within acceptable limits.All the cultural practices were carried out to prepare the experiment field before starting the experiment.After that experimental field was level to facilitate uniform watering to enter experimental plot.Well rotten Farmyard Manure (FYM) was applied before experiment to increase the fertility level of all sub-plots.Treatments details are given as follows:

Treatments (Sowing dates) =05 Variety= White prosperity
The details of treatments are furnished as follows:

Statistical analysis
The collected data were analyzed by using statistical software SPSS (8.1).Difference among treatments were tested by one way (ANOVA) followed by Tukey test at 0.05% probability level.

Results
The impact of planting dates on the flower production of gladiolus was investigated in an experiment carried out during 2017-18 to optimize sowing time for gladiolus.Five treatments based on different sowing dates were selected (T1=2 nd March, T2 =17 th March, T3 =1 st April, T4 =16 th April and T5 =1 st May).The characters of economic importance measured in this study included: days taken to sprouting, leaves plant -1 , plant height cm, days to opening of first floret, florets spike -1 , corms plant -1 , number of corm lets plant -1 , diameter of corm, floret size, number of spikes plant -1 and average weight of corms.The results on the above traits are shown in (Table 1 -11).

Days to sprouting of corms
Corm sprouting is the crucial for achieving desired gladiolus flower production.The results concerning to days to sprouting in gladiolus under the effect of various sowing time are presented in (Table 1).The experimental outcome revealed that sprouting of gladiolus delayed when the planting was early or too late and relatively lesser days to corm sprouting was noted in plots sown in intermediary dates of the planting season.The gladiolus corms planted on 1 st April showed earliest sprouting in 10.25 days while there was a relative delay in sprouting when the gladiolus was planted on 16 th April (11.65 days), or 17 th March (11.96days).However, the maximum delay in sprouting was noted when planting was done on 1 st May (12.18 days) and 2 nd March (12.62 days).The sprouting of gladiolus delayed when the planting was early or too late and relative decrease in days to sprouting was noted in plots sown in intermediary dates of the planting season.These results are in accordance with the findings of [24] Reported that growth period of gladiolus was significantly influenced by sowing time in relation to temperature change.

Number of leaves plant -1
The effect of planting time on leaves plant - 1 was investigated and result with regards to number of leaves plant -1 are given in (Table 2).The gladiolus planting on first April resulted in plants with maximum leaves in the (9.58) on average, and leaves number significantly decreased (9.08) when the gladiolus corms were planted on 16 th April.The number of leaves plant -1 were statistically in similarity (P>0.05) when corms were planted on 17 th March (8.91), 2 nd March (8.66) and first May (8.58).The results suggested that gladiolus corms planted in last week of March or full month of April favored the development of more foliage (leaves plant -1 ); while the delay in planting up to May caused least count of leaves plant -1 .Similarly, early sowing in March has also adverse effect on the leaves count plant -1 .It was assumed that leaves number plant -1 decreased when the planting was early or too late and number of leaves plant -1 exploited maximally when planting was done in the intermediary dates of the growing season.[25].Found that number of leaves in gladiolus affected significantly by sowing dates; while [15] Reported that sowing of gladiolus in March and April resulted in a greater number of leaves plant -1 in more leaves plant -1 .

Plant height (cm)
The impact of planting dates on the height of gladiolus plants was ascertained and relative results are given in (Table 3).The maximum plant height (116.83cm) was found in plots where planting of corms was done on 1 st April, followed by 114.91 cm and 114.41 cm plant height that was observed in plots where the gladiolus plants were sown on 17 th March and 16 th April, respectively.The plant height further decreased to 113.49 cm when corms were planted on 2 nd March; while minimum height of plants (113.08 cm) was observed in 1 st May planting.It is evident from the findings that gladiolus corms planted in last week of March up to second fortnight of April maximally favored plant development, while the delay in planting up to late April and May produced relatively shorter plants.Likewise, early sowing in March could hamper the plant height.Hence, planting gladiolus corms too early or too late may not grow and flower vigorously.The LSD test indicates that though the height of plants differed significantly (P<0.05)among all the planting dates.Similar results have also been reported by [26] Reported that plant height was significantly affected by sowing dates; while [27] Reported that apart from the varietal effect on flowering behavior of gladiolus, the sowing time had also significant impact on plant height.

Number of florets spike -1
The flower quality in gladiolus is mainly associated with number of florets spike -1 , which also reflects the treatment effect.The data in relation to number of florets spike -1 in gladiolus are given in (Table 4).Number of florets spike -1 were highest in number (18.68) when the gladiolus planting was done on 1 st April and florets decreased considerably to 15.50 and 15.15 spike -1 when the gladiolus planting was carried out on 16 th April and 1 st May respectively.Similarly, the gladiolus early planting on 17 th March and 2 nd March decreased the number of florets spike -1 to 18.18 and 17.80, respectively.It is evident from the results that last two weeks of March and up to 1 st week of April may be considered as the optimum planting time of the gladiolus.Planting earlier than third week of March or later than first week of April caused reduction in the florets spike -1 count over the described optimum planting period.This indicates that early planting could somehow compensate the loss due to environmental change, but late planting showed severe adverse effects and environment on the number of florets spike -1 .The results of the present study are in accordance with those of [28] Reported that florets number spike -1 were higher at optimum sowing date, but delayed sowing caused reduction in florets spike -1 .Similarly, [29] Found that sowing gladiolus too early would result in decreased florets number spike -1.

Days taken to first floret opening
The planting time impact on the number of days to opening of first floret in gladiolus was explored and data are given in (Table 5).The gladiolus corms planted on 17 th March took least number of days (81.8) to opening of first floret; while there was a successive delay in opening of first floret when the gladiolus was planted on 1 st April (85.9 days), 16 th April (92.62 days) and 1 st May (93.45 days) However, the early planted gladiolus corms took (89.8)days to opening of first floret.The results showed that last three weeks of March up to 1 st week of April could be considered as the optimum planting time of the gladiolus to get optimally early opening of first floret of the corms.However, planting earlier than second week of March and later than first week of April would cause delay in opening of first floret over the optimum planting period suggested in this study.The days to opening of first floret showed similarity (P>0.05) when corms were planted on 16 th April and 1 st May; while dissimilarity (P<0.05) was observed in days to opening of first floret when compared with remaining planting dates.

The results of [17]
Concluded that earliness and delayed sowing delayed the opening of first floret in gladiolus; while [30] Found that optimum sowing time resulted in early opening of florets in gladiolus.

Floret size (cm)
Floret size in gladiolus is one of the components that not only represent flower quality, but the flower production as well.This trait is generally associated with genotypes, but the soil fertility and other management aspects also influence this trait.The results pertaining to floret size of gladiolus are shown in (Table 6).The floret size was relatively greater (8.00 cm) in gladiolus that was planted on 1 st April, followed by the average floret size of 7.87 cm and 7.8 cm observed in plots planted on 17 th March and 2 nd March, respectively.There was greater adverse effect of delayed planting and gladiolus planted on 16 th April resulted in 7.77 cm floret size; while the considerable decrease in floret sizes (5.5 cm) was observed when gladiolus corms were planted on 16 th April, while the smallest florets (7.75 cm) on average were recorded in corms sown on 1 st May.There was a great association of floret size with the diameter of corms and other studied traits.The findings explain that early sowing would not affect the floret size considerably; however, the late sowing i.e., after first week of April would severely affect the floret size in negative direction.So far, the floret size is concerned; the optimum planting time of gladiolus would be second fortnight of March up to first week of April.Similar result has also been obtained by [31] Reported that the floret size was significantly affected by sowing temperature; while [32] Suggested that the gladiolus growers should adopt the optimum time of sowing for achieving desired floret size in gladiolus.

Spikes number of plant -1
The planting date impact on spikes number plant -1 of gladiolus was searched in the experiment and the relative data are presented as (Table 7).Gladiolus corms planted on 17 th April produced more spikes (1.50 plant -1 ), and 1 st April planting produced 1.45 spikes plant -1 ; while 2 nd March planting of gladiolus showed 1.30 spikes plant -1 .Likewise, the late planting of gladiolus on 16 th April and 1 st May equally produced least pikes (1.25 plant -1 ).It is apparent from the experimental outcome that apart from the 17 th of March and 1 st April sowing, all other rest of sowing dates resulted in a significant reduction in the number of spikes plant -1 .Planting earlier than third week of March or later than first week of April resulted in severe reduction in the number of spikes plant -1 over the optimum planting time.Moreover, early planting up to 17 th March did not show greater adverse effects on this trait but planting gladiolus later than first week of April caused significant reduction in the number of spikes plant -1 .The number of spikes plant -1 showed similarity (P>0.05) when corms were planted on 16 th April and 1 st May as well as between 2 nd March and 1 st April sowing.[14] Reported that apart from the varietal influence on the number of spikes plant 1 , the sowing data also had significant impact on spikes number in gladiolus it is suggested that there should be an effective role of extension workers to train the farmers for sowing of ornamental plants at proper sowing time.

Number of corms plant -1
Generally, flower yield in gladiolus is considerably influenced by the corms plant -1 and apart from the effect of inputs; the sowing time also influences this gladiolus plant trait.The data pertain in to corms plant - 1 in gladiolus are tabulated as (Table 8), indicates that gladiolus planted on 1 st April produced highest corms number plant -1 (1.5) and the number of corms decreased to 1.3 and 1.05 plant -1 when the planting was carried out late on 16 th April and 1 st May, respectively.Similarly, the early planting of gladiolus on 17 th March and 2 nd March produced 1.47 and 1.2 corms plant -1 , respectively.This indicates that the period from second fortnight of March and up to 1 st week of April could be considered as the optimum planting time of the gladiolus so far, the corms plant -1 are concerned.Planting earlier than mid-March or later than first week of April caused decrease in the number of corms plant -1 over the suggested optimum planting period.The results also show that the gladiolus planted earlier than optimum planting time may suffer a little as regards the corms plant -1 ; but delayed in planting over optimum period would harshly decrease the corms plant -1 .

Diameter of corms (cm)
Generally, the corm size inherits from the parental material; but crop management and the applied inputs also influence this trait of gladiolus.The impact of planting dates on the diameter of corms in gladiolus was investigated and the relative data are presented in (Table 9).The average corm diameter was maximum (6.9 cm) in gladiolus plantation sown on 17 th March, followed by corm diameter of 6.7 and 6.5 cm observed in plots sown on 1 st April and 2 nd March, respectively.A considerable reduction in corm diameter (5.5 cm) was seen when gladiolus corms were sown on 16 th April; while the least corm diameter of 4.8 cm was observed in plots planted on 1 st May.It is evident from the findings that gladiolus planted in the last fortnight of March up to first week of April maximally favored corm development, while the delay in planting up to second week of April and onwards resulted in a severe adverse effect on corm diameter of gladiolus.However, early sowing in first week or first fortnight of March slightly affected the diameter of corm in negative direction, while sowing in the second fortnight of March resulted in a maximum positive impact on diameter of gladiolus corms.Hence, planting gladiolus corms too late may not grow vigorously to produce healthy corms; but early planting did not result irrecoverable loss to this character.LSD test indicated that although, the diameter of corm differed significantly (P<0.05)among all the planting dates; but diameter of corm planted on 17 th March overlaps 1 st April planting (P<0.05).The findings of the present investigation are further supported by those of Adil et al. (2013) who reported that corm diameter decreased with to delay or too early in planting of gladiolus; while [33] Concluded that corm size was significantly affected by the sowing time.

Number of corm lets plant -1
The effect of planting time on number of corm lets plant -1 in gladiolus was scrutinized and relative data are given in (Table 10), indicates that cormlets number was highest (22.95 plant -1 ) in gladiolus plantation sown on 1 st April, closely followed by 17 th March planting of gladiolus with 22.65 number of cormlets plant -1 ; while 2 nd March planting of gladiolus caused 20.95 cormlets plant -1 .Likewise, the gladiolus late planting on 16 th April resulted in decreased number of cormlets (18.95 plant -1 ); while the least number of cormlets (16.10 plant -1 ) was recorded in gladiolus plantation (1 st May sowing date).The results indicated that apart from the 17 th March and 1 st April sowing, all other sowing dates resulted in a considerable reduction in the number of cormlets plant 1 .Planting earlier than third week of March or later than first week of April caused a severe reduction in the number of cormlets plant -1 over the optimum planting time.Moreover, it was observed that early planting did not show greater adverse effects on this trait but planting gladiolus later than first week of April caused irrecoverable loss to the number of cormlets plant -1 .The number of cormlets plant -1 showed similarity (P>0.05) when corms were planted on 17 th March and 1 st April as well as between 2 nd March and 16 th April sowing.These results agree with those of [14] Concluded that cormlets decreased in gladiolus with delayed sowing; while [29] Experienced that in early sown gladiolus, the cormlets were lower than the optimum sowing time.

Corm weight
Corm weight has linear effect on the gladiolus flower production in commercial sense.The impact of sowing time on weight of corms of gladiolus was investigated and relative data are shown in (Table 11).The average corms weight was highest (116.56g) in gladiolus when planted on 17 th March, closely followed by weight of corm (111.62g) in plots planted on 1 st April.A considerable reduction in weight of corms i.e., 101 g and 82.90 g was seen when the gladiolus corms were planted on 2 nd March and 16 th April, respectively.Conversely, the least corm weight (75.45 g) was recorded in 1 st May planting.It can be assumed from the results that gladiolus planted in March and up to first week of April showed positive impact on the weight of corms; while there was negative effect on the corm weight when planted after second week of April and onwards.It can be seen that early sowing only resulted in a slight adverse impact on the weight of corm; but late sowing resulted in a severe loss to corm weight.The LSD test describes that although weight of corm was statistically similar (P>0.05) between 17 th March and 1 st April planted gladiolus; while differences were significant when these treatments were compared with rest of the treatments.[33] Reported that the gladiolus plants sown at proper sowing temperature produced healthier corms than early of delayed sowing, while [29] Experienced a negative effect of delayed planting of gladiolus on corm weight.
May Observation recorded Days taken to sprouting Number of leaves plant -1 Plant height (cm) Number of florets spike -1 Days taken to first florets opening Floret size (cm) Spike plant -1 Number of corms plant -1 Diameter of corm (cm) Corm lets plant -1 Corm weight

Table 11 : Weight of corms (g) of gladiolus under the influence of different planting dates
Conclusion and RecommendationsIt was concluded that most of the gladiolus plant traits showed their best performance when planted on 17 th March and 1 st April, suggesting that gladiolus planting in third week of March and first week of April could be an optimum planting time of gladiolus under agro-ecological conditions of Quetta, Balochistan.In the present study17th March and 1st April of sowing date performed better for all the better sowing date of gladiolus under the on agro-climatic condition.Therefore, it is recommended for the farmers of Quetta to sow 17th March and 1st April sowing date to get yield under agro-climatic condition.However, further study in needed to sowing gladiolus flower under different sowing dates to validate the results of the present study