Research Article
Determination of Yield and Yield Components of Some Cotton Cultivars in Semi Arid Conditions
Department of Field Crops, Faculty of Agriculture, Harran University, 63040 anliurfa-Turkey
Cotton is widely grown in semi-arid and arid zones of the world (Wang et al., 2004). Harran plain is located in the Southeast of Turkey, which is a semi arid area. Cotton is an important cash crop for the farmer and textile industry Southeast area. Turkey is the seventh cotton growing country in the world, after China, the USA, India, Pakistan, Brazil and Uzbekistan, producing 821,000 tons or 3% of the annual lint cotton in the world (Anonymous, 2005). In Turkey, cotton (Gossypium hirsutum L.) is grown on about 635, 000 ha or 3% of the arable land. Approximately 400,000 rural families are involved in the cultivation of cotton, illustrating the economic and social significance of this crop.
For economical cotton production, cultivar use as well as cultural practices for the region is very important. There are several breeding methodologies for cotton cultivar development. Plant introduction is one of the first applicable breeding strategies in the development of new cultivars for the specific region. Plant introduction usually requires adaptation studies, determination of plant characteristics and yield potential. Therefore, preliminary information is gathered about the candidate cultivar and cultivar release (Çopur and Oğlakçı, 1997).
In recent years, the liberation of the seed market resulted in the introduction of a large number of cotton cultivars into Turkey from which the cotton growers had to choose one, a difficult decision indeed. Moreover, genotype expression is affected by the environment, limiting realization of the full genetic potential and making empirical evaluation more difficult (Bradow and Bauer, 1998).
For a long time, breeders have recognized a negative association between yield and fiber strength and have tried hard to break it (Green and Culp, 1990). In a study of six diverse cotton genotypes, complex linkages between lint yield and fiber strength and length were confirmed and elucidated (Coyle and Smith, 1997; Smith and Coyle, 1997). Soil properties such as water content, porosity, aeration, aggregation and fertilization can affect yield and fiber properties (Sawan et al., 2001; Gormus, 2002; Avgoulas et al., 2005).
In previous studies, the yield and adaptation of different varieties of cotton were investigated and results varied widely. Seed cotton yield varied between 2007. 2-5175.7 kg ha1, plant height were 65.2 to 101.3 cm, earliness ratio 65 to 90%, number of sympodial branch 11 to 22 number plant1, number of bolls were 10.1 to 14.2 number plant1, fiber percentage 37 to 42%, fiber length 26.2 to 30.5 mm, fiber fineness 3.80 to 5.06 micronaire and fiber strength 25 to 40 g tex1 (Gençer et al., 1992; Karademir et al., 2003; Basbag and Temiz, 2004; Wang et al., 2004; Ogur et al., 2005).
The aim of this study was to compare yield and fiber quality of the fifteen cotton cultivars under semi arid agro-environmental conditions and determination of the most suitable cotton varieties in Southeast Anatolia Region of Turkey.
This study was conducted at Harran Universitys experimental area during 2000 and 2001 growing seasons. The experimental field is located in Harran Plain, Southeast of Turkey, where the climate varies from arid to semi-arid. Altitude for the area is 465 m and latitude and longitude are 37°08 North and 38°46 East, respectively. Mediterranean and East Anatolian climates are generally dominant. The average annual temperature is 18.2°C, rainfall is 463.1 mm and the average relative humidity is about 49%. The average maximum temperature could be as high as 33.3°C in July and August while the lowest average can be 3°C in December and January. The earliest frost in the region is usually at the end of October and last frost around third week of April. Most of the rainfall in winter and there is no rainfall from July to September. The highest humidity (69%) occurs in winter and the lowest (28%) in summer time (Anonymous, 2003). Since most of the rain falls between October and April, cotton was irrigated every 7-10 days in average between May and September.
The soil of the experimental area was clay (40%) in the 0-120 m soil profile. Field capacity of the soil was 33.8% in dry basis. Permanent wilting point was 22.6% and bulk density of the soil was 1.41 g cm3. The soil was low in organic material and phosphorus (Anonymous, 2002).
Fifteen cotton varieties were used as a plant material in this research. The cultivars, their species and origins are shown in Table 1.
The experimental plots were arranged in a randomized complete block design with three replications. Seed was sown by experimental mechanical planter in four rows plots with row spacing 0.7 m apart. Intrarow spacing and row length were 0.2 and 12 m, respectively. Sowing date was April 30, 2000 and May 3, 2001. 70 kg ha1 pure nitrogen and 70 kg ha1 pure phosphorus at planting and 90 kg ha1 pure nitrogen at the beginning of flower were applied, while K2O was not applied due to its abundance in soil. Plants were hoed two times by hand and three times by tractors. All plots were grown under irrigated conditions. Cultural inputs applied were consistent with agronomic practices. Pest control was carried out according to the local standard.
Table 1: | Cotton cultivars belonging to G. hirsutum L. and G. barbadense L. and their origins |
The harvest was done by hand two times from 23 September to 21 October 2000 and from 30 September to 24 October in 2001. Before harvesting, 1 m was left in each parcels top and bottom and 1 row was left as side effect from each side of every plot.
In the study, seed cotton yield (kg ha1), first harvest ratio (%), plant height (cm), number of sympodia, (number plant1), number of boll (number plant1), ginning percentage (%) as agronomical characteristics; fiber length (mm), fiber fineness (micronaire) and fiber strength (g tex1) as fiber technological properties were investigated. Fiber technological properties were determined by using the HVI (High Volume Instrument) 900-A in the laboratories of Şanlıurfa Exchange. Data were analyzed according to randomized complete block design for each year with MSTAT-C statistic program and cultivars were compared by LSD (Least Significant Difference) test.
Seed cotton yield: Differences among the cultivars with respect to the seed cotton yield were significant for each year and over both years. The average seed cotton yield was 3119.1 kg ha1 in 2000 and 3062.4 kg ha1 in 2001. Averaging value was 3090.73 kg ha1. The highest seed cotton yield was obtained from Stoneville 453 that was followed by Sayar-314 in 2000 and in the second year again. Stoneville 453 produced the highest yield and followed by Sayar-314, DPL-5409 and Condor cultivars. Averaged over two years, Stoneville 453 (4077.93 kg ha1) had the highest seed cotton yield, followed by Sayar-314. It was not seen another genotype which passed the regions check varieties Stoneville 453 and Sayar-314, respectively (4077.93 and 3710.72 kg ha1). The lowest yields were obtained from Giza-75, Brown Cotton Line, Mc Namara (Table 2). Cotton yield showed differences among cultivars and years and it was lower in 2001. One of the reasons was that the climate and soil condition were not similar in both year. Also, the first week in May 2001, after seeding, the lower temperature affected the early growth of cotton.
First Harvest Ratio (FHR): Differences among the cultivars with respect to FHR for each year and over both years were significant (Table 2). The average FHR was 81.33% in 2000, 85.07% in 2001 and the two years average value was 83.19%. The highest FHR was obtained from N-727 in 2000 and it was followed by Condor, Luisa, Lachata and OFN-7 respectively. In 2001, Lachata produced the highest FHR and this was followed DPL-5409, Luisa, N-727 and DPL-90. Averaged over the two years, Lachata (91.88%) produced the highest FHR, followed N-727, Luisa, and Condor. Some researchers reported similar results (Gencer et al., 1992; Mert and Caliokan, 1999). FHR results showed that silk cotton, which is more expensive and mainly imported, could be produced in Turkey (Efe et al., 2004). The lowest FHR were obtained from Giza-75, Mc Namara, Sayar-314 and Stoneville 453 (Table 2). FHR showed differences among cultivars and years and it was lower in 2000. One of the reasons was that the climatically condition changing year by year. Also, Condor, Lachata, Luisa and N-727 varieties were originated from Spain and Australia and they were developed for short growing period. For that reason, these varieties were produced high earliness ratio.
Furthermore, DPL 5409 and DPL 90 varieties were affected by high temperature and bolls were opened early. In addition to this, DPL 90 and DPL 5409 varieties are not hairy and they were affected by Emposca sp. resulting in early maturity due to stress. Luisa, Condor, N-727 and Lachata varieties could be used as parent in breeding program for first harvest ratio.
Plant height: The plant height of the cotton cultivars are presented in Table 3. Differences between the cultivars with respect to the plant height were found significant for each year and average of these years. The average plant height was 82.73 cm in 2000, 78.74 cm in 2001. The average of two years was 80.74 cm.
Table 2: | The average seed cotton yields (kg ha1) and first harvest ratio (%) for the cultivars and LSD groupings |
*: Means shown with the same letter(s) in the same column are not significantly different at p = 0.05 probability level |
Table 3: | The average plant height (cm) and number of sympodial branch (plant1) with LSD groupings for the cultivars |
*: Means shown with the same letter(s) in the same column are not significantly different at p=0.05. §: (n p1) number plant1) |
The highest plant height was belong to Giza-75 in 2000 and were followed by Delcerro and OFN 7. In 2001, Giza-75 had the highest plant height and this was followed by Delcerro, OFN 7 and Mc Namara. Averaged over the years, Giza-75 (116.70 cm) had the highest plant height, followed by Delcerro, OFN 7 and Mc Namara, respectively. The lowest values were obtained from Luisa, DPL-5409, DPL-90, Condor and Lachata (Table 3). Differences observed for plant height among the cotton varieties were probably related to genetic variation and ambient conditions. Giza 75, Delcerro and OFN 7 cotton varieties could be used as parent in breeding for plant height.
Number of sympodial branch: From Table 3, sympodia number is very important in order to form yield. For the higher yield more sympodia number desired. It can be realized that the least sympodia number was counted in 2001 (12.21 number plant1), but the most sympodia number was counted in 2000 (12.41 number plant1). Both years and average, Stoneville-453 had the most sympodia number and this was followed by Sayar-314 and Giza 75 and others cultivars had similar results. Stoneville-453 and Sayar-314 were local standard. This situation explains the fact that Giza 75, Stoneville 453 and Sayar-314 cultivars were could be used as parent in breeding for the higher number of sympodial branch.
Number of boll: Number of boll of the cotton genotypes are presented in Table 4. Differences between the cultivars with respect to the number of bolls were found significant for each year and average of these years. The average number of boll was 13.37 (plant1) in 2000, 12.42 (plant1) in 2001 and two years average value was 12.89 (plant1). The highest number of boll value was from Stoneville-453 in 2000, they were followed by Giza-75, Nata and Sayar-314. In 2001, Stoneville 453 and Giza-75 had the highest number of boll and these were followed by Lachata, Sayar-314 and OFN 7. Averaged over two years, Stoneville-453 and Giza-75 had the highest number of bolls, followed consequently by Sayar-314, Nata and OFN-7. The lowest values were obtained from N-727, Mc Namara and Condor (Table 4). Boll number trait is one of the most important yield components. But it is not enough alone for higher yield. For example Giza-75 had lowest seed cotton yield due to having small bolls. Similar situation has also been mentioned on other varieties by Gencer et al., (1992); Efe et al. (2004). This may explain the fact that Stoneville 453, Giza-75 and Sayar-314 cultivars should be used as parent in breeding for higher number of bolls.
Ginning percentage: From the Table 4, there were significant differences between cultivars for each year and average of these years. It has been seen that the highest value of ginning percentage was obtained from DPL-90, followed by DPL-5690, DPL-5409, Luisa and N-727 in 2000. In 2001, the highest value of ginning percentage was obtained from DPL-5690 followed by Luisa, DPL-5409, DPL-90 and N727 and the two years average highest ginning percentage value was from DPL-5690 followed by DPL-90, Luisa, DPL-5409 and N-727. Conversely, these varieties were not high yielding cotton. This case showed that there arent positives relationships between yield and ginning percentage. Our findings were agreement with Wang et al. (2004), but it was not supported by Efe et al. (2004). This may be due to year effect, location difference or use of different cultivars in these studies.
Table 4: | The average number of boll (plant1) and ginning percentage (%) of different cultivars of cotton and statistical groupings |
*: Means shown with the same letter(s) in the same column are not significantly different at p = 0.05 probability level |
Table 5: | The average fiber length (mm) and fiber fineness (mic) of different cultivars of cotton and statistical groupings |
*: Means shown with the same letter(s) in the same column are not significantly different at p = 0.05 |
Fiber length: Fiber length of the cotton genotypes are presented in Table 5. Fiber length was significantly influenced by genotype. Giza-75 and Delcerro varieties had the longest fibers in 2000 and 2001 years and average of these years (Table 5). This result was expected. These results show that long fiber trait of silk cotton wasnt lost in the semi arid environmental conditions, which is highly remarkable observation. But fiber length values of others varieties (except Mc Namara and Brown color line) have marketable values in spinning industry. Fiber length depends on genotype but is also affected by environmental and cultural practices. Previous studies reported that fiber length could vary widely with plant variety and growing conditions (Bradow and Davidonis, 2000; Cagirgan and Barut, 2000). Giza-75 and Delcerro had low seed cotton yield, but these varieties should be used as parent in breeding for longer fibers.
Fiber fineness: Differences between the cultivars with respect to the fiber fineness were found significant for each year and average of these years (Table 5). The average fiber fineness was 4.52 micronaire in 2000, 4.82 micronaire in 2001 and the two years average value was 4.67 micronaire. The highest fiber fineness value was from N-727 in 2000, they were followed by DPL-5690 and Giza-75. In 2001, Giza-75 yielded the highest fiber fineness and this was followed by Delcerro, OFN 7. Averaged over two years, Giza-75 (4.10 mic.) had given the highest fiber fineness, followed consequently by Delcerro, and N-727. The coarsest values were obtained from DPL-90, Brown Color Line, Sayar-314 and Condor (Table 5). Heerden et al., 1989 reported that fiber fineness can vary according to genotypes and ecological conditions in different years and significant interactions were found between genetic additive variance and environmental variability for fiber fineness, fiber strength and fiber length (Tang et al., 1996).
Table 6: | The average fiber strength (g tex1) of different cultivars of cotton and statistical groupings |
*:Means shown with the same letter s) in the same column are not significantly different at p = 0.05 |
However, when Giza-75 and Delcerro are produced in the Southeast environmental conditions its fine fiber which is required by textile industry will be conserved and these cultivars should be used as parent in breeding for fiber fineness.
Fiber strength: Means for fiber strength of the varieties and arisen groups were given in Table 6. When looking at the results of fiber strength for two years, it was obvious that varieties were significantly different. These differences were correlated with genotype only (Green and Culp, 1990; Smith and Coyle, 1997). Delcerro variety had the highest fiber strength in both of years and the two years average. Except Brown Color Line, all cotton cultivars were in very strong class (28-35 g tex1). Giza-75 and Delcerro were given low seed cotton yield, but these varieties were should be used as parent in breeding for fiber strength.
As concluding remarks, it was not seen another genotype which passed the regions standard varieties Stoneville-453 and Sayar-314, but Giza-75 and Delcerro kept its long, fine and strong fiber characters under the Southeast Anatolian regions ambient conditions. However it was determined that Giza-75 and Delcerro had lower seed cotton yield compared to standard varieties. Although these cultivars are low yielding, they could be grown due to higher fiber quality characteristics. For this reason, economical analyses should be done to compensate yield vs. quality for these cultivars to make suggestions about growing these cultivars in Harran Plain.