Adaptability performance of cotton hybrids under dry conditions of Zimbabwe

1. Int. J. Agron. Agri. R. International Journal of Agronomy and Agricultural Research (IJAAR) ISSN: 2223-7054 (Print) 2225-3610 (Online) http://www.innspub.net Vol. 26, No. 2, p. 10-18, 2025 OPEN ACCESS OPEN ACCESS OPEN ACCESS RESEARCH PAPER OPEN ACCESS Adaptability performance of cotton hybrids under dry conditions of Zimbabwe Mare Marco*1 , Mubvekeri Washington2, Chingwara Victor2, Kutywayo Dumisani3 1Cotton Research Institute (CRI), Kadoma, Zimbabwe 2Department of Crops Research (CRD) 3Agricultural Research, Innovation and Specialist Services (ARISS) Article published on February 05, 2025 Key words: Hybrids, OPVs, Adaptability, Cotton yield Abstract Cotton (Gossypium hirsutum L.) is one of the most prominent and important industrial crops in Zimbabwe. Cotton production is largely practiced by smallholder farmers in Zimbabwe with an average of one hectare for every farmer. Production is mainly done in averagely drier parts of the country with considerably high temperatures and rainfall amounts averaging 500mm per annum (AMA Cotton Country Report, 2022). The adverse effects of climate change have raised concerns regarding the cotton sector's performance in the near future. However, to ascertain the significance and potential of hybrids in Zimbabwe, confirmatory tests were conducted to proffer knowledge that is critical for informed decision-making regarding the commercialization of cotton hybrids in Zimbabwe. Therefore, a two-year (2022 and 2023) multi-locational adaptability experiment to determine the performance of cotton hybrids was conducted. The experiment was carried out at seven locations following a Randomised Complete Block Design (RCBD) replicated three times. Included were seven OPVs and four hybrids. Significant differences in seed cotton yield mean performance were only realized at Svisvi P=0.002 and Kuwirirana P=0.007. An across-site and season analysis did not reveal any significant differences in yield. CRIMS1, Jaguar, and C569 recorded more bolls per plant, whilst all OPVs recorded significantly high ginning percentages over hybrids, and a similar trend was recorded on boll weight. The results hence indicate the need to support the production of locally adaptable Open Pollinated Varieties which is a response to import substitution since the hybrids are imported products. * Corresponding Author: Mare Marco  marcomare82@gmail.com Marco et al. Page 10

2. Int. J. Agron. Agri. R. Introduction rainfall analysis (Fig. 2). The government of Zimbabwe Cotton (Gossypium hirsutum) is an important crop intervened in 2015 through the introduction of the because of its global and valuable contribution to Presidential Input Scheme to revive the cotton sector many economies worldwide. The crop is dominant in (COTTCO, 2023). The declining trend has however been Zimbabwe as the second most important cash crop a great concern in the sector and led to some players in after tobacco. Cotton production in Zimbabwe is the sector introducing cotton hybrids in 2017 from predominantly constituted and driven by small-scale Maharashtra Hybrid Company (MAHYCO) of India, farmers and is chiefly rainfed. Since immemorial expecting a positive change in the production and times, the cotton sector in Zimbabwe has been productivity trend. dominated by open-pollinated variables (OPVs) due to their adaptability and superior performance under dryland conditions. The cotton sector in Zimbabwe recorded an average annual production of 198357.3 metric tons and an average yield of 669kgha-1 over 23 years (Fig. 1) (AMA 2022 Report) whilst the industrial crop’s global production in 2020 was 121.3 million bales (USDA, 2021). Fig. 2. Five year rainfall analysis from 2019 – 2023 Cotton hybrids were regarded as highly productive and profitable by some players who posed notions that they produced 120 bolls per plant with the potential to yield 11 tonnes of seed cotton per hectare against 30 bolls per plant for Zimbabwean Open Pollinated Varieties (OPVs), (The Herald, Zimbabwe, 11 June 2019). The performance details were based on Fig. 1. Production figures (Mt) from 2000 to 2022 the hybrids' performance in India and not in Zimbabwe. This means there was the need to perform The Zimbabwean cotton sector has an expected role confirmatory tests to proffer knowledge that is critical to play and contribute to the attainment of Vision for informed decision-making regarding the 2030 through strategies for improved production and commercialization of cotton hybrids in Zimbabwe, productivity. According to the COTTCO report, cotton putting into consideration that cotton hybrids have provides livelihoods to 2 million households country- not been traditionally grown in Zimbabwe. Therefore, wide, also offers employment to over 3000 people the Cotton Research Institute conducted a two-year and the country earns between US$30 –US$60 (2022 and 2023) multi-locational adaptability million foreign currency from lint exports annually. experiment to determine the performance of cotton The decline in cotton production since 2012 from hybrids under different agroecological conditions in 350703Mt (Fig. 1) has negatively affected the Zimbabwe. The experiments were carried out under performance of the cotton value chain. The dryland conditions, a real prototype, and deterioration in cotton production over the years was predominantly cotton-growing conditions in linked to many factors and among them, high cotton Zimbabwe. production costs, droughts, inadequate and late Materials and methods supply of inputs, low producer prices, viability issues, The experiment was conducted at different locations and climate change characterized by low rainfall (Table 1, Fig. 3) over two seasons; 2021/22 and leading to many farmers neglecting the crop 2022/23 seasons (COTTCO, 2023). This is indicated by a five-year Marco et al. Page 11

3. Int. J. Agron. Agri. R. Table 1. Experimental locations and their details Location Chitekete CRI Kuwirirana Matikwa Dande Tokwane Wozhele Source: AGRITEX planning branch: Zimbabwe natural regions and farming areas boundaries Latitude 17o25' South 18o19' South 17o54' South 20o48' South 16° 16' South 20o 51' South 19o31' South Longitude 28° 56' East 29o 53' East 29o1' East 32o14' East 31o34' East 31o 3' East 30o14' East Altitude (m) Av. annual rainfall (mm) Max temp°C 914 450-500 1156 750-1000 1483 500-600 300 450-500 436 450-500 1105 350-650 1345 650-700 45 38 38 40 42 37 37 Table 2. Cotton genotypes used in the multi-locational trials Treatment CRIMS 3 CRIMS 4 CRIMS 1 CRIMS 2 LS9219 MAHYCO C567 MAHYCO C569 MAHYCO 571 QM301 SZ 9314 Jaguar Description Government of Zimbabwe Open Pollinated Variety (OPV) - Check variety Government of Zimbabwe OPV - Check variety Government of Zimbabwe OPV - Check variety Government of Zimbabwe OPV - Check variety Government of Zimbabwe OPV - Check variety Indian Test Hybrid Indian Test Hybrid Indian Test Hybrid Quton OPV - Check variety Government of Zimbabwe OPV - Check variety Indian Test Hybrid Variance (ANOVA) were generated to account for variations brought about by genotype (entry), environment (location), and interaction between genotype and environment, as appropriate, across sites and seasons. Plot size a. Gross plot : 4 rows × 1m × 5m=20m2 b. Net Plot : 2rows × 1m × 4m=8m2 c. In-row spacing : 0.3cm d. Inter-row spacing: 1m Fig. 3. Experimental locations Measurements Seed cotton yield (kg) Experimental treatments Also known as the total seed cotton yield was Experimental genotypes used in the experiment recorded per net plot. This was a collection of all included Mahyco commercial hybrids and harvested fully split bolls which included bolls Zimbabwean released commercial OPVs (Table 2). samples, pick one, two, three and so on. Experimental design and data analysis Gin Out-Turn (GOT %) Randomised Complete Block Design (RCBD) with Also known as ginning percentage is sub-sample three replications was used. Genstat 18th Edition (approximated 1 kg) from each plot ginned (lint statistical package was used to generate an Analysis and seed). Ginning percentage, calculated as (100 of Variance and Means per site and across sites for × lint weight)/(weight of lint +seed + trash), and is all the measurements recorded. Statistical means (within and across trial sites) were calculated for used to convert seed cotton yield to lint yield the recorded parameters’ data. Analyses of (Watts et al., 2014). Marco et al. Page 12

4. Int. J. Agron. Agri. R. Boll weight (g) Average weight of seed cotton from a single undamaged boll calculated from a 50 or 100 boll sample taken from each plot prior to second pick (large values desirable). This is calculated as the total weight of a sample divided by sample size. Number of bolls per plant Number of bolls per plant was recorded as a total count of all harvestable bolls from 5 randomly selected plants in the net plot. The total number of bolls from the sample area and is divided by number of plants in the sample area. Results Seed cotton yield Significant differences were only at Svisvi and Kuwirirana, thus P=0.002 and P=0.007 respectively (Table 3). Svisvi recorded a grand mean performance of 862.6kg/ha whilst 1518.4kg/ha. Mahyco C567 recorded the highest mean at Svisvi (1455.5kg/ha), though similar to CRIMS 2 (1310kg/ha) whilst LS9219 and SZ-9314 recorded the lowest mean performance of 495kg/ha and 556.9kg/ha respectively. At Kuwirirana, Mahyco C569, CRIMS 1, and Jaguar recorded the highest means of 1719.2kg/ha, 1748.8kg/ha, and 1717.5kg/ha respectively (Table 3). Though no significant differences were recorded for Chitekete and Dande recorded the highest grand means of 2878.9kg/ha and 2283.8kg/ha respectively (Table 3). An across- site analysis (2021/22 season) revealed significant differences (P=0.040) (Table 7), with a grand mean record of 1483.65kg/ha. Mahyco C567 recorded the highest yield mean of 1651.23kg/ha, which was also statistically similar to Mahyco C569 (1588.23kg/ha), CRIMS 2 (1531.42kg/ha), Jaguar (1518.76kg/ha), CRIMS 1 (1515.60kg/ha) (1476.47kg/ha). A combined analysis (2022 & 2023) did not record significant differences (Table 8). and CRIMS 3 Kuwirirana recorded Table 3. Performance of Mahyco hybrids for total seed cotton yield (kg/ha) Treatment name CRIMS 3 CRIMS 4 CRIMS 1 CRIMS 2 Jaguar LS9219 C567 C569 QM301 SZ 9314 Grand Mean P. Value LSD 5% SED CV% Table 4. Performance of Mahyco hybrids for boll number per plant Seed cotton yield (kg/ha) Chitekete CRI 21.00 5.50bc 17.75 4.00ab 16.00 4.00ab 18.75 4.75ab 22.75 7.00c 17.00 3.25a 21.00 4.75ab 20.25 7.50c 18.75 3.25a 18.75 4.75ab 19.20 4.88 0.429 0.005 5.818 2.214 2.835 1.079 20.9 31.3 Chitekete 3080.3 2614.1 3228.8 2775.3 3222.2 2990.3 2825.3 2616.9 2519.7 2916.2 2878.9 0.549 779.55 379.93 18.7 CRI 446.7 282.4 337.3 543.9 688.8 307.0 359.5 516.2 217.7 268.1 403.4 0.500 8.701 4.233 31.1 Chitekete 21.00 17.75 16.00 18.75 22.75 17.00 21.00 20.25 18.75 18.75 19.20 0.429 5.818 2.835 20.9 CRI 5.50bc 4.00ab 4.00ab 4.75ab 7.00c 3.25a 4.75ab 7.50c 3.25a 4.75ab 4.88 0.005 2.214 1.079 31.3 Chitekete 21.00 17.75 16.00 18.75 22.75 17.00 21.00 20.25 18.75 18.75 19.20 0.429 5.818 2.835 20.9 CRI 5.50bc 4.00ab 4.00ab 4.75ab 7.00c 3.25a 4.75ab 7.50c 3.25a 4.75ab 4.88 0.005 2.214 1.079 31.3 Treatment name CRIMS 3 CRIMS 4 CRIMS 1 CRIMS 2 Jaguar LS9219 C567 C569 QM301 SZ 9314 Grand mean P. Value LSD 5% SED CV% Boll number per plant Matikwa Tokwane 649.0 665.8 860.3 653.6 479.5 659.2 686.5 707.1 672.8 596.6 663.0 0.438 268.55 130.88 27.9 Chitekete 21.00 17.75 16.00 18.75 22.75 17.00 21.00 20.25 18.75 18.75 19.20 0.429 5.818 2.835 20.9 CRI 5.50bc 4.00ab 4.00ab 4.75ab 7.00c 3.25a 4.75ab 7.50c 3.25a 4.75ab 4.88 0.005 2.214 1.079 31.3 Dande 985.0 837.5 865.0 956.3 577.3 886.1 984.8 926.2 868.8 839.7 872.7 0.104 251.01 122.33 19.8 Wozhele 684.4 652.8 542.1 673.9 611.6 612.5 702.1 580.6 746.0 720.0 652.6 0.876 272.04 132.58 28.7 Svisvi 275ab 352.9abc 289.4ab 530.8cd 254.7ab 198.1a 539.3d 338.3ab 398.8bcd 229.6ab 340.7 0.005 183.29 89.33 37.1 Kuwirirana 603.3abc 597.3abc 767.7d 676.4cd 546.9ab 606.3abc 632.8abc 673.6bcd 524.9a 542.9a 617.2 0.017 127.44 62.11 14.2 309.1 369.1 310.0 308.1 197.5 301.1 307.4 302.2 369.1 299.6 307.3 0.206 112.00 54.59 25.1 Marco et al. Page 13

5. Int. J. Agron. Agri. R. Number of bolls per plant number of bolls (15.5 bolls). Based on results Significant differences were recorded at CRI, obtained across sites during the 2021/22 season, a Dande, Kuwirirana, and Wozhele (Table 4). Dande grand mean of 16.56 bolls was recorded upon a recorded the highest number of bolls per plant realized statistically different genotypic mean (32.3) followed by Chitekete which recorded 19.20 performance (P<0.001). Jaguar recorded many bolls. CRI recorded the least number of bolls (4.88 bolls per plant (20.38 bolls), followed by Mahyco bolls). At Dande, CRIMS 1 and Mahyco C569 C569 and CRIMS 1 which recorded 18.56 and 18.44 recorded the highest number of bolls (50 and 46 bolls respectively. QM301 recorded the least bolls respectively) whilst QM301 recorded the least number of bolls (12.75 bolls). Table 5. Performance of Mahyco hybrids for Gin out turn (%) Treatment name Gin out turn (%) Dande Matikwa 40.1de 40.8de 40.4de 41.0e 29.5a 38.2c 36.0b 35.5b 40.5de 39.8d 38.2 <.001 1.04 0.51 1.9 Svisvi 41.2cde 42.5de 41.7cde 40.3cd 32.0a 40.0c 37.1b 36.9b 43.0e 41.4cde 39.7 <0.001 2.28 1.11 4.0 Chitekete 44.5de 45.0ef 45.3ef 44.6de 33.8a 42.1cd 41.1c 37.6b 47.3f 43.8de 42.5 <.001 2.55 1.24 4.1 CRI 44.4 46.4 31.0 45.5 35.6 41.7 40.9 39.3 37.2 42.1 40.4 0.181 11.13 5.41 18.9 Tokwane 41.7d 41.2cd 40.6bcd 42.1d 29.9a 38.2bc 37.8b 37.7b 42.5d 43.3d 39.5 <.001 3.01 1.47 5.3 Wozhele 44.1cd 43.8cd 43.7cd 45.8d 36.6a 40.8abc 42.5bcd 38.3ab 44.9cd 44.2cd 42.5 0.005 4.58 2.23 7.4 Kuwirirana 43.8efg 42.5de 44.0fg 43.2def 31.9a 41.0c 38.7b 37.6b 44.7g 42.5de 41.0 <.001 1.33 0.65 2.2 CRIMS 3 CRIMS 4 CRIMS 1 CRIMS 2 Jaguar LS9219 C567 C569 QM301 SZ 9314 Grand Mean P. Value LSD 5% SED CV% 43.6ef 43.2def 43.7ef 42.4de 31.8a 41.2cd 39.6c 36.5b 46.1g 45.2fg 41.3 <.001 2.30 1.12 3.8 Table 6. Performance of Mahyco hybrids for Boll weight (g) Treatment name Boll weight (g) Tokwane 5.1b 5.8bc 5.7bc 6.0c 4.3a 5.2b 5.2b 5.4bc 5.7bc 5.5bc 5.4 0.005 0.75 0.37 9.6 Chitekete 6.2de 5.7bcd 6.4e 5.7bc 4.1a 6.3e 5.3bc 5.3b 5.8cd 6.2de 5.7 <.001 0.52 0.25 6.2 CRI 6.0 4.8 5.3 5.7 4.8 5.1 5.2 5.7 4.8 5.7 5.3 0.844 1.82 0.88 23.5 Dande Kuwirirana 5.9bc 5.9bc 5.7bc 5.6b 4.2a 6.0bc 5.6b 5.8bc 6.1c 5.8bc 5.7 <.001 0.46 0.23 5.7 Wozhale 5.7bc 5.6bc 5.6bc 5.4abc 4.5a 5.7bc 6.2c 5.1ab 6.0c 5.8bc 5.6 0.040 0.89 0.43 11.0 Svisvi 6.0bc 6.1bc 6.1bc 6.1bc 4.8a 5.7b 6.2bc 5.7bc 6.6c 6.3bc 6.0bc 0.027 0.90 0.44 10.5 Matikwa 5.3bc 5.7c 5.6c 5.3bc 3.6a 5.7c 4.9b 5.3bc 5.6c 5.3bc 5.2 <.001 0.57 0.28 7.5 CRIMS 3 CRIMS 4 CRIMS 1 CRIMS 2 Jaguar LS9219 C567 C569 QM301 SZ 9314 Grand Mean P. Value LSD 5% SED CV% 6.1bc 6.6d 6.4cd 5.9b 4.5a 6.4cd 5.8b 5.9b 6.4cd 6.5d 6.0 <.001 0.32 0.16 3.7 Gin out turn (42.5%), CRIMS 1 (41.7%) and SZ-9314 (41.4%). The ginning percentage revealed significant Jaguar recorded the lowest mean performance of differences for all locations except CRI (Table 5). 32%, as well as Mahyco C567 and Mahyco C569 Chitekete and Wozhele recorded the highest grand (37.1% and 36.9% respectively). At Chitekete, mean performance of 42.5% whilst Dande recorded QM301 recorded the highest ginning percentage of the least performance of 38.2%. High means were 47.3%, whilst SZ-9314, CRIMS 1, CRIMS 2, CRIMS recorded at Svisvi for QM301 (43%), CRIMS 4 3 and CRIMS 4 recorded ginning percentages Marco et al. Page 14

6. Int. J. Agron. Agri. R. between 43.8% and 45.3% whilst Jaguar and An across-site analysis (2021/22 season) revealed Mahyco C569 recorded the least percentage of significant differences (P<0.001) (Table 7), CRIMS 4 33.8% and 37.6% respectively. and CRIMS 2 recorded the highest percentage of 43.18% and 43.11% respectively though similar to Dande showed the same trend whereby Jaguar CRIMS1, SZ9314, QM301, and CRIMS 3. Mahyco recorded the lowest percentage of 29.5%, whilst hybrids recorded the least with Jaguar recording Mahyco C567 and C569 recorded 35 and 36% against 32.66%, C569 recording 37.44% and C567 recording the performance of between 38.2% and 41%. 39.20%. Table 7. Key performance data on total seed cotton yield and related components of Mahyco hybrids evaluated at eight sites during the 2022/23 season Entry Seed cotton yield (kg/ha) Av. 1515.60abc 1531.42abc 1476.47abc 1388.74a 1518.76abc 1436.93ab 1651.23c 1588.23bc 1377.95a 1351.21a 1483.65 26.0 189.632 0.040 <.001 0.365 Average boll number per plant Av. 18.44de 16.56 cd 16.25c 15.41bc 20.38e 13.97ab 16.12c 18.56de 12.75a 17.16cd 16.56 25.0 2.037 <.001 <.001 <.001 Average boll weight (g) Av. 5.86cd 5.58bcd 5.87cd 5.84bcd 4.44a 5.77bcd 5.54bc 5.51b 5.76bcd 5.90d 5.61 11.5 0.318 <.001 <.001 0.139 Gin out turn % Av 42.58e 43.11e 42.93e 43.18e 32.66a 40.41d 39.20c 37.44b 43.44e 42.79e 40.77 5.5 1.113 <.001 <.001 0.022 CRIMS 1 CRIMS 2 CRIMS 3 CRIMS 4 Jaguar LS9219 MAHYCO C567 MAHYCO C569 QM301 SZ 9314 Grand Mean CV (%) LSD (5%) Genotype (G) Environment (E) GXE Table 8. Key performance data on total seed cotton yield and related components of Mahyco hybrids at five sites over two seasons (2021/22 and 2022/23 seasons) Entry Seed cotton yield (kg/ha) Plant height (cm) Av. 1980.44 1950.81 2024.93 1854.68 1880.40 1823.40 2046.01 1936.35 1932.79 1708.89 1912.26 1914.38 29.4 359.205 0.482 <.001 0.740 Gin out turn % Av. 43.04ef 43.51ef 43.26ef 43.37ef 32.38a 40.47d 39.01c 37.56b 41.34d 43.75f 42.66e 41.35 4.2 1.115 <.001 <.001 0.082 Boll weight (g) Av. 6.01d 5.82bcd 6.00d 5.78bcd 4.39a 6.04d 5.52b 5.68bc 5.76bcd 5.85cd 6.08d 5.78 10.4 0.385 <.001 <.001 0.770 Av. CRIMS 1 CRIMS 2 CRIMS 3 CRIMS 4 Jaguar LS9219 MAHYCO C567 MAHYCO C569 MAHYCO C571 QM301 SZ 9314 Grand Mean CV (%) LSD (5%) Genotype (G) Environment (E) GXE 107.19b 107.46bc 113.49c 109.39bc 125.39d 113.02bc 112.19bc 100.27a 109.67bc 107.22b 113.09bc 110.09 11.0 7.750 <.001 <.001 0.568 A season and site combined analysis revealed CRIMS 3, CRIMS 4, and SZ9314 which recorded significant differences (P<0.001) and recorded a 43.75%, 43.04%, 43.51%, 43.26%, 43.36%, and grand mean of 41.35%. High ginning percentages 42.66% respectively. Jaguar, C567, and C569 were recorded for QM301, CRIMS 1, CRIMS 2, recorded the lowest performance; 32.38%, 39.01%, Marco et al. Page 15

7. Int. J. Agron. Agri. R. and 37.56% respectively (Table 8). The results are in however several studies were conducted but focusing disagreement with a study which was conducted to mainly on irrigated conditions. The research findings improve upland cotton production through a from a study that was done by Gurmessa et al., 2022 comparative evaluation of hybrid generation and indicated that three introduced hybrid cotton the results indicated that lint yield for hybrids was varieties gave higher seed cotton yields than the two 24.8% higher in F1 and 11.6% in F2 than that of the local check varieties at all locations. control Ruiza816. The performance of SJ48 × Z98 was excellent in Alar which showed 36.5% higher Accordingly, the cotton hybrids showed seed cotton LY in F1 and 10.9% in F2 than control yield advantage of 35.59% (YD-211), 35.54% (YD- Zhongmiansuo 49. The superiority in terms of 206), and 29.43% (YD-223) over the best-performed ginning percentage for OPVs over hybrids could be local check variety (Deltapine 90). However, the study attributed to genetics. by Gurmessa et al., 2022 was conducted under irrigated conditions, unlike this current study which Boll weight was conducted under dryland conditions which is a The effect of genotypic mean performance on boll prototype of the cotton production landscape in weight was significantly different at all sites except for Zimbabwe. CRI only. Kuwirirana and Svisvi recorded the highest means both of 6.0g, whilst smaller bolls weighed 5.2g A study by Chen et al., 2022, on the comparative at Matikwa (Table 6). At Chitekete (p<0.001), CRIMS performance of hybrid generations reviewed the 1 recorded the largest bolls which weighed 6.4g, potential application of F1 hybrids in upland cotton. similar to LS9219 (6.3g), CRIMS3 and SZ-9314 (both The results showed that variance analysis had 6.2g) whilst Jaguar recorded the smallest bolls (4.1g). significant differences for agronomic, yield, and fiber This was the same trend for Dande, where Jaguar quality in both generations and environments. recorded the smallest bolls (4.2g), against QM301, Interestingly, hybrid L28×Z98 performed LS9219, SZ9314, CRIMS 1, CRIMS 2, CRIMS 3, and outstandingly in Anyang. Its lint yield was 24.8% CRIMS 4 which recorded more than 5.6g. Generally, higher in F1 and 11.6% in F2 than that of the control the same trend followed other sites like Kuwirirana, Ruiza816. The performance of SJ48 × Z98 was Tokwane, Wozhele, Svisvi, and Matikwa. Analysis of excellent in Alar which showed 36.5% higher LY in F1 variance across sites (2021/22 season) revealed and 10.9% in F2 than control Zhongmiansuo 49. significant differences (P<0.001) for boll weight These findings are however contrary to what was (Table 7). A grand mean of 5.61g was recorded, whilst obtained from the study which was carried out in SZ9314 recorded the largest bolls (5.9g) but similarly Zimbabwe under dry conditions. This is a general to CRIMS 1, CRIMS 2, CRIMS 3, CRIMS 4, LS9219 thumb of confirmation that cotton hybrids are more and QM301. Jaguar recorded the smallest bolls resource utilizers when compared to OPVs, hence (4.44g). A two-season combined analysis revealed given the climate change effects, OPVs have shown statistical differences (P<0.001) and a grand mean of resilience and adaptability. 5.78g (Table 8). Sz9314, LS9219, CRIMS 1, and CRIMS 3 recorded boll sizes above 6g, though similar Another study by Amanu et al., 2021, was again to CRIMS 2, CRIMS 4 and QM301. Jaguar recorded performed under irrigated conditions in Ethiopia to the smallest boll size of 4.39g. evaluate the performance of introduced hybrid cotton under irrigated conditions and the results showed Discussion that some medium staple length hybrid kinds of Few studies have been performed to evaluate the cotton namely, VBCH 1533, VBCH 1537and Hero differential performance between cotton hybrids and VBCH 1511 tested at Werer Agricultural Research Open Pollinated cotton varieties under dry conditions Center (WARC), Amibara (sheleko), Melkasedi, Marco et al. Page 16

8. Int. J. Agron. Agri. R. Gawane, Sille, and Woyto surpassed for seed cotton magnitude of heterosis for seed cotton yield/plant of yield of yielding 51.22, 50.05 and 49.97 q/ha, above 40 percent. The highest economic heterosis for respectively. The lowest seed cotton yield was scored seed cotton yield was observed by the cross H 1489 x at Amibara for the check variety DP-90 (7.55 q/ha). C 210 (64.02%), which also exhibited the highest per Almost all test candidate genotypes surpassed the se performance for important characters; bolls/plant check varieties for seed cotton yield at each location. and boll weight. It was followed by H 1472 × C 211 These results are conflicting with those from the (63.74%), H 1522 × C 211 (57.62%), H 1488 × C 211 study in Zimbabwe which was carried out under dry (52.60%) and H 1522 × C 201(47.87%). The cross H conditions. Gudeta et al., 2023 carried out an 1472 × C 211 (63.74%), H 1489 × C 210 (9.30%), and experiment involving Bt Hybrids where the author H 1098i × C 201 (19.72%) registered the highest realized that Hybrids JKCH 1947 and JKCH 1050 significant heterosis for boll weight, bolls/plant, and were the top high yielders under high and mild ginning out turn respectively. These obtained results bollworm infestations, with mean seed cotton yield of from various studies under irrigated provide a true 3.10t.ha-1 each and lint yield of 1.20 and 1.19t.ha-1 reflection of the gaps in testing both hybrids and respectively, whereas the standard check Deltapine- OPVs under dryland conditions. The study results 90 (OPV) recorded a mean seed cotton and lint yield have provided a conclusion that cotton hybrids and of 2.3t.ha-1 and 0.8t.ha-1, respectively. OPVs perform similarly for yield under dry conditions whilst pertaining parameters predominantly Shavkiev et al., 2021 discovered in an experiment controlled by genetics like GOT%, OPVs bred in under irrigated and non-irrigated conditions, that Zimbabwe showed superiority over hybrids. deficit irrigation conditions negatively affected the yield-contributing traits and eventually the seed Conclusion cotton yield. The parental cultivars Ishonch and The study revealed no significant variation between Navbakhor- and their F1 diallel hybrids were found to hybrids and Open Pollinated Varieties (OPV) in seed be more stable and performed better than the other cotton yield after an across season analysis. For genotypes under both water regimes. On average, the attributes like Gin-out-turn and Boll weight, significant genotypic and phenotypic variances for various traits variations after across site analysis were observed, and were greater under water deficit conditions than Open Pollinated Varieties showed superiority over the under the optimal irrigation regime. hybrids. Generally on Boll weight, OPVs recorded high means which were above 5.8g compared to some Shahzad et al., 2020 carried out a study to explore hybrids which recorded less than 5g, whilst on on Gin- how hybridization produces superior yield in upland out-turn all OPVs recorded at least 40% whilst some cotton is critical for efficient breeding programs. The hybrids recorded as low as 33%. The results indicated results were in contrasting trend with the current more weight in favour of OPVs than the hybrids. Based study and showed that a high hybrid produced a on the current study results, the author recommends mean of 14% more seed cotton yield than its better that more experiments should be done for hybrids under parent. The comparative performance of hybrid dry conditions upon realization that climate change generations reveals the potential application of F2 effects have continuously negatively affected cotton hybrids in upland cotton (Chen, 2022). production and productivity. There is also need to develop more drought stress tolerant cotton hybrids Bourgou et al., 2023 in a study conducted the results since the cotton production landscape in Zimbabwe and showed that hybrids were superior to their OPV other developing countries is dominated by smallholder parents on yield and other fiber properties. Zhang, and resource-constrained farmers. This will lead to 2021 experimented and the results were contrary to improved cotton production and productivity in the current study as eleven crosses recorded a Zimbabwe. Marco et al. Page 17

9. Int. J. Agron. Agri. R. Acknowledgements Damtew S, Gurmessa D, Balcha M, Egziabher A. 2023. Evaluating cotton (Gossypium hirsutum L.) Authors appreciate the Department of Crops genotypes for fiber quality traits over selected agro- Research and Cotton Research Institute for providing ecologies of Ethiopia. East African Journal of Sciences financial and labour resources in support of the 17(2). research work over the two seasons. Gudeta B, Kedisso EG, Gurmessa D, Tesfaye D, References Damtew S, Taye W, Gebre-Egziabher A, Balcha Agricultural Marketing Authority (AMA). M, Daba T, Workie A, Maredia K. 2022. 2022. Cotton country report. Adaptability of genetically engineered Bt cotton varieties in different growing regions of Ethiopia. Advances in Amanu AW, Arkebe GB, Gutmassa DE, Agriculture 2023(1), 8224053. Damitew S, Balcha M. 2021. Hybrid cotton https://doi.org/10.1155/2023/8224053. adaption performance under irrigations of Ethiopia. Gurmessa D, Gebregziabher A, Mohammed R. Baig K, Gaikwad A, Lahane G. 2022. 2022. Agronomic, yield, and fiber quality performance of Morphological, yield, and quality performance released introduced hybrid cotton varieties in irrigated introgression trispecies derivatives of cotton. agro-ecologies of Ethiopia. Muhammad W, Ahamad, Ahmad M. 2020. Bourghou L, Dever J, Sheehan K, Kelly C, Pollination behavior of cotton crop and its management. Daine S, Sawadogo M. 2023. Diallel crosses of Shahzad K, Zhang X, Guo L, Oi T, Bao L, Zhang cotton (Gossypium hirsutum L.) enhancement of fiber properties in future cultivars for Burkina Faso. M, Zhang B, Tang H. 2020. Comparative transcriptome analysis between inbred and hybrids Chen L, Tang H, Zhang X, Qi T, Gou L, reveals molecular insights into yield heterosis of upland Shahzad K, Wang H, Qiao X, Zang R, Zhang M, cotton. Wu J, Xing C. 2022. Comparative performance of Shavkiev J, Azimov A, Nabiev S, Khamdullaev S. hybrid generations reveals potential application of F1 2021. Comparative performance and genetic attributes hybrids in upland cotton. of upland cotton genotypes for yield-related traits under optimal and deficit irrigation conditions. SABRAO Chen L, Tang H, Zhang X, Qi T, Gou L, Journal of Breeding and Genetics 53(2), 157–171. Shahzad K, Wang H, Qiao X, Zang R, Zhang M, The Herald, Zimbabwe. 2019. Cottco optimistic of Wu J, Xing C. 2022. Comparative performance of hybrid generations reveals potential application of F2 new hybrid varieties. Retrieved from hybrids in upland cotton. https://www.herald.co.zw/cottco-optimistic-of-new- hybrid-varieties/. Chen Y, Gao Y, Chen P, Zhou J, Zhang C, Song United Z, Huo X, Du Z, Zhang J. 2022. Genome-wide States Department of Agriculture association study reveals novel quantitative trait loci (USDA). 2021. Retrieved from and candidate genes of lint percentage in upland https://www.usda.gov/sites/default/files/documents/2 cotton based on the CottonSNP80K array. 020-aof-cotton-outlook.pdf. Marco et al. Page 18