ABSTRACT
A field experiment was carried out in the Department of Crop Science Teaching and Research Farm of theUniversity of Calabar, Nigeria from 30October2020 to 31 January 2021to determine a suitable lime rate for growth and yield of a non-indigenous fruit vegetable, canary melon (Cucumis melo L. var. Inodorous).Six rates of lime (CaCO3) (0 t/ha, 1 t/ha, 2 t/ha, 3 t/ha, 4 t/ha and 5 t/ha) and one cultivar of canary melon was used for the study. The experiment waslaid out in a randomized complete block design with threereplications. Pre- and post-planting soil pH tests were conducted. Agronomic data were collected and analysis of variance (ANOVA) was conducted and followed with post hoc tests using Duncan’s New Multiple Range Test at 95% confidence limit. Simple linear regression analysis was used to model relationships between lime rates and the selected growth traits of canary melon. Pearson’s correlation analysis was conducted to determine the extent of association between yield and yield-related traits of the canarymelon as influenced by soil pH. Results of the study showed that pre-planting soil pH test result confirmed that the experimental soil was strongly acidic (pH (in water) = 4.13). Post-planting soil pH after liming (at the end of the experiment) ranged from 4.69 to 5.93. Lime application at 1 t/ha, 2 t/ha, 3 t/ha, 4 t/ha and 5 t/ha raised (i.e., increasing basicity) the soil pH by 13.5 6%, 33.89%, 36.32%, 40.44% and 43.58% respectively. Although lime application at 1 t/ha significantly (p ≤ 0.05) increased the initial soil pH, liming at 2 t/ha to 5 t/ha did not significantly (p > 0.05) influence the soil pH. Lime significantly (p ≤ 0.05) influenced selected growth traits of canary melon in Calabar, except for the leaf area index (p > 0.05). Also, fruit yield and related yield attributes varied (p ≤ 0.05) with lime rates. Simple linear regression prediction models were highly significant (p < 0.001) in describing the relationship between lime rates and seedling emergence (R2 = 0.89), leaf length (R2 =0.74), leaf breadth (R2 =0.92), leaf area (R2 =0.91), leaf area index (R2 =0.91), number of leaves per plant (R2 =0.79), vine length (R2 =0.66)and vine thickness (R2 =0.77)of canary melon. Correlation analysis indicated a significantly strong to relatively strong association (p < 0.001) between fruit yield (t/ha) and individual fruit weight (g/fruit) (r = 0.85), fruit volume (r = 0.75) and fruit diameter (r = 0.52). There was no association between Brix and any of the yield traits considered in the present study. Overall, from this study, it was observed that the effect of lime application on soil pH produced by 2 t/ha of agricultural lime (CaCO3) was statistically (p ≤ 0.05) different from no lime (0 t/ha) application but similar (p > 0.05) to higher lime rates (3 t/ha, 4 t/ha and 5 t/ha). The improved soil pH was between 5.5 and 6.0 which could be considered suitable for canary melon production in calabar. There, is therefore, a need to validate these results in a repeated study.