Effects Of Decapitation, Cattle Dung Manure And Npk 15:15:15 Fertilizer On Soil Characteristics And Okro (Abelmoschus Esculentus [L.] Moench) Growth And Yield In Makurdi Local Government Area (Lga), Benue State, Nigeria

Decapitation stops auxins' production at a plant's growing tips, thereby stimulating the development of lateral shoots.Vegetable crops, when decapitated, can respond differently to applied soil amendments.A field experiment was undertaken during the 2024 cropping season at Agan Settlement in Makurdi LGA of Benue State to assess the effects of decapitation, cattle dung manure (CDM) and NPK 15:15:15 fertilizer on soil characteristics and growth and yield components of 'Erguru' okro variety.Each experimental plot measured 3 m x 3 m (area = 9 m 2 ), with a furrow space of 1 m between the main plots/sub-plots.The experiment was arranged in a split plot design with eight treatments replicated thrice.The CDM and NPK 15:15:15 fertilizer treatments occupied the main plots and consisted of 15 t/ha CDM, 30 t/ha CDM, 300 kg/ha NPK 15:15:15 fertilizer treatments, and the control/non-amended soils.The decapitation treatments occupied the subplots and consisted of 'decapitated okro plants' (DOPs) and 'non-decapitated okro plants' (NDOPs/'control plants').Pre-amendment and post-harvest soil analyses (0-30 cm depth), post-soil amendment and post-decapitation analyses of okro growth and yield parameters, and pre-application analysis of the CDM's chemical/mineralogic composition were undertaken.In April, the CDM was incorporated into soils at the cleared experimental site and allowed to decompose for 4 weeks before sowing of the okro seeds.Thinning was done at 2 weeks after planting (WAP); manual weeding at 3 WAP and 6 WAP; NPK fertilizer was applied in 2 split doses (at 4 WAP and 7 WAP); insect pests were controlled chemically with cypermethrin; decapitation at 8 WAP, while post-soil amendment and postdecapitation measurement of okro growth and yield parameters (shoot height at 14 WAP, number of green leaves at 14 WAP, days to 50% flowering after germination, days to first fresh pod harvest after flowering, number of pods harvested, fresh green pod yield, and dry shoot matter) began at 14 WAP.The data generated on soil properties and okro growth and yield parameters were analyzed using arithmetic mean and ANOVA.The pre-application CDM had a moderately alkaline pH (H2O) (8.31) and high OC (16.9%),OM (29.14%),TN (1.7%), AP (86.08 mg/kg), Na (3.05 cmol/kg), K (6.52 cmol/kg), Mg (7.93 cmol/kg) and Ca (8.7 cmol/kg) contents.The pre-amended soils had a sandy texture, medium/moderately acidic solution pH (H2O) (5.7) and low OC (1.06%), OM (1.83%), TN (0.16%) and AP (6.69 mg/kg) contents and low exchangeable cations (Na + : 0.12, K + : 0.14, Mg 2+ : 0.33, and Ca 2+ : 1.78 cmol/kg) levels.Decapitation had no effect on the soils' investigated properties.Similarly, decapitation, CDM and NPK fertilizer did not alter the soils' textural class.The post-harvest soils had a sandy texture, significantly (P 0.05) improved solution pH (H2O) status of 6.5 (slightly acidic reaction), high OC (2.63%), OM (4.53%), TN (1.39%) and AP (18.7 mg/kg) contents, and high exchangeable cations (Na + : 0.28, K + : 1.41, Mg 2+ : 1.52, and Ca 2+ : 3.79 cmol/kg) levels.The DOPs had a lower mean shoot height (120 cm at 14 WAP), more green leaves per plant (56 at 14 WAP), and produced more harvested pods ( 15), fresh pod yield (2.98 t/ha) and dry shoot matter (39.7 g/plant), but took a longer mean time-period to attain 50% flowering after germination (71 days) and first pod harvest after flowering (50 days).The NDOPs possessed a greater shoot height (145 cm at 14 WAP), fewer green leaves per plant (43 at 14 WAP) and produced fewer harvested pods ( 9) and lower mean fresh pod yield (2.33 t/ha) and dry shoot matter (26.4 g/plant), but took a shorter time-length to attain 50% flowering after germination (66 days) and first pod harvest after flowering (45 days).Soils amended with 30 t/ha CDM produced okro plants with the greatest mean shoot height (164 cm at 14 WAP), highest mean number of green leaves (63 at 14 WAP) and harvested pods ( 27) and greatest mean fresh pod yield (5.58 t/ha) and dry shoot matter (51.7 g/plant), but took the lowest time-period to attain 50% flowering after germination (54 days) and first pod harvest after flowering (42 days).However, the control/non-amended soils produced okro plants with the lowest mean shoot height (129 cm at 14 WAP), least mean number of green leaves (30 at 14 WAP), fewest harvested pods (10) and lowest mean fresh pod yield (2.13 t/ha) and dry shoot matter (23.3 g/plant), and delayed longest to attain 50% flowering after germination (79 days) and first pod harvest after flowering (60 days).Thus, it was concluded that decapitation had no effect on soil properties; CDM and NPK fertilizer had no effect on soil texture, but both exerted significant positive effects on the investigated soil characteristics (except texture) and, hence, on the vegetative growth and yield components of okro; the 30 t/ha CDM application rate (followed by the 300 kg/ha NPK 15:15:15 fertilizer application rate) made the best impacts on okro growth and yield components; and decapitation, CDM and NPK 15:15:15 fertilizer had significant positive effects on the growth and yield of okro.Decapitation at 8 WAP and soil amendment with either 30 t/ha CDM or 300 kg/ha NPK 15:15:15 fertilizer were, therefore, recommended as being economical for soil amendment and, hence, optimum growth and yield of okro in the study area.