Responses of green bean (Phaseolus vulgaris L.) varieties to month of sowing and nutrient source in Bauchi State, Nigeria

Abstract

Field experiment was conducted during the dry seasons of 2019/2020, 2020/2021 and 2021/2022 at the Teaching and Research Farm, Gubi  campus, Abubakar Tafawa Balewa University, Bauchi (10◦ 22´N and 9◦ 47´E) to determine the responses of two green bean varieties  to month of sowing and nutrient source. The treatment consisted of two varieties of green bean (Yarsalina and Garji), three month of  sowing (Mid - October Mid - November and Mid - December) and three nutrient sources (NPK fertilizer at 20;40;40 kg/ha, cow dung at 2 t/ ha and poultry manure at 2 t/ha) and a control (no nutrient added). These were factorially combined to give twelve 12 treatment  combinations and laid out in a randomized complete block design with three replications. Data were collected on plant height, number of  leaves, leaf area, leaf area index, number of flowers, number of pods, total and marketable pods yield. All data collected were  subjected to analysis of variance using ANOVA significantly different means were separated using Duncan Multiple Range Test (DMRT).  There was significant (p≤ 0.05) variation between the two varieties, the three month of sowing and the nutrient sources on almost all the  growth (plant height, number of leaves, leaf area, leaf area index) and yield components (Number of flowers, number of pods, total and  market pods yield) of green bean. Yarsalina outperformed Garji by producing taller plants (32.52cm), more leaves (45.6), larger leaf area  (46.6cm) and leaf area index (4.71), number of flower (60), number of pods (28.52) and total (7.41t/ha) and marketable pods yield (6.89t/ ha). The crops sown in Mid - October had taller plants (32.01cm), more leaves (49.51), wider leaf area (45.14cm² ) and leaf area index  (4.52) while crops sown in Mid - December produced more flowers (60.81) than both the Mid - October and Mid - November sowings.  Crops sown in Mid - October however produced more pods (27.82) while Mid - October and Mid - December sowings produced the  highest total pod (7.12t/ha) yield than the Mid - November sowing. Application of poultry manure had significantly (p≤ 0.05) taller plants  (36.69cm), more leaves (52.24), wider leaf area (56.58cm² ) and leaf area index (5.73). Furthermore, it produced significantly higher (p≤  0.05) number of flowers (69.24) and pods (36.59) and higher total (10.68t/ha) and marketable pod (10.13t/ha) yield. At the different  season under investigation, 2019/2020 and 2021/2022 dry season produced significantly (p≤ 0.05) taller plants, and more leaves, higher  leaf area and leaf area index than the 2020/2021season. Higher number of flowers, number of pods and total pod yield was produced in  2021/2022 dry season. Based on the finding of this study, it can be concluded that Yarsalina sown in either Mid - October or Mid - December with application of poultry manure at the rate of 2t/ha produced best vegetative growth and yield component and was  observed to produced higher pod yield and therefore can be adopted by farmers for improved green bean production in the study area.