Development of seed vigour in West African okra [Abelmoschus Caillei (A. Chev.) stevels

Awosanmi, Femi Emmanuel (2016)

xv,106p

Thesis

The study investigated the seed yield and vigour of West African okra in response to season of planting, identified the stage and determinants of physiological maturity of West African okra and investigated the relationship between the acquisition of hardseededness and vigour during seed development and maturation in West African okra; with a view to providing information on the physiological basis of the development of seed vigour which could lead to solutions to myriads of problems associated with its production. Seeds of two varieties of Abelmoschus caillei (CEN001 and NGAE-96-0069) were used for the study. Planting was done in May during the early season and September during the late season of 2014. Data on morphological, flowering and yield parameters were obtained from 10 tagged competitive plants in the middle row of each plot. Seed development was monitored from the point of flower opening with the flowers tagged fortnightly and harvesting was done at 7 days interval commencing from 14 to 42 days after flower opening (DAF). After drying, seeds were manually extracted from the oven dried (350C) fruits and subjected to the following tests: seed moisture content, viability and vigour tests, mineral ion and proximate analyses. Data collected were subjected to analysis of variance (ANOVA) using the General Linear Model and means were separated using Duncan’s multiple range test (DMRT). All analyses were carried out using Statistical package software version 9.1. Results showed that, about one-fifth of the number of fruits produced per plant in the early season was produced in the late season, also with a 38.8% reduction in the number of seeds per fruit culminating in an 87% loss in the number of seeds produced per plant. The vigour of the seeds produced in the late season was however higher by 16% and 25% in accelerated ageing and conductivity tests respectively, compared to seeds produced in the early season. The composition of crude protein within the seeds increased from 11.01 – 22.17% as the development of the seeds progressed from 14 – 42 days after flower opening. Conversely, the ash, moisture and carbohydrate contents reduced from 6.41%, 16.41% and 36.62% to 3.02%, 12.58% and 23.46% respectively from 14 – 42 days after flower opening in both seasons combined. Crude protein and crude fat contents had a very strong significant (P<0.01) correlation with the main vigour tests namely germination test, accelerated ageing test and conductivity test. Seeds with higher viability and vigour were produced in the late season and the non-uniformity in emergence of the seeds was a function of the amount of water required to complete germination, not the hardness of the seed coat as generally believed

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