Aims: The experiment aimed to investigate the effect of seasons (early raining and late raining) and mulching materials (Black polyethylene, White polyethylene, Grass-mulch and control) on marketable fruit yield of cucumber. Study Design: The experimental design was a 4 x 4 factorial laid out in a randomized complete block design (RCBD) with three replications. Data were collected on plant morphology and fruit components; number of leave, vine length, branch number, tendril number, stem diameter;  number of fruits per plant, fruit length, fruit circumference, fruit weight, number of marketable fruits per plot and number of non-marketable fruit per plot and fruit yield per plot (converted to per hectare). Place and Duration of Study: The present study was carried out at Teaching and Research Farm of Obafemi Awolowo University (OAU), Ile-Ife, Nigeria (located on longitude 04º33lE and latitude 08º28lN at 244 m above sea level) during the growing seasons of 2017 and 2018. Methodology: The data collected were subjected to analysis of variance (ANOVA) using (SAS, 2003 version). Means of significant treatments were separated using Duncan`s Multiple Range Test (DMRT). Results: The obtained results revealed that seasons and mulching materials had significant effect on some of the parameters investigated. Late season significantly enhanced the fruit length, fruit weight and total fruit yield when compared with the early seasons. The mulching materials, black polyethylene mulching materials significantly enhanced the morphology and some of fruit components; fruit length and fruit weight while white plastic mulch significantly improved the number of fruit per plant, fruit diameter and total yield of cucumber at both early and late seasons followed by grass-mulch. However, control consistently produced the highest number of non-marketable fruits when compared with other treatments investigated.  Conclusion: Therefore, planting of Poinsett76 variety towards the ending of raining seasons with the application of white plastic mulching is highly recommended for the small holder farmers.

Low plant regeneration and transformation frequencies in cassava have been attributed to recycling of cassava secondary somatic embryos for long periods. This study examined the suitability of low-temperature storage of dehydrated cassava secondary somatic embryos as an alternative short-term conservation approach to recycling. The study included two experiments: in the first one, somatic embryogenesis from cotyledons of dehydrated secondary somatic embryos stored at six temperatures for 4, 8 and 12 months was established; and in the second, plant regeneration via shoot organogenesis using somatic cotyledon explants obtained in the first experiment was examined. The growth, photosynthetic pigment contents and genetic stability of the regenerated plants were assessed. At each storage temperature, the survival of explants, somatic embryogenesis, shoot induction and elongation decreased with increases in storage period. At 4 months after storage (MAS), explant survival, frequency of somatic embryogenesis, shoot induction, elongation and rooting had the best responses at 16EC and 20EC. Similarly, the growth and photosynthetic pigment contents of plants regenerated from somatic embryos preserved at 16EC and 20EC recorded the best results at 4 MAS. However, at 8 and 12 MAS, the best explant survival, somatic embryogenesis, shoot induction and elongation were recorded at 16EC. Eight RAPD primers produced a total of 56 distinct and scorable bands, ranging from 250 bp to 3000 bp in size. An random amplified DNA (RAPD) analysis showed a uniform banding profile among regenerants and to that of the mother plant, indicating no genetic variation among regenerants and between the regenerants and the mother plant. The data presented here suggest that cassava secondary somatic embryos dehydrated to 50% moisture content should be preserved at 16-20EC for 4 months; for 8 and 12 months storage, the embryos should be stored at 16EC. No genetic alteration was detected among the regenerants. Therefore, the method is a suitable means for short-term conservation of cassava secondary somatic embryos.

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Somatic embryogenesis, plant regeneration and genetic stability of regenerants grown from cassava secondary somatic cotyledon preserved at 16 0 C on medium containing mannitol or sorbitol alone and their combinations were investigated. Irrespective of osmotic agents in the medium, survival of cotyledon explant, frequency of somatic embryos, shoot induction, number of somatic embryo per explant, shoot elongation and rooting decreased as preservation period increased. The highest survival rate of cotyledon explants, frequency of somatic embryos, shoot induction and shoot elongation were observed on media containing 2% mannitol. However, the highest per cent rooting occurred on medium containing mannitol alone at 8 months after storage (MAS) and on media containing mannitol or sorbitol alone at 16 MAS. RAPD analysis suggested genetic uniformity among regenerants and their control plant. Osmotic preservation of secondary somatic embryos of cassava on 2% mannitol at 16 0 C is the best slow-growth method.

Inadequacy of planting materials is limiting the distribution of three high-β-carotene (pro-vitamin A) cassava varieties released in Nigeria to increase public vitamin A intake. However, studies have established the suitability of in vitro shoot culture for mass propagation of elite crop varieties for quick distribution to farmers. We investigated multiple shoot induction from axillary bud of three β-carotene enriched cassava varieties using BAP and assessed the genetic stability of the regenerated plants to establish mass propagation system. Multiple shoots were induced from BAP-enlarged axillary bud on basal medium supplemented with 10 mg/l BAP. Shootbuds were elongated on basal medium supplemented with 1.0 mg/l BAP and 10.0 IBA mg/l. Genetic stability of regenerated plants was assessed byeight RAPD markers. There were significant (P < 0.05) differences in survival of isolated axillary bud, shootbud formation, survival of shootbud, regenerated shoots, root formation and survived regenerated plants among cassava varieties. The order of shootbud formation among the cassava varieties was UMUCASS 37 > UMUCASS 36 >TMS 30555 > UMUCASS 38. The best (83.4%) shoot regeneration was recorded in TMS 30572 and lowest (47.8%) in UMUCASS 37, however, UMUCASS 36 recorded the best (98.5%) survival of regenerated shoot after hardening. Eight RAPD primers produced 56 bands, ranging from 200 to 3000 bp in size. RAPD analysis showed a uniform profile among regenerants and between mother plant and regenerants. The study concluded that multiple shoot formation could be induced in pro-vitamin A cassava varieties using BAP from axillary bud with no genetic infidelity of the regenerants.