Search

Growth and yield of watermelon are significantly influenced by spacing and variety. To quantify these effects, field experiments were conducted from August to November 2016 in Ogbomoso and Sepeteri, Oyo State, Nigeria. The treatments consisted of four watermelon cultivars (Sugar baby, Kaolack, Grey belle and Collos F1) and five spacings (1.0 × 0.5 m, 1.0 × 0.75 m, 1.0 × 1.0 m, 1.0 × 1.5 m and 1.0 × 2.0 m). Data collection on reproductive and fruit yield attributes. Results showed that the growth parameters of the crop grown at Sepeteri were significantly better while those grown at Ogbomoso had higher fruit yield/yield parameters. In both locations, spacing significantly (p = 0.05) influenced the fruit yield parameters for all the varieties. In Collos F1, vine line, number of secondary vines, leaves, flowers and rotten fruits were the highest while the number of fruits/plot and fruit yield (t/ha) were significantly higher in Kaolack cultivar. Spacing however had no significant influence on growth parameters but significantly affected number of fruits/plot and fruit yield/ha. In Ogbomoso, Kaolack sown at 1.0 x 0.75 m had highest fruit yield (41.7 t/ha) while the least (9.3 t/ha) was obtained from Sugar baby sown at 1.0 x 0.5m. Similarly, in Sepeteri, Kaolack sown at 1.0 x 0.75 m produced the highest fruit yield (19.4 t/ha) while the least (5.0 t/ha) was obtained from Collos F1 at 1.0 x 1.5 m. Planting Kaolack at spacing 1.0 x 0.75 m in both Ogbomoso and Sepeteri was the best agronomic practices for achieving the best fruit yield. [ABSTRACT FROM AUTHOR]

The growing realization of nutritional and health benefits, and the potential of watermelon (Citrullus lanatus L.) as a cash-producing crop has renewed interest in reducing loss in its post-harvest handling. Information on the extent of loss in different parts of its post-harvest system under tropical conditions is scarce. Key constraints identified by producers were insect infestation, insufficient working capital, poor handling of produce, lack of access to market, and lack of technology while inadequate access to funds, lack of storage facilities, and poor packaging of produce were identified by marketers. Post-harvest trouble spots were determined through adequate evaluation of the proportion of loss and associated factors along the watermelon supply chain. The majority of producers and marketers experienced loss of up to 40%, some >60%. Interventions in trouble-spots can have an impact on the reduction of post-harvest loss. A better understanding of loss along the supply chain was developed which can lead to the determination of effective strategies to manage watermelon loss in the tropics. [ABSTRACT FROM AUTHOR]

Summary: Little information is available for nematode pests associated with watermelon in sub-Saharan Africa (SSA). This study recorded the abundance and prevalence of plant-parasitic nematodes from 25 localities across south-west Nigeria during 2016/2017. Of the 11 nematode species identified, those belonging to Meloidogyne spp. were predominant according to Prominence Values, followed by Helicotylenchus dihystera , Pratylenchus zeae and Scutellonema bradys. Morphological and molecular analyses revealed the identity of four species of root-knot nematodes: Meloidogyne enterolobii , M. incognita , M. javanica and M. arenaria (in descending order of abundance and occurrence). Meloidogyne arenaria is reported for the first time from south-west Nigeria, while S. bradys and Xiphinema nigeriense are first reports for watermelon. Significant associations were observed between the frequency of occurrence of the predominant nematode species and soil properties as well as rainfall. Results provide baseline information on the nematode pest occurrence on watermelon in Nigeria and in a wider context for SSA. [ABSTRACT FROM AUTHOR]

Introduction: Watermelon is one of the commonly eaten fruit in most homes in Nigeria and has been used in the management of diabetes mellitus traditionally. This study was carried out to explore the antidiabetic potential of watermelon (Citrullus lanatus) juice in alloxan-induced diabetic rats. Methods: Watermelon juice was used for the determination of in vitro parameters such as 1,1-diphenyl-2-picryl-hydrazil (DPPH), nitric oxide and ferric reducing antioxidant potential (FRAP) as well as phytochemicals such as total phenol, total flavonoids. In vitro, α-glucosidase and α-amylase inhibitory activities were also accessed using standard procedures. Diabetes was induced in the rats by a single intraperitoneal (I.P) injection of freshly prepared alloxan (150 mg/kg body weight). The animals were randomly grouped into five groups of normal control, untreated diabetic control, diabetic rats administered 200 mg/kg body weight of metformin, diabetic rats administered 500 mg/kg body weight of watermelon (Citrullus lanatus) juice and diabetic rats administered 1000 mg/kg body weight of watermelon juice. The rats were sacrificed on the 14th day of the experiment and various in vivo biochemical parameters were also evaluated in the serum and tissue homogenates of diabetic rats. Results: The watermelon juice exhibits anti-oxidant properties and inhibitory activities against α-glucosidase and α-amylase in a dose-dependent manner. Added to this, the administration of different doses of the watermelon juice significantly (p < 0.05) reduced the fasting blood glucose level, serum lipid profile, glucose-6-phosphatase, lipid peroxidation and anti-inflammatory activities in alloxan-induced diabetic rats. There was a significant (p < 0.05) increase in antioxidant enzyme activities, hexokinase activity as well as glucose transporters (GLUT 2 and GLUT 4) levels in diabetic rats administered different doses of Citrullus lanatus. Conclusion: Taken together, this study demonstrates that watermelon (Citrullus lanatus) juice exhibits its antidiabetic potential in experimental diabetic animal model via multiple pathways involving modulation of glucose transporters, anti-inflammatory activities as well as antioxidant defense system and inhibition of α-glucosidase and α-amylase. This suggests that the watermelon (Citrullus lanatus) juice may have a useful clinical application in the management of diabetes mellitus and its metabolic complications if developed as adjuvant therapy. [ABSTRACT FROM AUTHOR]

Summary: Watermelon is increasingly produced and consumed in Nigeria and sub-Saharan Africa. However, limited information exists regarding nematode pests and beneficial/free-living nematodes associated with the crop. The present study recorded the abundance and diversity of free-living nematodes from 50 watermelon fields across south-west Nigeria during 2016/2017. Of the 30 genera identified from soil samples, Cephalobus , followed by Rhabditis , Aphelenchus and Aporcelaimus , were predominant. Variation in nematode community structures across the 50 fields was apparent for mean maturity indices, metabolic footprints, feeding-type composition and coloniser-persister (c-p) structure. Faunal analyses characterised 52% of the fields as having stable and enriched soil food webs, which is beneficial for crop production. Significant correlations were apparent between some nematode genera and selected soil properties, and rainfall. This study provides the first information of free-living nematodes associated with watermelon from sub-Saharan Africa, offering novel and baseline information on their abundance and diversity in south-west Nigeria. [ABSTRACT FROM AUTHOR]

Watermelon [Citrullus lanatus (Thunb.)] marketing efficient distribution is needed to maximize economic returns to marketers and consumers. An economic analysis of watermelon marketing was done in Lagos state, Nigeria, between January and February 2018. Data were collected using a questionnaire employed to collect information from 56 marketers in the study area. Half of the marketers used urban markets as points of sale and watermelon were supplied weekly. Watermelon marketing was profitable. The major constraint encountered by marketers was their inability to access credit. Regardless of level of education sufficient market information enhanced economic returns of watermelon marketers. [ABSTRACT FROM AUTHOR]