Citrulus Lanatus Research Articles

A Modeling Approach to Studying the Influence of Grafting on the Anatomical Features and SAUR Gene Expression in Watermelons

Grafting alters the genetic and anatomical features of plants. Although grafting has been widely applied in plant propagation, the underlying processes that govern the effects of the procedure are not fully understood. Samples were collected to study the long-term influence of grafting on the leaf-shoot morphology, leaf-shoot anatomy, and genetic signature of the grafted plants. Citrulus lanatus (Thunb.) Matsum. & Nakai (cv. Lady) was used as the scion, and Lagenaria siceraria (Molina) Standl (cv. Argentario) as a rootstock. In grafted plants, leaf blades and petioles were 20.92% and 12.82% longer, respectively, while the midrib collenchyma was 35.68% thicker, and the diameter of the vessel member was 11.17% larger than in ungrafted plants. In the stem, grafting affected the arrangement and number of vascular bundles (from 1 to 2 rings). The thickness of the epidermis decreased by 69.79%, and the size of the external fascicular phloem decreased by 23.56%. The diameter of the vessel member of the grafted plants increased by 28.94%. Eight out of ten evaluated primers met the requirements (stability in both watermelons and bottle gourd, tissue-specific). In the genetic tests, we examined whether this change in the gene expression pattern is due to the grafting and, if so, to what extent. Seven out of eight tested Small Auxin Up-Regulated RNA (SAUR) genes were expressed in the ungrafted and grafted C. lanatus lines in four cases; the expression increased by more than 10% after grafting. The morpho-anatomical changes and genetic variation reported in this study for grafted lines of C. lanatus contribute to the understanding of the underlying mechanisms of plant growth observations resulting from grafting.

Kualitas Semen Babi yang ditambahkan Antioksidan Semangka Merah (Citrullus Lanatus)

This study is aimed at recognizing the effect that the addition of juice from watermelon (Citrulus lanatus) as antioxidants against motility and semen viability of pigs. The source of cement used in research came from the landrace boar. The semen of the pig was collected using the method of massage with the help of dummy sow. Cement is macroscopic and microscopic. The natural dilution material used is lontar. The treatment of the juice of 100 µL/10 mL, 200 µL/10 mL, 300 µL/10 mL, 400 µL/10 mL, 500 µL/10 mL. Liquid semen evaluations are performed every two hours after storage and sperm motility and viability evaluations of spermatozoa. The addition of watermelon juice (Citrulus lanatus) P3 treatment group at a dose of 300 µL/10mL has the best possible result in sustaining the motility of spermatozoa.

Subacute Use of Aqueous Extract of Water Melon (Citrullus lanatus) Seeds Mitigates against Pyramidal Neuronal Toxicity of Lead Acetate in Adult Wistar Rats

Introduction: Lead exposure remains a significant public health burden across the globe, impacting millions of individuals and posing a major threat to nervous system development and function As a reported bio-toxic environmental and industrial pollutant, Lead (Pb) do accumulates in almost all body tissues to cause health complications with the cerebellar region of the central nervous system reported to be more susceptible to cellular distortions. As a flowering plant species of the Cucurbitaceae family, watermelon (Citrullus lanatus) is associated with numerous medicinal properties. Aim: This study aim to investigate the possible neuroprotective potential of aqueous extract of citrulus lanatus seed on lead acetates-induced neurotoxicity in the Cerebral cortex of adult Wistar rats. Place of Study: Department of Anatomy, Faculty of Basic Medical Sciences Olabisi Onabanjo University, Ogun State, Nigeria. Methods: Twenty (20) healthy adult female wistar rats weighing 150±50g were randomly assigned into 4 groups (n=5). The Control group received 2mls/kg of distilled water, Treatment group (T1) was administered 7.5 mg/kg of lead acetate, Treatment group (T2) was administered 200 mg/kg of aqueous extract of citrullus lanatus and Treatment group (T3) was administered 7.5 mg/kg of lead acetate and 200 mg/kg of aqueous extract of citrullus lanatus concomitantly orally for fourteen (14) days. H&E and Cresyl violet histological stains and Biochemical assays for SOD, CAT activities and MDA concentration was determined. Data obtained from the study were analyzed using one-way ANOVA and subjected to Turkeys post hoc test from the multiple comparison. Results: Revealed no statistically significant differences (p>0.05) in body weight and brain weight changes across groups relatives to the control group while SOD and Catalase activities were increased significantly in the Treatment groups compared to control group. Histological findings in control group and T2 showed normal histoarchitectural appearance of cerebral cortex Pyramidal neurons while the lead exposed group (T1) revealed features of neurodegenerative changes evident by nuclear shrinkage with pyknosis and karryorrhexis. while T3 revealed near normal presentations. Conclusion: In summary, Citrullus lanatus mitigates against pyramidal neuronal cells distortions following lead acetate induced toxicity in Wistar Rats and also further affirms its antioxidative potential.

Agronomic and disease responses of three watermelon (citrilus lanatus l.) varieties to fungicide spraying regimes in a tropical environment

usarium wilt disease is a major biotic factor limiting watermelon production in the derived savanna agroecology of southeast Nigeria. The study hypothesized that variety could interact with the fungicide spraying regime to improve the agronomic performance of watermelon (Citrulus lanatus (Thunb) Matsum and Nakai). The objectives of the study were: to assess the effect of fungicide spraying regimes on disease incidence, severity, and agronomic performance of three watermelon varieties; and to identify and characterize the fungal causal organism of Fusarium wilt of watermelon in the derived savanna agroecology of southeast Nigeria. Three varieties of watermelon (Jubaly, red diamond, and sweet sangaria) and four fungicide spraying regimes (No spray, weekly, bi-weekly, and tri-weekly spray) were evaluated for agronomic performance, and disease incidence and severity in a 3 × 4 factorial in a randomized complete block design replicated thrice. Data were collected on phenological, growth and yield indices, and disease incidence and severity. Analysis of variance was done using Genstat 16th edition and GraphPad Prism 9 was used to construct the graphs. Variety significantly affected agronomic traits as well as disease incidence and severity. The Jubaly variety performed better than other varieties in most of the growth and yield parameters measured despite recording higher disease incidence and severity scores. Weekly application of fungiforce recorded the lowest disease incidence (16.67, 16.67, and 50%) and severity (6.7, 6.7, and 10%) at 9, 10, and 11 weeks after planting, respectively. The interaction effect of the Jubaly variety and weekly spray was consistently higher in vine length, node number, fruit number, and fruit yield. Morphological isolation and identification of the fungal causal organism showed the presence of Fusarium species. Further molecular characterization by DNA extraction from the Fusarium isolate and sequencing using the Sanger sequencing method confirmed the presence of Fusarium equiseti. The basic local alignment search tool result showed 94–100% similarity with F. equiseti strain WZ-98 from the NCBI Gene bank. The organism was identified as F. equiseti based on the Phylogeny.

Disparity of fungi responsible for the spoilage of fruits sold in Sokoto Central Senatorial District, Sokoto State, Nigeria

This study was carried out in Sokoto central Senatorial District to identify the disparity of the fungal frequency responsible for spoilage of fruits sold at various markets of the district. A total of 240 spoilage fruits consisting of twelve (12) fruits each of Mangifera indica, Citrulus lanatus, Citrus sinnensis and Cucubita maxima were collected from five (5) different markets. Each of the fruits was cut into small pieces and inoculated on Potato Dextrose Agar then incubated at 250C and observed for 5 days. The isolates were identified using cultural and morphological features. Analysis of variance (ANOVA) was used to determine the significant difference for the mean frequency of these fungal species at P<0.05 level of significance. The results obtained showed the presence of Aspergillus niger Rhizopus stolonifera, R. oryzae, Alternaria altinata, Mucor, and Fusarium. Significant disparities were reported from Tangaza (P=0.004), Kware (P=0.000), Binji (P=0.000), and Wamakko (P=0.002) markets. However, there was no significant disparity for the mean frequency of the fungi responsible for the spoilage of fruits in Kasuwar Daji Market (P=0.129). It was recommended that proper storage method be adopted in the area to mitigate the adverse effect of the pathogens on the fruits and human health.

Quality Assessment and Food Potentials of Flour Obtained From Sprouted and Non-Sprouted Watermelon Seeds (Citrulus lanatus) and Its Akara Making Potentials


 This study formulated different flours from sprouted water melon seed and evaluated the proximate and sensory properties akara-analogue potential in Nigeria. The results showed that proximate composition: moisture (7.06-8.46%), protein (19.14%-37.24%), fibre (0.23-0.36%), fat (22.77-26.58%), ash (2.44-3.47%) and carbohydrate (30.58-41.91%) were significantly different at p<0.05. The bulk density ranged from 0.51-0.53g/ml, solubility index (40.30-40.01%), water absorption capacity (1.21-1.25%), swelling capacity (5.32-6.67%), pH (6.13-6.14); for sprouted and non-sprouted samples. Tannins, saponin, sterols, oxalate and phytate were detected in sprouted and unsprouted flour. Sprouting enhanced the amino acid content of composite flour. Mineral contents of Ca, P, K, Mg, Na, Cu, Zn and Mn were increased due to sprouting. The sensory analysis showed that the control samples have the highest taste score (7.35) and aroma (7.60) and were significantly different at p<0.05. Enhanced amino acid composition of watermelon may enhance the use of this flour as protein supplement for the development of new food product.

New Approach in Obtaining the Ideal Watermelon (Citrullus lanatus) Seedling: Tebuconazole

The study was conducted in March-May 2020 in greenhouse in Erzincan Horticultural Research Institute. Sahra F1 variety of watermelon (Citrulus lanatus) was used as plant material in the experiment. In this study, the effects of different doses (0, 25, 50, 75, 100, 125, 150 and 175 ppm) of Tebuconazole substance on the quality and development of watermelon seedlings were investigated. It was determined that different dose applications caused a significant change in seedling characteristics According to the data obtained, a average reduction of 38.45% and 17.81% was achieved in seedling length and stem length, respectively, compared to the control application. Also, the stem diameter increased in 3.03% after the applications. The all doses applications also provided an increase in leaf chlorophyll content (SPAD). In this study, applications of Tebuconazole at different doses were found to control the seedling height in watermelon and positively affected on specific quality characteristics of seedlings.

Occurrence and distribution of viruses infecting Zucchini and Watermelon in Morocco

Zucchini (Cucurbita pepo) and watermelon (Citrulus lanatus) rank among the most cultivated cucurbits in Morocco. These crops are prone to infection with a wide range of viral diseases responsible for tremendous losses. Field surveys carried out in 2016 and 2017 in four major cucurbit-growing areas revealed the presence of many virus-like symptoms on these crops, including severe yellowing and chlorosis. Therefore, symptomatic samples were collected and analysed serologically with DAS-ELISA for ZYMV, WMV, PRSV, CABYV and CMV and by The PCR and RT-PCR for ToLCNDV, and CVYV and MNSV, respectively. Results indicated that out of 136 samples, 79% of zucchini and 60% of watermelon samples were serologically positive for ZYMV, CMV, WMV, PRSV and CABYV. CVYV and MNSV were negatively amplified by RT-PCR using specific primer pairs. Interestingly, the PCR test revealed the occurrence of natural infection with ToLCNDV in Morocco.

The effect of chemical refining process on the physicochemical and fatty acid composition of water melon seed oil (Citrulus lanatus L.)

A lot of watermelon seed waste is wasted, generally its only used to make “kuaci”, a kind of salted saline a snack made from watermelon seeds. As a member of Cucurbitaceae family, watermelon seeds can be used as a source of vegetable oil that predicted contains squalene inside like other Cucurbitaceae members. This study aims to determine the effect of refining process on the physicochemical properties and composition watermelon seed oil. Watermelon seed oil which is obtained by using Soxhlet extractor in n-hexane solvent was refined in 3 steps, which was degumming, neutralization, and bleaching, respectively. Degumming process used 3 concentrations of H3PO4, which were 0,15%; 0,20%; and 0,25%, respectively; whereas 3 zeolit concentrations of 2%; 4%; and 8%, respectively were used in bleaching steps. Data were analyzed by using 3x3 Factorial design and it was laid out with Randomized Completely Block Design, 3 replications and as the block is time analysis. The optimum yield of the watermelon (C. lanatus L.) seed oil is obtained in the amount of 48.47±0.91 % at 0.25% phosphoric acid concentration and 4% Zeolite concentration. The result of physicochemical analysis before and after the refining process have changed. The density, peroxide value and acid value show a significantly decrease, while only the saponification value shows an increase. Fatty acid composition (profile) of WSO before and after refining process does not change, comprises linoleic acid, palmitic acid, stearic acid and squalene (unsaturated hydrocarbon). Linoleic acid is the main compound of WSO (76.69%), followed by palmitic acid (14.60%), stearic acid (6.53%) and squalene (2.18%), respectively.

Bioactivity and effects of spraying interval of selected plant extracts for control of pre-flowering insect pests of watermelon (Citrulus lanatus[Thunb.] Matsum. & Nakai)

This experiment was conducted to determine the efficacy of plant extracts of Tephrosial vogelii Hook. f., Moringa oleifera Lam., Annona squamosa L. and cashew nut (Anacardium occidentale L.) at two intervals of spraying against major pre-flowering insect pests of watermelon. The results show that the effectiveness of each plant extracts depends on the interval of spraying. Plants sprayed at 7-day intervals had significantly less insect infestation when compared with that of 10-day interval of spraying. T. vogelii and M. oleifera had higher insecticidal efficacy than A. squamosa and cashew nut extracts but the applied plant extracts had the same insecticidal potential with Lambda-cyhalothrin against the observed insects during late planting season. Therefore, the plant extracts proved to be alternative to synthetic insecticide in the management of insect pests of watermelon at 7-day interval application sequence.

Phytochemical and Physicochemical Studies of Fermented Liquid of Citrulus lanatus (Egusi) Pod as a Potential Herbicide

The fermented liquid of Citrulus lanatus (Egusi) pod was observed to have a herbicidal behavior after discarding it on grasses in the process of removing the seed from the pod which includes washing and filteration. Preliminary studies like phytochemical screening, physicochemical analysis (colour, pH, chloride, phosphate, phosphorus, total alkalinity, odour) and heavy metals (Zn and Cu) determination were carried out on the fermented Egusi pod liquid. The phytochemical screening showed that steroids, triterpenoids, saponins, terpenoids and triterpenes were present, while phenol, alkaloids, glycosides, anthracenes and flavonoids were absent. The physical analysis showed that the fermented liquid colour is creamy, turbid in appearance, a pH of 4.59, with an objectionable odour. The chemical analysis showed the absence of chloride, total alkalinity and total hardness. The total amount of phosphate and phosphorus present were 217.8 mg/L (4.35%) and 71.03 mg/L (1.42%) respectively, while the amount of Zn and Cu were 0.4426 mg/L and 4.4352 mg/L respectively. The herbicidal behavior could be attributed to its acidic nature and the high amount of phosphate.

Reação de plântulas de melancia forrageira aos ambientes aberto e protegido

Destacada no semiárido nordestino como uma planta de excepcional capacidade forrageira e notória resistência às adversidades do local, a melancia forrageira (Citrulus lanatus cv. Citroides) é mais uma espécie cujo pouco conhecimento a limita como alternativa comercial. A pesquisa foi conduzida na área experimental da Universidade Federal do Piauí, em Teresina, no período de junho a agosto de 2019, e teve como objetivo identificar as reações das plantas em ambiente aberto e protegido, conduzidas em bandejas de poliestireno expandido. O desenho experimental foi feito em blocos casualizados com 4 repetições e os tratamentos em arranjo fatorial 2x2, com os fatores tipo de bandeja (72 e 128 células) e ambiente (céu aberto e cultivo protegido). As bandejas foram preenchidas com substrato comercial e adubação química, distribuídas em suportes a céu aberto e dentro de uma unidade de cultivo protegido com 50% de sombreamento. Para aferir as respostas, foram avaliados os parâmetros: altura da plântula do colo à gema terminal, comprimento da raiz, peso da matéria fresca da parte aérea e das folhas cotiledonares, sendo possível concluir que: as plântulas reagem mais ao tipo de bandeja do que ao ambiente de cultivo, onde bandejas maiores (72 células) influenciam positivamente no peso das folhas cotiledonares, no número de folhas e no peso da matéria fresca da parte aérea. Tanto ambiente quanto o tipo de bandeja interfere no comprimento da raiz, ficando mais profunda nas unidades de 72 células e ambiente aberto e, independentemente do tipo de bandeja, será mais comprida no ambiente aberto.

NEUROPROTECTIVE EFFECT OF CITRULLUS LANATUS SEED EXTRACTS ON CEREBRAL ISCHEMIC REPERFUSION INJURY INDUCED COGNITIVE IMPAIRMENT AND OXIDATIVE STRESS

Objective: Oxidative stress appears to be an early event involved in the pathogenesis of Alzheimer's disease (AD). The present study was designed to investigate the neuroprotective effects of citrullus lanatus on bilateral common carotid artery occlusion (BCCAO) induced cognitive impairment and oxidative stress in Wistar albino rats.
 Methods: Cognitive impairment and oxidative stress were induced by BCCAO for 30 min, followed by 7 d reperfusion of male wistar rats. Morris water maze and rectangular maze performance tests and locomotor activity were used to assess memory performance tasks. To study the activity, rats weighing 250-300g were pre-treated with successive extracts of n-hexane fraction (HF), ethyl acetate fraction (EAF), ethanol fraction (EF) and aqueous fraction (AF) of 400 mg/kg, 200 mg/kg, p. o of each for 10 d and the treatment was continued for another 7 d after cerebral ischemia. Various biochemical parameters like lipid peroxidation, Catalase, DPPH and AchE were also estimated in the brain after the treatment.
 Results: There was significantly increased oxidative stress and cholinesterase activity with cognitive decline in the hippocampus in rats of BCCAO group as compared to sham-operated (p<0.05). The animals treated with Donepezil, HF and EF prevented the biochemical changes significantly (p<0.001) and there was significant (p<0.001) improvement in cognitive parameters compared to BCCAO treated rats.
 Conclusion: Thus present study indicates the neuroprotective effect of citrulus lanatus seed extract (HF and EF) against BCCAO induced cognitive impairment and associative oxidative damage.

Therapeutic Benefits of Commercially Available Gourd Family in Improvement and Sustainability of Human Health

Cucurbit family are a fruit producing plants with 130 genera and 800 species and it is one of the genetically discrete groups of food plants such as pumpkin, cucumber, squash, gourd and melon. Cucurbit family provide an important dietary fibre, β-carotene (pro-vitamin A), potassium and vitamin C. Consuming dietary fibre regularly can prevent diabetes mellitus, obesity and cardiovascular disease. Pumpkin (cucurbita maxima) is widely cooked as desserts in Malay cuisines. 60-80% content of polysaccharides in pumpkin pulp functions as anti-tumour, anti-diabetic, hypolipidemic, and immune-stimulating activities. Winter melon (Benincasa hispida) is a source of water soluble polysaccharides, vitamin C while the taste is pleasant, sub acid and aromatic juicy flesh; a great source of functional food production and can be stored up a year. Rockmelon (Cucumis melo L) has nutritional value namely carbohydrates, ascorbic acid, folic acid and potassium while the seeds are rich in oil and protein, and the compounds of this fruit are functioning to prevent cancer, fighting depression, dandruff, ulcers and stimulate the immune system. The red flesh of watermelon (Citrulus lanatus) has anti-carcinogenic compounds. Cucurbit fruits have blood glucose lowering properties and the active ingredient has been shown to be polysaccharides; able to modulate the immune system, anti-tumour, decrease inflammation and act as hypoglycaemic agent.

Comparative assessment of insect pests population densities of three selected cucurbit crops

Comparative assessment of insect pests population densities of three selected cucurbit crops

The Dominant True Spiders in Seed Watermelon Plantations, and Efficiency of Traps in Collecting Occurring Species

Seed watermelon, Citrulus lanatus (Thumb) is an early summer crop, which is a subject to infestations by several insect pests resulting in damage and losses in the crop production. A study was undertaken at Rasheed region, Beheira Governorate during 2015 and 2016 summer seasons to detect the true spider species occurring in seed watermelon plantations, and monitor the population fluctuation of the most dominant ones. In addition, a comparison study was conducted to find out the efficiency of traps, used in spider catch, as related with spider species. Six true spider species were surveyed beginning from first of May up to mid-July. Paradosa sp. and Lycosa sp. (Fam. Lycosidae) and Thanatus albini (Fam. Philodromidae) were captured throughout the season; May to July. On the other hand, Clubiona sp. (Fam. Clubionidae), Singa sp. (Fam. Araneidae) and Thomisus sp. (Fam. Thomisidae) were trapped only during July. The most dominant spider species in 2015 season was Thanatus albini (43.77%), followed by Pardsoa sp. (42.64%), and then Lycosa sp. (4.91%). A reverse situation was found in 2016 season, as the most dominant spider was Pardosa sp. (45.14%), followed by Thanatus albini (41.32%) and the third rank was occupied by Lycosa sp. (4.17%). However, the dominance percentages of the remaining spiders ranged between 0.17 and 4.17% in both seasons. Tools used for capturing spiders were variable in their efficiency. Pardosa sp. was captured mainly by pitfall traps, with values of 90.27 and 93.08%, out of total catch of different traps, in the first and second seasons, respectively. Lycosa sp. was not captured by the sweep net, and captured in low numbers by each of pitfall and water pan traps. Thanatus albini was captured by the sweep net (39.66 & 41.86%) and water pan trap (47.41 & 50.39%) in 2015 and 2016 seasons, respectively, but was captured in low numbers in the pitfall traps. Clubiona sp., Singa sp. and Thomisus sp. were all not detected in the pitfall traps, and were found in low numbers in each of sweep net and water pan traps.

Evaluation Microbiologique Et Origines De La Contamination Des Produits De 4ème Gamme Vendus Sur Les Marchés D’abidjan, Cote D'ivoire

The sources and degree of microbial contamination of 4 th range products or ready-to-eat products made from traditional processes were evaluated in three markets in the city of Abidjan. This study initially consisted of searching for microorganisms such as Staphylococcus aureus, faecal coliforms, E. coli and Salmonella spp. Then, Ishikawa's method or diagram was used to determine potential sources of food contamination consisting of three (3) fruit and two (2) fruit vegetables and one (1) leafy vegetable, respectively, pineapple (Ananas comosus) papaya (Carica papaya), watermelon (Citrulus lanatus), onion (Allium cepa), tomato (Lycopersicum esculentum Mill.) and amaranthus (Amaranthus hybridus). Fecal coliform loads were very high at the fruit level (1.8 × 103 - 9.1 × 102 CFU / g), onion (1.3 × 104 CFU / g), tomato puree (1, 82 × 103 CFU / g) and an E. coli load at the tomato puree which is 9.1 × 102 CFU / g. The analysis using the Ishikawa diagram shows that contamination sources were the poor quality of water, raw material, lack of sanitation, illiteracy, unsafe traditional practices and sellers hygiene.

English

The present study aimed to evaluate some agronomical, physical and nutritional characteristics of seeds of three species of Cucurbitaceous, namely Citrulus lanatus, Lagenaria siceraria and Cucumeropsis edulus. Agronomic experiments were investigated over a two-year period during which, some agronomic performances of the tested varieties were evaluated. The physical characteristics of the collected fruits were also determined. The nutritional composition of the seeds, in particular their moisture, oils and proteins contents were then evaluated. Finally, the physicochemical characteristics, such as acidity, peroxide index, saponification index and the composition of fatty acids present in the oils extracted from seeds were performed. Results show that the species of C. lanatus and L. siceraria germinated respectively five and seven days after sowing. The flowering was observed 36 and 42 days, respectively, after sowing while the fructification appeared 44 and 58 days after sowing. According to results obtained during the two years of experimentation, the three species of Cucurbitaceous investigated in the present study could be ranged in short-cycle species (C. lanatus and L. siceraria) and long cycle species (C. edulus). Moreover, C. lanatus could be classified as the most productive as compared to others species of Cucurbitaceous plants investigated in the present study. C. edulus seeds are the longest (1.76 and 1.83 cm) in opposition to the seeds from C. lanatus (1.33 and 1.49 cm). Results of physicochemical analyses revealed the presence of fat (49.5 - 51.9%), with a high protein contents (18.46 - 31.41%). The composition of the fatty acids detected in oils extracted from seeds showed a strong concentration of linoleic acid (66.65%) and the presence of oleic acid (13.76%). The high unsaturated fatty acids proportion detected in oils from L. siceraria seeds was 80.40%. The saturated fatty acids detected were C16:0 and C18:0; and were more concentrated in the species of C. lanatus. Key words: Cucurbitaceous, Citrullus lanatus, Lagenaria siceraria, Cucumeropsis edulis, oil, seeds, Benin.

Germination of selected African leafy vegetables in response to different dormancy pre-sowing treatments

When the cultivation of weedy species is being considered, knowledge of seed dormancy is important, because dormancy impedes timing and extent of seed germination. In this study the effect of dormancy on seed germination of eight selected African leafy vegetables was investigated. The objective was to determine whether these vegetables had any form of seed dormancy and if so, whether pre-sowing treatments could break seed dormancy. The different factors associated with seed dormancy that were investigated included:- 1) physical barriers, such as hardness of the seed coat; (2) physiological dormancy, such as the effect of temperature (thermodormancy) and light (photodormancy) on embryo differentiation and development; and (3) chemical dormancy, such as the presence of chemical inhibitors in the seed cotyledons. Fresh, mature seeds of Amaranthus cruentus, Brassica rapa subsp. chinensis, Citrulus lanatus, Cleome gynandra, Corchorus olitorius, Cucurbita maxima, Solanum retroflexum and Vigna unguiculata were studied, whilst Beta vulgaris var. cicla served as the reference crop. The findings showed that A. cruentus, B. rapa subsp. chinensis, C. gynandra and S. retroflexum exhibited some form of physical, embryo or physiological dormancy within their seed. Scarification improved onset and final germination of A. cruentus and B. rapa subsp. chinensis seed, whilst pre-chilling improved the germination of A. cruentus. Soaking seed in KNO3 improved both onset and final germination of B. rapa subsp. chinensis and S. retroflexum.

An assessment of some growth and yield indices of six varieties of watermelon (Citrulus lanatus thumb) in Asaba area of Delta state, Nigeria

Tropical Agricultural Research and Extension is a peer-reviewed international scientific journal covering a wide range of subject areas in tropical and subtropical agriculture published quarterly by the Faculty of Agriculture, University of Ruhuna, Sri Lanka. The journal is also available on the Faculty of Agriculture, University of Ruhuna website https://www.agri.ruh.ac.lk/tare/index.htm .