Dietary intake of vegetables is low in Sub-Sahara Africa (SSA) compared to the world's average. This situation is worsened by low water availability for vegetable production especially in the dry season. However, amaranth which can be grown in the different agro-ecologies of Nigeria is a dual purpose crop with edible leaves and seeds rich in essential nutrients, minerals and proteins. The crop is also a drought tolerant C4 plant which has the ability to survive under minimum soil moisture condition, hence the reason for its use in the study. This investigation was therefore conducted to discover the optimum water requirements in a screen house, and evaluation of different moisture stress based on the derived optima in two subsequent field trials. In the screen house and field, water stress treatments varied from: -6.0, -1.2 to -0.3 bar (the control). Results in the screen house study showed that optimum soil water potential for amaranth was reached at -1.2 bar, and that variety NH84/493 performed better than the others, in all growth and yield parameters measured. In field trials, bringing the moisture content from dry (-6.0 bar) to -1.5 bar optimum soil water potential favored seedling emergence better than all other treatment combinations. However, treatment combination -0.3, -1.5 bar when the soil was initially wet (-0.3 bar) then bringing it to the optimum (-1.5 bar) gave the best seedling establishment and productivity. Variety NH84/493 grown at -0.3, -1.5 bar performed better than all other interactions. We therefore recommend -1.5 bar and variety NH84/493 amaranth for the SSA vegetable industry, especially for improving dry season productivity.

No abstract

. 2006. Response of cucumber to timing of fertilizer application in southwest Nigeria. Can. J. Plant Sci. 86: 1391-1394. A field trial was conducted at the experimental farm of the Department of Crop Protection and Environmental Biology, University of Ibadan, Nigeria, to determine the growth and yield response of cucumber (cv. Poinsett) to timing of fertilizer application. Fertilizer (20:10:10), at the rate of 150 kg N ha -1 , was applied at: planting, 3 weeks after planting (WAP) and 6 WAP. Similarly, split applications were given at planting + 3 WAP, at planting + 6 WAP and at 3 WAP + 6 WAP. The experimental design was a randomized complete block with seven treatments (six fertilizer application treatments plus a non fertilizer control) and four replications. Means were separated using Duncan's Multiple Range Test at the 5% level of significance. In general, plants that were fertilized performed better than control plants in terms of vegetative growth and yield. A split application at 3 WAP + 6 WAP performed the best in terms of vegetative growth and fruit yield. Fertilizer applied once-over at 6 WAP was the least beneficial; application of fertilizer once-over at planting, or a split application at planting + 3 WAP, resulted in a high level of vegetative growth but lower fruit yield compared with the split application at 3 WAP + 6 WAP. L'application fractionnée trois et six semaines après la plantation donne les meilleurs résultats tant pour la croissance que pour le nombre de fruits. L'application d'engrais une seule fois six semaines après la plantation s'avère la moins bénéfique; l'application unique à la plantation ou l'application fractionnée à la plantation et trois semaines plus tard donnent la meilleure croissance mais pas autant de fruits que l'application fractionnée trois et six semaines après la plantation.

Iron toxicity is a major nutrient disorder affecting rice production of wetland rice in the irrigated and rain fed ecosystem in West Africa sub-region. Little attention has been paid to evaluating nutrient contents of rice cultivars grown on such soils and their relationship to the iron toxicity scores, grain yield and dry matter yields. A pot experiment was conducted on two potentially Fe-toxic soils (Aeric Fluvaquent and Aeric Tropaquept). The experiment was a 2 x 2 x 4 factorial experiment, with three replicates arranged in a randomized model. The factors were two soil types, two rice cultivars ('ITA 212') and tolerant ('Suakoko 8') and four Fe 2 + levels (control, 1000, 3000 and 4000 mg L-1). The results showed that for both susceptible cultivar ('ITA 212') and the relatively tolerant ('Suakoko 8') cultivar, little or no differences were observed in their elemental composition regarding micro and macro-nutrients. For the susceptible cultivar, results showed that none of the tissue nutrients significantly relates to iron toxicity scores (ITS), grain yield and dry matter yield on both soil types. However, for the tolerant cultivar, ITS was observed to be significantly related to tissue K and P contents, on the two soil types respectively. Tissue Ca and Mg were observed to be significantly related to the dry matter yield (DMY) on Aeric Tropquept. It could be concluded that for these rice cultivars grown on two potentially Fe-toxic soils, different tissue nutrients may trigger the manifestation of bronzing or yellowing symptoms of rice cultivars.

Experiments were conducted in the screen house of National Horticultural Research Institute (NIHORT), Ibadan, Nigeria, to evaluate the level of germination and emergence of seeds from the different sections of inflorescences of two varieties each of Amaranthus (NHAc3, ED82/1040A) and Celosia (TLV8, Local green) chosen on the basis of maturity period. Seeds were taken from the basal, middle and top parts of the inflorescences of the varieties of these crops grown in the nursery. Seeds from whole inflorescence served as control. A split-plot design was used in which species served as main plot and inflorescence sections served as sub-plot with four replicates. Data were analyzed using SAS and LSD (P= 0.05). Results showed that there is distinct inflorescence maturity pattern for the two crops. The basal seeds germinated earlier and gave the highest seedling emergence while the apical seeds gave the lowest seedling emergence. Similarly, apical seeds of inflorescence gave root and plumule length that were 57% of those of the seedlings from the basal regions. Maturity of inflorescence was therefore acropetal in the crops. The determinate early flowering varieties of both species were significantly (P=0.05) superior to the indeterminate late flowering ones in seedling emergence, plumule length as well as rooting depth. It seems therefore that early seedling growth which is better in the determinate early flowering varieties of Amaranthus and Celosia is a function of varietal differences as well as growth habit of the plant.