Field trials were conducted during 2004 and 2005 to determine the effect of sowing seeds from plants with multiple heads and seeds from single headed plants of sunflower on seed yield, head characteristics and oil content of three widely grown open pollinated varieties (Funtua, Record and Isaanka) in the humid forest -savanna transition zone which is outside the current growing areas with a view to improving stability and sunflower productivity in this region. Seeds from multiple headed plants produced plants that flowered and matured 2-3 days later than plants from single headed plants. Apart from days to flowering in 2004, number of days to maturity and plant height were affected independently by variety and seed source factors. However, the seeds from single headed plants produced plants that recorded significantly (P < 0.01) higher head weight, head diameter, achene weight and number per head than plants from seeds of plants with multiple heads. Seed source had little effect on sunflower seed yield and oil content. However, Funtua produced significantly (P < 0.05) high seed yield (1956.0 kg ha −1 ± 76.06) when seeds from plants with multiple heads were sown, while Isaanka recorded comparatively high seed yield from seeds of plants from either multiple (1221.0 kg ha −1 ± 165.90) or single heads (1388.0 kg ha −1 ± 135.84) and Record (1201.0 kg ha −1 ± 96.97) when seeds from single headed plants were sown. Therefore, it is recommended that prospective sunflower growers who wish to cultivate Isaanka, can sow seeds from either the multiple or single head and preferably the multiple head for Funtua, and single head for Record.

Sesame (Sesamum indicum L.) is an important oilseed crop that ranks sixth among vegetable oils worldwide. Asia and Africa respecti vely account for 2. and 0.9 of the 3.66 million tons produced worldwide. However, Africa's net export of the commodity is just 38% of its producti on, despite the fact that the Conti nent has favourable weather conditi ons that would support large-scale growing of the crop for commercial purposes. Presently, majority of the primary growers of the crop on the conti nent produce non-certi fi ed organic Sesame but which meets the specifi c requirements for organic Sesame. Recently released varieti es of the crop, i.e. NCRIBEN-01M, NCRIBEN-02M, NCRIBEN-03L and Ex-Sudan (exoti c variety) readily meet the premium quality requirements for export (i.e. 1000 seed weight>3.0 g, 40-0% oil content and pearly-white seed colour). This paper presents data on the agronomic performance of these varieti es.

The impact of hydrothermal variability on organic sunflower seed yield in the humid tropical region of Nigeria was studied between 2001 and 2008 using rainfall and temperature as proxies for climate variability. The test variety was "Funtua", a local adapted, open pollinated, and late maturing sunflower variety. Rainfall amount during the period of study compared favorably with the long-term mean (25 years). September recorded adequate amount of rain throughout the period of study, except in 2002. Sum of effective temperature and growing degree days (GDD) ranged between 1,907.1 and 2,440.3°C and 2,435.2 and 3,634.3°C and appeared adequate for the production of organic sunflower in the region. Sunflower seed yield obtained between 2001 and 2005 ranged between 1.03 and 1.26 t/ha and were superior to the Nigerian average of 1.00 t/ha, African average of 0.81 t/ha, and a little below the world average of 1.52 t/ha. Grain yield, however, declined in 2006 and thereafter remained below 1.0 t/ha till 2008. Nevertheless, it could be concluded that despite the global increase in climatic variability a good yield of sunflower is still possible in the humid tropical region.