Effect of planting date on growth and grain yield of fonio millet (Digitaria exilis Stapf) in the Southeast of Senegal

Abstract

A field experiment was carried out during the rainy cropping seasons of 2010 and 2011 in Southeastern Senegal. The study aimed at investigating the effects of sowing dates on plant growth and grain yield of fonio millet (Digitaria exilis Stapf). Seven planting times (from early July to mid August with 7-day interval) were laid out in a randomized complete block design. In general, plant growth and grain yield were significantly better for the early July sowing dates compared to other sowing dates. However, tillering capacity and grain size were not influenced by the sowing date. Highest grain yields were obtained on 15-July planting date with an average of 1,111 kg ha^-1 in 2010 and 1,269 kg ha^-1 in 2011. Compared to this planting date, the delay in sowing reduced grain yield by 50% in 2010 and 87% in 2011. Detrimental high rains to seedling vigor, decreasing sunshine during the plant growth, and rain deficit during the reproductive phase were among the main limiting factors for late sowings. Hence, the first fortnight of July could be recommended as optimal sowing period for early maturing cultivars of fonio in Southeastern Senegal.

Key words: Fonio, Digitaria exilis, sowing date, growth, yield, Senegal.