This is a guide to the techniques required to produce pure and vigorous seed from varieties of this cross-pollinated crop. Multiplication rates, through sequential breeder, foundation, and certified seed stages, are high:3 kg of seed are adequate for sowing 1 ha, subsequently producing 1 tonne of clean seed. Nucleus seed plots (stage 0), sown for regeneration once every 4 years, should be effectively is o- lated . They should be between 0,1 and 0.2 ha in size, and contain at least 3000 plants. Plots of breeder seed(stage1)should similarly be well isolated, and rigorously inspected and rogued, and not more than 1% of off – types should be permit tedatfinal inspection. Plot sizes are normally between 0.1 and 0.5 ha, according to how much certified seed is required, using a conservative multiplication factor of X200. At the end of the foundation seed stage (stage 2), through protective perimeter planting, inspection, and rogueing, off-types should be less than 2%. At the final certified seed stage(3), the permitted level of off-types is 5%. Six points of guidance are given for extension staff to pass on to farmers who(as may be expected) at tempt to multiply their own improved seed.
Tag: millets
Separating the effects of trees on crops: the case of Faidherbia albida and millet in Niger
Faidherbia albida (Del.) A. Chev. is an important tree species of the scattered tree or parkland systems in the Sahel. The improved crop growth under its canopy is well known, and has been attributed to various components notably: higher soil fertility, improved microclimate and better soil physical properties. The relative contributions of each of these components are not known, but knowledge about this is essential for making proper decisions concerning management options. The overall tree effect on crop production (expressed as fraction of the sole crop production) is analysed here as a weighted sum of (positive and negative) relative net tree effects on the resources for crop growth. In this sum, the weights reflect the degree of limitation of the resources in the environment at the tree-crop interface. The paper shows how the relative net tree effects and the accompanying weights can be estimated from field experiments. In an on-farm field experiment in Niger, millet production under the F. albida canopy was about 36% higher than in the open field. The nitrogen availability under trees was estimated to be more than 200% higher than in the open causing a 26% production increase. The phosphorus availability was estimated to be almost 30% higher and because of its high limitation causing a production increase of 13%. The net effect via other resources (notably light and water) was negligible (3% production reduction) and not significant.