However, plant architecture is a major determinant of the crops' resource use efficiency.
Their origin and development reflected factors such as social organization, the distribution of food-crop resources, and defense considerations.
Findings indicate potential for simplified agricultural landscapes to be 'selectively' manipulated to enhance colonization of the crop by natural enemies, but not herbivores, by improving connectivity between crops and non-crop resources, through the presence of woody vegetation.
It has been proposed that the benefits of local manipulations will depend on the landscape context, with greater benefits in simplified landscapes and smaller benefits in landscapes with an abundance of non-crop resources.
By preserving their traditional agricultural practices, small-scale farmers conserve not only crop resources, but also many wild varieties associated with their traditional systems, an approach to food sovereignty that emphasizes local values, autonomy, and biodiversity.
In April 2007, the Department of Science and Technology Education of the Ministry of Agriculture released an investigation and assessment letter to all provinces and cities regarding the development of suitable energy crop resources in marginal land.
Moreover, for most crops, these resources are available for only a limited period of the year.
Viable soil fertility strategies have to be implemented to make use of the available manure and crop residue resources for improving soil fertility and crop productivity by minimizing their competitive demands for fuel and feed.
Although considered untenable in the past (Frankel 1970b; Hawkes 1983; Williams 1984), in situ (or on-farm) conservation of crop genetic resources – particularly of landraces and wild crop relatives – is now recognized as a crucial complement to ex situ conservation (Bretting and Duvick 1997; Maxted et al. 1997).
A better understanding of this distribution can help assist in establishing representative collections of crop genetic resources, which form the basis of modern crop improvement [3] [4].
The increasing availability of crop genome resources has greatly facilitated the elucidation of crop evolution; this elucidation involves the discovery of key loci, thereby contributing to genetic-based domestication and improvement [ 5].
