Crop production under changing environment

Roy Sadeh, Simeon Ntawugurana

 

The highly variable and unpredictable rainfall within and between seasons, which characterize the Mediterranean region, results in significant wheat yield losses. More effective use of the entire growing season is essential for enhancing wheat yields. If wheat seeds are sown into the dry soil in the early season, they are exposed to high risk due to high precipitation fluctuation. Sporadic 30-50 mm of rainfall could suffice for germination, but with no additional rainfall, drought stress will be imposed upon the young seedling and, in severe cases, force re-sowing. This has become more important in wheat where crop establishment is poor if seeds of the ‘Green Revolution' varieties containing the Gibberellin Insensitive (GAI) dwarfing genes Rht-B1b and Rht-D1b are sown deep (to access deep soil moisture) and where conservation farming systems and stubble retention practices have been adopted. Such varieties have shorter coleoptiles and will not establish well if sown too deep. To counter these widely used dwarfing genes, several alternative dwarfing genes that are responsive to Gibberellin (GAR) and exhibit no reduction in coleoptile length have been identified and characterized. Lines containing these genes emerge more successfully when sown deep or when used in conservation farming systems.

 

 

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