Dwarf cereals

Some modern varieties of cereals such as wheat and rice achieve high yield potential through genetic factors for plant dwarfness that improve harvest index. A popular notion among plant breeders is that high-yielding... 

It would obviously be of great interest to know whether two distinct patterns of reserve mobilization really do occur within cereals. It is still possible that there is fundamentally only one (GA-dependent) and that the endosperms of maize and sorghum contain sufficient endogenous GA (produced there during development) to stimulate maximum hydrolase production without a requirement for a further supply from the embryo, or without any additional effect of exogenously added GA. The effect of added GA on maize endosperm (aleurone layer) probably varies in different hybrid or inbred lines because some already have a high endogenous GA level while others, e.g. dwarf maize, are naturally deficient in GA. The latter show a three- to five-fold increase in hydrolase production in response to added GA [64] (see Chap. 7). 

Stunted growth. This is seen in severe cases of barley yellow dwarf vims and with some root diseases such as take-all in cereals. 

Transmission of viruses, some animals act as vectors for some important viras diseases. Examples include free-living nematodes transmitting spraing in potatoes, aphids transmitting barley yellow dwarf virus in cereals and mites that transmit ryegrass mozaic viras. 

Time of sowing can be very important for reducing pest problerrrs. Cereal growers in high-risk areas normally drill winter cereals after the rrtiddle of October to reduce aphid attack arrd trarrsfer of barley yellow dwarf virus (BYDV). MairKrop carrots are sown at the end of May or in early Jrme to avoid the first generation of carrot fly. 

CEREAL GRAINS. Much of the world is dependent upon calories supplied by a single cereal staple which supplies carbohydrate in the form of starch. For example, in Afghanistan and Pakistan the staple is wheat, and in Mexico and Central America it is corn (maize). In China and southeastern Asia, regions of the world with the largest population, the staple is rice. Annually, world production of these three cereals dwarfs the production of all other plant foods. American diets derive carbohydrates from wheat, corn, and rice because they appear in so many forms. Other cereal... 

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