VARIETIES.   For getting the maximum yield, the choice of the variety plays a very important role. Disease resistance, fertilizer responsiveness, lodging and shattering resistance and the desired maturity are some of the important considerations in choosing a variety for cultivation under irrigated conditions. Under rain-fed conditions, the ability to withstand soil and atmospheric drought is most needed. In the absence of a right variety, the production technology cannot be applied effectively.

Before the Wheat-Revolution; all the wheats grown in India were of the tall conventional type. In the irrigated areas, most of these wheats have been replaced by the semi-dwarf wheats. In low-fertility soils or in rain-fed areas, the tall varieties are still grown. Experiments have shown that the semi-dwarf wheats are superior in yield to the tall conventional wheats at all levels of fertility. The tall wheats were suitable only for low inputs. Whenever the fertilizer dose was increased, or more intensive production practices were followed, they generally lodged. As the farmer wanted the straw for his cattle, he preferred the tall types and the breeders in the past had to keep this requirement in view while producing the new varieties. Some of the older varieties were outstanding for their good grain quality and regional adaptibility and for their performance under low-input conditions. With the exception of a few, most of the old wheats have now been replaced by newer varieties, particularly under irrigated conditions. With the identification of semi-dwarf wheats by the wheat-breeders in 1963 and the establishment of their high-yield potential at all levels of fertility the emphasis has shifted in India to the producing of semi-dwarf wheats for the areas where assured water-supply is available. In addition to the dwarf aestivums, dwarf durums were released for the first time in India.

Many of the older wheats were replaced in the past few years with new wheats. The older varieties have either gone out of cultivation or are occupying a limited area. Information on the old and new varieties is summarized in Table 1.