With the rising cost of P fertilizer, the potential
of using nutrient efficient cultivars to increase and/
or stabilize crop production becomes increasing
attractive. Results of this study indicate that rice
cultivars differ significantly in their P requirements.
From a practical point of view, the cultivars which
produced well under a low level of P and responded
well to added P are the most desirable. Cultivars
such as CNA 5164, CNA 4097, CNA 5170, IR
3646-8-1-2, CNA 4137, A8-391 and IAC 47 fall
into this category. Shoot as well as root dry weight
can be used as a criterion for P-screening studies of
rice under greenhouse conditions.