SIZE OF CORN CROP SHARPLY REDUCED BY LONG DROUGHT
US Agr Dept, in wake of prolonged drought in Middle West grain growing regions, reduces drastically corn crop forecast, a development that is expected to increase meat and poultry prices in '75; corn crop is expected to total 4.97-billion bu, which would be 12% lower than '73 record crop; earlier forecasts estimated corn crop at 6.5-billion bu; dept economist J Dawson Ahalt says sharply reduced corn crop will not have much effect on consumer prices for rest of '74, although prices may soar in '75; says main impact of smaller crop will be on pork and poultry products; contends that beef supply is likely to continue high, but more of beef will come to mkt fed on grass; implies that not all price increases at farm level will be passed along to consumers, noting that there is 'unsually wide spread' between farm and retail prices; dept rept points out that feed grains are off 17% in current yr, although wheat production is still expected to set record; rice production is also rising sharply; Ahalt and Deputy Asst Agr Sec Richard E Bell point out that crop rept was based on growing conditions as of Aug 1 and that some rain has fallen since; new wheat crop is 1.84-billion bu, down from 1.93-billion 1 mo ago; grain sorghum output is expected to decline 34%; illus; graph of '74 grain forecasts (M)