Table 4.2 reports results of this regression. Irrigation is not included because the variable for percent of total land under irrigation was never statistically significant. The coefficient for percent of maize area planted to hybrids is positive and significant in all specifications. The trend variable is positive and significant and lowers the coefficient for hybrids. Fertilizer is not significant in the regressions except when the trend variable is not included; over the period, national average fertilizer use and hence calculated use on maize grew slowly.

Figure 4.6 shows actual yield of maize and projected yield using estimated coefficients from specification two and actual values for fertilizer use, rainfall, and trend, but with zeros for postreform hybrids. The gap between actual and projected yields was greatest in 1990 at almost 2 t/ha. Impact of post-reform private hybrids on maize yields in Turkey parallels a similar impact of imported hybrids on maize yields in Greece during the 1970s (see Figure 4.7). Virtually all maize in Greece is irrigated, which largely explains why national average yields for Greece exceed those for Turkey. Figure 4.7 also shows lower maize yields in Syria, which limits variety introduction, and higher yields in EU countries, which allow free intra-EU movement of varieties.

During 1990-92, farm-level annual gross financial value of additional production due to postreform hybrids was about $ 130 million ($ 255/ha over 515,000 ha; see Table 4.3). CIMMYT reports 1992 farm-level maize and nitrogen prices of $ 178, which we use to calculate financial benefits. We did not find cost of production surveys showing cost differences between local and hybrid maize; we estimate higher costs for hybrid seed and for harvesting and drying a larger crop (see Table 4.3); we assume similar fertilizer use on local and hybrid maize. With these assumptions about costs, we estimate annual net financial benefits in 1990-92 of $ 97 million (see Table 4.3). This is the sum of net increases in farm incomes realized by all maize farmers.

Adjusting farm-level maize and fertilizer prices to international prices, the annual net economic benefit from private maize hybrids in 1990-92 was $79 million (see Table 4.3), or 24 percent of the gross economic value of Turkey's average annual maize production ($ 330 million) during 199092.

# **4.2.2 Sunflower**

Sunflower was originally introduced from Europe. It has gone through several cycles of area expansion due to imported varieties then decline due to spread of the orobanche parasite. The most recent complete cycle started in 1963 with introduction of Vinimik, an OPV orobanche-resistant variety from Russia. In the late 1970s, Vinimik's resistance to orobanche began to break down, with 1981 being the worst year. Private foreign hybrids, introduced on a large scale from 1985, are resistant to the parasite. They also have higher yield potential. However, sunflower is commonly grown as a rainfed crop in relatively dry climates. In such conditions, lack of moisture limits yield gains possible with hybrids. The government also developed some resistant hybrids, releasing them in 1984; these never became popular with farmers. In 1985 Vinimik and private hybrids covered almost equal shares of Turkish sunflower area. By 1992, Turkish seed companies produced only 193 tons of Vinimik seed compared to 3,500 tons of hybrid seed (including some for export), and about 90 percent of area was planted to hybrids.

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