ChileanJAR

At “La Platina” Experiment Station ([NIA), in Santiago, Chile, several trials were carried out to find the best wheat sowing date. This research was done during the years 1978, 1979 and 1980, and the sowing dates were from May 24 to September 6. Every year, seven wheat varieties were studied ;five of them were tested during three years; four other varieties were studied for one or two years. Each year, yield, hectoliter weight and Puccinia graminis attack were recorded. Except for the first date of sowing, affected by birds damage, usually the early sowings yielded more than the ater ones. The best sowing time was the second half of June. Wheat yield was reduced 10 per cent when seeded on the second half of July; 20 per cent when seeded on the first half of August, and 30 per cent when seeded on the last part of August. This reduction was 50 per cent in September. AH these results are similar to other trials done 35 years ago. In years with heavy attack of Puccinia graminis, the susceptible varieties show a larger reduction in yield than the resistant varieties, as the seeding date is postponed.