The Metro variety of maize was studied for its reproductive efficiency. The basic fertility o f the crop was found to be adequate for yield s u p to 5000 kg per hectare. However, in the s tu d y it was shown that less than 50 percent of this potential was achieved un d er normal cropping conditions. The main reason fo r the low reproductive efficiency was the lack o f syn chronisation between tasselling and silking periods. As a consequence, late earshoots did n o t receive an adequate supply of pollen. A kernel y ie ld o f 2,300 kg. per hectare was produced by cobs from early earshoots. Earshoot silking during the fir s t 2 weeks o f tasselling acco u n ted fo r 88 p ercen t o f the y ie ld obtained. Although the female flowrs were receptive from the fir s t day o f silking, pollen viability was low with only 46 perecent germination on the fir s t day and decreasing rapidly on the follow in g days. The planting o f pollen donors and selection o f plants with simultaneous tasselling and silking periods can improve yield through increased e ffic ien c y in pollination.