Factors affecting the success of pollination in corn
Lonnquist, J.H. | Jugenheimer, R.W.
Factors affecting seed setting in corn were studied during the summers of 1940 and 1941. Significant negative correlations were obtained between high temperatures and seed setting on inbred lines when self-pollinated. Some lines set seed well at the highest recorded temperatures while others set few seeds at relatively optimum temperatures. As an average of 2 years, seed setting ranged from 65 to 8% when the maximum temperature on the day of pollination ranged from 80 degrees to 110 degrees F, respectively. Maximum seed setting was obtained when silks were exposed to pollen 2 days after emergence, and it declined rapidly thereafter for each additional 2-day period that pollen was withheld from the silks. Lines resistant to leaf firing, as well as the single crosses among them, set more seed throughout the life of the silks and remained receptive longer than did the susceptible lines and crosses. Loss of receptivity was more rapid in the inbred lines than in the single crosses. Adequate soil moisture provided by irrigation, together with the associated lower temperatures and higher humidity, was effective in prolonging silk receptivity. Highly significant positive correlations were obtained between rate of silk emergence and percentage of seed set for successive 2-day intervals following initial silk emergence. Lines and hybrids whose silks remain receptive for longer periods have a specific advantage under drought conditions. Pollen of 25 lines placed the same day on randomly selected silks of the single cross Wf(9)X38-11 gave highly significant differences in resulting seed set. The differences obtained are thought to be due to varying degrees of cross-incompatibility existing beteen the pollen of various lines and the silks of the seed parent.Show more [+] Less [-]