Production of hybrid corn

Corn is a cross-pollinated crop; that is, pollination of the silks of any ear is largely accomplished by pollen from some other plant. When allowed to reproduce normally the resulting plants exhibit variation in all measurable characteristics. Each plant has received an assortment of hereditary potentialities from its two parents, some good and some bad. Even plants of excellent appearance may carry undesirable elements in a masked condition. These undesirable characteristics will reappear in later generations as a result of the reassortment of the hereditary material. If the undesirable elements are not masked, the affected plant may be low in yield or even barren. The frequent occurrence of barren plants or plants with small ears in open-pollinated varieties is responsible for most of the difference in yielding ability between such strains and the best hybrids. The mode of pollination has been the major factor responsible for the failure or success of past and present systems of com breeding. The methods which have been used may be classified under the general heading of mass selection, ear-to-row selection, varietal hybridization and selection within and among inbred lines

Better Protein More Oil in Your Corn

Corn that is higher in oil, corn with a better balance of protein - that\u27s something farmers can look forward to. The new improvements will be useful. But they\u27re not as spectacular as they sound. Higher oil content, better proteins can\u27t be seen in the field or in the crib. Farmers are apt to be disappointed if they expect too much

Building New Corn Hybrids

Iowa farmers no longer look upon hybrid corn as a new fangled idea that may or may not prove practical. Ten years ago less than 1 acre out of every hundred grown in Iowa was hybrid; in 1941, probably at least 95 acres out of every hundred are hybrid

Transmission tests of maize mutants induced by ultra-violet radiation

Brief descriptions are presented for various ultra-violet-induced changes. Among 78 inviable types, the mutant type was recovered in F3 in 71 cases. In several instances the mutant type appeared in low ratios. This tendency was most marked in the segregations for germless seeds. Male and female transmission tests were made with 24 viable mutant types. In 15 cases the male and female transmission rates were not significantly different. In the remaining nine cases male and female transmission rates were unequal, and in two instances transmission through the male gametophyte was significantly greater than through the female

Corn hybrids for Missouri

Caption title.Digitized 2006 AES MoU

Effects of Metallicity on the Rotation Rates of Massive Stars

Recent theoretical predictions for low metallicity massive stars predict that these stars should have drastically reduced equatorial winds (mass loss) while on the main sequence, and as such should retain most of their angular momentum. Observations of both the Be/(B+Be) ratio and the blue-to-red supergiant ratio appear to have a metallicity dependence that may be caused by high rotational velocities. We have analyzed 39 archival Hubble Space Telescope Imaging Spectrograph (STIS), high resolution, ultraviolet spectra of O-type stars in the Magellanic Clouds to determine their projected rotational velocities V sin i. Our methodology is based on a previous study of the projected rotational velocities of Galactic O-type stars using International Ultraviolet Explorer (IUE) Short Wavelength Prime (SWP) Camera high dispersion spectra, which resulted in a catalog of V sin i values for 177 O stars. Here we present complementary V sin i values for 21 Large Magellanic Cloud and 22 Small Magellanic Cloud O-type stars based on STIS and IUE UV spectroscopy. The distribution of V sin i values for O type stars in the Magellanic Clouds is compared to that of Galactic O type stars. Despite the theoretical predictions and indirect observational evidence for high rotation, the O type stars in the Magellanic Clouds do not appear to rotate faster than their Galactic counterparts.Comment: accepted by ApJ, to appear 20 December 2004 editio

New Corn Hybrids for Iowa

Four new lines in the cooperative Iowa corn breeding program are available for the production of several new hybrids in 1951. The lines themselves won\u27t be released this year. They\u27ll be released in single-cross combintions. The release procedure to be used is similar to that of the other north-central states and is called delayed release