PS 7-56
A new growing season for Helianthus coming to a field near you?
Helianthus annuus is the most common species of sunflower in North America and is commonly found growing and flowering year-round in Corpus Christi, Texas. To determine if there are differences in growth and photosynthetic characteristics between progeny from summer-active and winter-active plants during each season, plants were grown individually and with 2 or 4 associates from the opposite progeny type during the winter and summer growing seasons. We previously presented data from our winter growing season. This poster presents results from our summer experiment. Our hypothesis, which is supported by our winter experiment, is that there is no difference in growth and photosynthetic characteristics between progeny from winter-active and summer-active plants during either season. If so, summer plants would continue to do well during the summer and, with climate change, there could be an establishment of winter-active cohorts in more northern areas.
Results/Conclusions
In the summer growing season, progeny from winter-active plants are doing as well as progeny from summer-active plants. An Analysis of Covariance (ANCOVA) of target plant dry weight from an additive design competition experiment shows no significant difference for size between progeny types (P = 0.436) and no significant difference in competitive effect of progeny type (P = 0.216). These results, along with our previous results, indicate that progeny from summer-active and winter-active plants are doing equally well in both growing seasons. We believe that H. annuus could extend its growing season in regions farther north of our area if winters become warmer in these areas.