A Comparison of the Effect of Complete and Partial Cross‐pollination of Alfalfa on Pod Sets, Seeds Per Pod, and Pod and Seed Weight¹

Abstract

Synopsis On each of 6 pairs of alfalfa clones, all flowers on 1 member and one third on the other were cross‐pollinated. With “one third”, 66.4% formed pods with an average weight of 12.7 mg., while with “all flowers”, 46.7% formed pods of 11.3 mg. average weight. Clones differed in percentage of cross‐pollinated flowers forming pods but behaved similarly at the high and low intensities. Both pod weight and pod set varied for different dates among clones but in no consistent trend. Heavier pods at low cross‐pollination intensity are attributed to heavier seeds and pod tissue rather than number of seeds per pod.

Effects of Between‐Row and Within‐Row Spacing on Alfalfa Seed Yields

“…High seed yields were maintained throughout the third and fourth harvest years (2006 and 2007) despite having lower stems per square meter. These findings are in agreement with other studies that suggest that stems per square meter is not the only deciding factor in determining seed yields but are probably the result of the uninhibited production of racemes per stem in thinner stands (Pederson et al, 1956; Teuber and Brick, 1988). On the other hand, in the later three years, the lowest seed yields were consistently obtained from the combination of 100‐cm between‐row spacing and 60‐cm within‐row spacing treatments, suggesting that with the thinner plant density, the increased racemes per stem could no longer compensate for declines in stem per square meter.…”

Fertilization Dynamics and Parental Effects Upon Fruit Development in Raphanus Raphanistrum: Consequences for Seed Size Variation

“…Most previous studies of maternal and paternal factors influencing seed production have focussed on the number of seeds produced rather than on seed size or quality (Barnes and Cleveland, 1963;Sayers and Murphy, 1966). Recently, however, investigators have begun to examine maternal and paternal effects upon seed size and the relationship between seed size and fitness (Pederson et al, 1956;Mulcahy and Mulcahy, 1975;Bertin, 1982;Schemske and Pautler, 1984;Marshall and Ellstrand, in press). In many species, seed size is positively correlated with germination rate, seedling success, adult biomass or fruit production, particularly in competitive situations (Black, 1958;Schaal, 1980;Gross and Soule, 1981;Howe and Richter, 1982;Weis, 1982;Hendrix, 1984;Dolan, 1984;Stanton, 1984a).…”

Quantitative Traits Breeding for Multifunctional Grasslands and Turf

“…Different authors suggest that alfalfa could potentially produce more than 2 t ha −1 of seed (Pedersen et al 1956 ). Different authors suggest that alfalfa could potentially produce more than 2 t ha −1 of seed (Pedersen et al 1956 ).…”