Single-Cross Bermudagrass Seed Production under Different Management1
- R. M. Ahring,
- C. M. Taliaferro and
- W. L. Richardson2
The ease with which bermudagrass [Cynodon dactylon (L.) Pers.] plants are vegetatively propagated, combined with their usual high degree of sexual self-incompatibility, provides a simple mechanism for producing single-cross seed. Such seed could be produced using two cross-compatible, self-incompatible plants vegetatively propagated in alternate rows in a production field. The feasibility of the system depends firstly on the seed yield potential of the parental plants and secondly on the acceptability of the hybrid plant population. This experiment was conducted to measure single-cross seed yields and seed yield components from such a production block, as influenced by N fertilization and early-season forage removal.
The cross-compatible, self-incompatible bermudagrass plants were Oklahoma Agric. Exp. Stn. accessions ‘A-9959’ (PI 253302) and ‘Guymon’. Four levels of N fertilization (N = 22, 34, 67, and 101 kg/ha) and two spring mowing treatments were used in each of the 3 years of the experiment. The experimental design was a Latin Square, split-block, replicated four times. The soil was a Brewer clay loam (fine, mixed, thermic Pachic Arguistolls). The mowing treatments consisted of mowing and removing all growth on or about 1 May (Management A) or mowing and removing all growth on or about 1 May and again on about 20 May (Management B). Nitrogen fertilizer was applied at the selected rates in single annual applications soon after the plots were mowed on or about 1 May. Seed yield (kg/ha) and seedhead density (seedheads/m2) were measured for 3 years (1975-1977), and florets/raceme and % seed set were measured for 2 years.
Seed yields (kg/ha) averaged over treatments ranged from 658 in 1975 to 818 in 1976 and had a 3-year average of 743. Nitrogen fertilizer rates had no significant (P > 0.05) or discernible effect on any of the response variables. Significant effects due to management occurred for seed yield (P < 0.05) and seedheads/m2 (P < 0.05) in 1975 and for florets/raceme (P < 0.01) in 1976. Differences attributable to years were significant (P < 0.01) for seed yield and seedheads/m2. The only significant interaction was management x years for seedheads/m2 (P < 0.05). Seed yields were higher under Management A during each year of the experiment, though the difference was significant only in 1975. Management A plots had significantly more seedheads/m2 than Management B plots in 1975, but slightly fewer in 1976 and 1977. Management A plots also bore racemes with significantly more florets in 1976.
While the elucidation of management effects on bermudagrass seed production will require further experiments conducted over time, our results support the feasibility of using presently available germplasm to produce new single-cross seed propagated cultivars.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © . .