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Comparative production data from commercial and non-commercial subterranean clover lines

D. Little

Department of Agriculture Turretfield Research Centre, Rosedale, S.A. 5350

Clover production and persistence depends on the ability of the plant to grow and set seed in the particular environment in which it is grown. Selection of a clover or mixture of clovers for pasture establishment is often based on independent assessments of clover strains. Direct comparison of a number of clover lines in specific environments is useful in highlighting the advantages and disadvantages of each line. Ten lines of subterranean clover were compare( in terms of dry matter production (DMP), seed reserves (SR) and plant establishment counts (PEC) over 3 seasons in a 460 mm rainfall zone.

Methods

Four commercial cultivars and 6 other lines of subterranean clover, selected for persistence under grazing, were grown in 5 x 1 m plots. The plots were sow] at 20 kg/ha in June 1985. The soil was a loamy red-brown earth, pH 6.1 (water with a soil phosphate level of 35 ppm (Colwell NaH CO3). Plots were harvested for DMP with a lawnmower and SR were estimated by extracting seed from soil cores taken in summer. Plant establishment counts were taken after the final break to the season. No estimates of DMP were made in 1985.

Results and discussion

Table 1. Comparative production data for 10 subterranean clover lines grown o a red-brown earth in a 460 mm rainfall district (mean of 4 reps).

Rainfall in 1985, 1986 and 1987 was 516, 457 and 457 and effective rainfall (Apr.-Oct.) 434, 414 and 360 mm respectively. These rainfall figures are reflected in the DMP and SR data. The 1987 DMP and SR data were lowered by a severe hailstorm which damaged the plots in October, and Rhizoctonia attack on strains 70 and 72.

There was a trend for earlier maturing lines to be less affected by the 1937 season in terms of their SR at the end of 1987 but their generally greater hardseededness may have been a factor in this observation. It is of interest to note that the recognised softer seeded lines (Clare, Woogenellup, 70058A) had the least seed reserves after 3 seasons. Despite the variable seed reserves plant establishment counts were high in all lines. Correlations between SR and subsequent PEC were not consistent over the 2 regenerating years. There was no correlation between PEC and DMP.

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