The effect of sowing time, sowing technique and post-sowing weed competition on tall fescue (Festuca arundinacea Schreb.) seedling establishment

Abstract

The effects of sowing time (autumn and spring), sowing technique (conventional cultivation, inverted T direct drill, triple disc direct drill and aerial sowing) and post-sowing weed competition on the establishment of tall fescue were assessed at a field site on the Northern Tablelands of N.S.W. Weed competition [principally Vulpia rnyuros (L.) Gmel.] was removed by pre-sowing herbicide and post-sowing weed control treatments of 0, 30, 60 or 90 days duration. The seedling emergence percentage was monitored until 9 months after the autumn sowing and plots were harvested 9 and 18 months after the autumn sowing. Tall fescue establishment averaged 46 seedlings m-2 from the spring sowing, successful establishment of 15% of viable seed, and 3.5 times better than for the autumn sowing. Eighteen months after sowing, the average dry matter yield of fescue was 960 kg ha-1 for the spring sowing, 33% higher than for the autumn sowing. Aerial sowing resulted in less than 3% establishment at either sowing time. The establishment from the direct drilling machines were equal to that of the cultivated seedbed in the autumn sowing (16 seedlings m-1). In the spring sowing, 79 seedlings m-2 established from the inverted T sowing technique, 43% more than for the cultivated seedbed, and 115% more than for the triple disc. Fourteen months after the spring sowing, post-sowing weed control had reduced the yield of the unsown species 82% on average, and increased the yield of tall fescue by 11956, but had no effect on the final number of established fescue plants. These results show the potential for the establishment of tall fescue on the Northern Tablelands from direct drilling in spring, avoiding many of the problems currently associated with establishment from conventional cultivation in autumn.