Effect of damaging main stem terminals at various stages of flowering, on yield of cotton in south-east Queensland

Abstract

Damage by the cotton tipworm, Crocidosema plebeiana Zeller, was simulated in field trials by the removal of terminal buds (tipping) at different phenological stages coinciding with tipworm presence on cotton grown in south-eastern Queensland. The effect of this damage was considered in relation to the induced changes in crop morphology, fruit production, yield and harvestability of cotton grown under field conditions. No significant differences in fruit formation and yield were established. There were significant delays in times to 50 per cent flowering and boll opening in plants tipped before squaring had commenced. Changes in the location of monopodial branches arising from the main stem were induced in plants tipped pre-squaring but this did not significantly affect the harvestability.