Narrow row cotton in the Namoi valley. 1. Growth, yield and quality of four cultivars

Abstract

Field experiments were done in three successive seasons to determine the effects of cultivar and row spacing on growth, yield and quality of cotton. Narrow rows had a higher early season LAI than wide rows, but differences in LAI between row spacings disappeared by the peak flowering stage. Hopicala and Deltapine 16 had a higher LAI than Riverina Poplar and Super Okra M8. Narrow rows produced 28 per cent more fruiting points than wide rows, but this was not reflected as a consistent increase in yield, as fruit shedding was greater and boll size was smaller in narrow rows than in wide rows. Narrow rows yielded 44 per cent more than wide rows in 1972-73 but 7 per cent less in 1973-74 and 1 per cent less in 1974-75. Earlier crop maturity was obtained with narrow rows in all cultivars in 1974-75 and Hopicala only in 1972-73. Deltapine 16 and Super Okra M8 had the highest average yield at both row spacings, with Super Okra M8 having the highest yield at the first pick. No fibre properties were consistently affected by row spacing. Cultivar differences were as expected with the early maturing cultivar Riverina Poplar having the shortest fibres and the later maturing cultivar Hopicala having the greatest fibre strength.