Juvenile lodging in barley: a yield-depressing phenomenon

Abstract

A field experiment was conducted in South Australia to examine the relationship between juvenile lodging (lodging prior to stem elongation) and ear production in barley. Two levels of nitrogen application and six treatments were used either to prevent or increase juvenile lodging in two cultivars.

Applications of 2-chloroethyltrimethylammonium chloride (CCC) at the fourth and sixth leaf stages shortened both pseudostems and leaves, prevented juvenile lodging, and increased the number of ears and the grain yield. CCC did not reduce the mature plant height, but did increase the incidence of Rhynchosporium secalis in one cultivar.

Ear numbers were marginally increased by supporting the crop with a wire grid or by defoliating the crop to 20 cm at the fifth leaf stage, but this advantage was nullified by a compensating decrease in the other yield components. Removing up to 4 units of leaf area index at this stage did not reduce the yield. Deliberately lodging the crop before stem elongation had little effect since most of the controls lodged naturally. All treatments became erect during stem elongation, and the plants did not lodge again before maturity.

It is concluded that short pseudostems, a maximum leaf length under 30 cm, fewer leaves per culm and a shorter period prior to stem elongation are characters which will reduce the juvenile lodging in barley which occurs when the crop is sown early at high plant densities or is grown at high fertility levels.