Water stress and yield potential: the research

Recent research has looked at the impacts of early season water deficits on fruit production, fruit retention, boll distribution, seed and lint yield in high retention Bollgard ll variety Sicot 71BR cotton.

Experiments were conducted over two seasons (2006-07 and 2007-08) at the Gatton Campus of the University of Queensland. The research consisted of four experiments which had different planting dates, area, rainfall and irrigations after the stress period.

All four experiments consisted of three different water treatment scenarios which included:

• irrigation (I) over the whole crop growth
• water stress periods with no irrigation until squaring (NIS) followed by irrigation until the end of crop growth.
• water stress periods with no irrigation until flowering (NIF) followed by irrigation until the end of crop growth.

The results below show reductions of between 6-44 per cent when comparing NIS and NIF treatment scenarios to the full irrigation scenario. The results also show more fruit and green bolls in the full irrigation scenario than the two other stress treatments. It should be noted that these effects can still apply to conventional cotton varieties.