The 2011 ASHS Annual Conference

Water use efficiency (WUE) was determined for two separate blackberry cultural management studies conducted during the years 2006-2008 (Expt. 1) and 2008-2010 (Expt. 2) in a semi-arid subtropical area in south Texas (Lat. 26° N).  Adjustments were made for natural precipitation and total season water requirements.  In Expt. 1, use of weed barriers, compared to bare soil, increased WUE with an opaque white plastic giving the best results in both harvest years.  As some of the less expensive weed barriers deteriorated, WUE diminished in the second fruiting year.  In Expt. 2, factorial comparisons were made between white plastic (for weed control), bare ground (conventional practice and kept weed free monthly), shade (40% beginning after the third harvest), and no shade.  The improvement to WUE increased as follows:  bare ground and no shading < white plastic = bare ground + shading < white plastic + shading.  Environmental factors which may have influencedWUE between treatments included soil temperature at 10 cm (Expt. 1), fruit and canopy temperatures (Expt. 2), and seasonal differences in rainfall, light (MJ/m²) and monthly mean temperatures (in all years).