Effect of two vs. three year harvest intervals on yields of Short Rotation Coppice (SRC) willow

Five genotypes of Short Rotation Coppice (SRC) willow: 'Beagle' ((S. viminalis 'L810203' x viminalis 'L81102') x 'Astrid' x male parent unknown), 'Olof' (S. viminalis 'Bowles Hybrid') x ((S. schwerinii 'L79069') x ((S. viminalis 'L78195' x viminalis 'L78101') 'Orm') 'Bjorn'). 'Ashton Stott' (S.viminalis 'Bowles Hybrid') x S.dasyclados 'Korso', 'Tora' (S. schwerinii 'L79069') x ((S. viminalis 'L78195' x viminalis 'L78101') 'Orm'), and 'Torhild' ((S. schwerinii '79,069') x ((S. viminalis) x S. viminalis 'L78195' x viminalis 'L78101')) 'Orm') 'Tora') x ((S.viminalis 'L78195' x viminalis 'L78101') 'Orm') were grown in large mono-plots or within plots of intimate mixtures. Over a seven year period half of the plots were harvested on a two-year harvest cycle (three harvests) and the rest on a three-year harvest cycle (two harvests). At the end of this 7 year trial period there were no significant differences between total dry weights or stool survival, irrespective of harvest interval. With the realisation of the importance of this finding for more regular crop management practices, the experiment was continued for a further six years allowing for a further round of two and three year harvests. Results suggest that there ultimately are yield penalties, although these may be minimised by careful and appropriate clonal selection.

Automated summary

In the study of Short Rotation Coppice (SRC) willow, five genotypes were tested over a seven-year period with no significant differences in total dry weights or stool survival between different harvest intervals. Yield penalties were observed, but could potentially be minimized through careful clonal selection.