Assessment of morphological changes and determination of best cane collection time for 140 RU and 5 BB

Abstract

This study was carried out to assess morphological changes in the canes of 140 Ru and 5 BB and to determine best time for cane collection. The first part of the study included the morphological assessment of the rootstock canes during the winters of 2003–2004 and 2004–2005. Canes collected in the second part of the study in 2005–2006 were grown in pots to relate the changes with the vegetative growth characteristics. Cane collection commenced at leaf fall and they were collected three more times at 15-day intervals. Morphological changes were determined from the transverse internodal cuts and included: width of pith, xylem, phloem plus bark tissues, ratios of cane width/pith, cane width/bark + phloem, xylem/pith and xylem/bark + phloem, and cane water content. Findings showed that lignification was best 30 and 45 days after leaf fall for 140 Ru and 15, 30 and 45 days after leaf fall for 5 BB. Canes collected in 2005–2006 were used to relate the changes observed in the previous 2 years with the vegetative development. Two-bud cuttings were grown in pots and viable plant and rooting ratios, root fresh weight, shoot number and length, and node number were determined. Data obtained were found in agreement with the morphological findings. A 140 Ru had the best vegetative growth 30 and 45 days after leaf fall, and 5 BB grew well at each collection period. Results showed that it is best not to collect canes from rootstock nurseries at or right after leaf fall due to poor lignification and subsequent poor growth.