Selection and evaluation of superior planting materials of Ailanthus triphysa (Dennst.) in Thrissur

Abstract

A nursery and field experiment was conducted to evaluate the superior performance of selected candidate plus trees of Ailanthus triphysafrom the Thrissur District, Kerala. The demand of this timber was very much increased because of its fast growing nature and diversity of utilizations. Hence, the tree improvement of this species is the need of the hour that might result increased quality and reduced rotation time. The possible gain expected through the phenotypic selection can also be directly utilised by the tree growers. The candidate plus trees were identified and selected by adopting the comparison tree method. The seeds collected were used to study the germination parameters at tree nursery of College of Forestry, Kerala Agricultural University. The initial growth performances of the progenies of the selected CPTs were evaluated at nursery in a completely randomised design and also at the field in a randomised block design and the data were statistically analysed using Analysis of Variance technique. The progenies of the selected CPTs showed significant variation in their initial growth parameters. The highest germination per cent of 83.50 was exhibited by CPT-11 and the lowest of 67 per cent by CPT-1. After the six months of observation in the nursery, CPT-11 attained the maximum height of 88.67cm and lowest height by CPT-5 (76.33cm). The maximum plant height (99 cm) and girth (21.04 cm)in the field was also exhibited by CPT-11. The CPT-11, CPT-10 and CPT-9 were the top performers compared to other selections. The CPT-1 was the inferior in the nursery and also in the field. The CPTs that exhibited superiority in germination percentage, germination value and mean daily germination also exhibited distinctively superior growth in the nursery and in the field. In fact, the identification and selection of superior quality planting materials of Ailanthus triphysahas a greater role in the tree improvement. The single tree selection is the best method for the production of superior progenies and this can be useful for the future afforestation and seedling production for getting high quality timber with short rotation period. From this study we recommend CPT-11, CPT-10 and CPT-9 for achieving these objectives.