چکیده:
The high quality and quantity seed production in old saxual shrubs are essential for regeneration and sustainable development of saxual forests in desert areas. The objective of this study was to determine the effects of different pruning height on saxual seed production. The study was carried out in an obviously wilted saxual forest located in Ashkezar desert in Yazd in 1994. The experiment was carried out in a split-plot design with 3 replications, with saxual density (250 and 125 shrubs/ha) as the main plots, and pruning height (10, 35, 70 cm, and a no-cut check) as the sub-plots. Pruning was done on autumn 1994. The forest was protected completely and the quality and quantity of seed production of marked shrubs were investigated on autumn 1999 and 2000. The 2-year results showed that saxual density did not have any significant effect on quality and quantity of saxual seed production (P<0.05). Pruning height had significant effect on percent seed longevity and net saxual seed production (P<0.05). Although no significant difference was observed in viable net seed production under different pruning height, the amount of viable net seed production at 35cm pruning height was 9.7 kg/ha, which seems adequate for saxual regeneration.
خلاصه ماشینی:
PRUNING HEIGHT AND ITS EFFECT ON QUANTITATIVE AND QUALITATIVE SEED PRODUCTION IN OLD SAXUAL (Haloxylon aphyllum) FORESTS OF YAZD, IRAN N.
com, 2,3- Weed Research Department, Plant Pest and Disease Research Institute Abstract The high quality and quantity seed production in old saxual shrubs are essential for regeneration and sustainable development of saxual forests in desert areas.
, 2004) studied different pruning height in saxual forests in Yazd under two planting density (250 and 125 shrubs/ha).
, 2003) reported that pruning did not have any significant reductive effect on saxual infection to Proceratia caesariella compared to non-pruned shrubs, but no investigation had been performed on the quality and quantity of seed production in their study.
The objective of this study was to determine the effect of different pruning/ pruning height on the quantity and quality of seed production by old saxual shrubs in Ashkezar, Yazd.
Table 3: Seed longevity, net seed weight, and net viable seed weight of saxual shrubs separately for each experimental year in Yazd.
30 Table 4: Seed longevity, net seed weight, and net viable seed weight of saxual shrubs at different pruning height in Yazd in 1999-2000.
The results of the present study are not consistent with those in other studies, which had indicated the positive effect of pruning on increasing saxual seed production ability (Arabzadeh, 1995, Jamzad, 1992 and Valentine, 1990).
Investigation on the effects of several pruning methods on the growth and vigourity of old saxual man- made forests in Yazd province.