ISHS Acta Horticulturae 713: VI International Peach Symposium
CROP LOAD EFFECTS ON YIELD AND PAR INTERCEPTION OF ´AUGUST RED´ NECTARINE |
| Authors: | H. Lazaro, G. Reginato, V. Garcia de Cortazar |
| Keywords: | fruit size, yield efficiency, vegetative growth |
| Abstract:
To establish the influence of crop load on productive parameters and PAR interception of nectarine trees, a trial was performed in the late season cultivar ‘August Red’. The orchard was seven years old, trained in the V-shaped system, and planted at 5 m x 2 m (1,000 trees/ha), near Linderos, 40 km south of Santiago (33.8° Lat S, 71.7° Long W). A completely randomized block design was implemented 40 days after flowering and before pit hardening and consisted of three crop load treatments: low (284±4 fruits/tree), medium (435±18) and high (578±32). PAR interception was measured at midday every twenty days from October to February. By the time of the first measurement the fractional PAR interception was similar to a completely developed canopy, since only a little increase was verified up to December 18th. There was no effect of the treatments on PAR interception at any of the dates. Yield was significantly (P<0.05) affected by the treatments: high crop load produced 68.9 kg/tree, medium crop load 57.6 kg/tree and low crop load 45.4 kg/tree. Yield was linearly related with the number of fruits per tree (r²=0.95) and the number of fruits per fraction of PAR intercepted (r²=0.93). Mean fruit weight was also significantly (P<0.05) affected by the treatments: High 119.9 g, Medium 134 g and Low 161.3 g. Fruit weight was explained by the number of fruits per tree (r²=0.91), fruits per cm² TCSA (r²=0.95) and fruits per fraction of PAR intercepted (r2=0.97). | |
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