Preliminary studies of the effects of reflective mulch, shading, training system and rootstock on red colour development were undertaken by a visiting student from Wageningen University in the Netherlands.
Red colour coverage and intensity is critical for marketing these pear cultivars.
- the reflected radiation from a white material laid in the inter-row is insufficient to increase colour in 'ANP-0131'
- red colour can be completely lost when fruit is shaded but for much of the season is recovered when fruit is exposed to sunlight
- fruit towards the top of the canopy is redder but there were no differences between trees trained vertically and in a V system
Influence of light exposure on seasonal pattern of red colour development
The degree of red coloration is determined by the content and composition of anthocyanins in the peel of pears. Biosynthesis of anthocyanins in plant tissues either requires, or is enhanced by light.
During this experiment the effect of artificial shading on the red colour development of newly bred ANP-0534 blush pears was investigated. Six different treatments were applied which consist of a control treatment and five artificial shading periods which were differing in duration and timing.
- Red colour was measured several times during the experiment.
- Quality measurements, which included weight, firmness and total soluble solids, were investigated at the end.
Effect of reflective mulch on red colour development
The study investigated the use of reflective mulch (Extenday™) to improve fruit colouration in trees under netting and outside netting. The reflective mulch covered approximately 90% of the area between the rows, which maximises the amount of light that can be reflected back into the trees.
Effect of training system and rootstock on red colour development
The study investigated different training systems, Open Tatura and vertical training systems, to see the effect of fruit colouration in trees for new red-blushed pear cultivar ANP-0131 (branded Deliza®). In addition, the effect of rootstock was also investigated for blush pears that were grafted on BP1, QA or D6 within the training experiment.