Netting of different shade factors affect light penetration, fruit and vegetative growth, yield and fruit quality in an Australian blush pear

Abstract

The recent introduction of new blush pear cultivars has gained increasing consumer interest. The purpose of this study was to investigate the influence of different protective netting shade factors on environmental conditions, fruit growth, vegetative growth, blush colour, blush coverage, fruit quality and yield of the Australian blush pear cultivar 'ANP-0118′. Three nets of varying shade factors (30, 50 and 80%) were assigned to experimental plots, in addition to unnetted plots. All netting used was black in colour. Photosynthetically active radiation (PAR) penetration near sample fruit was assessed and blush colour parameters, fruit diameter and shoot length were monitored weekly. Whole trees were harvested and measured for fruit weight and blush coverage with a fruit grader. Fruit was assessed manually for flesh firmness and soluble solids concentration. Fruit and shoot growth were negatively and positively affected by shade factor, respectively. Overall, increasing shade factor was detrimental to fruit size, blush redness, blush coverage and soluble solids concentration but did not affect flesh firmness. Unnetted fruit achieved highest PAR exposure, and consequently expressed highest blush redness and blush coverage. Yield was similar in unnetted and 30% shade factor plots. The results of this study suggest that the use of shading nets should be limited in order to avoid unfavourable effects on key quality traits in Australian blush pears, yet further exploration into the influence of lower shade factor nets in combination with reflective mulch and biostimulants would be beneficial to the industry.