Effects of Different Ridge Covering Materials on Growth, Development, and Quality of Passion fruits

Objective Effects of different mulching materials covering the ridges of orchard field on the growth, flowering, fruiting, and quality of passion fruits were investigated.

Method Grafted and cutting seedlings of ‘Wujin’ passion fruit were planted in the field covered on the ridges with 3 kinds of mulching materials, i.e., silvery black reflective film (SF), black plastic film (BF), and horticultural antiweed cloth (HC), or clear tillage without mulching (CC). Seventeen agronomic traits related to the secondary fruit vine growth, flowering, fruiting, yield, and quality of the two types of passion fruit seedlings grown on the test lots were monitored.

Result The field experimentation held from 2022 to 2023 showed that the branch number on seedling and the acidity and solid-to-acid ratio of passion fruits differed significantly depending upon the seedling types (ST). Other than flowering number, the remaining agronomic traits varied significantly by the mulching types (CM) applied. The stem diameter, leaf count, and branch number of plants grown with the mulching were significantly greater than those under CC. And by using the mulches, a flowering rate of 90% and a fruit setting rate of 85% were reached and the actual passion fruit yield increased by 11.33-63.48% without significant differences in the 17 agronomic traits on the plants of the two different STs. Among the mulching treatments, SF produced plants with the largest stem diameter, leaf count, and branch number, the greatest increases of 48.12-63.48% on fruit yield, 48.14-63.48% on yield per plant, 24.85-33.70% on average fruit weight, and 59.93-79.07% on medium-large fruit ratio, and the significantly escalated passion fruit edible proportion by 4.53-5.14%, soluble solids content by 6.41-9.29%, and solid-to-acid ratio by 33.51-42.35% over CC.

Conclusion The application of silvery black reflective film for ridge mulching significantly enhanced the growth, flowering, and fruiting of the grafted and cutting passion fruit seedlings achieving improved fruit yield and quality for the orchards in the south subtropical region.