Effects of sulphur dioxide and chlorine dioxide treatments on quality of ‘Sultana Seedless’ table grapes in storage

Sulphur dioxide fumigation is one of the most important factors that determine storability of table grapes. Despite its beneficial effects, there is a risk of having sulphite residues in grapes. In this study, the effects of sulphur dioxide (SO2) pads and chlorine dioxide (ClO2) generators on storability of table grapes ‘Sultana Seedless’ packed in modified atmosphere packages (MAP) was investigated. Grape samples were subjected to 6 different treatments as a) MAP1, b) MAP1+ClO2, c) MAP2, d) MAP2+ClO2, e) MAP2+SO2 and f) Polyethylene (PE)+SO2 (commercial) after pre-cooling and packages sealed with plastic clips. Grapes in all treatments were stored at -0.5°C and 90% relative humidity for 3 months. SO2 concentrations of grapes in MAP’s and PE packages were determined as 0.53 and 8.30 ppm, respectively. Decay rates increased significantly (26%) in ClO2 treatment after 3 months of storage. Sensory evaluation scores also decreased due to increases in stem browning and decrease in texture. ClO2 treated grapes lost their marketability due to high decay development and loss of sensory properties after 3 months. Effects of different treatments on color, berry removal force, berry firmness and chemical attributes of table grapes were similar. The results showed that table grapes could be successfully stored up to 2 months with ClO2 generators and 3 months with SO2 pads. © 2020 International Society for Horticultural Science. All rights reserved

Effects of plant growth promoting microorganisms on yield and quality parameters of lettuce (Lactuca sativa L.)

This study was conducted to determine the effects of plant growth promoting microorganisms on yield and some quality attributes of 'Abbice' crisp lettuce variety. Tested treatments were applied via drip irrigation at a dose of 10 ml / L Perla Vita, as water (95%) and molasses (5%) mixture of Lactobacillus casei (107), Lactobacillus plantarum (107), Rhodopseudomonas palustris (105), and Saccharomyces cervisiae (103)] four times as 1, 2, 3 and 4 weeks after planting the lettuce seedlings. The lettuces in the control did not receive any treatments. Head weight, diameter and height, unmarketable and marketable leaf weight and number, leaf number, root crown diameter, stem length and thickness, and leaf colour (L*, a*, b*) were determined in harvested plants. Treatment with plant growth promoting microorganisms increased head weight and diameter by 7.4% and 6.2%, respectively compared to the control plants. Applications also increased marketable head and leaf weight by 12.0 % and 12.1%, respectively. Unmarketable leaf number and weight were lower (2.8 leaves/head and 11.4 g/head) in treated plants than the untreated lettuces (3.8 leaves/head and 22.3 g/head). Effects of tested microorganisms on other quality parameters showed similarity with control group. The results displayed that plant growth promoting microorganism treatments increases head weight and diameter, marketable head and leaf number whereas decreases unmarketable leaf number and weight