Effectiveness of integrated solarization technology in managing soil-borne pathogens and weeds in citrus seedlings under greenhouse conditions

Abstract

Solarization Technology utilizes solar radiation to kill soil-borne pests, diseases, and weeds in an environmentally and eco-friendly way. In this study, we assessed the efficacy of integrating solarisation with sticky traps on two potting mixtures (sawdust and soil) for three Citrus species (Citrus sinensis, C. reticulata, and C. limon). Eight treatments were tested viz., non-solarized sawdust, non-solarized soil, solarized soil, solarized soil with sticky traps, non-solarized soil with sticky traps, non-solarized sawdust with sticky traps, solarized sawdust, and solarized sawdust with sticky traps, each replicated thrice and were arranged in a randomized complete block design (RCBD). Thirty sterilized seeds of each Citrus species were sown per treatment and monitored for one year in 2019. Analysis of variance (ANOVA) revealed a significant difference in weed control between the treatments at p ≤ 0.05. Tukey’s post hoc test showed weed growth differences between treatments with sawdust and ones with soil as media. More weeds grew in non-solarized soil (32%), compared to non-solarized soil with sticky traps (30%), solarized soil with sticky traps (21%), solarized soil (17%), and treatments with sawdust media did not allow weed growth (0%). A Kruskal Wallis test revealed a significant effect of treatments on the survival percentage of Citrus seedlings (X2 = 36.008, df = 7, p< 0.001), mean of chewed leaves (X2 = 20.850, df = 7, p = 0.004) and percentage levels of low chlorophyll (X2 = 21.073, df = 7, p =0.004) at the p ≤ 0.05 level. Highest number of Citrus seedlings with folded leaves were observed in non-solarized sawdust with sticky traps (mean rank = 119.50), followed by non-solarized soil with sticky traps (112.22), and solarized sawdust (107.69), while the lowest in non-solarized sawdust (90.96), solarized soil (90.91), non-solarized soil (88.25), solarized sawdust with sticky traps (85.44) and lastly solarized soil with sticky traps (82.54). Citrus seedlings with sawdust media were observed to be nitrogen deficient (Mean ranks 118.43 - 141.63). Solarized soil with sticky traps had the least number of Citrus seedlings with leaf miner symptoms (Mean rank = 12.50). Therefore, solarized soil with sticky traps was the most suitable treatment for the control of soil-borne pathogens. Treatments with sawdust media effectively stopped weed growth while those with solarized soil media reduced their growth. Integration of sticky traps was very pivotal in the management of whiteflies and other honey dew secreting insects. We recommend a similar study under field conditions.