Name: Jaderson Fernando Neves de Freitas
Type: MSc dissertation
Publication date: 23/02/2018
Advisor:
Name |
Role |
|---|---|
| CAMILLA ZANOTTI GALLON | Co-advisor * |
| Diolina Moura Silva | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| CAMILLA ZANOTTI GALLON | Internal Examiner * |
| Diolina Moura Silva | Advisor * |
| MOISÉS ZUCOLOTO | External Examiner * |
| Sara Dousseau Arantes | External Examiner * |
Summary: ABSTRACT
This work evaluated the effects of mud from the Doce River bed (19º41'54550 "S, 40º 07 '43960" O) on the photosynthetic activity and the growth of three cultivars of Mangífera Indica L. at the seedlings stadium. The Rio Doce, over the years, has been suffering from the deposition of contaminated materials from the extraction of iron mineral. This situation worsened with the disruption of the Mariana-MG dam in November 2015, when millions of cubic meters of mining tailings were deposited and dragged along the Rio Doce basin. So far, little is known about the magnitude of the impact caused by mud on the development of plant species. The agricultural activity of the regions close to the disaster was highly impaired, the tailings compacted the soil making it infertile. Understanding the physiology of plants submitted to this new environmental reality is paramount for the recovery strategies of both the environmental and socioeconomic levels. For this, three different cultivars of Mangífera indicate L. with prominence in the fruit market were used to evaluate the effects of the mining residues on the growth and the vitality of the plants. The treatments were characterized according to the cultivars (Rosa, Tommy Atkins and Palmer) submitted to three concentrations of the mining residues (0%, 20% and 50%) present in the substrate based on peat. These concentrations were characterized according to the physical and chemical properties. Simultaneously, the nutritional analyzes of the leaves of the cultivars were evaluated. Growth measures and photosynthetic analyzes were performed monthly between October 2016 and October 2017. In the last month of analysis, the first fruits of the cultivars were counted, establishing them to have categories according to their size. The parameters that best represented the effects of mining residues on the development of seedlings were PITOTAL (Total Index of photosynthesis stage performance) and PIABS (FSII performance index). The damage caused was evident in cv.Rosa, growth analyzes, chlorophyll indices, normalized OJIPs curves together with the JIP test parameters used, corroborate this assertion. Through these analyzes it was also possible to observe that the cultivars Tommy Atkins and Palmer did not show significant reduction in response to the increase of the residual concentrations. Results of leaf macro and micro nutrients revealed that cv.Rosa (Treatment 50%) presented toxic levels of Mn, which may have contributed to the observed severity of stress. The results indicated that the cv.Rosa showed the most severe symptoms, resulting in less developed seedlings with a reduced initial productivity, while the cultivars Tommy Atkins and Palmer showed high tolerance to the effects of contamination.
Keywords: Disaster, fluorescence, growth, compaction, hose.
