Full text
| |
| Author(s): |
Gabriel Asa Corrêa Gruberger
Total Authors: 1
|
| Document type: | Master's Dissertation |
| Press: | Piracicaba. |
| Institution: | Universidade de São Paulo (USP). Centro de Energia Nuclear na Agricultura (CENA/STB) |
| Defense date: | 2017-01-20 |
| Examining board members: |
Cassio Hamilton Abreu Junior;
Cleide Aparecida Abreu;
Ana Dionisia da Luz Coelho Novembre
|
| Advisor: | Cassio Hamilton Abreu Junior |
| Abstract | |
The application of cobalt (Co) and molybdenum (Mo) directly to soybean (Glycine max (L.) Merrill) seeds is a common practice in Brazil. However, this technique presents limitations, provoking phytotoxicity, interfering in the absorption of iron by roots, decreasing the population of nitrogen-fixing bacteria of the genus Bradyrhizobium in the seeds, and requiring an additional step in the pre-planting stage. One way to overcome these limitations would be to use seeds enriched with Co and Mo. However, there is a lack of research aimed at increasing Co content in soybean seeds, since the potential for enrichment with Mo has already been established. The aim of this study is to determine the feasibility of enriching soybean seeds with both Co and Mo and to relate the enrichment to increase in the physiological quality of the seeds. The project consists of two experiments. The first experiment was carried out under greenhouse conditions, located at the Center for Nuclear Energy in Agriculture (CENA / USP), in Piracicaba (SP). The experimental design was completely randomized, with three replications, in a factorial scheme (4x2)+1 and (4x2)+2 of which 4 Co doses, 2 varieties, 2 application modes and the control without Co and Mo. Plants of two soybean varieties (one long and one precocious cycle) were grown in pots containing 3 dm3 of sandy soil. The following treatments of Co and Mo (g ha-1) were applied: 0 + 800, 10 + 800, 20 + 800, 30 + 800, via leaf and soil, after planting, at the R5.4 phenological stage of development. The second experiment was conducted in the field, at Geraldo Schultz research center, in Iracemápolis (SP), using only the long cycle genotype. The doses of Co + Mo used were identical to those of the greenhouse experiment; however, the application was exclusively via leaf. The experimental design was in randomized blocks with 6 replications. Co and Mo content in soil, leaves and seeds as well as indices for chlorophyll (IC), flavonoids (IF), nitrogen balance (NBI), germination and vigor of enriched seeds were evaluated by means of Accelerated Aging and computer analysis of seedlings by means of SVIS® (Seed Vigor Imaging System) software. Enrichment of soybean seeds by means Co and Mo proved to be viable, with the earlier varieties having a higher Co and Mo content in the seeds. Seed vigor was positively influenced by Co enrichment; best results were obtained with application of 20 g ha-1 of Co. Enrichment with Mo, however, had no influence on seed vigor. Application via leaf resulted in higher levels of Co in seeds compared to application carried out via soil. On the other hand, application via soil resulted in higher levels of Mo in seeds in comparison to application carried out via leaf (AU) | |
| FAPESP's process: | 14/26259-3 - Cobalt and molybdenum soybean seeds enrichment |
| Grantee: | Gabriel Asa Corrêa Gruberger |
| Support Opportunities: | Scholarships in Brazil - Master |