Polímeros para retardo de germinação com a finalidade de sincronismo de florescimento entre plantas de milho

Abstract

Corn is a crop of great national and international importance, and the production of hybrids depends on flowering synchronization, often achieved at a higher cost. To overcome this challenge, several strategies have been studied, including the use of polymeric coatings on seeds. These coatings regulate water absorption and germination, increasing uniformity. Biodegradable polymers are more sustainable but have limitations, while synthetic polymers can delay germination and favor synchronization, making them strategic for the production of hybrid seeds. The objective was to evaluate the efficiency of biopolymeric and acrylic resin formulations, the latter at different doses and concentrations, in coating corn seeds to delay germination and favor flowering synchronization. The first experiment was divided into two phases. In the first phase, the effect of the coating on corn seeds, a commercial single hybrid and line 64 of the Corn Genetic Improvement Program, DAG-UFLA, was evaluated using 9 biopolymeric formulations through an emergence test. In the second phase, the effect of 22 biopolymeric formulations on seed coating of line 64 was investigated. The dose used was 1.1 L of the formulation per 100 kg⁻¹. In the second experiment, the effect of coating seeds of line 64 with acrylic resin (RA) at concentrations of 50%, 60%, 80%, and 100% resin was evaluated, applied at doses of 3 L and 6 L per 100 kg of seeds. Uncoated seeds were used as a control. The water content, emergence speed (ES), time to emergence of 50% of seedlings (T50), first count, and percentage of emerged seedlings at the final count were determined, obtained four and seven days after sowing, respectively. Coating with the biopolymeric formulations did not alter the water content and showed genotype-dependent responses. Formulations 1 and 2 showed potential for delaying emergence without compromising the final stand. However, coating with RA alters the moisture content of the seeds of line 64 and accelerates seedling emergence, not being suitable for delaying emergence, although it favors initial development and the establishment of the final stand.