Adubação com silício na cultura de grão-de-bico

Abstract

Resumo em língua estrangeira: A source of protein, fiber, and iron, chickpeas (Cicer arietnum L.) stand out in the world scenario for their economic and social relevance, and versatility. For the good development of the plant, nutrition is one of the most influential factors. Studies have shown that silicon is involved in several structural, biochemical and physiological aspects in plant life, promoting improvements in metabolism, activating genes involved in the production of phenols and enzymes related to defense mechanisms. The high grain production and the inadequate management of crops have caused high incidences of soil fungi, which can remain present in the soil for years. Among the soil pathogens that cause most damage to chickpea culture, it can be mentioned the sclerotial wilt (Sclerotium rolfisii Sacc). Thus, in this work, the first experiment aimed to evaluate biomass yield and silicon content in the plant as a function of different doses of Si applied as a base dressing in chickpea culture. It was conducted at the Universidade Estadual de Goiás, Campus Ipameri, in a protected environment. The cultivar used was BRS Cicero and the design was entirely randomized, with five treatments (0, 100, 150, 200 and 250 kg ha-1 of silicon) and four repetitions. The analyses performed were: plant height, root length, aboveground fresh mass, root fresh mass, total fresh mass, aboveground dry mass, root dry mass, total dry mass and silicon content in biomass. It can be concluded that silicon fertilization influenced plant height. Higher levels were found in the roots of chickpea than in the aboveground part. The best dose of Si for accumulation in the leaves was 96 kg ha-1 . The second experiment aimed to evaluate the effect of different doses of silicon on the productivity of chickpea and on the resistance to the pathogen Sclerotium rolfsii. The research was conducted in Pires do Rio - Goiás, with geographical coordinates 17°17'33" S 48°16'19" W, has approximately 755 m of altitude. The chickpea cultivar used was BRS Cícero. The design used was entirely randomized, with five treatments (0, 100, 150, 200 and 250 kg ha-1 of silicon) and eight repetitions. The plants were inoculated when they were 20 days after emergence, inoculating pieces of mycelium at three points on the leaves. The variables analyzed were: relative chlorophyll index, plant height, stem diameter, number of pods per plant, leaf area and biomass. The Si content in leaves and stems and the severity of the disease were evaluated. Silicon positively influenced the leaf area index and the levels of silicon in stems and leaves. In the stems, the best dose was 122 kg ha-1 and for accumulation in the leaves was the dose of 139 kg ha-1 . The development of sclerotium wilt was not observed, regardless of the use or not of silicon fertilization.