Desempenho agronômico do cártamo (Carthamus tinctorius L.) em função da época de semeadura e do controle químico da mancha de alternaria

Abstract

The study aimed to evaluate the performance of Safflower according to the sowing date and chemical control of Alternaria leaf spot using different chemical groups and active ingredients of fungicides. The sowing date experiments were performed at the “Fazenda Experimental de Ciências Agrárias da Universidade Federal da Grande Dourados – UFGD” in the years of 2010 and 2011. The experiment with fungicides for control of alternaria leaf spot was performed at the “Campus Experimental da Faculdade De Ciências Agrárias (FCA – UFGD)”, both located in Dourados - MS. The experimental design used for the planting season (2010/2011) was a randomized block with five treatments (five sowing dates) and four replicates. The experimental design used for the experiment of fungicides for control of alternaria leaf spot was a randomized block with treatments arranged in a factorial design with an additional treatment (3x3 +1), three fungicides, three applications each, and one witness, totaling an amount of ten treatments. The fungicides used were iprodione, azoxystrobin and difenoconazole. The doses used were those specified by the manufacturer. Applications occurred as follows: the first in a preventive manner, the second at flowering and the third in full bloom. The characteristics evaluated in all experiments were: plant height, number of branches per plant, number of chapters per plant, head diameter, height in order to observe diseases in the plant (only for fungicide), grain yield, weight of 1000 grain N content and grain protein and oil content in grains. It was not possible to establish the correct time to plant for the experiments of sowing dates. The highest yields occurred in 2010 with 106.40 kg ha-1 at sowing on 19/03 and 2011, sown in the season 09/02 yield was 71.60 kg ha- 1. With regard to oil content for the year 2010, sown in the season 19/02 Total yield of 26.79% for 2011 and sown in the season 09/02 obtained 37.36%. In relation to the experiment for control of alternaria leaf spot, it was observed the highest yield and oil content with just one application of azoxystrobin, 1923.53 kg ha-1 and 30.44% respectively.