Germinação de sementes e crescimento de plântulas de tomateiro (Solanum lycopersicum) submetidas à concetrações de zinco (Zn)

Abstract

Although zinc is an essential micronutrient for plant development, when in high concentrations it can cause a toxic effect on cultivated species and studies on its effects are still scarce and unclear. The objective of this experiment was to evaluate seed germination and morphological characteristics of tomato seedlings under different zinc concentrations. The experiment was controlled in the Seeds and Grains laboratory located at the Federal University of Fronteira Sul, Chapecó campus, under a plotted scheme splitted in time in a randomized experimental block design, with cross classification and 4 replications. The seeds were divided into 4 lots of 40 repetitions of 50 seeds and each repetition was sown on paper substrates for seed germination (J. Prolab®). The water used for soaking the 4 batches was added with different concentrations of zinc sulfate (ZnSO4), so that the final concentrations of zinc were 0.0, 100.0, 200.0 and 400.0 mg/L, generating four different treatments. The germination variables of normal and abnormal seedlings, root and shoot size were evaluated and the germination speed index was calculated. For data analysis, Tukey's test of variance and comparison of means were performed, both at 1% probability. The use of zinc doses influenced the germination of normal tomato seedlings only on the fourth day, in the other estimates as different doses did not interfere with germination. The germination speed was reduced due to the increase in the zinc dose. The use of zinc caused toxicity and increased the germination of abnormal tomato seedlings, with the highest doses showing the highest amount of abnormality. Increasing doses of zinc influenced root and shoot size on all evaluated days.