Ajuste metodológico do teste de comprimento de plântulas para avaliação de vigor de sementes de soja e milho

Abstract

The objective of this work was to adjust the methodology of the seedling length test and to evaluate the initial plant performance for soybean and maize seeds, as a function of seed vigor and seed size. For this, soybean seeds of cultivar 5855 RSF IPRO (BMX ELITE) were classified in two sizes of sieve and two levels of vigor, and corn seeds Viptera formula hybrid classified in two sieve sizes and three levels of vigor. The objective of this chapter was to evaluate the effect of seed size and vigor level on the initial growth of soybean seedlings and to detect the best time to carry out the evaluation of seedling length. A completely randomized design with four replications was adopted. Germination, first germination count, emergence in bed, emergence speed index, emergence velocity, aerial part length, root and total (evaluated every 12 hours), aerial part, root and total dry mass were evaluated. In the evaluation of initial seedling performance, root, root and total length, root volume and dry mass were evaluated at 7, 11 and 14 days after sowing. Chapter II had as objective to evaluate the physiological performance and the initial growth of maize seedlings, originating from seeds with different sizes and levels of vigor. The design was completely randomized, with four replications. Germination, first germination count, emergence in bed, emergence speed index, emergence velocity, aerial part length, root and total (evaluated every 12 hours), aerial part, root and total dry mass were evaluated. In the evaluation of the initial seedling performance, root, root and root length, root volume, shoot dry weight and roots were evaluated at 7, 14 and 21 days after sowing. The results obtained can infer that the classification of soybean seeds by size exerts a direct influence on the germination and vigor of the seeds and, consequently, no seedlings length, where the seeds of high vigor of the 6.50 mm sieve, the growth rates, in relation to the seeds of low vigor, the sieve 6.00 mm. The level of vigor influences the physiological quality of corn seeds. Root length and total corn seedlings are prohibited at different levels of vigor and size of isolated seeds. The best time to perform a seedling size assessment on soybean seeds is 96 hours and 120 hours in soybean.