Seed molybdenum content of common bean in response to rates of micronutrient sprayed over the plants/Conteudo de molibdenio das sementes de feijoeiro em resposta a doses do micronutriente pulverizado sobre as plantas

The objectives of this research were to verify if high Mo rates sprayed on foliage are toxic to common bean and to determine seed Mo content in response to these rates. One experiment was carried out in Coimbra, MG, in soil with pH of 5.2, where it was tested the rates of 0, 90, 1000, 2000, 3000, and 4000g [ha.sup.-1] of Mo. The rate of 90 was applied at V4 phase of common bean. The rate of 1000 was applied in three ways: all at V4 phase; 1/2 at V4 and 1/2 at R5; and 1/4 at V4, 1/4 at R5, A at R6, A at R7. The rates of 2000, 3000, and 4000 were divided in four equal portions and sprayed at V4, R5, R6, and R7 phases. Mo rates had no effect on seed yield, seed mass and seed germination, indicating that Mo rates as high as 4000g [ha.sup.-1] is not toxic to common bean. Mo content in seed increased from 0.007 to 6.961ig with increasing doses of Mo rates. Key words: Phaseolus vulgaris, Mo concentration, seed germination. Os objetivos deste estudo foram verificar se altas doses de Mo aplicado na folhagem sao toxicas ao feijoeiro e determinar o conteudo de Mo das sementes em resposta a essas doses. Para tanto, foi conduzido um ensaio em Coimbra, Minas Gerais (MG), em solo com pH de 5,2, onde testaram-se as doses de 0, 90, 1000, 2000, 3000 e 4000g [ha.sup.-] de Mo. A dose de 90 foi aplicada na fase V4 dos feijoeiros. A dose de 1000 foi distribuida de tres modos: toda ela na fase V4; 1/2 na V4 e 1/2 na R5; e 1/4 na 1/4, A na R5, 1/4 na R6, 1/4 na R7. As doses de 2000, 3000 e 4000 foram divididas em quatro partes iguais e aplicadas nas fases V4, R5, R6 e R7. As doses de Mo nao influenciaram a produtividade de graos, a massa de semente e a germinacao das sementes, o que indica que o Mo, ate a dose de 4000kg [ha.sup.-1], nao e toxico ao feijoeiro. O conteudo de Mo da semente aumentou de 0,007 a 6,961ig com o incremento das doses de Mo. Palavras-chave: Phaseolus vulgaris, teor de molibdenio, germinacao das sementes.