O tratamento de pré-emergência com o 2, 4-D no milho

Heitor W. S. Montenegro Helmut Paulo Krug

Resumo

In order to study the action of herbicides - sodium salt, amine salt and ester of 2,4-D, TCA and 2,4,5-T a preliminary experiment for pre-emergence weed control was corried out, and the corresponding results are given in table I and II. The corn used in the experiments was of the flint type 1A 3531. The loam soil on which the experiment has been carried out is called "terra roxa". All treatments were highly significant when compared with the check plots, except the 2B one in the control of broad leaf weeds, and 4B in the control of grass weeds. Among these treatments there are no significant differences. But we note the following: (table I). a) treatments of higher concentrations were superior to lower ones. b) the treatments which gave the best control for broad leaf weeds were in the following decreasing order: 1A, 5A and 3A. For grass weeds, they were 5A, 1A and 3A. c) the amine 2,4-D (600 grs. per hectare) supplied very good control when we get into consideration that on the acid basis, it was in very low concentration. d) TCA in high concentration affected the germination, growth and yield, in the lower one it did not show good control of weeds, especially of grasses. It is not suitable for pre-emergence control in corn. e) 2,4,5-T was not better than the 2,4-D products. As it is much more expensive than the others, economically its use in pre-emergence weed control in corn is not praticable. f) all the products used controled grass weeds as well as broad leaf ones; this show the superiority of the pre-emergence treatment method over that of post-emergence. g) Even a dose as strong as the treatment 1A (3.400g. of 2,4-D acid per hectare) did not damage corn production (table II). h) the superiority noted in the production of all the treatments with the exception of 2A, which damaged the plants, we atribute to the lack of competion between corn and weeds; all chek-plots suffered this competition, because they were not Probably, there was, also, hormonial effect of 2,4-D on the corn plant. Not withstanding the fact that the present experiment has been successful, we think that new researches are necessary, especially with the purpose of studying factors as climate and soil which in other countries, interferred with the success of the pre-emergence weed control.


SUMMARY

In order to study the action of herbicides - sodium salt, amine salt and ester of 2,4-D, TCA and 2,4,5-T a preliminary experiment for pre-emergence weed control was corried out, and the corresponding results are given in table I and II.

The corn used in the experiments was of the flint type 1A 3531. The loam soil on which the experiment has been carried out is called "terra roxa".

All treatments were highly significant when compared with the check plots, except the 2B one in the control of broad leaf weeds, and 4B in the control of grass weeds.

Among these treatments there are no significant differences. But we note the following: (table I).

a) treatments of higher concentrations were superior to lower ones.

b) the treatments which gave the best control for broad leaf weeds were in the following decreasing order: 1A, 5A and 3A. For grass weeds, they were 5A, 1A and 3A.

c) the amine 2,4-D (600 grs. per hectare) supplied very good control when we get into consideration that on the acid basis, it was in very low concentration.

d) TCA in high concentration affected the germination, growth and yield, in the lower one it did not show good control of weeds, especially of grasses. It is not suitable for pre-emergence control in corn.

e) 2,4,5-T was not better than the 2,4-D products. As it is much more expensive than the others, economically its use in pre-emergence weed control in corn is not praticable.

f) all the products used controled grass weeds as well as broad leaf ones; this show the superiority of the pre-emergence treatment method over that of post-emergence.

g) Even a dose as strong as the treatment 1A (3.400g. of 2,4-D acid per hectare) did not damage corn production (table II).

h) the superiority noted in the production of all the treatments with the exception of 2A, which damaged the plants, we atribute to the lack of competion between corn and weeds; all chek-plots suffered this competition, because they were not Probably, there was, also, hormonial effect of 2,4-D on the corn plant.

Not withstanding the fact that the present experiment has been successful, we think that new researches are necessary, especially with the purpose of studying factors as climate and soil which in other countries, interferred with the success of the pre-emergence weed control.

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AGRADECIMENTOS

Somos gratos a Blemco S. A. representante da Dow Chemical Company, pelos produtos utilizados nesta pesquisa. Estendemos os nossos agradecimentos ao Dr. Frederico Pimentel Gomes que mui gentilmente fez a análise estatística dos resultados.

BIBLIOGRAFIA

  • 1 - ALBAN, E. K. and V. E. Keirns. 1948 - Pre-emergence and post-emergence weed control in vegetable crops with 2,4-D, and oil. 51:526-532.
  • 2 - ANDERSON, J. C. and D. E. Wolf. 1947 - Pré-emergence of weeds in corn with 2,4-D. Journal American Society of Agronomy, 39: 341-342.
  • 3 -ARAKERI, H. R. and R. S. Dunham. 1950 - Eviromental factors relating to the pre-emergence treatment of corn with 2,4-D and Soybeans with TCA. Technical Bulletin 190. University of Minnesota.
  • 4 -DEARBORN, C. H. e Sweet, R. D. and Havis, J. R. 1948 - Weeding sweet cornwith 2,4-D: effects of timing, rates and varieties. Proceedings of the American Society for Horticultural Science. 5 1: 536-540.
  • 5 - ELLIS, N. K. and Bullard, E. T. 1948 - Varietal response of sweet corn to 2,4-D. spray and the effect of different for mulations of 2,4-D on yield. Proceedings of the American Society for Horticultural Science. 51: 505-508.
  • 6 -HAMNER, C. L.; Tukey, H. B.; Carbon, R. J. 1948 - 2,4-D no milho. A Fazenda. 43 (6): 44.
  • 7 - HELM, C. A. 1951 - The use of pre-emergence sprays in corn production. Down to Eath 6 (4): 12.
  • 8 - LEE, Oliver C. 1948 - Suggestions for weed control in corn with 2,4-D. Down to Earth 4 (1): 6-7.
  • 9 -WARREN, G. F. and T. P. Hernandez. 1948 - Weed control in certain vegetable crops with soil applications of 2,4-D. Proceedings of the American Society for Horticultural Science 51: 515-525.

  • O tratamento de pré-emergência com o 2, 4-D no milho
    Heitor W. S. Montenegro; Helmut Paulo Krug

Datas de Publicação

  • Publicação nesta coleção
    06 Nov 2012
  • Data do Fascículo
    1951
Universidade de São Paulo, Escola Superior de Agricultura Av.Páduas Dias, 11, C.P 9 / Piracicaba - São Paulo, Brasil, tel. (019)3429-4486, (019)3429-4401 - Piracicaba - SP - Brazil
E-mail: scientia@esalq.usp.br