Carryover of herbicides used in cotton stalk control on soybean cultivated in succession

C. Francischini, Alessandra; Constantin, Jamil; D. Matte, Willian; S. Oliveira Jr., Rubem; G. Machado, Fellipe; K. Morota, Felipe

doi:10.1590/S0100-83582020380100056

Abstract

Background:

Information on the carryover of herbicides applied to the destruction of cotton stalks, as well as the withdrawal period necessary to prevent the development and productivity of the crop in succession from being affected are limited in the literature.

Objective:

The objective was to identify the carryover effect promoted by herbicides used in the management of the destruction of cotton stalks and to estimate the host free period for sowing soybean in succession.

Methods:

Two individual experiments were conducted simultaneously, one for single application and the other for sequential application of herbicide treatments. The experiments were installed in a factorial scheme (15x5), in a randomized block design with four replications. The first factor evaluated was herbicide treatments and the second factor was five soybean sowing times after application (0, 30, 60, 90 and 120 days). The herbicides used in the treatments were 2,4-D, glyphosate, saflufenacil, [imazapic + imazapyr], dicamba, fluroxypyr and sulfentrazone.

Results:

As this work was conducted, the results provide a carryover indicator. It is concluded that the single application and the sequential application of the glyphosate + dicamba + saflufenacil treatment has great carryover potential for soybean crops, with the host free period for sowing the crop exceeding 120 days after application.

Conclusions:

The treatments 2,4-D, 2,4-D + glyphosate, glyphosate + saflufenacil + fluroxypyr had the lowest host free period intervals, even when in sequential application. The treatment with application of 2,4-D alone showed the lowest carryover potential for soybean.

Keywords:
residual activity; safety interval; synthetic auxins

[1] *Corresponding author: <willianmatte@hotmail.com>

Herbicidal treatment	Aplication A and B
Herbicidal treatment	Dose a.i. or a.e. g ha^-1
2,4-D	1340
2,4-D + glyphosate	1340 + 720
2,4-D + saflufenacil	1340 + 105
2,4-D + [imazapic + imazapyr]	1340 + 105
2,4-D + glyphosate + saflufenacil	1340 + 720 +105
2,4-D + glyphosate + [imazapic+imazapyr]	1340 + 720 +105
2,4-D + glyphosate + saflufenacil + [imazapic+imazapyr]	1340 + 720 +105 + 105
Glyphosate + saflufenacil + [imazapic+imazapyr]	720 +105 + 105
Glyphosate + saflufenacil + fluroxypyr	720 +105 + 400
Glyphosate + fluroxypyr + [imazapic+imazapyr]	720 + 400 + 105
Glyphosate + dicamba + saflufenacil	720 + 960 + 105
Glyphosate + sulfentrazone + 2,4-D	720 + 40 + 1340
Sulfentrazone + 2,4-D	40 + 1340
Fluroxypyr	400
Testemunha sem aplicação	-

Modelo de regressão	Equation
Boltzmann's Sigmoidal Model (3 parameters)	$y = \frac{a}{1 + e^{- (x - \frac{x 0}{b})}}$
Boltzmann's Sigmoidal Model (4 parameters)	$y = y 0 + \frac{a - y 0}{1 + e^{- (x - \frac{x 0}{b})}}$
Streibig's Logistic Model (1988) (3 parameters)	$y = \frac{a}{[1 + {(\frac{x}{x 0})}^{b}]}$
Streibig's Logistic Model (1988) (4 parameters)	$y = y 0 + \frac{a}{[1 + {(\frac{x}{x 0})}^{b}]}$
Exponential Model (2 parameters)	$y = a e^{- b x}$
Simetric Model (3 parameters)	$y = a {\|x - x 0\|}^{b}$

Treatment (application A)	Phytointoxication (%) of soybean plants at 14 DAS
Treatment (application A)	0 Days		30 Days		60 Days		90 Days		120 Days
2,4-D	33.7	-	5.5	+	5.2	+	0.5	+	0.0	+
2,4-D + glyphosate	70.7	-	73.5	-	2.2	+	0.2	+	0.0	+
2,4-D + saflufenacil	89.7	-	89.3	-	31.0	-	2.5	+	1.2	+
2,4-D + [imazapic+imazapyr]	89.7	-	90.8	-	52.0	-	4.0	-	0.3	+
2,4-D + glyphosate + saflufenacil	40.2	-	40.3	-	1.7	+	0.0	+	0.0	+
2,4-D + glyphosate + [imazapic + imazapyr]	75.2	-	60.5	-	36.5	-	1.2	+	0.0	+
2,4-D + glyphosate + saflufenacil + [imazapic+imazapyr]	83.7	-	62.5	-	7.0	-	0.7	+	0.0	+
2,4-D + glyphosate + sulfentrazone	78.2	-	73.0	-	43.7	-	6.0	-	1.3	+
2,4-D + sulfentrazone	91.5	-	75.5	-	34.3	-	0.0	+	0.0	+
Glyphosate + saflufenacil + fluroxypyr	9.2	-	8.2	+	1.7	+	0.0	+	0.0	+
Glyphosate + [imazapic+imazapyr] + fluroxypyr	50.0	-	46.7	-	31.5	-	1.0	+	0.0	+
Glyphosate + dicamba + saflufenacil	100.0	-	98.0	-	89.0	-	80.0	-	9.8	-
Glyphosate + saflufenacil + [imazapic+imazapyr]	69.7	-	68.3	-	33.7	-	4.7	-	2.0	+
Fluroxypyr	68.7	-	63.3	-	7.0	-	0.5	+	0.0	+
Check	0.0	+	0.0	+	0.0	+	0.0	+	0.0	+
CV (%)	6.1		8.4		11.3		25.5		103.5
MSD	8.0		9.9		5.9		3.6		2.1

Treatment (application A)	Relative height (%) of soybean plants at 30 DAS
Treatment (application A)	0 Days		30 Days		60 Days		90 Days		120 Days
2,4-D	77.2	-	98.8	+	94.7	+	94.7	+	98.6	+
2,4-D + glyphosate	27.1	-	22.9	-	93.4	+	94.0	+	100.0	+
2,4-D + saflufenacil	7.1	-	9.1	-	49.2	-	96.3	+	99.7	+
2,4-D + [imazapic+imazapyr]	4.9	-	12.7	-	49.8	-	96.8	+	94.2	+
2,4-D + glyphosate + saflufenacil	73.2	-	63.8	-	100.0	+	95.4	+	92.6	+
2,4-D + glyphosate + [imazapic + imazapyr]	30.8	-	45.3	-	56.6	-	92.9	+	99.3	+
2,4-D + glyphosate + saflufenacil + [imazapic+imazapyr]	33.3	-	41.9	-	92.3	+	96.9	+	97.5	+
2,4-D + glyphosate + sulfentrazone	28.3	-	39.2	-	58.4	-	98.4	+	96.9	+
2,4-D + sulfentrazone	8.7	-	30.1	-	59.2	-	100.0	+	90.4	+
Glyphosate + saflufenacil + fluroxypyr	84.1	+	94.7	+	98.9	+	92.7	+	97.7	+
Glyphosate + [imazapic+imazapyr] + fluroxypyr	52.0	-	53.0	-	67.1	-	90.0	+	89.8	+
Glyphosate + dicamba + saflufenacil	0.0	-	1.3	-	10.7	-	43.2	-	100.0	+
Glyphosate + saflufenacil + [imazapic+imazapyr]	39.5	-	51.9	-	71.3	-	91.1	+	90.7	+
Fluroxypyr	36.4	-	51.9	-	91.0	+	93.1	+	97.7	+
Check	100.0	+	100.0	+	100.0	+	100.0	+	100.0	+
CV (%)	25.1		18.8		8.2		6.4		7.1
MSD	21.2		18.6		12.5		12.3		14.2

Treatment (application A)	Relative dry mass (%) of soybean plants at 30 DAS
Treatment (application A)	0 Days		30 Days		60 Days		90 Days		120 Days
2,4-D	77.3	-	100.0	+	100.0	+	100.0	+	98.6	+
2,4-D + glyphosate	29.9	-	41.2	-	97.3	+	99.5	+	96.0	+
2,4-D + saflufenacil	20.3	-	23.5	-	79.9	-	96.2	+	95.6	+
2,4-D + [imazapic+imazapyr]	17.2	-	30.2	-	68.9	-	100.0	+	97.2	+
2,4-D + glyphosate + saflufenacil	64.4	-	83.3	+	99.2	+	97.6	+	92.4	+
2,4-D + glyphosate + [imazapic + imazapyr]	40.6	-	61.3	-	72.3	-	97.2	+	96.5	+
2,4-D + glyphosate + saflufenacil + [imazapic+imazapyr]	42.6	-	47.1	-	98.4	+	100.0	+	94.8	+
2,4-D + glyphosate + sulfentrazone	35.1	-	55.5	-	75.9	-	99.9	+	93.1	+
2,4-D + sulfentrazone	12.2	-	44.1	-	68.6	-	100.0	+	93.4	+
Glyphosate + saflufenacil + fluroxypyr	75.6	-	97.7	+	100.0	+	96.2	+	92.7	+
Glyphosate + [imazapic+imazapyr] + fluroxypyr	62.4	-	65.2	-	83.1	-	96.6	+	97.8	+
Glyphosate + dicamba + saflufenacil	0.0	-	2.5	-	13.1	-	58.3	-	95.1	+
Glyphosate + saflufenacil + [imazapic+imazapyr]	47.8	-	72.7	-	75.3	-	100.0	+	94.8	+
Fluroxypyr	47.4	-	73.2	-	98.2	+	97.3	+	98.2	+
Check	100.0	+	100.0	+	100.0	+	100.0	+	100.0	+
CV (%)	23.5		20.4		8.1		7.3		6.1
MSD	22.0		25.3		13.8		14.6		12.1

Brasil