Pengaruh campuran herbisida berbahan aktif atrazin 500 g/L dan mesotrion 50 g/L terhadap gulma dominan pada tanaman jagung (Zea mays L.)

Sari. Pengendalian gulma dengan menggunakan herbisida tunggal bila dilakukan terus menerus akan menimbulkan gulma resisten. Pencampuran herbisida perlu dilakukan untuk menanggulanginya. Campuran herbisida dengan dua atau lebih jenis bahan aktif dapat bersifat sinergis, aditif, atau antagonis. Tujuan dari penelitian adalah untuk mengetahui sifat campuran herbisida Atrazin 500 g/L + Mesutrion 50 g/L terhadap beberapa jenis gulma dominan pada tanaman jagung. Percobaan dilaksanakan pada bulan November 2018 sampai Januari 2019, di Rumah Kaca Fakultas Pertanian Unpad, Jatinangor. Perlakuan terdiri dari tiga jenis herbisida dengan enam tingkat dosis, yaitu herbisida tunggal Atrazin (1200, 600, 300, 150, 75, 0 g/ha), Mesotrion (120, 60, 30, 15, 7,5, 0 g/ha) dan campuran herbisida dari Atrazin 500g/L dan Mesotrion 50 g/L (1056, 528, 264, 132, 66, 0 g/ha) dengan empat ulangan. Gulma target adalah gulma A. conyzoides, S. nodiflora, C. rotundus, dan E. indica. Analisis data menggunakan analisis regresi linear dan metode MSM untuk menentukan LD50 perlakuan dan LD50 harapan. Hasil percobaan menunjukkan bahwa pencampuran herbisida berbahan aktif Atrazin 500 g/L dan Mesotrion 50 g/L memiliki nilai LD50 perlakuan (85,11 g/ha) lebih kecil dari nilai LD50 harapan (86,9 g/ha) sehingga dapat disimpulkan sifat campuran herbisida tersebut bersifat sinergis.Kata kunci : Atrazin, Mesotrion, Herbisida campuran, Gulma dominan tanaman jagung Abstract. Weed control by using a single herbicide continuously will cause weeds resistant, so it is necessary to mix herbicides. Mixture of herbicide with two or more types of active ingredient can be synergistic, additive, or antagonistic. The objective of this research is to know the effect of herbicide mixture of Atrazin 500 g/L and Mesotrion 50 g/L to several types of dominant weeds. The research was conducted from November 2018 until January 2019, at the Green house of Faculty of Agriculture, Padjadjaran University, Jatinangor. The treatment was consisted of three types of herbicide with six level of doses. There were herbicide Atrazine 500 g/L (1200, 600, 300, 150, 75,0 g /ha), Mesotrion 50 g/L (120, 60, 30, 15, 7.5, 0 g/ha) and herbicide mixtures Atrazine 500 g/L and Mesotrion 50 g/L (1056, 528, 264, 132, 66, 0 g/ha) with four replications. The target weeds were A. conyzoides, S. nodiflora, C. rotundus and E. indica. Data was analyzed by linear regression and MSM method to determine the value of LD50 treatment and LD50 expectation. The results showed that herbicides mixture of Atrazine 500 g/L and Mesotrion 50 g/L had a value of LD50 treatment 85.11 g/ha which is smaller than the value of LD50 expectation (86.9 g/ha), this indicating that the herbicide mixtures was synergistic.Keywords: Atrazine, Mesotrion, Mixed herbicides, dominant weeds of corn

Morphological and Metabolic Changes in Soybean Plants Cultivated in Irrigated Rice Rotation and as Affected by Imazapyr and Imazapic Herbicides Carryover

ABSTRACT: The appearance of soybean cultivars that are tolerant to herbicides from the imidazolinone group enables irrigated rice rotation conducted on Clearfield® system. The objective of this work was to evaluate the morphological and metabolic changes of soybean cultivars containing Cultivance® (CV), which is tolerant to imidazolinone, sulphonylurea toletant (STS) and Roundup Ready® (RR), which is tolerant to glyphosate as affected by carryover of increasing doses of imazapyr and imazapic herbicides mixture, applied in the management of irrigated rice crop. Thus, experiments were conducted on the field and in greenhouse, evaluating phytotoxicity, height, leaf area, shoot dry matter, as well as variables related to the secondary metabolism of plants like chlorophyll, carotenoids, hydrogen peroxide, lipid peroxidation and electrolytes leakage. Soybean cultivars RR and STS are susceptibles to the carryover of imazapyr and imazapic mixture applied in the management of irrigated rice crop, whereas the CV cultivar is resistant. The rise in the herbicide carryover dose increases the reactive oxygen species (ROS) production in soybean plants. The RR cultivar, in general, shows higher ROS production compared to the other soybean cultivars.

Response of Soybean Cultivars in Rotation with Irrigated Rice Crops Cultivated in Clearfield® System

ABSTRACT: Soybean crop rotation with irrigated rice is an alternative for the management of weedy rice (Oryza sativa) resistant to herbicides from the imidazolinone chemical group. This work had the purpose to evaluate the phytotoxicity of soybean crops containing the technologies Cultivance® (CV) and tolerance to sulphonylurea and Roundup Ready® (RR), deriving from increasing doses of the imazapyr and imazapic herbicide mixture, applied in the irrigated rice crop management. Thus, the experiment was performed on field, where treatments consisted in three soybean cultivars (BRS382CV, CD249STS and NA5909RR) and five doses of the imazapyr and imazapic herbicides mixture (0, 49, 98, 196 and 392 g a.i. ha-1). The evaluated variables were phytotoxicity, yield components and physiological quality of the seeds. Soybean cultivar BRS382CV is tolerant to herbicide carryover, applied in the management of weedy rice in irrigated rice crops, but the other cultivars are susceptible to it. Cultivar productivity, yield components and physiological quality of the seeds are affected by the carryover increase of the imazapyr and imazapic herbicide mixture.

INTERAÇÕES ENTRE HERBICIDAS NO MANEJO DO MILHO RR® VOLUNTÁRIO

RESUMO - A mistura entre herbicidas pode resultar em efeitos sinérgicos, antagônicos ou aditivos no controle do milho voluntário e de outras espécies de plantas daninhas. Objetivou-se com este trabalho avaliar a eficiência de diferentes doses do fluazifop-p-butil isolado e na associação com os herbicidas glyphosate, 2,4-D e a mistura glyphosate + 2,4-D. O experimento foi conduzido em vasos contendo cinco litros de solo, com seis doses do herbicida fluazifopp- butil aplicadas em mistura com três herbicidas/mistura [glyphosate, 2,4-D e glyphosate + 2,4-D] em três formas de aplicação (mistura em tanque, aplicados separadamente no mesmo dia e separadamente cinco dias antes da aplicação do fluazipop-p-butil), mais as seis doses do fluazifop-p-butil sem mistura. Verificou-se que o herbicida fluazifop-pbutil aplicado isoladamente controla de modo eficiente plantas voluntárias de híbrido de milho AS 1660 PRO RR nas doses 75 g ha-1, 28 dias após a aplicação (DAA). Porém, a mistura em tanque do fluazifop-p-butil com 2,4-D resultou em redução do nível de controle do milho voluntário. Não houve redução da eficácia no controle do milho quando se aplicou o herbicida fluazifop-p-butil associado ao glyphosate, 2,4-D e a mistura glyphosate + 2,4-D, separadamente no mesmo dia ou cinco dias após.Palavras-chave: antagonismo, fluazifop-p-butil, glyphosate, 2,4-D, Zea mays.INTERACTIONS AMONG HERBICIDES IN THE MANAGEMENT OF THE VOLUNTARY MAIZE RR®ABSTRACT - Mixing herbicides may result in synergistic, antagonistic or additive effects on the control of volunteer maize and other weed species. The objective of this work was to evaluate the efficiency of different doses of fluazifopp- butyl alone and in association with the herbicides glyphosate, 2,4-D and glyphosate + 2,4-D mixture. The experiment was carried out in pots containing five liters of soil, with six doses of the herbicide fluazifop-p-butyl applied in a mixture of three herbicides/mixture [glyphosate, 2,4-D and glyphosate + 2,4-D] (tank mix, applied separately on the same day and separately five days prior to the application of fluazipop-p-butyl) plus the six doses of fluazifop-p-butyl without mixing. The isolated fluazifop-p-butyl herbicide was monitored efficiently to control volunteer maize hybrids AS 1660 PRO RR at doses 75 g ha-1, 28 days after application (DAA). However, tank mixing of fluazifop-p-butyl with 2,4-D resulted in a reduction in the level of voluntary maize control. There was no reduction in efficacy in maize control when applied we the herbicide fluazifop-p-butyl associated with glyphosate, 2,4-D and glyphosate + 2,4-D mixture, separately on the same day or five days later.Keywords: antagonism, fluazifop-p-butyl, glyphosate, 2,4-D, Zea mays.