Estudou-se no presente trabalho a eficiência da grade de discos, enxada rotativa, grade de dentes flexíveis e grade de dentes rotativos na incorporação de trifluralin para cultura de algodão, nos anos agrícolas 1978/79 e 1979/80. Em laboratório, procurou-se verificar a profundidade de atuação do herbicida, mediante amostras de solo nas quais foram semeadas "plantas-teste". A enxada rotativa foi o equipamento de maior eficiência na incorporação do herbicida ao solo. Quanto à grade de discos, o equipamento mais utilizado nesta prática, obteve-se maior eficiência de incorporação efetuando-se duas passadas, com sobreposição de meia grade, a diferentes profundidades.

This research investigates the efficiency of trifluralin incorporation in soils using four different equipments, such as, disk harrow, rotary plow, flexible spiketooth harrow and rotary hoe, during 1978/1979 and 1979/1980, at Campinas, State of São Paulo, Brazil, in cotton fields. Laboratory tests were also carried out to verify the depth of the herbicide action using soil samples collected through special cylinders with known diameter and height and sowing seeds of check plants. Rotary plow showed the best results. In regarding to the disk harrow, normally used to incorporate trifluralin, double harrowing at different depths is suggested as a good practice, superposing up to half harrowing width in the second pass.

Com o objetivo de verificar a eficiência de hebraicas no controle de plantas daninhas e sua seletividade à cultura do sisal, foi instalado, em setembro de 1976, um experimento de campo em solo argiloso, com os seguintes tratamentos (i.a./hectare) trifluralin a 0,84 e 0,96kg em pré-plantio com incorporação; alachlor a 2,40 e 3,26kg; metribuzin a 0,70 e 0,84kg; bromacil a 1,60 e 2,40kg; terbacil a 1,60 e 2,40kg; diuron a 2,40 e 3,20kg; simazine a 3,20 e 4,00kg; fluometuron a 1,20 e 1,60kg, todos em pré-emergência; uma testemunha carpida e outra sem capina. Foram feitas avaliações de controle do mato aos 67 e 114 dias e da condição da cultura aos 600 dias após a aplicação. Aos 114 dias, o controle de gramíneas foi acima de 90% pelo trifluralin, bromacil e terbacil, em torno de 80% pelo simazine, e inferior a 75% pelos demais; para dícotiledôneas, o controle foi de 90 a 100% pelo bromacil e terbacil, e de 80 a 85%o pelo simazine. Nenhum dos tratamentos afetou a cultura durante o período considerado, que foi de 600 dias. Aos 550 dias, fez-se avaliação da área coberta por reinfestação do mato, tendo o terbacil controlado ainda 75 e 95% do total, respectivamente, para as doses menor e maior; o trifluralin, 60 e 70% e, os demais, abaixo de 45%. Na avaliação final da cultura, aos 600 dias, foram considerados: população de plantas, número de plantas com perfilhos e condição da cultura. Os tratamentos que realizaram melhor controle do mato apresentaram também os melhores índices de desenvolvimento da cultura, atestando sua seletividade.

The weed control with herbicides and its selectivity to sisal were studied on a clay soil field trial. The treatments (in a.i./ha) were: 0.84 and 0.96kg of pre-plant incorporated trifluralin; 2.40 and 3.26kg of alachlor; 0.70 and 0.84kg of metribuzin; 1.60 and 2.40kg of bromacil; 1.60 and 2.40kg of terbacil; 2.40 and 3.20k- of diuron; 3.20 and 4.00kg of simazine; 1.20 and 1.60kg of fluometuron; a hoed check and a not hoed check. Trifluralin was applied on September 24, 1976, the bulbils were transplanted on the 29th of the same month and the PRE herbicides applied on the 30th. Weed control was evaluated at 67 and 114 days after PRE application. The grass control was over 90% by trifluralin, bromacil and terbacil, around 80% by simazine and below 75% by the remaining herbicides. The broadleaves were controlled at a level of 90 to 100% by bromacil and terbacil and 80 to 85% by simazine. None of the herbicides affected the growth of sisal plants during the considered period of 600 days. At 550 days the area covered by weeds was evaluated. Terbacil controlled still 75 and 95% of the total quantity of weeds, at the lower and higher doyes, respectively, trifluralin controlled 60 to 70% and the remainder below 45%. For final evaluation at 600 days, crop stand, number of plants with sprouts, number of leaves per plant and crop condition were considered. The treatments with best weed control also showed the best scores for crop development, partly due to their selectivity to sisal.

Foram conduzidos estudos em vasos e no campo, para conhecer até que profundidade ocorria germinação de capim-carrapicho (Cenchrus echinatus L.). Em vasos esta ocorreu até 11 cm de profundidade e no campo até 9 cm em solo argiloso, e 10 cm em solo barrento. Foi frequente a germinação de duas ou mais cariopses por infrutescência. Em dois outros testes em vasos foi estudado o local de ação do trifluralin na dose de 0,84 kg/ha de i.a., em solo barrento. Verificou-se ação do herbicida nas zonas meristemáticas da raiz e do coleóptilo, causando inibição de desenvolvimento longitudinal do mesocótilo e da raiz. Na ponta da raiz primária, no primeiro nó e nó coleoptilar verificou-se aumento pronunciado de diâmetro.

Studies were performed in pots and in field to know the capacity of germination of Cenchrus echinatus L. at different depths. In pots the seeds germinated from 1 to 11 cm and in the field from 1 to 9 cm in clay soil and from 1 to 10 cm in loamy soil. The germination of two or three seeds from the same fructescence was frequent. In two other tests the side of action of trifluralin at 0.84 kg/ha, in loamy soil, was studied. The herbicide showed activity on the meristematic zones of the root and coleoptile, inhibiting the growth of the shoot and root. The affected regions showed an increase in diameter.

Estudou-se o controle da tiririca (Cyperus rotundus L.) por meio de aplicações sucessivas de EPTC, uma e duas vezes ao ano, por dois anos. Aliou-se a eficiência do produto contra a tiririca à sua seletividade ao feijoeiro (Phaseotus vulgaris L.), cv. carioca. As doses variaram desde 0 a 21,6 kg/ha do ingrediente ativo, sendo que a dose máxima não se mostrou esterilizante do solo, nem com duas aplicações ao ano, o que se verificou pela população de carrapicho-de-carneiro (Acanthospermum hispidum DC) e serralha-falsa (Emilia sonchifolia L.). Houve redução gradativa e significativa da população de tiririca, com duas aplicações por ano, em todas as doses. Nas mais elevadas verificou-se redução total após dois anos. Com uma aplicação por ano, nas doses mais elevadas, houve recuperação parcial, e nas mais baixas, recuperação total. As produções e a qualidade da cultura não foram afetadas pelo herbicida. Houve aumento de produção com a elevação da dose na segunda e quarta safras, devido, aparentemente, à eliminação da competição da tiririca.

The control of nutsedge (Cyperus rotundas L.) with sucessive applications of EPTC was studied, during two years, combining the selectivity of the herbicide to beans (Phaseolus vulgaris L.) and its efficiency against the weed, even with two applications per year. The rates ranged from 4.32 to 21.60 kg/ha of EPTC. The highest rate did not sterilize the soil, even with two applications per year. There was a gradual and significant reduction of the nutsedge population at all rates with two applications per year. The weed had time to recover with only one application per year even with the highest rate, but was totally killed by it with two applications after two years. The bean quality and yields were not affected by the herbicide. There was an increase of yields with the increasing of the EPTC rates, due, apparently, to the elimination of the nutsedge competition.

Um ensaio em Latossolo Roxo foi conduzido para verificar a influência dos herbicidas EPTC e Trifluralin na nodulação e produção do feijoeiro, e, também, a resposta dêste à inoculação das sementes com estirpe selecionada de Rhizobium sp. A análise estatística dos dados coletados mostrou aumento significativo no pêso sêco dos nódulos, devido à inoculação das sementes. O aumento na nodulação não foi acompanhado de incremento significativo da produção. A aplicação dos herbicidas não influenciou a nodulação, mas proporcionou perfeito contrôle de gramíneas invasoras.

A field trial was carried out in a Latosolic B Terra Roxa, to investigate the influence of the herbicides EPTC and Trifluralin on nodulation and dry bean production. Sampling of nodules and plants was made at flowering. Data of bean production were also collected. A system of scores was used to evaluate the control of weeds. Statistical analysis of data showed significant increase in dry weight of nodules due to seed inoculation but there was no correspondent increase in bean production due to seed inoculation. It was observed that herbicides EPTC and Trifluralin had no influence on nodulation. Control of weeds was effective.

Duas variedades de quiabeiro foram testadas, em condições de casa de vegetação, com solo de textura areno-barrenta, na sua tolerância para 16 herbicidas, cada qual aplicado em uma única dose. Dentre os herbicidas aplicados em pré-plantio incorporado o triflu-ralin destacou-se no combate às ervas daninhas gramíneas e não causou nenhum dano para a planta do quiabeiro. Os herbicidas cloroxuron, linuron, norea e propachlor mostraram ótimos resultados no cambate às ervas más e quanto à tolerância dessa malvácea. Do grupo das triazinas, todos os herbicidas usados nas condições do teste provocaram danos para o quiabeiro.

Two okra (Hibiscus esculentus L.) varieties were tested for their tolerance to sixteen herbicides at one rate each, as a pre-planting and as a pre-emergence applications in greenhouse trials. The results with the incorporated herbicides showed that only tri-fluralin at 0,75 kg/ha active ingredient was promising to this crop. Different results were obtained with the pre-emergence applications of the group of urea and anilide herbicides. While no symptoms of injury were observed with chloroxuron, norea, linuron, and propachlor, injury symptoms were evident with diuron, fluometuron, metobromuron and siduron. The four triazine herbicides were very damaging to the okra plants. Under the conditions of these tests, only the herbicides trifluralin, chloroxuron, norea, and linuron were promising to the okra crop.

Experimentos foram conduzidos, em solo areno-argiloso da formação Glacial, em Campinas, para estudar os efeitos da aplicação do herbicida «Ramrod» em canteiros para formação de mudas de cebola. Foram testadas as doses de 1,30, 1,95, 2,60, 3,90 e 5,20 kg/ha de ingrediente ativo. Em relação ao combate às ervas más dicotiledôneas, apenas a dose de 1,30 kg/ha não foi superior à da testemunha. Para qualquer das doses utilizadas não se verificaram sintomas visuais de fitotoxicidade nas plantas. Pequeno efeito residual do produto foi constatado em todas as doses, aos 50-60 dias após a aplicação.

Two experiments to determine the effect of various rates of Ramrod herbicide on the development of onion seedlings were conducted on sandy-clay soil type, of Glacial formation, at the «Theodureto de Camargo» Experiment Station, Campinas. The results may be summarized as follows: 1 - Ramrod herbicide as pre-emergence application may be used for weed control on onion seedling formation. No apparent damage was noted with the application of the different rates of the herbicide. 2 - The comparison between Ramrod at 1.30 kg per hectare a. i. with the check treatment revealed no significant difference in the control of dicotyledoneous species that were found 22 days after sowing. 3 - The comparison of Ramrod at 1.95 and 2.60 kg per hectare a.i. of experiment 1, and 2.60, 3.90 and 5.20 kg per hectare a.i. of experiment 2 with the check treatment, showed highly significant differences in the control of dicotyledoneous species after 22 and 34 days. 4 - After 8 weeks no residual effect was observed from any rate of application of Ramrod. There was a regrowth of weeds after that period. 5 - Based on these experiments Ramrod at 1.95 up to 3.90 kg per hectare a.i., depending on soil type, could be recommended for weed control in onion seedbeds.

Foram estudados os efeitos das variações nos métodos de aplicação dos herbicidas Diuron e Trifluralin na cultura algodoeira, para verificar sua eficiência no combate às ervas daninhas. O tratamento Trifluralin aplicado em pré-plantio incorporado, provocou excelente combate às ervas daninhas gramíneas, porém irrisória redução da população das dicotiledôneas. A aplicação de Trifluralin em pré-plantio incorporado e a de Diuron em pré-emergência, aumentaram consideravelmente a área de contrôle nos dois grupos de ervas más. O tratamento Diuron aplicado em pré-emergência foi bastante efetivo no combate às ervas de "fôlhas largas", enquanto que no combate às gramineas não foi tão eficiente. O incorporação do Diuron, aplicado em pré-plantio, não aumentou a eficiência do produto químico. A redução da dose de Diuron em pré-plantio incorporado ou em pré-emergência não proporcionou combate adequado às ervas más.

1 - An experiment to study the various modalities of the application of the herbicides diuron and trifluralin in cotton plantings was carried out in purple latosol soil, Chapadão series. The two herbicides were applied in various doses and at different times. The most common weeds in the trial area were capim pé-de-galinha (goosegrass), capim carrapicho (sandbur), capim colchão (crabgrass), beldroega (purslane), carraplcho de carneiro, and poaia. 2 - The effectiveness of diuron (1.60 kg/ha), applied pre-planting, was not increased by incorporation into the soil. The control of weeds was efficient, but the yield was inferior to that of plots without incorporation. Of the weeds that survived the treatment, a predominance of grass species was noted. Some of the cotton leaves turned yellow in plots that received this herbicide, but this chlorosis was temporary and the plants regained their normal color within a few weeks. The tolerance of cotton for the treatments did not appear to be affected by the method of application of the herbicides. The method of incorporation in pre-planting was not found to be more advantageous than the pre-emergence treatment. 3 - A reduction in the dosage of diuron (0.80 kg/ha) in pre-pianting, with subsequent incorporation into the soil, did not give adequate control of annual weeds. 4 - The application of trifluralin (1 kg/ha), incorporated in pre-planting, gave excellent control of grass weeds, but the dicotyledonous species were little affected. 5 - A combination of diuron (0.80 kg/ha) and trifluralin (0.5 kg/ha) appears to be practical. The application of trifluralin in pre-planting, incorporated into the soil, and of diuron in pre-emergence, increased considerably the area of control of both groups of weeds. This practice, using two herbicides, offers the following advantages; a) greater variety of weeds controlled; b) a lessening of the opportunity for chlorosis to appear in the cotton by the use of a smaller dosage of diuron; c) a reduced residual effect for the subsequent crops; d) the band application of two products and reduction in cost of applied material; e) the possibility of cultivating between rows without loss of efficiency of the incorporated product. 6 - The treatment with diuron (1.60 kg/ha) applied in pre-emergence was sufficiently effective in the control of broad leaf weeds, while control of grass species was less so. Slight symptoms of phytotoxicity were noted, but these were not sufficient to affect the yield and with further development of the crop they disappeared. The yield from herbicide-treated plots was greater than that from check plots which received manual hoeing.

Vários inseticidas foram ensaiados no contrôle da moléstia de vírus do tomateiro denominada vira-cabeça, transmitida por um tripes do gênero Frankliniella. Os resultados obtidos nestes ensaios mostraram que, dos inseticidas ensaiados, Rhodiatox e Hexason 2540M foram os mais eficientes. Os dados obtidos permitem que se sugira o seguinte programa de pulverização de tomateiros, para o contrôle de vira-cabeça. Na sementeira: Pulverizações de 3 a 5 dias com Rhodiatox (0,25 a 0,50%) ou Hexason 2540M (0,15%). No canteiro de repicagem: Pulverizações cada 3 a 5 dias com Rhodiatox (0,50%) ou Hexason 2540M (0,15%). Na plantação definitiva: Pulverizações cada 5 a 7 dias com Rhodiatox (0,50% a 1%) ou Hexason 2540M (0,25%) até cêrca de 40 dias após a transplantação.

Spraying tests were made with several insecticides in an attempt to control the "vira-cabeça" disease of tomatoes (tomato spotted wilt) by killing the insect vector, a species of thrips belonging to the genus Frankliniella. The results obtained indicate that Rhodiatox (Brazilian trade name for a commercial preparation similar to Parathion, containing 5 per cent of p-nitrophenyl diethyl thiosphosphate) and Hexason 2540 M (a mixture of BHC with 2% gamma isomer, 5 per cent DDT and 40 per cent wettable sulfur) were better than tartar emetic or toxaphene, although these were somewhat effective. Based on the results of these tests a tentative spraying program for the control of the disease in local tomato plantings is suggested.