Michelangelo Muzell Trezzi

Action of auxin inhibitors on growth and grain yield of soybean

Soybean genotypes grown in sub-tropical climate may exhibit lodging. The plant lodging is influenced by soil type and fertility level, sowing date, latitude and altitude of the location, plant population and conditions of crop development. Plant regulators and herbicides are able to avoid or reduce plant lodging. This study aimed to verify the effects of the growth regulators TIBA and daminozide on vegetative growth and yield of soybean cultivar CD 214 RR. The experiment was carried out at a field in randomized block design with four replications in a factorial scheme. The A factor was represented by the combination of regulators TIBA and daminozide and its concentrations, and the Factor B was seven times of evaluation of injury and plant height or eight times of evaluation of lodging. In the range of doses used, the application of daminozide resulted in greater injury to soybean plants than TIBA. The smaller plant height was achieved by the application of 6 g ha -1 of TIBA and 1200 g ha-π of daminozide. Treatments with daminozide (100 g ha-π) and TIBA (10 g ha -1 ) stood out due to the reduced lodging of soybean plants. Grain weight increased linearly when the levels of TIBA increased. There was a negative correlation between lodging and grain yield and a positive correlation between plant height and lodging. There was also a negative correlation between injury caused by the application of plant regulators and lodging.

Tolerance of dry bean cultivars to saflufenacil

The herbicide saflufenacil is a Protox inhibitor, with differential translocation mode in comparison to other herbicides with the same mechanism of action. Selectivity, efficacy and safety to the environment are important characteristics for practical application of a herbicide in agriculture. The aim of this study was to determine the tolerance of ten dry bean cultivars to saflufenacil, applied on preemergence. The experiment was conducted in split plot randomized blocks design with ten dry bean cultivars (IAPAR 81; IPR Tiziu, IPR Corujinha; BRS Estilo; BRS Talisma; BRS Esplendor; BRS Campeiro; BRS Radiante, BRS Vereda and Jalo Precoce) allocated in plots and saflufenacil concentrations (0, 14.7 and 29.4 g ha- 1) in subplots. Evaluations were performed at 21 and 28 days after application (DAA) and plant height at 28 and 35 DAA. At physiological maturity were evaluated plant height, first pod height , number of pods per plant, 400 grains weight and dry beans grain yield. The cultivar Talisma showed low sensitivity to the herbicide and the cultivar Jalo Precoce high sensitivity to the herbicide, considering all variables analyzed.

Methods to promote Borreria latifolia seed germination

Specific knowledge on dormancy and germination patterns of weed species aids the development of integrated management strategies. This study aimed to evaluate and select effective methods for overcoming dormancy in B. latifolia seeds, as well as determining their influence on the germination process. A completely randomized experimental design was used, with four replications and 20 seeds per repetition. Seven tests were conducted, with the corresponding B. latifolia seed treatments: Test 1- mechanical scarification (EM), sulfuric acid (H2SO4), hot water (IAQ) and running water (LAC); Test 2- pre-cooling at 4 °C (PE) and dry heat (CS) at 60 °C. Test 3- gibberellic acid (AG) at concentrations of 0, 50, 100, 200 and 400 ppm; Test 4- acetic acid (AC) and KNO3 2%; Test 5- dual combinations of the three best treatments observed in the first four tests. Test 6- pre-soaking in a sandbox (EST) and in germination paper (PE) and; Test 7- imbibition curve. The seeds were submitted to the germination test in BOD at 25 °C with a photoperiod of 12h, in transparent polypropylene boxes. Germination percentage (GP), mean germination time (MGT) and relative frequency of germination (RFG) were determined and the weight of the seeds after soaking in Test 7 was measured. The best treatments for overcoming seed dormancy were CS, AG 283 ppm and KNO3 3h. The association of CS+KNO3 and KNO3+AG increased GP by 25% compared to isolated treatments.

Morning glory species interference on the development and yield of soybeans

AbstrAct: Plants from the genus ipomoea are among the most important weeds in Brazil. The objective of this study was to determine the impact of different densities of 2 species of Ipomoea ( I. grandifolia and I. purpurea ) under different environments (counties of Pato Branco and Renascenca, Parana state, Brazil) on soybean biometric variables, yield components and crop yield loss. Field experiments in 2 distinct places were conducted in a randomized block design, where 1 factor consisted of 8 plant densities (0, 2, 4, 6, 8, 10, 15 and 20 plants·m −2 ), whereas the other factor consisted of the 2 Ipomoea species. Joint analysis of the data was performed bAsIc ArEAs - Article Morning glory species interference on the development and yield of soybeans Fortunato De Bortoli Pagnoncelli 1 *, Michelangelo Muzell Trezzi , Betania Brum , Ribas Antonio Vidal 2 , Alvaro Fernando Portes 1 , Everton Luiz Scalcon , Adriano Machado 1 1.Universidade Tecnologica Federal do Parana - Agronomia - Pato Branco (PR), Brazil.2.Universidade Federal do Rio Grande do Sul - Porto Alegre (RS), Brazil.

Sistemas de adubação de girassol e milho em consórcio de substituição

The relay intercropping, where a second crop is established after the first one has reached the reproductive stage of growth, is a system that reveal great potential use in small farms. However, to achieve a more efficient system, it is necessary to determine management practices more suitable to this system, such as date and manner of fertilizer application in both crops. This work was conducted in Eldorado do Sul, state of Rio Grande do Sul, Brazil, in the 1993/94 growing season. The objective ot these work was to compare the effect ot three tertilization systems in the relay intercropping of corn into suntiower. A early season and a late season corn cultivars were established in relay intercropping into sunflower. The fertilization systems were double row fertilization in sunflower, double broadcast fertilization in sunflower and individual row fertilization for sunflower and corn. The checks were two corn monocultures with individual row fertilization. Grain yield and yield components of sunflower crop were not affected by the fertilization systems tested. Sunflower biomass was 12.5% higher in double broadcast than in individual row fertilization system. Using double row fertilization in sunflower, the grain yield ot both com cultivars was similar to individual row fertilization in each crop. Differences were obtained between corn cultivars when double broadcast fertilization was used. The grain yield ot early season corn cultivar was lower than the grain yield of individual row fertilization, however, the grain yield of late season corn cultivar was similar.

SISTEMAS DE CULTIVO DE MILHO EM CONSÓRCIO DE SUBSTITUIÇÃO E EM SUCESSÃO A GIRASSOL

Relay intercropping and double cropping are the main types of multiple cropping systems and they are promising alternatives to small farm. This work was conducted in Eldorado do Sul, state of Rio Grande do Sul, Brazil, in the 1991/92 growing season with the objectives of comparing relay intercropping and double cropping systems of corn into sunflower with corn as a sole crop, relay intercropping with double cropping systems and determining the best combination of sunflower and corn cultivars cycles. The treatments were composed by relay intercropping or double cropping with early (Cargill 805) or long season (AG 106) corn cultivar into early (Contisol 711) or long season (Dekalb 180) sunflower cultivar established in late July, and their respective corn monocultures. There were no differences between relay intercropping or double cropping corn grain yield and the respective corn monocultures, regardiess of cycle of the cultivar used. Only the relay intercropping system with early corn into early season sunflower presented corn grain yield higher than in the double cropping systems.

CONSÓRCIO DE SUBSTITUIÇÃO DE CULTURAS: ALTERNATIVA PARA A PEQUENA PROPRIEDADE RURAL

In relay intercropping, a second crop is established after the first one has reached its reproductive stage of growth before it is ready for harvesting. In this system the competition between component crops is smaller than in simultaneous intercropping. The second crop planting in relay intercropping is done by hand, in a similar way to the no-tillage system, resulting in better moisture conservation, erosion control and maintenance of soil temperature more suitable than in the sequential cropping. Beyond, the shadow of remained leaves of the first crop reduces growth of weeds during the initial stages of the second crop. In the state of Rio Grande do Sul, Brazil, several crops nave potential to participate in relay intercropping system. However, to achieve success in relay intercropping utilization, there are requirements for compatible species and varieties, suitable plant arrangement, adequate date selection for second crop introduction and effective weed control during the first crop.