Resumo em Inglês:

ABSTRACT For its production, broccoli requires large quantities of nutrients in relatively short periods. As a conservation technique, the no-tillage planting of broccoli over the pearl millet straw in succession may interfere with the dynamics of nutrient release, inflorescence production and the chemical attributes of the soil. The objectives of this work were to evaluate nutrient cycling, broccoli production and soil chemical attributes in a no-tillage system in succession to pearl millet for two consecutive years. The treatments consisted of pearl millet (BRS 1501) with the straw maintaned whole over the soil, pearl millet with the ground straw, spontaneous plants with biomass maintaned on the soil and conventional system with soil tillage without cover maintenance. It was found that ground pearl millet on the soil surface intensifies the nutrients release rate and provides a less use by broccoli grown in succession. The continuous conventional system reduces the absorption of nutrients and the production of inflorescence of broccoli grown in highly-fertile soil. Pearl millet is efficient in maintaining potassium levels in the soil over broccoli crops in succession. The maintenance of whole pearl millet straw on the soil surface is a promising technique for growing broccoli in succession.

Resumo em Inglês:

ABSTRACT The use of growth regulators as a technique that can reduce plant height and thus strengthen stalks, which may be an option to eliminate or reduce plant lodging, thereby avoiding crop loss. However, there is a lack of information on the subject. The purpose of this study was to evaluate the effect of the dose (0; 37.5; 75.0; 112.5 e 150.0 g ha-1 active ingredient) and the application times of trinexapac-ethyl (sixth, seventh and eighth leaves), in a randomized complete block, in a 5x3 factorial scheme, with four replicates. The field experiment was performed during the 2016/17 crop season, in the experimental farm located in Selvíria, Mato Grosso do Sul State, Brazil, at Universidade Estadual Paulista- UNESP, Ilha Solteira, São Paulo State, Brazil - Campus. It is not recommended to apply the trinexapac-ethyl at eighth leaf, especially in the doses of 75.0; 112.5 and 150.0 g ha-1, since they generated the lowest values for yield parameters, thus reducing productivity, and providing greater number of unfilled grains. Taking into account the reduction in plant height, the minimization of lodging and grain yield, trinexapac-ethyl should be applied to the seventh leaf of the BRS Esmeralda rice at the dose of 75 g ha-1.

Resumo em Inglês:

ABSTRACT The objective of this study was to investigate the effect of different rates of ethephon on return bloom and yield, and fruit quality of ‘Fuji’ apple trees. The experiment was performed during the 2014/2015 and 2015/2016 growing seasons. Eighteen-year-old Fuji Standard apple trees grafted on M.9 were sprayed with different rates of ethephon (300 mg L-1, 400 mg L-1, and 500 mg L-1) 30 days after full bloom (DAFB) and compared to an unsprayed control. Yield components (number of fruit per tree, yield, fruit weight, and estimated yield) and fruit quality attributes (fruit firmness, total soluble solids and starch-iodine index) were evaluated in both seasons. Return bloom (percentage of flowering spurs and 1-year-shoots) was assessed only the year following the application. Our results show that ethephon increases return bloom and yield of ‘Fuji Standard’ apple trees, without affecting fruit quality attributes.

Resumo em Inglês:

ABSTRACT Bugs are pest insects that, when not adequately controlled, may cause significant losses in the soybean crop. Their damage to grains compromises delivery in the storage unit and storage success. Thus, the objective of this study was to evaluate, during storage, the effect of temperature and moisture content on soybean grain quality with high damage caused by bugs in the crop. The experiment was set in a completely randomized design with a 2 x 4 x 5 factorial design, with two moisture contents (11.75 and 13.84% (w.b.)), four storage temperatures (20, 25, 30 and 35 °C), and five evaluation periods (0, 2, 4, 6 and 8 months). The percentage of damaged/fermented, damaged, fermented, broken grains, and electrical conductivity were analyzed. It can be inferred that bug-damaged soybean grains have reduced quality when stored at higher temperatures and for more extended periods. It is not recommended to store bug-damaged grains in moisture contents of 13.84% (w.b.) at temperatures above 30 °C for longer than four months. Grains stored at 35 °C when not damaged by bugs, ferment after six months of storage. Bug-damaged grains evolve to fermented grains during storage.

Resumo em Inglês:

ABSTRACT Conyza sp. was the first glyphosate-resistant weed in Brazil’s soybean crop. Synthetic auxin herbicides followed by paraquat has improved the hairy fleabane control, and time of day of herbicide application can affect the control efficacy. There are no studies reporting the effects of the application time of synthetic auxins in tank-mixture with paraquat, or in sequential application with paraquat at two growth stages of hairy fleabane, applied at different times of the day. The herbicides were sprayed during the morning and night. 2,4-D applied alone was more effective applied during the day, while dicamba efficiency was higher when applied at night in the rosette stage. The mixture of 2,4-D and paraquat was more efficient when applied during the night. Tall hairy fleabane were more effectively controlled by dicamba + paraquat as well as any synthetic auxin followed by paraquat. When herbicides were applied at night, efficiency was slightly higher.

Resumo em Inglês:

ABSTRACT This study aimed to estimate and compare parameters of adaptability and stability for maize grain yield in a variety of environments by different projection methods. Data from experiments on 36 maize genotypes, in simple lattice 6x6, in 2012/13 season performed at nine growing locations in central Brazil were used. Adaptability and stability analyses were performed using the methods of Lin & Binns (1988) with decomposition, MHPRVG through REML/BLUP, AMMI-Biplot, and GGE-Biplot analysis. These methods have similarities in terms of genotype ordering but differ in precision and amount of information provided on genotype-environment (GxE) interactions. When compared to GGE-Biplot, AMMI method retained a good percentage of the total square sum, based on pattern of GxE interaction. The method of Lin & Binns with decomposition is similar to MHPRVG, but these one is more accurate, practice and informative. MHPRVG and GGE-Biplot methods should be used together to select the most promising genotypes. The genotypes G5 and G8 can be recommended for cultivation in central Brazil due to their adaptability, stability, and yield.

Resumo em Inglês:

ABSTRACT This study broadens the knowledge of plant-pathogen interactions using phytohormone-deficient and low-sensitivity mutant tomatoes. The experiment was performed under greenhouse conditions and the mutants used were provided by the HCPD laboratory, at ESALQ/USP. The hormone mutant Never ripe showed a larger final lesion size when inoculated with Botrytis cinerea, whereas curl3 was relatively resistant to this pathogen and more susceptible when inoculated with Phytophthora infestans. The transgenic 35S :: nahG was more susceptible to Oidium lycopersici, and the double mutant dgt, Nr more resistant. The low sensitivity to brassinosteroids confers greater susceptibility to P. infestans and higher resistance to B. cinerea. The deficiency of the hormone auxin promotes high resistance to diseases caused by O. lycopersici, P. infestans and B. cinerea.

Resumo em Inglês:

ABSTRACT The use of pre-emergent herbicides is important for the current agricultural production systems that present weeds resistant to herbicides. Considering the complexity of using these products, the objective of this work was to evaluate their selectivity and residual weed control in soybean crops and their effect on the weeds Amaranthus hybridus, Bidens pilosa, Digitaria insularis, Eleusine indica, and Euphorbia heterophylla. The herbicide selectivity experiments were conducted under field conditions in the 2017/18 and 2019/20 crop seasons and the herbicide efficacy experiments were conducted under greenhouse conditions. The herbicides s-metolachlor and flumioxazin can be applied on day of the soybean sowing without causing significant grain yield losses. Diclosulam and sulfentrazone are safe for soybean crops when applied at least 14 days before sowing. The herbicides used proved to be good options for weed management systems for soybean crops; flumioxazin and sulfentrazone were the herbicides that promoted the best control for all evaluated weed species and ensured a residual effect of at least 30 days.

Resumo em Inglês:

ABSTRACT To reduce peach tree losses due the Peach Tree Short Life (PTSL), the main research line in Brazil is to select tolerant rootstock and perpetuate it by cloning methods. The objective was to evaluate adventitious rooting capacity of softwood cuttings of three cultivars and several clonal rootstock selections of Prunus spp., under intermittent mist system. Two trials were conducted and ‘Capdeboscq’, ‘Okinawa’ (P. persica) and ‘Sharpe’ [‘Chickasaw’ (P. angustifolia Marsh.) x Prunus spp.] were used as reference cultivars. After 53 days (trial 1) and 72 days (trial 2) from the cutting setting, we conclude that softwood cuttings under intermittent mist system are a feasible way to propagate peach rootstock selections of 2010/2011 PTSL selection cycle. Root quality was satisfactory in most selections, with high percentages of cuttings suitable for transplanting and excellent root number and root length. OS-GRA-10-17, VEH-GRA-10-31, VEH-GRA-10-32, VEH-GRA-10-37 and VEH-GRA-10-38 selections had the highest mortality and the lower percentages of live rooted cuttings. The ease of vegetative propagation must be taken into account in more promising rootstock.

Resumo em Inglês:

ABSTRACT The Cerrado biome has several species that can generate income, and the cajá-manga is one of these native species with great potential but with scarce information about its morphological characterization. Thus, this work aimed to characterize the fruit, endocarp, seeds, and seedlings of cajá-manga morphologically. The fruits were evaluated by the characteristics of the length, width, and diameter of the fruit, endocarp, and seeds, the number of loculi, and the weight of fruits and endocarp. The plantlets were evaluated for the number of seedlings per endocarp, number of leaflets, number of leaflets of the 3rd and 4th leaves, stem diameter, length of the shoot and root, root and shoot dry matter and data analyzed by descriptive analysis. The morphometric characteristics of the fruits, endocarp, and seeds were analyzed using the Scott-Knott test. The morphological characteristics of the fruits, the endocarps, the seeds, and the plantlets of cajá-manga varied within the mother plants. These results can be used as a basis for future selection of plants with desirable characteristics on breeding programs.