ABSTRACT The objective with the work was to evaluate, during storage, the rice seeds physical and physiological quality, cultivar IRGA 424 RI, dried with different drying air temperatures. For such, rice seeds were harvested with a moisture content of 22%. Then, they were subjected to drying in a cross-flow dryer, operating in an intermittent system and using the 55 and 65 ºC drying air temperatures. After, samples containing 50 kg of seeds were stored in PP Woven Bags for 240 days. After drying and every 60 days, physical and physiological analyses were performed. The experiment was conducted under a completely randomized design, arranged in a split-plot scheme, with 4 replications. The physical quality, estimated by the seed hectoliter weight, decreased during storage, regardless of the drying air temperature. The germination percentage, as well as the vigor increased during storage, regardless of drying air temperature due to the dormancy overcoming process. The dry seeds with the highest drying air temperature showed less vigor throughout the storage, according to the cold test. The rice seeds drying with an air temperature of 65 ºC, promoted a higher drying speed and did not negatively influence the seeds physical and physiological quality, however, reduced the vigor.

ABSTRACT The objective with the work was to evaluate, during storage, the rice seeds physical and physiological quality, cultivar IRGA 424 RI, dried with different drying air temperatures. For such, rice seeds were harvested with a moisture content of 22%. Then, they were subjected to drying in a cross-flow dryer, operating in an intermittent system and using the 55 and 65 ºC drying air temperatures. After, samples containing 50 kg of seeds were stored in PP Woven Bags for 240 days. After drying and every 60 days, physical and physiological analyses were performed. The experiment was conducted under a completely randomized design, arranged in a split-plot scheme, with 4 replications. The physical quality, estimated by the seed hectoliter weight, decreased during storage, regardless of the drying air temperature. The germination percentage, as well as the vigor increased during storage, regardless of drying air temperature due to the dormancy overcoming process. The dry seeds with the highest drying air temperature showed less vigor throughout the storage, according to the cold test. The rice seeds drying with an air temperature of 65 ºC, promoted a higher drying speed and did not negatively influence the seeds physical and physiological quality, however, reduced the vigor.

ABSTRACT The search for techniques that maximize the use of water is becoming necessary for the sustainability of agriculture in semi-arid areas. In this sense, the present work aimed to evaluate the effects of soil protection against water loss and the use of bovine biofertilizer on fruit production and chlorophyll content in bell pepper plants. The experiment was conducted in the municipal district of Nova Floresta in the semi-arid region of the State of Paraíba during the period of August 2010 to February 2011. The experimental design was a randomized block design with four repetitions in a 2 × 2 × 2 factorial scheme, corresponding to soil without and with bovine biofertilizer, without and with mulch, and without and with side coating of the grooves with polyethylene film, to reduce water loss through evaporation and lateral movement of water. The results showed that the use of side coatings of the grooves led to greater production, generating productivity gains in bell pepper cultivation. The association between side coating of the grooves and mulching of the soil resulted in increased levels of chlorophyll, but the bovine biofertilizer × side coating × mulch interaction inhibited the production of chlorophyll in the plants.

ABSTRACT The search for techniques that maximize the use of water is becoming necessary for the sustainability of agriculture in semi-arid areas. In this sense, the present work aimed to evaluate the effects of soil protection against water loss and the use of bovine biofertilizer on fruit production and chlorophyll content in bell pepper plants. The experiment was conducted in the municipal district of Nova Floresta in the semi-arid region of the State of Paraíba during the period of August 2010 to February 2011. The experimental design was a randomized block design with four repetitions in a 2 × 2 × 2 factorial scheme, corresponding to soil without and with bovine biofertilizer, without and with mulch, and without and with side coating of the grooves with polyethylene film, to reduce water loss through evaporation and lateral movement of water. The results showed that the use of side coatings of the grooves led to greater production, generating productivity gains in bell pepper cultivation. The association between side coating of the grooves and mulching of the soil resulted in increased levels of chlorophyll, but the bovine biofertilizer × side coating × mulch interaction inhibited the production of chlorophyll in the plants.

ABSTRACT Nitrogen fertilization, besides increasing productivity, can favor the production of well-formed, large, and heavy grains, which are traits valued by the oat processing industry. However, high nitrogen (N) doses may lead to plant lodging, which could be solved by using growth retardant. This study aimed to evaluate the industrial quality of white oat grains cultivated under different nitrogen doses and associated with the growth retardant trinexapac-ethyl in two growing environments. Experiments were conducted in Londrina and Mauá da Serra, PR, Brazil, using the cultivar IPR Afrodite in a randomized block design in a 4 × 2 factorial scheme and four replications. Treatments consisted of four topdressing N doses (0, 30, 60, and 90 kg ha−1) and the application or not of growth retardant. Thousand-grain weight, hectoliter weight, grain index greater than two millimeters, peeling index, and industrial grain yield were evaluated. The effect of N fertilization and growth retardant on the industrial quality of white oat grains depends on the characteristics of the growing environment. The trinexapac-ethyl application reduces grain quality in Londrina and Mauá da Serra. However, the industrial quality of grains is high in both growing environments when the growth retardant is associated with nitrogen doses.

ABSTRACT Nitrogen fertilization, besides increasing productivity, can favor the production of well-formed, large, and heavy grains, which are traits valued by the oat processing industry. However, high nitrogen (N) doses may lead to plant lodging, which could be solved by using growth retardant. This study aimed to evaluate the industrial quality of white oat grains cultivated under different nitrogen doses and associated with the growth retardant trinexapac-ethyl in two growing environments. Experiments were conducted in Londrina and Mauá da Serra, PR, Brazil, using the cultivar IPR Afrodite in a randomized block design in a 4 × 2 factorial scheme and four replications. Treatments consisted of four topdressing N doses (0, 30, 60, and 90 kg ha−1) and the application or not of growth retardant. Thousand-grain weight, hectoliter weight, grain index greater than two millimeters, peeling index, and industrial grain yield were evaluated. The effect of N fertilization and growth retardant on the industrial quality of white oat grains depends on the characteristics of the growing environment. The trinexapac-ethyl application reduces grain quality in Londrina and Mauá da Serra. However, the industrial quality of grains is high in both growing environments when the growth retardant is associated with nitrogen doses.

ABSTRACT Ear rot caused by fungi of genus Fusarium (FER) is one of the potentially harmful diseases to grain quality in maize. Given the capacity to produce mycotoxins, FER presents a risk to food safety. This study sought to identify parents and indicate hybrids of popcorn with a higher level of resistance to the incidence and severity of FER. Hybrids were produced from the crossing of 15 lines in S7 generation and 5 testers. The hybrids, together with the parents and five more genotypes used as control, were evaluated in a field trial. It was used a randomized block design arranged in 10 x 10 lattice. Data were submitted to analysis of variance by the F test (p < 0.05) and then by the mean grouping test of Scott Knott (p < 0.05). The results showed the possible to explore new sources of resistance to FER among germplasm evaluated. Both additive and non-additive gene effects are important in FER resistance. To obtain gains in FER resistance, the development of popcorn hybrids should consider the use of parental lines with low means of severity and good general combining ability.

ABSTRACT Ear rot caused by fungi of genus Fusarium (FER) is one of the potentially harmful diseases to grain quality in maize. Given the capacity to produce mycotoxins, FER presents a risk to food safety. This study sought to identify parents and indicate hybrids of popcorn with a higher level of resistance to the incidence and severity of FER. Hybrids were produced from the crossing of 15 lines in S7 generation and 5 testers. The hybrids, together with the parents and five more genotypes used as control, were evaluated in a field trial. It was used a randomized block design arranged in 10 x 10 lattice. Data were submitted to analysis of variance by the F test (p < 0.05) and then by the mean grouping test of Scott Knott (p < 0.05). The results showed the possible to explore new sources of resistance to FER among germplasm evaluated. Both additive and non-additive gene effects are important in FER resistance. To obtain gains in FER resistance, the development of popcorn hybrids should consider the use of parental lines with low means of severity and good general combining ability.

ABSTRACT Improved methods of weed control are required to support expansion of large-scale cowpea cultivation in mid-west Brazil. With the aim of testing our hypothesis that the tolerance of cowpea cultivars to sulfentrazone is dose- and genotype-dependent, we assessed the effects of increasing doses (0, 250, 500 and 1,000 g ha-1 of sulfentrazone) on the cultivars BRS Imponente, BRS Novaera, BRS Tumucumaque and BRS Itaim. The phytotoxic effects of sulfentrazone varied according to the dose of herbicide applied, although the symptoms were mild and only observable at the initial stages of development and at the highest dose tested. No statistically significant interactions were detected between cultivars and doses, and there were no significant differences between doses regarding population density, plant height, yield components and grain yield. Our results demonstrate that sulfentrazone is highly selective and can be applied to the studied cultivars without affecting growth or yield.

ABSTRACT Improved methods of weed control are required to support expansion of large-scale cowpea cultivation in mid-west Brazil. With the aim of testing our hypothesis that the tolerance of cowpea cultivars to sulfentrazone is dose- and genotype-dependent, we assessed the effects of increasing doses (0, 250, 500 and 1,000 g ha-1 of sulfentrazone) on the cultivars BRS Imponente, BRS Novaera, BRS Tumucumaque and BRS Itaim. The phytotoxic effects of sulfentrazone varied according to the dose of herbicide applied, although the symptoms were mild and only observable at the initial stages of development and at the highest dose tested. No statistically significant interactions were detected between cultivars and doses, and there were no significant differences between doses regarding population density, plant height, yield components and grain yield. Our results demonstrate that sulfentrazone is highly selective and can be applied to the studied cultivars without affecting growth or yield.

ABSTRACT The successful use of native species in conservation actions depends on basic knowledge of their biology, beginning with the identification of regenerating individuals in the field, up to the behavior and development of the species from the early stages of germination. Moreover, seed propagation and germination may be limited by the occurrence of dormancy. The objective of this work was to identify the best method to overcome seed dormancy of Hymenaea parvifolia Huber, besides characterizing the fruits, seeds, post-seminal development and seedlings of naturally occurring specimens in Amazonia. For this, (i) tests for the breakdown of dormancy were performed through thermal, chemical and mechanical treatments; (ii) analyses of their effects on seed germination were made; and (iii) morphology of germinative development of Hymenaea parvifolia was described. The treatments based on sulfuric acid for 15, 25 and 35 minutes were the most efficient in overcoming the integumentary dormancy. However, scarification by grinding is recommended because it had been less impact on the environment. External characteristics and shape of the fruit, seed and epicotyl can aid taxonomy of the genus and identification of its species in the field. In addition, morphological characters of the fruit, seed, germination and seedling were illustrated.

ABSTRACT The successful use of native species in conservation actions depends on basic knowledge of their biology, beginning with the identification of regenerating individuals in the field, up to the behavior and development of the species from the early stages of germination. Moreover, seed propagation and germination may be limited by the occurrence of dormancy. The objective of this work was to identify the best method to overcome seed dormancy of Hymenaea parvifolia Huber, besides characterizing the fruits, seeds, post-seminal development and seedlings of naturally occurring specimens in Amazonia. For this, (i) tests for the breakdown of dormancy were performed through thermal, chemical and mechanical treatments; (ii) analyses of their effects on seed germination were made; and (iii) morphology of germinative development of Hymenaea parvifolia was described. The treatments based on sulfuric acid for 15, 25 and 35 minutes were the most efficient in overcoming the integumentary dormancy. However, scarification by grinding is recommended because it had been less impact on the environment. External characteristics and shape of the fruit, seed and epicotyl can aid taxonomy of the genus and identification of its species in the field. In addition, morphological characters of the fruit, seed, germination and seedling were illustrated.