Maria de Lourdes da Silva Leal

Adaptabilidade e estabilidade de cultivares de milho no nordeste brasileiro

Forty six maize cultivars were evaluated during two years in 11 different places of Brazilian Northeast Region. Trials were carried out during the biennium 2001/2002 using experimental randomized block design, three repetitions, in order to know the adaptability and stability for cultivars recommendation. It was verified that the cultivars showed differentiated behavior among themselves in the mean of environments. The magnitude of the variance for local x cultivars interaction was more expressive than cultivars x years interaction, which suggests that the evaluations have to be done in a larger number of environments. Evaluated cultivars differed in adaptability and stability, and are very important for Brazilian Northeast Region.

Yield of tomato in monocrop and intercropping with aromatics plants

Tomato is mainly cultivated in monocrops, by intensive use of chemical products. It is an activity with economic, social and environmental risks. The intercropping has been used as a form to reduce these risks. In this work the yield of tomato in sole crop and intercropping with Foeniculum vulgare, Mentha piperita, Ocimum basilicum and Ruta graveolens was evaluated. The monocrop of tomato and its intercropping was evaluated with aromatic plants in a complete randomized design, with five treatments and four blocks. We evaluated height, canopy area, production, yield and land equivalent ratio. On the population density adopted, the F. vulgare (fennel) presented greater height and canopy area, and caused significant reduction on total production of tomato, from 12.23 kg, in monocrop, to 7.88 kg, when intercropped with fennel. However, intercropping with fennel contributed to a lesser loose caused by fruits borer (24%). The greatest loose caused by fruits borer occurred in monocropping and in intercropping with M. piperita (peppermint). Intercropping with Ruta graveolens (rue) resulted significant increase of commercial production of fruits, about 26%. The relative yield of tomato was greater in intercropping with rue (13.6 t ha-1), followed by intercropping with peppermint (9.8 t ha-1) and with O. basilicum (basil) (9.1 t ha-1), and lesser on intercropping with fennel (6.4 t ha-1). These results showed that the intercropping with rue was more advantageous than others producing more fruits. Among the studied aromatic plants, basil presented the highest yield (96.5 t ha-1). The tomato intercropping with aromatic cultures permits better use of land and higher yield, mainly when intercropping with rue. All aromatics plants evaluated represent an alternative source of gain.

Adaptabilidade e estabilidade de produção de cultivares de milho no nordeste brasileiro

Twenty five cultivars of maize (Zea mays L.) were evaluated in 1994, in twelve different environments of the Northeast Region of Brazil. The trials were arranged in randomized block designs with three replications aiming to obtain knowledge concerning to the adaptability and yield stability of the cultivars in each environment. The significant effects related to environment, cultivars and cultivars x environments interaction gave the evidence of outstanding differences among that parameters. The hybrids showed better performance than the varieties, yielding in average 22.5% higher in relation to the environmental variations. Only the Cargill 505 and AG 510 hybrids showed poor adaptability in unfavorable environments. Taking in account the means presented by the varieties, CMS 39 was the most adjusted to the optimal genotype proposed in the model. None of the materials studied gave a determination coefficient (R2) lower than 80%, indicating a good production stability.

Estimativas de parâmetros genéticos na população de milho CPATC-3 em dois locais de Sergipe

From 1999 to 2001, the maize population CPATC-3 was submitted to three selection cycles among and within half sib families in two sites of Sergipe State in order to obtain genetic parameters estimates and to verify the behavior of the genetic variability for ear weight. In each selection cycle, 196 half sib families were evaluated in a completely randomized block design with two replications per local and the recombination of the best families within the same agricultural year was made. The results showed highly significant differences among the families from the base population and for all selection cycles, evidencing the genetic variability presence for ear weight. The genetic parameters estimates showed that the maize population CPATC-3 presents genetic variability for increasing ear weight and offers good perspectives to continue the breeding program.

Resposta da laranjeira-pêra à adubação com nitrogênio, fósforo e potássio em um Latossolo Amarelo dos Tabuleiros Costeiros

The effects of N, P, and K applications on yield and fruit quality of orange (Citrus sinensis (L.) Osbeck) was studied in a factorial experiment carried out in a Yellow Latosol, of the Coastal Plateau of the Northeast of Brazil. Zero, 150 e 300 kg ha-1 N as urea; 0, 26 and 52 kg ha-1 of P as concentrated superfosfate and 0, 96 and 192 kg ha-1 of K as KCl were used. A linear yield response to N was observed in one, out of four years of observation. Nitrogen decreased fruit size and had no influence on fruit quality measured by percentage of juice, total soluble solids, acidity and ratio total soluble solids/acidity. Yield was highly responsive to P in each year observed. The nutrient increased percentage of juice and the total soluble solids/acidity ratio. Potassium increased yield and fruit size, but decreased the total soluble solids/acidity ratio.

Adaptabilidade e estabilidade de comportamento de cultivares de milho em treze ambientes nos tabuleiros costeiros do nordeste brasileiro

The potential of the Brazilian Northeast coastal tablelands for corn production and the adaptability and stability of sixteen corn cultivars were evaluated at thirteen environments of this region in 1994/95 on a randomized block design experiment with three replications. The large potential of this coastal strip for corn production was evidenced by the obtained yield, highlighting the hybrids, on the coastal tablelands of Piaui, Sergipe and Bahia States, where corn would become a major crop option for the growers. Pooled variance analysis showed significant difference for environments and cultivars, and the interactions environment x cultivar, which were inconsistent. Hybrids had better adaptation than varieties and populations; they are recommended for higher input situations. The AG 510 hybrid showed good adaptation to low and high input conditions, and therefore is recommended for both situations. The BR 5011, BR 5028, BR 106 and BR 5033 varieties had reasonable yields and are suitable for small and medium corn growers.