Elaine Bahia Wutke

EFEITO DO NITROGÊNIO NO CULTIVO DE FEIJÃO IRRIGADO NO INVERNO

An experiment was conducted at three localities, namely, Ribeirao Preto (Latosolic B Terra Roxa), Votuporanga (Dark red latossol sandy phase) and Pindorama (Podzolic Lins-Marilia), in the State of Sao Paulo, Brazil. The objetive was to evaluate the response of nitrogen on irrigated dry beans during a two year period at Ribeirao Preto and Votuporanga (1990, 1991) and in Pindorama (1992, 1993). The experimental design was a complete randomized blocks design with five replications. The results showed that the yield of irrigated dry beans in the winter can be increased adding nitrogen. The sprint application is recommendable for the low fertility soil (Pindorama). The combination of N applied to the soil and on the leaves was more effective than that only on the leaves. The single dose applied at the 25th day after germination was more effective than the one aplied at the sowing date.

Efeitos da adubação nitrogenada e com micronutrientes na qualidade de sementes do feijoeiro cultivar IAC-Carioca

Foram realizados ensaios de laboratorio com amostras de sementes obtidas de dois experimentos em campo, no municipio de Pindorama, de maio a agosto, em 1992 e 1993, visando estudar o efeito do nitrogenio e de micronutrientes, aplicados sob varias formas,xa0 na qualidade das sementes do feijoeiro cultivar IAC-Carioca. Tomaram-se amostras de sementes de cada tratamento aplicado em campo, acondicionando-as em sacos de papel e conservando-as em câmara seca com temperatura de 15o C e umidade relativa do ar de 40%, sendo efetuados testes de germinacao imediatamente apos a colheita e apos 12 e 24 meses. Os resultados foram analisados e as medias, comparadas pelo teste de Duncan:tanto o fornecimento diferencial de N como o de micronutrientes nao afetaram a qualidade fisiologica das sementes, medida por meio da percentagem de germinacao e de plântulas anormais, nao se observando acumulo ou deficit de elementos nutrientes nas sementes do feijoeiro.

RENDIMENTO DO FEIJOEIRO IRRIGADO EM ROTAÇÃO COM CULTURAS GRANÍFERAS E ADUBOS VERDES

An experiment was carried out from May 1992 to January 1996 to study the residual effect of grain and green manure crops on the grain yield of irrigated common bean, variety IAC-Carioca. The experiment was installed at the Experimental Station of Instituto Agronomico, at Ribeirao Preto, Sao Paulo State, Brazil, in a typic Haplorthox soil. The experimental design was a randomized complete block with six treatments and six replications. The rotation schemes consisted of irrigated common bean from July to December, followed by an early variety of corn, from December to April and by fallow, corn, oats (Avena strigosa), sunnhemp (Crotalaria juncea L.), pigeonpea [Cajanus cajan (L.) Millsp.] and velvet beans (Mucuna aterrima), from March to August. The soil nutrient contents at 0-20 cm depth, were reduced during the three year period, being normal for organic matter and medium for phosphorus, potassium, calcium and magnesium. The medium to high acidity level did not restrict the grain yield of common beans. The inclusion of velvet bean, sunnhemp and corn in rotation with common bean and corn is feasible. These crops produced the greatest amounts of green matter. The basic infiltration rate of the soil was also increased. There was an effect of the rotations during the years with the inclusion of velvet bean, in the non-conventional Autumn-Winter season, which increased the grain yield of irrigated common beans in relation to the fallow treatment.

RESPOSTA DA APLICAÇÃO DE MICRONUTRIENTES NO CULTIVO DE FEIJÃO IRRIGADO NO INVERNO

An experiment was conducted at three localities, Ribeirao Preto (Latosolic B Terra Roxa), Votuporanga (Dark red latossol sandy phase) and Pindorama (Podzolic Lins-Marilia), in the State of Sao Paulo, Brazil, to evaluate the response of micronutrients on irrigated dry beans during a two year period at Ribeirao Preto and Votuporanga (1990, 1991) and in the next two years in Pindorama. The experimental design consisted of completely randomized blocks, with five replications. Treatments were: check, 20 kg ha-1 of borogram (8% B); 20 kg ha-1 of zincogram (20% Zn); 30 kg ha-1 of FTE-BR-12 and 60 kg ha-1 of FTE-BR-12 all applied in the soil. The foliar application of macronutrients consisted of: N (1 kg ha-1 ), P (0,5 kg ha-1), K (1,4 kg ha-1), which were sprayed 15, 25 and 35 days after emergence. An additional treatment consisted of NPK plus micronutrients (Mo, B and Zn) which was applied during the same period. The results showed that the yield of irrigated dry beans in the winter can be increased using the mixture of micronutrients (30 kg ha-1 FTE-BR-12). The aplication of micronutrients including molibdeniun increase the concentration of nitrogen in the leaves of dry beans, in the case of low fertility soils, as in Pindorama.

Comparação da morfologia de folhas lisas e rugosas de plantas de feijoeiro

Em campo de producao de sementes na Estacao Experimental de Ribeirao Preto (SP), do Instituto Agronomico, em 1986, identificou-se uma plantada feijoeiro (Phaseolus vulgaris L.) Goiano Precoce, com folhas rugosas e coloracao mais intensa que a tipica do cultivar. Efetuaram-se estudos anatomicos comparativos entre as folhas tipicas do feijao (lisas) e as rugosas, com o objetivo de avaliar se o carater rugoso era vantajoso. Observacoes na sua epiderme indicaram que as folhas rugosas apresentam maior densidade de tricomas e estomatos, alem de celulas epidermicas irregulares e menores. As plantas rugosas apresentam tambem um mesofilo denso, com pequenos espacos intercelulares e um limbo mais espesso.

Discriminação entre lotes de sementes de grão-de-bico mediante teste de envelhecimento artificial

Sementes de onze lotes de grao-de-bico (Cicer arietinurn L.) foram submetidas ao teste de envelhecimento artificial, utilizando-se a temperatura de 42°C e aproximadamente 100% de umidade relativa por periodos de 0, 24, 48, 72 e 96 horas de exposicao, na tentativa de melhor discriminar os lotes quanto ao seu nivel de vigor. 0 periodo de 96 horas foi excessivo para a semente de grao-de-bico; o de 48 horas tambem se mostrou ineficiente para a especie. Os tempos de 24 e 72 horas classificaram os lotes no mesmo numero de niveis de vigor; entretanto, recomenda-se o maior periodo, uma vez que os lotes que apresentaram germinacao acima de 82% foram mais bem discriminados quando se utilizaram 72 horas de câmara de vigor.