Domingos Antonio Monteiro

ACÚMULO DE MATÉRIA SECA NA PRESENÇA E NA AUSÊNCIA DE PLANTAS INFESTANTES NO CULTIVAR DE MANDIOCA SRT 59 - BRANCA DE SANTA CATARINA

The period for cassava planting is very wide in Sao Paulo State, Brazil, covering the whole dry season (May to October). There are large differences in the plant growth and its interference with the weed community when the planting time is early or late in the dry season. Aiming to study the weed interference on cassava growth and productivity, four field assays were carried out under different planting times (06/28/1989, 06/30/1989, 10/30/1989, and 07/23/1990) in a randomized complete blocks experimental design with three or four replications. The treatments were divided in two groups: in the first one (group 1), the crop was maintained weedy from the planting date to 30, 60, 90, 120, 150, 180, 210, 240, 270 and 360 days. In the second group (group 2), the crop was kept weed free from the planting date to 30, 60, 90, 120, 150, 180, 210, 240, 270, and 360 days. The weed interference reduced drastically the dry matter accumulation by the cassava plants and the root production losses reached up to 90%. The increase in the rate of dry matter accumulation in the cassava roots in the presence of weed could not be analyzed in two assays. In the group 2, all the data were properly analyzed in the four assays. The Boltzman Sigmoidal Equation suited well the data on cassava root dry matter accumulation and provides good prediction models. The best dry matter production was obtained for 360 day old roots.

Avaliação de cultivares de mandioca de mesa no Vale do Ribeira (SP)

The present paper reports a final evaluation of the best cassava clones for table, selected in the Ribeira Valley, State of Sao Paulo, Brazil, from a genetic basis of 306 cultivars of the germoplasm bank of the Agronomic Institute. Three experiments were carried out at the Pariquera-Acu Experimental Station, during the 1989/90, 1990/91 and 1991/92 seasons under a randomized design with 12 treatments (cultivars) and four replications. The most relevant results, were: (a) the cultivars had different root yields in relation to years. However, the cultivar IAC 576-70 was the most productive, with a yield of 34.3 t/ha in average, meanwhile the cultivar used as test plant showed an average yield of 17.8 t/ha; (b) the results of the cooking tests were not significant for the relationship cultivar x year interaction. The local cultivar presented the lowest average cooking time of 26 minutes in boiling water.

Adubação do trigo VII: Experiências com N, P, K e S em diferentes tipos de solos do estado de São Paulo

No periodo de 1969 a 1973 foram realizados ensaios de adubacao N, P, K e S em cultura de trigo (Triticum aestivum L.) na Estacao Experimental de Tiete, na Estacao Experimental de Capao Bonito, na Fazenda Santa Isabel localizada no municipio de Itabera e na Estacao Experimental de Itarare. Os dados medios obtidos em Tiete e Capao Bonito nao mostraram respostas significativas a nitrogenio, fosforo, potassio e enxofre. Nos experimentos plantados em Itabera e Itarare, os dados medios mostraram efeitos lineares de fosforo e adubacao mineral completa altamente significativos.

EFEITO DO TAMANHO DO RIZOMA-SEMENTE, DA ÉPOCA E DO LOCAL DE PLANTIO, NA PRODUÇÃO DE RIZOMAS DE MANGARÁ

Tannia or yutia (Xanthosoma mafaffa Schott) is actually produced as a self supply food for farmers and for consumption in local markets. Research progresses for increasing tannia corms yields will possibly result in a new option in marketing, as a profitable vegetable. Three field trials, without irrigation, were carried out in different locations of the Sao Paulo State, to study the effects of climate, cormel size and soil type on plant growth and corm production. In the experiment at Itu, plants did not grow well because of the soil (sandy well drained soil) and climate (Cwa type) conditions. At Serra Negra, in a climate Cfa type and alluvial soil, the final corm yield was 17,1 t/ha, while at Monte Alegre do Sul, in an Ortho-Red Yellow Podzolic soil, the yield was 10,2 t/ha. Larger cormel seeds (5 g), resulted in higher corm yields. Although these tests indicated that better yields were obtained with earlier planting dates, interaction among the seed weight, and planting time and site was observed.

Extração e isolamento de diosgenina de barbasco

Dioscorea composita Hemsl. and D. floribunda Mart. & Gal., introduced in Brazil, showed diosgenin contents of 3.15 ± 1.41% and 4.72 ± 0.24% on dried tubers, and minimum purities of 54.7% and 39.2%, respectively. Yamogenin co-occurs in the tubers of both species. The diosgenin content in D. composita increases according to the age of the plant, showing a pronounced maximum around the third year and stabilizing around the sixth year of cultivation. Methods for extraction, isolation and purification are also described.

Avaliação de variedades de mandioca no estado de São Paulo

Quinze experimentos de variedades de mandioca (Manihot Esculenta Crantz) foram conduzidos e colhidos com dois ciclos vegetativos (18 a 24 meses), em varios municipios do Estado de Sao Paulo. Estes ensaios foram distribuidos em quatro series com nove, dez ou doze variedades cada uma. O delineamento estatistico utilizado foi de blocos ao acaso com quatro repeticoes. Foram efetuadas analises individuais e conjuntas dos experimentos. Os resultados mostraram que, em media, apenas a variedade IAC 12-829 (39,0t/ha) superou, estatisticamente, em producao de raizes, a variedade testemunha SRT 59 - Branca-de-Santa-Catarina (25,4t/ha).

Producao de sementes de mandioca em plantas com um e dois ciclos vegetativos

O presente trabalho teve por objetivo comparar a producao de sementes botânicas de mandioca entre campos anuais e campos conduzidos por mais um ciclo vegetativo. As plantas com dois ciclos vegetativos foram conduzidas sem poda e com poda a 10cm acima do solo. Os resultados mostraram que as plantas com um ciclo vegetativo produziram em media 31,70 sementes por planta, enquanto as de dois ciclos, podados ou nao, produziram, respectivamente, 23,39 e 64,64 sementes por planta. O tratamento sem poda, embora mais produtivo, apresentou dificuldades para os trabalhos de campo, tais como, praticas culturais e ensacamento dos frutos, devidas a arquitetura da parte aerea. Entretanto, tais dificuldades poderao nao ocorrer quando a cultura for conduzida em solos pobres.

Influência do armazenamento de ramas para plantio em algumas características agronômicas da mandioca

While weather is not appropriate for cassava planting, growers in the State of Sao Paulo, usually keep their planting material (stems) stored in different ways. It is used the horizontal or vertical heaping systems, being the first one more common. The use of the fresh-harvested stem for planting is rare. The objective of this work was to evaluate the storage systems, and none storage, of cassava (Manihot esculenta Crantz) stems on some agronomic and physiological aspects. Two cultivars and three types of cuttings were used in a 2 x 3 factorial experiment in a randomized block design with four replications. The cultivars used were IAC 12-829 and SRT 1287-Fibra, with high and low ability of branching, respectively. The types of cuttings were originated from fresh-harvested stems and from stems stored for 105 days period in horizontal and vertical heaping systems. The experiment was carried out during the 1991/1992 season, at the Vale do Paranapanema Experimental Station, Instituto Agronomico de Campinas, Assis, State of Sao Paulo, Brazil, in a Allic Dark Red Latosol, medium texture. The results showed that: (a) the storage of the stems in horizontal position lead to an increase in the number of primary shoots of the two varieties and increased the weight of the aerial part of the SRT 1287-Fibra; (b) SRT 1287-Fibra cultivar was more influenced by the horizontal storage than the IAC 12-829; (c) IAC 12-829 had superior root production, without differing from the SRT 1287-Fibra when the cuttings were derived from the horizontal storage stems; (d) the storage in the vertical position had a similar behaviour as the fresh-harvested stems.

Produção de sementes de batata-doce, por fecundações artificiais, em casa de vegetação

Seed setting of five sweet potato genotypes: SRT 72-Jacarei; SRT 248; SRT 252-Rama Grossa; IAC 66-118-Monalisa and IAC 3-4-Irani was studied under greenhouse conditions. Flowers from vine cuttings growing in water were hand pollinated. All five lines functioned about equally well as pollen parents but there were significant differences in their ability to function as seed parents. Cultivars SRT 248 and SRT 72 when used as female showed a low ability to seed production both when selfed and crossed. Such ability appeared to be a varietal characteristic which affected seed set. Differences were found between the percentage of seed set of open and cross-pollinated flowers. Self incompatibility was observed for four cultivars. The highest degree of self compatibility was showed by the cultivars SRT 252. There was an observed decline in seed set during the month of June, with the highest seed set during April.

Mandioca: distribuição no estado de São Paulo do micoplasma causador do superbrotamento-de-santa-bárbara-do-rio-pardo

Cassava is a basic food staple of poor families in Brazil and it is common for them to have backyard patches of cassava plants from which they dig roots for daily use. This is particularly true in houses lying on the outskirts of most small towns in the State of Sao Paulo, Brazil. A survey for new table cassava types was being carried out in 126 counties of this State, inspecting 5 to 10 patches adjacent to residences on the outlying parts of each county seat, when the Santa Barbara mycoplasma disease showed to be present in 12 out of the 126 counties. This disease occurred mostly in the counties near Aguas de Santa Barbara, the city where the disease was first recorded. In the other 114 counties no mycoplasma disease was noticed. Control measures such as propagation of cuttings only from healthy plants have provided good control of other types of cassava mycoplasma disease in large commercial plantings in the past. It is thought, however, the eradication of the Santa Barbara type of mycoplasma disease from cassava backyard patches is difficult to accomplish because the owners do not care for selecting healthy planting material and eliminating sick plants.