Ivan José Antunes Ribeiro

Determinação da área foliar em videira cultivar Niagara Rosada

Width of leaf blade was closely correlated with leaf area in leaves of grapes cv. Niagara Rosada. It was found that the shape of any leaf was similar to a circle. A short-cut procedure for estimating easily, rapidly and precisely the leaf area was developed. The equation relating leaf area (AF) to width of leaf blade (L) was: AF = 0.85 p (L/2)2.

Influência da luz e da temperatura na germinação de uredosporos de Puccinia psidii

The objective of this experiment was to study the influence of light and temperature on uredospore germination of Puccinia psidii Winter. Two temperatures (18°C and 22°C) and five patterns of illumination (0, 4, 8, 16, and 24 hours of darkness) were tested. The results showed that the temperature of 18°C and 8 hours of darkness were the most favorable conditions for the uredospores germination.

Gomose da acácia-negra causada por Ceratocystis fimbriata Ell. & Halst.

Several plants of Acacia decurrens showed wilting and subsequent branche drying. The branches showed wood splitting and gum exudation. The transversally cut wood showed ashy colored pith, that desenvolved numerous perithecia when kept in a humid chamber. These perithecia were transferred aseptically to potato-dextrose-agar and the culture was classified as Ceratocystis fimbriata Ell. & Halst. Four mounth old Acacia plants inoculated with the isolate died after 14 days. The fungus was again isolated from these dead plants. Cross inoculation tests with isolate of C. fimbriata from Acacia and mango (Mangifera indica L.) showed pathogenic effects for both hosts.

Qualidade de frutos de videira 'Niagara Rosada' em cultivo intercalar com gramínea e leguminosas

Grape vineyard in Southern Brazil utilize a large amount of mulch during autum-winter season demanding extra efforts and costs related to its acquisition, transportation and distribution in the plant inter-rows. In order to evaluate the possibility of replacing the tradicional use of mulch by cover cropped (green manuring species) in the inter-row strip, two experiments were carried out in Indaiatuba and Jundiai, SP, Brazil, from 1999 to 2002, with the table grape variety Niagara Rosada. The experimental design was a randomized block with four replications and six treatments: 1.check (no weeded); 2. cutted spontaneous local vegetation; 3. mulch of Brachiaria decumbens; 4. Avena strigosa from March to October followed by Mucuna deeringiana from October to March; 5. Lathyrus sativus from March to October followed by M. deeringiana from October to March; and 6. Lupinus albus from March to October followed by M. deeringiana from October to March The juice quality was evaluated by content of total soluble solids (TSS), pH, total titratable acidity (TTA) and ratio TSS/TTA. In general and according to the average of the years the results of all characteristics obtained at the treatments with the green cover were equal ou more favorable than those ones using mulch cover. This leads to the conclusion that is possible the utilization of green manure crops in the inter-rows of grape vineyard without any negative interference on quality characteristics of grape fruits, which was influenced by the annual climatic conditions of the cultivation regions.

Efeito de alta temperatura no desenvolvimento de Hemileia vastatrix em cafeeiro suscetível

The development of rust epidemics in tropical conditions of Brazil has been different than previously expected. Despite of high humidity the development is reduced to a minimum during the summer. High temperature was assumed to have a detrimental effect on the rust development. This paper reports the results of a study concerning the effect of high temperature on Hemileia vastatrix development. Temperature treatment of inoculated young plants at 400C for 4 hours in 4 consecutive days was sufficient to prevent rust development. The curative effect was permanent indicating that the fungus was destroyed inside the plant tissue. Practical implications of such results are considered.

Avaliação dos acessos de alho coleção do Instituto Agronômico de Campinas

Fifty accesses from the garlic germplasm bank of Instituto Agronomico de Campinas were evaluated in Tiete and Jundiai, Sao Paulo State, Brazil. The field trials were carried out in 2003, and the experimental design was randomized blocks with three replicates. The data were subjected to an ANOVA and the means compared using the Skott-Knott test at a 5% probability level. The access Piedade and Gigante de Curitibanos showed excellent performance for yield and bulb quality in both locations. On the other hand, environmental interaction occurred for access Bulbilho Aereo 2 and Andradas Manoel Lopes 2. For the first one, the bulb size was different and for the second the yield changed. A greater genetic diversity on yield and bulb diameter was observed in Jundiai, due to lower environmental effects.

Produtividade da videira 'Niagara Rosada' em cultivo intercalar com adubos verdes

Influence of green covers on yield of the table grape variety Niagara Rosada. In order to evaluate the possibility of replacing the traditionally used mulch by cover cropping (green manuring species) in the inter-row strip, maintaining its productivity, two experiments were carried out in Indaiatuba and Jundiai, SP, Brazil, from 1999/00 to 2003/04, with the table grape variety Niagara Rosada. The experimental design was a randomized block with four replications and six treatments: no weeded; spontaneous local vegetation cutting; usual mulch of Brachiaria decumbens (check) and three other treatments with cover crops Avena strigosa, Lathyrus sativus and Lupinus albus, from March to October, followed by Mucuna deeringiana from October to March. Productivity, the number and the weight of cluster of grape were evaluated. The medium values were compared by using the Duncan test at 5% of significance. According to the average of the years, the results of all characteristics observed in the treatments with the green cover were similar ou more favorable than those ones using mulch cover. This leads to the conclusion that it is possible to cultivate green manure crops in the inter-rows of a grape vineyard instead of the mulch, without any negative interference on productivity of the grapevine.

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.

Melhoramento da crotalária. I - Autocompatibilidade e resistência à murcha de Ceratocystis fimbriata

O presente trabalho foi desenvolvido visando a obtencao de linhagens de Crotalaria juncea autocompativeis e resistentes a murcha de Ceratocystis fimbriata. Plantios sucessivos de crotalaria comum foram efetuados em area altamente infestada pelo patogeno. Em cada ciclo foram selecionadas plantas que chegaram a produzir sementes, sendo estas plantadas no ano seguinte. Apos quatro anos, o material resultante foi cruzado com linhagens autocompativeis, visando reunir o carater resistencia a condicao de autocompatibilidade. A geracao F1 desse cruzamento foi retrocruzada com pais resistentes e com pais autocompativeis. As populacoes assim obtidas foram levadas ate a geracao F4, sendo que em cada geracao eram feitas inoculacoes e selecao de plantas resistentes e autocompativeis. A geracao F5, com 1.030 plantas, foi selecionada para producao e qualidade de sementes, resultando em 111 plantas com as caracteristicas desejadas. As linhagens dessas plantas, apos inoculacao com isolados do fungo, mostraram alta porcentagem de plantas autocompativeis, com resistencia a murcha.This paper describes the methods used in obtaining lines of Crotalaria juncea to self compatibility and resistance to wilt (Ceratocystis fimbriata). Successive plantings of Crotalaria juncea were made in areas highly infected with wilt. In each cycle, plants which produced seeds were selected and the seeds were replanted. After four years this material was crossed with lines with self compatibility with the common goal of reuniting resistance to wilt and self compatibility. In f1 generation of this cross was backcrossed with the parents resistant to wilt and self compatibility respectively. The population obtained was multiplied up to F4 having been inoculated at each generation with wilt pathogen and selections made of plants resistant to the disease and self compatibility. In the F5 generation 1,030 plants were selected for seed production and seed quality, and of these only 111 plants showed the desired characteristics. The lines of these plants after inoculation with the wilt pathogen showed high percentage of resistance to disease and self compatibility.

Influência da cobertura vegetal do solo na qualidade dos frutos de videira 'Niagara Rosada'

Grape vineyard in Southern Brazil utilize a large amount of mulch during autumn-winter season demanding extra efforts and costs, being its acquisition very difficult nowadays. In order to evaluate the possibility of replacing the tradicionally mulch by green cover species in the inter-row strip, two experiments were carried out in Indaiatuba and Jundiai, SP, Brazil, from 1999/00 to 2003/04, with the table variety Niagara Rosada. The experimental design was a randomized block with four replications and six treatments: 1) no weeded area; 2) cut spontaneous local vegetation; 3) mulch of Brachiaria decumbens; 4) green cover of Avena strigosa from March to October followed by green cover of Mucuna deeringiana from October to March; 5) green cover of Lathyrus sativus from March to October followed by green cover of M. deeringiana from October to March; and 6) Lupinus albus from March to October followed by green cover of M. deeringiana from October to March. The weight, lengh and width of cluster, rachis and berries of grape, the total number of berries and its pedicel diameter were evaluated. The average values were compared by Duncan test at the level of 5%. The results of all characteristics obtained with the green cover crops were equal or more favorable than those ones using grass mulch cover (B. decumbens), being possible to utilize green manure crops in the inter-rows of grape vineyard without any negative interference on some commercial characteristics of grape fruits.