Pedro Roberto Furlani

Composição mineral de diversas hortaliças

Objetivou-se conhecer, na epoca normal de colheita, as quantidades de materia seca acumuladas, as concentracoes dos elementos essenciais as plantas, mais as de cobalto, aluminio e sodio na materia fresca e seca de 50 cultivares de hortalicas num total de 35 especies. As amostras, normalmente constituidas de produtos da colheita, foram na sua maioria procedentes da regiao de Campinas, Estado de Sao Paulo e separadas em: melancia - em casca + polpa branca, polpa vermelha e semente; melao - em casca + polpa e semente; ervilha - em vagem e grao; berinjela - em fruto e pedunculo; couve-flor - em folha e inflorescencia; beterraba, cenoura, nabo e rabanete - em folha e raiz; alcachofra - em folha + caule e inflorescencia. Das demais hortalicas foram utilizados o fruto todo, as folhas ou os bulbos sem separacao. Verificou-se que as leguminosas extrairam maiores quantidades de N, P, K, Mg, Cu, Mo, Zn e Co; as tuberosas, de Cl, Fe e Mn; as amarilidaceas, de S, B e Al; as folhosas, de Ca e Na. As cucurbitaceas extrairam menores quantidades da maioria dos nutrientes.

Efficiency of maize cultivars for zinc uptake and use

Zinc deficiency usually occurs in maize grown in Brazilian acidic soils. The aim of this study was to evaluate commercial maize cultivars for their Zn uptake and utilization efficiency. A greenhouse experiment using nutrient solution with young plants was carried out at Campinas, State of Sao Paulo, Brazil, in 2002. Treatments consisted of: 0.0; 0.1; 0.2; 0.4 and 0.8 mg L-1 Zn in the main plots and 24 commercial maize cultivars in the subplots, in a randomized complete block design. Zn concentration in shoot dry matter (SDM) ranged from 28.4 to 41.6 mg kg-1 among cultivars, clearly indicating a dilution effect, since a negative relation between SDM and plant height was shown. Total Zn-shoot content was a good parameter to discriminate cultivars, once correlated with plant height and SDM (r = 0.66** and r = 0.67**, respectively). Analysis of variance and polynomial regression for total Zn-shoot content was highly significant among cultivars and for the interaction cultivar vs Zn-concentration. Plants under low Zn presented up to three-fold differences among efficiency index values (E.I. = 8.59 to 26.42 mg2 DM mg-1 Zn). The results with young plants indicated six maize cultivars classified as Zn-efficient and responsive (AG 7575, Tork, AL Bandeirante, AL 34, AGN 2012, Master) and six cultivars classified as efficient non-responsive (P30F33, P30K75, P30F80, AS 1533, DOW 8420 e AL 30). Other nutrient concentrations in the SDM were within normal limits (K, P, Ca, Mg, Cu, Fe, Mn) for maize young plants.

Cultivo de manjericão em hidroponia e em diferentes substratos sob ambiente protegido

Among the aromatical herbs, basil is of great economic importance in Brazil. This species is used as fresh herb and also for essential oil extraction. To evaluate the productivity of basil in protected environment, two species, Ocimum minimum L. (narrow leaf basil) and Ocimum basilicum L. (wide leaf basil) were cultivated under greenhouse conditions, using a hydroponic system and two types of substrata. The experiment was carried out in a completely randomized design with three repetitions. Samples were obtained during the flowering period. The yield and the chemical composition of the essential oils were evaluated. The highest yield of green mass from the two species, was obtained in the hydroponic system, with higher productivity (aprox. 44%) than the plants cultivated in prepared commercial substratum. Plants of Ocimum minimum L. produced more essential oil (aprox. 10%) than plants of Ocimum basilicum L. Significant differences were found in the chemical composition of essential oil between species. No differences were observed in the chemical composition of essential oil, comparing the three cultivation systems.

Genetics of aluminum tolerance in maize Cateto

Maize Cateto inbred line has shown high aluminum tolerance. Due to the importance of this trait in commercial hybrids as well as the lack of consistent informations about the inheritance mechanism involved, the genetics of aluminum tolerance in one maize Cateto inbred line was studied. The inbred lines lp 48-5-3 (Cateto), Col 2(22) (flint from Colombia) and the F1, F2 and backcrosses generations were used. Two replicated experiments were carried ou at Campinas, State of Sao Paulo, Brazil, in 1985, to evaluate these genotypes grown in nutrient solutions containing 4.5 ppm of Al. Radicle net growth (CLR) was the most adequate measurement to distinguish maize genotypes for Al tolerance. The F2 frequency distribution was continuous, unimodal and yielded only classes resembling those of the F1 and the tolerant parent. The high Al tolerance of the maize inbred line lp 48-5-3 was due to the action of additive minor genes. Both broad and narrow sense heritabilities were high, indicating that plant selection in F2 generation for Al tolerance is efficient.

Absorção de chumbo e potencial de fitorremediação de Canavalia ensiformes L.

Phytoextraction is an important technique used for decontamination of areas polluted by heavy metals. Consequently, understanding the physiological responses in relation to the tolerance of tropical species subjected to increasing levels of contamination is fundamental before considering their use as phytoextractans in contaminated areas. The objective of our study was to assess the potential of Canavalia ensiformes L. for the phytoextraction of lead (Pb). Plants were cultivated with nutrient solution in greenhouse under partially controlled conditions. Pb was tested at concentrations of 100, 200 and 400 µmol.L-1. The experimental set-up was a randomized blocks design, using a 4 x 1 factorial scheme, with three replicates. Follow-ups of physiological symptoms were carried out, determining fresh and dried mass for shoot and root, leaf area, plant height, Pb content in nutrient solution and in roots and shoot of the plants. The samples of shoot and roots and of the nutrient solution were submitted to chemical analysis for the determination of Pb, using dry digestion. The Canavalia ensiformes plants proved to be both accumulators and tolerant to Pb, demonstrating their potential as a phytoextractants.

Tolerância a alumínio e eficiência a fósforo em milho e arroz: características independentes

Eight experiments were carried out in nutrient solutions under greenhouse conditions at the Instituto Agronomico Experimental Center, located at Campinas, State of Sao Paulo, Brazil. The main objective of this study was to determine the relationship between P-use efficiency and Al-tolerance of 50 lowland rice cultivars, 50 upland rice cultivars, and 40 maize inbred lines. Using the 99.9% confidence interval for the mean values of P-efficiency and Al-tolerance, respectively for each crop group, the genotypes were classified in nine classes: I. Efficient to P and tolerant to Al (ET); II. Efficient to P and intermediate to Al (El); III. Efficient to Pand non-tolerant to Al (ENT); IV. Intermediate to P and tolerant to Al (IT); V. Intermediate to P and intermediate to Al (II); VI. Intermediate to P and non-tolerant to Al (INT); VII. Non-efficient to P and tolerant to Al (NET); VIII. Non-efficient to P and intermediate to Al (NEI); and, IX Non-efficient to P and non-tolerant to Al (NENT). The non-efficient or non-tolerant, the intermediate, and the efficient or tolerant are those classes whose values are lesser, equal or greater than the confidence interval, respectively. In rice, the upland cultivars were more tolerant to Al but less efficient to P than the lowland cultivars. Ten upland and five lowland rice cultivars could be classified as efficient to P and tolerant to Al (ET). In maize, an inverse relationship was found between efficiency to P and tolerance to Al. Three inbred lines could be classified as intermediate to P and tolerant to Al (IT). For the genetic material used in this study, it was found a poor correlation between the two plant traits indicating that they are independent.

Irrigation frequency and substrate volume effects in the growth and yield of tomato plants under greenhouse conditions

Tomato cropping (Solanum lycopersicum L.) under protected cultivation using substrates and drip fertigation has improved sustainable production systems especially fruit quality and plant health. However, little is known for tomato plants when considering the interaction between substrate volume and irrigation frequency. The aim of this study was to evaluate the effects of coconut (Cocos nucifera L.) fiber substrate volumes and drip irrigation frequencies on the vegetative growth and fruit yield of tomato plants under greenhouse conditions. The experimental design consisted of randomized blocks arranged in a 3 × 2 factorial with four replicates. Treatments consisted of three substrate volumes (5.0; 7.5 and 10.0 L per plant) and two irrigation frequencies (once and five times per day). Leaf area index tended to increase in plants grown with the largest substrate volume (10 L). Although substrate volumes affected shoot dry matter, no effects on tomato yield and its components were observed. However, plants grown with 5 L of substrate and irrigated once a day produced a greater number of non-marketable fruit due to the higher incidence of calcium deficiency symptoms (blossom end rot). When plants were grown in 5 L or 7.5 L of substrate volume, high irrigation frequency favored the vegetative growth, stomatal conductance, CO2 assimilation and transpiration and fruit yield. Fruit yield and healthy fruits were favored by high irrigation frequency and did not depend on the substrate volume.

Tolerância à toxicidade de alumínio de linhagens e híbridos de milho em solução nutritiva

Ten inbred lines and the resulting forty-five hybrids from the maize IAC breeding program were evaluated for Al tolerance by the nutrient solution technique. Net radicle lengths (CLR) of plants grown with 4.5 mg.L-1 were used to estimate Al tolerance. The experimental design was randomized complete block with four replications, and it was used two divergent inbred lines IAC Taiuba as control for Al tolerance and sensitivity, respectively. In addition to these data, it is shown also the grain yield of the same materials from field plots. It was identified two inbred lines (L 06 and L 09) as Al tolerance sources and hybrids potentially adapted to acid soil conditions (tolerant to Al toxicity). From the diallel analysis, the treatment effects were separated into general (CGC) and specific (CEC) combining ability and indicated the predominance of additive effects on the Al tolerance manifestation. High values of hybrid vigor were obtained, indicating the existence of interactions non-allelic in the manifestation of CLR. The hybrid HS 10X11 (named IAC 21) showed higher productivity and Al tolerance, and also a higher CEC estimate for CLR.

Variability in soybean germ plasm for phosphorus uptake and use efficiency for dry matter yield

Twenty nine soybean [Glycine max (L.) Merr.] cultivars were evaluated and classified in relation to the response to P levels in the nutrient solution. P uptake and use efficiency, top and root dry matter yield, P concentrations and contents in plant parts and P efficiency index were estimated. The experiment was set up in a greenhouse, in 1999, in an Experiment Station of the Institute Agronomico, at Campinas, State of Sao Paulo, Brasil, and consisted of a randomized complete block design, arranged in a split-plot, with three replications. The main plots were the P levels in the nutrient solution (0.0645; 0.129; 0.258 and 0.516 mmol. L−1), and the subplots were the 29 soybean cultivars, grouped according to the cycle. The plants were harvested at flowering, separated into tops and roots and processed for dry matter determinations and chemical analysis of nutrients. Plant responses fit quadratic polynomial regression equations. Multivariate analysis showed high correlation among the variables: top and total dry matter (DM), P concentration in tops and P efficiency index (P-EI). Cultivars were classified in efficient-responsive (ER), efficient-non-responsive (ENR), inefficient-responsive (IR) and inefficient-nonresponsive (INR). The ER soybean cultivars showed the highest values for top and total DM and P-EI, and the lowest P-concentrations in the tops.

Resposta de cultivares de arroz-de-sequeiro à calagem

A field experiment was laid out in a quartz sandy soil (Quartzipsamment) in Assis, State of Sao Paulo, Brazil, having cation exchange capacity of 35 mmolc.dm-3 and 9% base saturation. The differential response of the upland rice cultivars IAC 25, IAC 47, IAC 165 and Araguaia to the rates of 0, 2, 4 e 6 t.ha-1 of dolomitic and 2 t.ha-1 of calcitic limestone as additional treatment was evaluated. The limestone was applied in October of 1991 and the evaluations were carried out during the 1992-93 growth period. Twenty days after the plant emergence, the shoots were sampled for nutrient chemical analysis and twenty days later roots were sampled for anatomical studies. Two years after liming the largest base saturation was only 55%. The root structure remained unaltered with the liming treatments; some differences occurred only on the cortex central vascular ratio. The IAC 165 cultivar was the only one that did not respond to the limestone rates and that decreased the cortex/central vascular ratio. The liming decreased the plant manganese contents associated with the temporary soil flooding. There was also a decrease in phosphorus, potassium and zinc contents, but the nitrogen, calcium, magnesium, and iron contents increased. Shoot fresh matter yield was larger with dolomitic than with calcitic limestone for all cultivars, except IAC 47. All the cultivars showed higher magnesium and lower calcium contents in the shoots with dolomitic than with calcitic limestone. Although a positive yield response could not be obtained in the present study, it can be inferred that when upland rice is used in these soils for crop pasture renewals, dolomitic limestone might be recommended to correct acidity and magnesium deficiency in plant.