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Search Results: 1 - 10 of 563397 matches for " Klar A.E. "
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WHEAT CULTIVARS: RESPONSE TO IRRIGATION AND SOWING DATES
Klar, A.E.;Hossokawa, T.;
Scientia Agricola , 1996, DOI: 10.1590/S0103-90161996000200004
Abstract: this study was carried out in an alfisol-oxisol transition sandy-clay texture, using six wheat cultivars (triticum aestivum, l.): two tall and tolerant to soil aluminium toxicity (bh-1146, and iac-18), and four semi-dwarf cultivars - anahuac, iac-162, iac-24, and iac-60 - of which only the first two are sensitive to soil aluminium toxicity. two minimum soil water potentials (ys) levels were used: 1. watered, when ys reached about -0.05 mpa; 2. dry, when the water potential reached around -1.5 mpa. two sowing dates, 05/22/92 and 06/11/92, were used. the results showed that anahuac and iac-60 are the most indicated cultivars for the studied region; when irrigated all cultivars presented similar yield level under no irrigation conditions; the irrigation was not sufficient to avoid yield differences between the two growing seasons; differences in rainfall were important for the crop in the dry treatment for both seasons.
WHEAT CULTIVARS: RESPONSE TO IRRIGATION AND SOWING DATES
Klar A.E.,Hossokawa T.
Scientia Agricola , 1996,
Abstract: This study was carried out in an Alfisol-Oxisol transition sandy-clay texture, using six wheat cultivars (Triticum aestivum, L.): two tall and tolerant to soil aluminium toxicity (BH-1146, and IAC-18), and four semi-dwarf cultivars - Anahuac, IAC-162, IAC-24, and IAC-60 - of which only the first two are sensitive to soil aluminium toxicity. Two minimum soil water potentials (ys) levels were used: 1. watered, when Ys reached about -0.05 MPa; 2. dry, when the water potential reached around -1.5 MPa. Two sowing dates, 05/22/92 and 06/11/92, were used. The results showed that Anahuac and IAC-60 are the most indicated cultivars for the studied region; when irrigated all cultivars presented similar yield level under no irrigation conditions; the irrigation was not sufficient to avoid yield differences between the two growing seasons; differences in rainfall were important for the crop in the dry treatment for both seasons.
A influência da irriga??o e aduba??o no rendimento, tamanho e número de tubérculos de batata (Solanum tuberosum L.)
Scalopi, E.J.;Scardua, R.;Klar, A.E.;
Anais da Escola Superior de Agricultura Luiz de Queiroz , 1975, DOI: 10.1590/S0071-12761975000100033
Abstract: a study was made on the effects of irrigation and fertilization on the yield, number, and size of potato tubers. irrigation was based on the mean soil moisture tension of 0.3, 0.6, 1.0, 3.0 and 10.0 bars. fertilizer in 40 kg/ha of n, and k20 and 80 kg/ha of p2os, being the dosis 1, 40-80-40 kg/ha, of n, p205, and k2o, respectively. better yields were achieved at soil moisture tensions lower than 1.0 bar and fertilizer dosis 3,4 and 5. there was no significant difference in the number of tubers among the treatment. a increase in the percentage of large tubers was observed in the treatments with soil moisture tension of 0.3, 0.6, and 1.0 bar and fertilizer dosis 4 and 5. on the other hand, a high percentage of small tubers were obtained at higher tensions (over 1.0 bar) and fertilizer dosis 1 and 2.
WATER NEEDS FOR WINTER BEAN CROP
Klar, A.E.;Fernandes, M.A.;
Scientia Agricola , 1997, DOI: 10.1590/S0103-90161997000200004
Abstract: a study of water use by bean winter crop (phaseolus vulgaris, l., cv. carioca) was carried out in a red yellow latosol, clay texture. a furrow irrigation system maintained soil water potentials higher than -40 kpa. two broadcast nitrogen treatments (0 and 30 kg n/ha) were applied 25 days after planting. the major objectives were to study the nitrogen and evapotranspiration interaction and measure the crop coefficients (kc). the maximum average evapotranspiration (etm) was 1.71 mm/day, or 157.16 mm over 92 days of observations; the etm values for the vegetative (1), flowering (2) and pod formation (3) phases were 1.48, 2.35, and 1.50 mm/day, respectively, for the 30 kg/ha nitrogen treatment, and 1.48, 1.88 and 1.45 mm/day for the no nitrogen treatment. the crop coefficients (kc = etm / eto) were 0.62 and 0.78 for the phase 1, 0.80 and 1.10 for the phase 2, 0.45 and 0.55 for the phase 3 and 0.61 and 0.80 for the entire cycle, based on the fao-penman and class a pan reference methods (eto), respectively. the latter one was the best approach to estimate maximum water use by winter bean crop. nitrogen treatments did not affect evapotranspiration significantly. however, the measured evapotranspiration obtained from the water balance method was 59.78 and 27.12% higher in the flowering than in the vegetative phase, respectively, under 30 and 0 kg n/ha.
Resistência à seca em quatro cultivares de trigo: parametros fisiológicos
Denadai, I.A.M.;Klar, A.E.;
Scientia Agricola , 1995, DOI: 10.1590/S0103-90161995000200012
Abstract: the drought resistance was studied for four wheat cultivars: two dwarfs: anahuac and iac-24 and two tall ones: bh-1146 and iac-23, using a treatment i constantly wetted by cailarity, and other one, ii, which received water when soil water potential reached -1,5 mpa. leaf water potential and relative water content were higher in treatment ii than in treatment i, at the same soil water potentials for all cultivars, in the two development stages (vegetative, and reprodutive). there was no way of separating genotypes more or less resistant to drought, only using the relations between leaf water potential and leaf diffusive resistance to water vapour.
WATER NEEDS FOR WINTER BEAN CROP
Klar A.E.,Fernandes M.A.
Scientia Agricola , 1997,
Abstract: A study of water use by bean winter crop (Phaseolus vulgaris, L., cv. Carioca) was carried out in a Red Yellow Latosol, clay texture. A furrow irrigation system maintained soil water potentials higher than -40 KPa. Two broadcast nitrogen treatments (0 and 30 kg N/ha) were applied 25 days after planting. The major objectives were to study the nitrogen and evapotranspiration interaction and measure the crop coefficients (Kc). The maximum average evapotranspiration (ETm) was 1.71 mm/day, or 157.16 mm over 92 days of observations; the ETm values for the vegetative (1), flowering (2) and pod formation (3) phases were 1.48, 2.35, and 1.50 mm/day, respectively, for the 30 kg/ha nitrogen treatment, and 1.48, 1.88 and 1.45 mm/day for the no nitrogen treatment. The crop coefficients (Kc = ETm / ETo) were 0.62 and 0.78 for the phase 1, 0.80 and 1.10 for the phase 2, 0.45 and 0.55 for the phase 3 and 0.61 and 0.80 for the entire cycle, based on the FAO-Penman and Class A Pan reference methods (ETo), respectively. The latter one was the best approach to estimate maximum water use by winter bean crop. Nitrogen treatments did not affect evapotranspiration significantly. However, the measured evapotranspiration obtained from the water balance method was 59.78 and 27.12% higher in the flowering than in the vegetative phase, respectively, under 30 and 0 kg N/ha.
Uso do tanque "classe A" para a avalia??o da evapotranspira??o de uma cultura de cebola
Klar, A.E.;Moretti Filho, J.;Sim?o, S.;
Anais da Escola Superior de Agricultura Luiz de Queiroz , 1975, DOI: 10.1590/S0071-12761975000100004
Abstract: water requirement for onion (baia periforme precoce variety) was studied by means of field experiments in which water was supplied by the furrow-irrigation method. the "class a" pan was used to evaluate the water need or this crop. four treatments were used in which soil water potential was maintained at a minimum of -0.5; -1.0; -6.0 and -15.0 bars. soil moisture content was controlled gravimetrically. the results obtained led to the following main conclusions: a) yield of onion bulbs increased with soil water potential; b) the following ratios (er/e0) were determined for the best treatment in which the minimum soil moisture potential was -0.5 bar: 0.64; 0.63 and 0.63 for the second, third stages and the addition of these, respectively.
Avalia??o de métodos climatológicos para estimativa da evapotranspira??o
Scaloppi, E.J.;Klar, A.E.;Villa Nova, N.A.;
Anais da Escola Superior de Agricultura Luiz de Queiroz , 1978, DOI: 10.1590/S0071-12761978000100006
Abstract: the majos purposes of this work were to measure the evapotranspiration in a potato field-crop under three soil moisture regimes and to correlate these values with solar radiation data and to those employing penman's formula. the estimatives obtained by the two methods studied were significantly correlated to the evapotranspiration values measured in the various periods of the plant growth. in the first stage of the growth season, penman's formula uppertestimated the measured values in about 25-30%, however from the stage of tuber growth to maturity, it suplied the best estimates, except in the tratment where the matric potencial of soil water reached -2.0 bars. this contributed to reduce evapotranspiration rate during all growin season. the relationship between evapotranspiration and solar radiation is presented for varius stages of the plant growth.
Determina??o da umidade do solo pelo método das pesagens
Klar, A.E.;Villa Nova, N. A.;Marcos, Z. Z.;Cervéllini, A.;
Anais da Escola Superior de Agricultura Luiz de Queiroz , 1966, DOI: 10.1590/S0071-12761966000100003
Abstract: soil moisture determinations are of considerable importance to estimate the need for irrigation and to determine the amount of water to apply. there is a constant demand for a method to determine soil moisture content for irrigation purposes that is at one time reliable, rapid and inexpensive. the multiple-weighing method presented in this work was developed independently from the method proposed years ago by papadakis. it offers a few advantages over the method of papadakis which are discussed in detail. a comparison was made between the multiple-weighing method and the usual oven-drying method, for the determination of soil moisture of different soils. the data was statistically analysed. no significant difference was found between methods. a correlation coefficient of 0,99 was found between the two methods for each of the three soils.
MANEJO DA IRRIGA??O DA CULTURA DA ALFACE (Lactuca sativa L.) ATRAVéS DO TANQUE CLASSE A
ANDRADE JúNIOR, A.S. de;KLAR, A.E;
Scientia Agricola , 1997, DOI: 10.1590/S0103-90161997000100005
Abstract: an experiment was carried out to evaluate the effects of four irrigation levels, based on fractions of the class a pan evaporation (0.25; 0.50; 0.75 e 1.00) on the yield and the water use efficiency of a lettuce crop, grown under plastic house conditions and drip irrigation, from july to september, 1993. the results of yield and fresh matter showed a quadratic response of the applied irrigation levels, with maximum values of 818.72 g and 90.97 t.ha-1 for the 0.75 class a pan evaporation level, respectively. the water use efficiency showed, however, a decreasing linear response with respect to the irrigation levels.
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