João Carlos Felício

Trigo: tolerância ao alumínio em solução nutritiva

Twenty one wheat cultivars were studied in aerated nutrient solutions for aluminum tolerance with six different levels, 0, 2, 4, 6, 8 and 10 mg/litro of Al3+, under constant temperature, 25° ± 1°C and pH 4.0. Aluminum tolerance was evaluated by measuring the root growth in an aluminum-free complete nutrient solution after a treatment of 48 hours in an aluminum solution. The cultivars BH-1146, IAC-18, IAC-28, IAC-5, IAC-74, IAC-13, PAT-72247, IAC-22, BR-2, IAC-21 and IAC-24 were considered as tolerant because they exhibited growth of the central primary root after a treatment in solutions with 10 mg/l of Al3+. However cultivars IAC-17, IAC-161, Mitacore and CEP-7780 showed moderate tolerance to Al3+ because they showed growth of the central primary root after a treatment in solutions containing 6 mg/l of Al3+. Moreover the cultivars CNT-8, Alondra-S-46, IAC-162, Paraguay-281 and IAC-23 were considered as sensitive to Al3+ because they did not present root growth after a treatment in solutions with 6 mg/l of Al3+. The cultivar Anahuac did not show any root growth after a treatment in solutions containing 2 mg/l of Al3+ therefore being considered the most Al sensitive among the studied cultivars.

Avaliação de genótipos de triticale e trigo em ambientes favoráveis e desfavoráveis no Estado de São Paulo

The environment adaptation of eighteen triticale and two wheat genotypes were evaluated in experiments carried out at two different sites of the Mococa Agronomy Experimental Station, Sao Paulo State, Brazil, in the period 1996-99. The favorable environment was provided with sprinkler irrigation on an upland; the unfavorable condition consisted of a moist flat area with basin irrigation system. The environment diversity induced different genotypes response patterns. Under the sprinkler irrigation system the yields were higher for both species, but the triticale genotype TATU 4/ARDI 1 presented the highest grain yield. Under moist and flat area condition the triticale LT 978.82/ASAD//TARASCA showed the highest yield. The wheat genotype IAC 60 showed large variations in grain yield in the moist flat area over the two cropping years. The plant cycle from emergence to heading showed higher variation among the triticale genotypes under moist low and flat area in comparison with the upland sprinkler irrigation condition. The results suggested the wheat genotypes presented a specific adaptation for upland with sprinkler irrigation environment and the triticale group of genotypes presented a broader adaptation.

Effects of different conditions of irrigation and crop density on microclimate and occurrence of spot blotch and powdery mildew.

Field experiments (1990 and 1991) were carried out in Campinas, State of Sao Paulo, Brazil, during winter season, in order to study sprinkler irrigation and crop density effects on micrometeorological parameters (average air temperature and dew duration) and to evaluate their influence in the occurrence of spot blotch and powdery mildew in wheat crop. The results obtained were submitted to statistical analysis: comparison of means of two independent sample analysis (microclimate) and confidence interval analysis (infection rates). It was verified that in the most dense and irrigated plots the average air temperatures were lower (0.7°C) and the dew durations (DPM) were longer (45 minutes) than in the other plots. The infection rates of diseases were influenced positively by irrigation and crop density when the macroclimatic conditions were not favorable to disease development.

Iguaçu (IAC-21) e Araguaia (IAC -22): cultivares de trigo de sequeiro para o Estado de São Paulo

Two new selected germoplasms of wheat (Iguacu and Araguaia) were tested against two commercial varieties (BH-1146 and IAC-5) for yield and resistance to stem and leaf rusts in several experiments carried out in different locations of the wheat areas of the State of Sao Paulo, Brazil, in the period 1978-1982. Cultivar Iguacu produced 8% and 12% more grain per hectare in comparison with respectively, cultivars BH-1146 and IAC-5; cultivar Araguaia had, respectively, 5% and 14% more grain yield than the same commercial varieties. Iguacu and Araguaia cultivars presented less stem rust infection than BH-1146 and IAC-5 while Araguaia had a lower infection level than Iguacu under field conditions. It was not observed differences in resistance to leaf rust among them. Araguaia exhibited better bread qualities than Iguacu but both showed better qualities than the used commercial wheat flour.

TEMPERATURA-BASE, GRAUS-DIA E DURAÇÃO DO CICLO PARA CULTIVARES DE TRITICALE (1)

BASE-TEMPERATURE, GROWING DEGREE-DAYS AND CROP GROWTH CYCLE DURATION OF TRITICALE CULTIVARS Base temperature, growing degree-days and cycle growth length were evaluated at Capao Bonito, Sao Paulo State (Brazil), during the years from 1992 to 1995, for three triticale cultivars: CEP 15, IAC 2 and IAC 3. The obtained values of base temperature varied from 8 to 10 o C and the amount of growing degree-days required for the triticale cultivars to complete their cycle varied from 1048 to e 1263, according to the cultivar. The duration of the emergency-flowering growth stage varied from 50 to 63 days, according to the cultivar, while the duration of the flowering-maturation (harvest) growth stage was 70 days for the three cultivars analised. The low air temperature enlarged the length of the total cycle for the triticale cultivars.

Comportamento agronômico de linhagens de trigo no Estado de São Paulo

Eighteen wheat lines and the check cultivars IAC-24 and IAC-289 were evaluated in six trials carried out at different locations under dryland and sprinkler irrigation conditions, for grain yield, agronomic characteristics and disease resistance. In laboratory conditions, the germplasms were evaluated for their Al toxicity tolerance in nutrient solutions. The line L9 and the cultivar IAC-289 were superior in grain yield, considering the average of the six trials. The line L8 exhibited short stature associated to lodging resistance and early maturity. In relation to leaf rust the lines L1, L17 and L20 were resistant. All genotypes were susceptible to the causal agents of leaf spot and mildew. The line L7, showed long heads with the highest number of spikelets; IAC-289 and L17, the largest number of grain per head and per spikelet, respectively; and L11, the heaviest grains. All evaluated genotypes were tolerant to Al3+ toxicity, excepting the control cultivar Anahuac and the lines L15 and L20, which exhibited high sensibility.

Diferentes épocas de colheita, secagem e armazenamento na qualidade de grãos de trigo comum e duro

The objective of the present work was to analyse the effects of initial moisture content, drying parameters and storage period in grain quality. The experiment was installed in Campinas Agronomic Institute (IAC), using two genotypes of common wheat (Triticum aestivum L), one with spike dormancy (IAC 24), harvested with 30.0%; 21.4% and 12.2% moisture content and the other without it (IAC 289), harvested with 35.0%; 23.4% and 12.5% moisture content; additionally, one hard wheat genotype (Triticum durum L.) without dormancy (IAC 1003), harvested with 31.6%, 22.2% and 11.7% moisture content was also analysed. Drying operations were performed at 40, 60 and 80 oC under an air flow of 20m3 min-1.m-2. Dried grains were then stored in polyethylene packets for a period of 0, 2, 4, 6 and 8-months at 20±2oC. Grain quality parameters analysed were number of falls, viscosity, general force of gluten and hectolitre weight. The genotype IAC 289 presented an increase on alpha-amylase activity due to harvest delay. Harvest anticipation and drying process had no effect on grain quality, whereas storage period improved the technological quality of the wheat flour.

Linhagens diaplóides de trigo: desempenho agronômico em dois locais do estado de São Paulo e tolerância à toxicidade de alumínio em laboratório

Twenty wheat genotypes (18 dihaploid lines and the IAC-24 and IAC-370 cultivars) were evaluated in experiments carried out under dryland and acid soil conditions in Capao Bonito and under sprinkler irrigation and limed soil conditions in Tatui in 2001-03 period. Grain yield, yield components, agronomic characteristics and disease resistance were evaluated. The genotypes were also evaluated for their tolerance to Al toxicity, in nutrient solutions, under laboratory conditions. IAC-24 and the dihaploid lines (L3, L4, L5, L8, L14, L15, L16, L17, L18, L19 e L20), in Capao Bonito, were superior for grain yield. In nutrient solutions, these were the most tolerant genotypes to aluminum toxicity. All genotypes exhibited semi-dwarf plant type. The dihaploid line L15 and L16, presented lodging resistance, IAC-370 longer spikes and higher number of grain per spike and per spikelet, L8 higher number of spikelets per spike and L6 and L7 the heavier grains. All evaluated genotypes were susceptible to leaf spot. The lines L4, L14, L15, L16, L17 and L18 originated from the cross R27/GHL121//KAL/BB/3/BUC/BUL/4/IAC-24 showed resistance to leaf rust. The higher grain yield genotypes, under dryland and acid soil conditions, were associated to taller semi-dwarf plants with tolerance to aluminum toxicity. Under sprinkler irrigation and limed soil conditions the highest yielding genotypes were not associated to either semi-dwarf plants or those tolerant to aluminum toxicity.

Tolerância de genótipos de trigo comum, trigo duro e triticale à toxicidade de alumínio em soluções nutritivas

Twelve bread wheat (Triticum aestivum L.), one durum wheat (Triticum durum L.) and one triticale (Triticosecale sp) genotypes were studied in nutrient solutions with a high salt concentration in experiment 1 and a weak salt concentration in experiment 2, for aluminum tolerance at six levels: 0, 2, 4, 6, 8 and 10 mg L-1, under temperature 25 ± 1oC and pH 4,0. Four replications were used per experiment. Aluminum tolerance was evaluated by measuring root growth in an aluminum-free complete nutrient solution after a treatment of 48 hours in an aluminum solution associated with a particular salt concentration, according to the experiment. The bread wheats IAC-289, IAC-350 and IAC-370, the durum wheat IAC-1003 and the triticale IAC-5 genotypes were the most sensitive for increasing levels of Al3+in treatment nutrient solutions. Thus, they would be indicated only for cultivation in limed soils. The bread wheat IAC-24 and IAC-378 genotypes and the check cultivar BH-1146 were the most tolerant to Al3+ toxicity, being able to show good performance in acidic soils and/or to be used as genetic sources for tolerance in future crosses. Under constant temperature 25 ± 1oC and pH 4,0 aluminum toxicity results in inhibition of root growth wich was dependent on the increase of the aluminum concentration or on the reduction of the salt concentration of the nutrient solution for all evaluated genotypes.

Comportamento de linhagens diaplóides de trigo em dois locais do Estado de São Paulo

Twenty wheat genotypes (18 dihaploid lines and the IAC-24 and IAC-289 cultivars) were evaluated in experiments carried out under dryland and acid soil conditions in Capao Bonito (1997-99), and under sprinkler irrigation and acid soil conditions with lime application in Tatui (1997-2000). Grain yield, yield components, agronomic characteristics and disease resistance were analyzed. In addition, the genotypes were evaluated for their tolerance to Al toxicity, in nutrient solutions, at laboratory conditions. The dihaploid lines 10 and 11 and the cultivar IAC-24, in Capao Bonito, and the cultivar IAC-24 and the dihaploid line 19, in Tatui, were superior for grain yield. The dihaploid line 5 presented lodging resistance, the line 20 showed short stature and early plants to mature, and the cultivar IAC-289 exhibited higher number of spikelets per spike and heavier grains. All evaluated genotypes were susceptible to leaf spot. In relation to leaf rust, all lines were resistant, except the line 20 which was moderately resistant. The cultivar IAC-24 and all evaluated dihaploid lines were tolerant to aluminum toxicity. The higher grain yield genotypes, under dryland and acid soil conditions, were associated to tall plants, with long spikes, with high number of grains per spike and per spikelet and with tolerance to aluminum. Under sprinkler irrigation and acid soil conditions with lime application the most productive genotypes were associated to tall plants (semidwarf type) with heavy grains, and presenting no correlation with tolerance to aluminum.