Lucindo Somavilla

Desempenho de métodos de estimativa da evapotranspiração de referência nas localidades de Frederico Westphalen e Palmeira das Missões, RS

The estimation of reference evapotranspiration (ETo), used in water balance, allows to determine soil water content, assisting on irrigation management. The present study aimed to compare simple ETo estimating methods with the Penman-Monteith (FAO), in the folowing time scales: daily, 5, 10, 15 and 30 days and monthly in the counties of Frederico Westphalen and Palmeira das Missoes, in the Rio Grande do Sul state, Brazil. The methods tested had their efficiency improved by increasing the time scale of analysis, keeping the same performance for both locations. The highest and lowest ETo values occurred in December and June, respectively. Most methods underestimated ETo. For any of the time scales Makking and Radiaton FAO24 methods can replace the Penman-Monteith for estimating ETo.

Temperatura basal, duração do ciclo e constante térmica para a cultura do crambe

Crambe is an alternative crop, precocious and with potential to produce oil during the cold season. The scarcity of information about climatic and phenological parameters led to the determination of basal temperature, crop growth cycle duration and growing degree-days of Crambe. The research was composed of seven sowing dates in 2009 and four in 2010. Basal temperature was determined by the methods of least variability and relative development. The basal temperature for the subperiod emergence-maturation (EME-MAT) was 9.5 °C, whereas for the subperiods seedling emergency-early flowering stage (EME-IFLO), seedling emergency-end of flowering (EME-FFLO) and early flowering-end of flowering (IFLO-FFLO) were 10.2 oC, 10.8 °C and 10.0 oC, respectively. The subperiod between EME-MAT ranged from 74 to 136 days with an average duration of 96 days. For EME-FLO, EME-FFLO and IFLO- FFLO the average duration was 52, 82 and 29 days, respectively. Considering the values †of basal temperature for each period or subperiod, the average time between EME-MAT was 691 oC day, ranging between 576 oC day and 792 oC day. For EME-IFLO, EME-FFLO and IFLO-FFLO, the average was 279 oC day, varying between 444 °C day and 220 oC day.

Vinhaça como fonte de potássio: resposta da sucessão aveia-preta/milho silagem/milho safrinha e alterações químicas do solo na Região Noroeste do Rio Grande do Sul

A vinhaca, residuo do processo de destilacao do alcool e rica em potassio (K) e sua aplicacao ao solo pode aumentar a disponibilidade do nutriente, mas tambem provocar alteracoes nas propriedades quimicas do solo. O trabalho objetivou avaliar a viabilidade tecnica da utilizacao da vinhaca como fonte alternativa de K na sucessao aveia preta/milho silagem/milho safrinha, alem de possiveis alteracoes em atributos quimicos do solo na camada de 0-10cm. O experimento foi conduzido no Municipio de Ajuricaba (RS), no periodo 04/2010 a 06/2011. Os tratamentos utilizados foram: T1) adubacao mineral NPK; T2) N + P sem vinhaca; T3) N+P+50m3 ha-1 de vinhaca; T4) N+P+100m3 ha-1 de vinhaca; T5) N+P+150m3 ha-1 de vinhaca; e T6) N+P+200m3 ha-1 de vinhaca. Na aveia preta, foram avaliados os teores totais foliares de P, K e o acumulo de materia seca. No milho silagem, a altura de plantas, altura de insercao da espiga e a produtividade de forragem e, no milho safrinha, o peso de mil sementes e a produtividade de graos. Quanto aos atributos quimicos do solo, foi avaliado o pH, os teores de P, K, Ca, Mg e a capacidade de troca cationica. Na aveia-preta, as maiores doses de vinhaca proporcionaram os menores acumulos de materia seca, sendo 100m3 ha-1 a melhor dose observada. Para a cultura do milho, a dose de 100m3 ha-1 de vinhaca proporcionou produtividade de silagem semelhante a adubacao mineral e foi capaz de suprir a necessidade de potassio tambem para o cultivo do milho safrinha. Em relacao aos atributos quimicos do solo, nao se observaram alteracoes significativas na camada avaliada (0-10cm). A utilizacao da vinhaca como fonte de potassio mostrou-se uma alternativa tecnicamente viavel e a sua utilizacao em nivel de lavoura uma forma de descarte desse residuo.

Dinâmica floral e abortamento de flores em híbridos de canola e mostarda castanha

The objective of this work was to evaluate the floral dynamics and to determine the index of flower abortion in canola (Brassica napus) and Indian mustard (Brassica juncea) hybrids, as well as to determine their relation with meteorological conditions of southern Brazil. During flowering, ten hybrids of canola and two of Indian mustard were evaluated every three days as to the number of open flowers, pods, and aborted flowers. The cumulative and the relative number of flowers were used to evaluate floral dynamics. The relation of these numbers with the accumulated thermal sum during flowering was determined with a logistic model. Groups of genotypes with different flowering rates were identified using the model coefficients. Flower abortion among hybrids ranged from 10.53 to 45.96% and was correlated with temperature and hydric demand of the atmosphere. Genotypes with larger thermal times between the peak and the end of flowering generally had higher percentages of flower abortion. The adjustment of data from flower emission to those of the thermal sum of the flowering period, using a logistic model, allows simulating floral dynamics of hybrids of canola and Indian mustard.

RESISTÊNCIA À GEADA E CRESCIMENTO INICIAL DE Toona ciliata EM CULTIVOS CONSORCIADOS COM Eucalyptus grandis EM DIFERENTES ADUBAÇÕES

Nutritional restriction and the occurrence of frost in southern Brazil often affects the growth of forest stands. In order to quantify the initial growth and resistance to frost of Toonna ciliata plants, in crops intercropped with Eucalyptus grandis in different fertilization, an experiment was conducted at UFSM, campus Frederico Westphalen, Brazil. The experimental design was a randomized block design with three replications, in factorial 2 x 2 x 3: two forest species ( Eucalyptus grandis Hill ex Maiden and Toona ciliata M. Roem var. australis), two types of stands (single and intercropped) and three types of fertilizer (NPK, NPK + Si and NP slow-release + K + biostimulant). The growth of plant height was measured at different dates, up to 346 days after planting. At the end of this period, it was quantified the diameter at breast height and dry mass of shoots. The assesment of the level of damage to the plants and the degree of resistance to frost was with grading based on the entire plant and tree canopy. The data were submitted to variance analysis and when significant (p ≤ 0.05), we proceeded to compare the treatment by means of Tukey test (p ≤ 0.05). The two forest species were tolerant to frost, but with greater damage to the leaf area in plants Toona ciliata against the Eucalyptus grandis . The cultivation Toona ciliata under protection the Eucalyptus grandis has not diminished the damage to frost in the first year of field deployment. The use of slow-release fertilizer, Si and biostimulant did not contribute to increasing growth and resistance to frost the plants of the two forest species.

Uso de Substrato Compostado na Produção de Mudas de Eucalyptus dunnii e Cordia trichotoma

The substrates have influence on germination and growth of forest species seedlings. Aiming to evaluate the germination, growth and quality of Eucalyptus dunnii and Cordia trichotom seedlings on substrates obtained by composting of organic waste we conducted an experiment at UFSM, campus Frederico Westphalen, Brazil. Four substrates composting (university restaurant waste, recycling household waste, liquid cattle manure and flotation process sludge) and commercial substrate (with and without mineral fertilizer) were used. The design was completely randomized with four replications. The substrates influenced the germination rate, but did not affect the final germination percentage. Alternative substrates from waste of university restaurant waste and flotation process sludge provided greater height and diameter of E. dunni and C. trichotoma seedlings and can be used to replace the commercial substrate.

Uso de Substrato Compostado na Produção de Mudas de Eucalyptus dunnii e Cordia trichotoma / Composted Substrate in the Production of Eucalyptus dunnii and Cordia trichotoma Seedlings

The substrates have influence on germination and growth of forest species seedlings. Aiming to evaluate the germination, growth and quality of Eucalyptus dunnii and Cordia trichotom seedlings on substrates obtained by composting of organic waste we conducted an experiment at UFSM, campus Frederico Westphalen, Brazil. Four substrates composting (university restaurant waste, recycling household waste, liquid cattle manure and flotation process sludge) and commercial substrate (with and without mineral fertilizer) were used. The design was completely randomized with four replications. The substrates influenced the germination rate, but did not affect the final germination percentage. Alternative substrates from waste of university restaurant waste and flotation process sludge provided greater height and diameter of E. dunni and C. trichotoma seedlings and can be used to replace the commercial substrate.