Diniz Fronza

Water consumption of the estevia (Stevia rebaudiana (Bert.) Bertoni) crop estimated through microlysimeter

The knowledge of water requirement of crops in the different growing phases elicits higher crop yield and rational use of water resource. The aim of this work was to estimate the water consumption of stevia using two constant watertable microlysimeters. The research was conducted in San Piero a Grado, Pisa, Italy. The data were collected daily from June, 1st, to October, 22th, 2000. Reference evapotranspiration was determined by the Penman-Monteith-FAO method, in the same period. Microlysimeters watertables level were maintained at the 35 cm depth. Crop evapotranspiration for the total cicle (80 days) was 464 mm. For the most water consuming phase, crop average evapotranspiration was 5.44 mm day-1. The crop coefficient values were 1.45 for the first 25 days, 1.14 for the next period (26 to 50 days), and 1.16 for the latest period (51 to 80 days). The stevia leaf yield of the microlysimeters was 4.369 kg ha-1 and their steviosideo content 6.49%.

Atmosfera controlada para o armazenamento de goiaba cultivar ‘Paluma’

Guava is a highly perishable fruit. Controlled atmosphere (CA) storage techniques could extend its shelf life while maintaining the quality of fruit. The aim of this work was to determine the best CA conditions for the storage of ‘Paluma’ guava. The experiment consisted in a randomized block design with the follow treatments: [1] 20.9 kPa O 2 + 0.03 kPa CO 2 (CS - control); [2] 1.0 kPa O 2 + 2.0 kPa CO 2 ; [3] 2.0 kPa O 2 + 2.0 kPa CO 2 ; [4] 3.0 kPa O 2 + 2.0 kPa CO 2 ; and [5] 3.0 kPa O 2 + 4.0 kPa CO 2 . Fruit were stored at 8°C (±0.2) at a relative humidity of 95% (±2.0). After 28 days of storage the fruits were evaluated for their physicochemical characteristics. The best CA storage conditions for ‘Paluma’ guava is 1 and 2 kPa O 2 combined with 2 kPa CO 2 . These conditions reduced the degradation of the peel green color , loss of firmness and acidity, and keeps the flesh color more ef fectively, but the high occurrence of decay during self-life is the limiting factor of the storage period.

Produtividade e qualidade de figos Roxo de Valinhos submetidos à fertirrigação e ao armazenamento refrigerado

Effect of fertigation and cold storage on yield and quality of ‘Roxo de Valinhos’ figs The low productivity of figs in Brazil is usually associated with water and nutrition deficiency. The aim of this work was evaluate the effect of fertigation with doses of nitrogen and potassium on yield and quality of the ‘Roxo de Valinhos’ figs during cold storage. The field experiment was conducted during two years, and in the last year, the fruits were stored at 0.5° C for fifteen days. The treatments were a combination of doses of of nitrogen (150, 250, 350 and 450 kg ha -1 ) and potassium (150, 250 and 350 kg ha -1 ) applied by fertigation. The results showed that doses up to 250 kg ha 1 of N and K in fertigation increased the yield of ‘Roxo de Valinhos’ figs, and these doses increased the yield among the treatments. Fertigation increased yield of green figs by by 96.7% and ripe figs by 49% compared with the control. The rates of N and K and the application form did not affect the fruit quality during cold storage.

Storability of ‘Tupy’ and ‘Guarani’ blackberries in controlled atmosphere

The aim of this work was to compare the storage potential of ‘Guarani’ and ‘Tupy’ blackberries in controlled atmosphere (CA) and thereafter to determinate the best CA storage conditions for ‘Tupy’ blackberries. Two experiments were carried out. In the first one, ‘Guarani’ and ‘Tupy’ blackberries were stored in CA condition (10 kPa O2 + 15 kPa CO2). We found that ‘Tupy’ blackberry has the best storage potential. Therefore, in the second experiment, several CA conditions were evaluated for ‘Tupy’ blackberries storage, as follows: [1] cold storage (CS): 20.9 kPa O2 + 0.04 kPa CO2; [2] CA with 10 kPa O2 + 15 kPa CO2; [3] CA with 5 kPa O2 + 15 kPa CO2; [4] CA with 10 kPa O2 + 10 kPa CO2. All treatments were stored at 1 °C and 98% (± 1) of relative humidity. The ‘Tupy’ blackberry, despite showing a significant decrease in ascorbic acid content, presented a higher storage potential than ‘Guarani’ blackberry, if stored at recommended CA condition for other cultivars. ‘Tupy’ blackberry stored at 5 kPa O2 + 15 kPa CO2 showed higher ascorbic acid content, soluble solids and titratable acidity as compared to the other storage conditions. In CA with 10 kPa O2 + 15 kPa CO2, the juice was lighter (high L), but differed significantly only from those fruit of CS. The best CA condition for ‘Tupy’ blackberries storage is 5 kPa O2 with 15 kPa CO2.