Fernando Teruhiko Hata

First Record of Heliothis virescens (Lepidoptera: Noctuidae) Damaging Table Grape Bunches

Summary Heliothis virescens (F.) was observed damaging table grape bunches (18 d after onset of the flowering period), in Marialva County, Paraná State, Brazil. The pest fully ruined the bunches for the fresh market, and the damage was characterized as quite different from that of other lepidopteran larvae on grapes. Proximity to soybean (Glycine max L. Merrill) fields in which H. virescens developed was the probable cause of its occurrence on grapes.

Postharvest quality, antioxidant activity and acceptability of strawberries grown in conventional and organic systems

The aim of this study was to evaluate the influence of organic and conventional cultivation systems and the cultivars on the postharvest quality, antioxidant activity and acceptability of strawberries. Strawberries of the cultivars Albion, Monterey and San Andreas were analysed with respect to the soluble solids content (SS), titratable acidity (TA), SS/TA ratio, fruit colour, vitamin C content, antioxidant activity by the DDPH method, mineral composition and acceptability. The cultivation systems and cultivars had different influences on the SS, TA, pH, SS/TA and colour of the strawberries. The vitamin C content of cv. Monterey was higher (78.68 mg ascorbic acid 100 g-1) than that of cv. San Andreas (70.28 mg ascorbic acid 100 g-1) in the conventional system, while in the organic system, the cultivars did not differ. Differences were not observed amongst the cultivars and cultivation conditions for antioxidant activity and the cultivation systems and cultivars had no effect on the P, Cu and Mg mineral contents. The conventionally cultivated strawberries of cv. Monterey obtained the highest value for acceptance (7.51) while the organically cultivated strawberries of cv. San Andreas received the lowest value (6.58).

Mulching with Sugarcane Straw Reduces Weed Density in Sugarcane Field

Occurrence of weeds in sugarcane crop according to levels of straw over the soil was studied. Experiment was carried out during two annual cycles. Treatments were 0 % (no straw); 25, 50, 75 and 100% (i.e., 5, 10, 15 and 20 t/ha of straw, respectively); and straw burned over the soil. Floristic analysis of weed species was achieved. Percent area occupied by weeds was assessed visually and regression analysis between weeds and amount of straw mulch was performed. Floristic analysis characterized 19 weed species, from eight botanical families: Amaranthaceae, Asteraceae, Commelinaceae, Convolvulaceae, Euphorbiaceae, Poaceae, Portulacaceae and Solanaceae. Highest richness of species was observed for Asteraceae and Poaceae, with seven and four species, respectively. Higher frequency was found for Amaranthus hybridus, A. viridis and Physalis angulata (85% of samples) for first annual crop cycle; and A. hybridus, Bidens pilosa and Cenchrus echinatus predominated (83% of samples) in second cycle. A. hybridus was the most frequent species in both cycles. The highest density of weeds was observed in treatments with straw burned. Application of 75 and 100% straw showed highest suppression for low and high density of weeds, respectively. Increasing level of straw leads correspondent weed control. That information is vital to orientate decision which amount will deposit over the soil since in recent years the straw is also demanded for alternative sources of energy, as thermal or second generation bio-ethanol.