Gustavo Klamer de Almeida

Brazil is one of the largest banana producers and despite overall adequate climatic conditions to produce good quality fruit, postharvest handling procedures still are inappropriate. Only a few growers have degreening facilities at their groves. Mostly, bananas are prepared for the market by distributors. Two banana cultivars: Grande Naine (group AAA) and Prata Anã (AAB) were harvested from commercial groves and immediately submitted to degreening procedures in which three temperatures and four ethylene concentrations were evaluated. Bananas were degreened at 24 hour intervals at 13, 17 and 21 ºC with a commercial ethylene source (Banasil®) from which 12.5, 25, 50, and 100mL were placed in an ethylene generator. During the degreening process, ethylene concentrations in the degreening room were monitored for periods up to 6 hours. At the beginning of the degreening process and after three and five more days, epidermal color and pulp firmness were determined. Ethylene concentrations did not influence color changes and ripening processes of both cultivars. A maximum ethylene concentration (1,350 µL L-1) was determined in the degreening room when 100 mL of Banasil® was used at 21ºC. Even with the lowest Banasil® amount, a 90 µL L-1 ethylene peak was determined in the degreening room, enough to ripen adequately both cultivars. Degreening at 13 ºC delayed for two days the ripening of ‘Grande Naine’ bananas. ‘Grande Naine’ reached the fully ripe stage in four days while ‘Prata Anã’ completed ripening after three days. ‘Prata Anã’ bananas are more responsive to ethylene degreening than ‘Grande Naine’ bananas.

The objective of this work was to evaluate the vegetative growth and yield of the 'Abate Fetel' and 'Rocha' pear (Pyrus communis) trees grafted onto the 'Adams', 'Ba29', and 'EMC' quince (Cydonia oblonga) rootstocks in the climatic conditions of Southern Brazil. The plants were trained on a central leader system, at a 4.0x1.0-m spacing. Vegetative growth, yield, and fruit size were evaluated. 'Rocha' showed greater vegetative growth, but also alternate bearing, mainly due to fructification problems. 'Abate Fetel' presented high flowering intensity, but a very low fructification, which limited its yield. Among rootstocks, 'Adams' induced a higher vigor during the initial stages and an increased intensity in flowering in the sixth year. In the following seasons, there was no rootstock effect on the assessed variables. 'Rocha' has a satisfactory production, whereas 'Abate Fetel' shows a weak vegetative growth and a very low production. The 'Adams', 'Ba29', and 'EMC' rootstocks induce similar vegetative and productive behavior in the 'Abate Fetel' and 'Rocha' pear trees.

Spraying of dormancy-breaking chemicals is a mandatory procedure to produce temperate fruits in low-chill regions. Although hydrogen cyanamide (HC) + mineral oil (MO) show efficiency enhancing budburst, the usage of HC is restricted in some countries due to its toxicity. Therefore, this research aimed to evaluate the efficiency of spraying different dormancy-breaking agents on ‘Eva’ apple tree buds, under the conditions of the Depressão Central of Rio Grande do Sul, Brazil. Different doses of Erger® (0, 2, 3, 4, 5%) + 3% Ca(NO3)2 were tested and compared with MO (4%) or MO (4%) + HC (0.6%). Budburst rate of apical and axillary buds, physiological alterations in buds, return bloom, yield and fruit weight were evaluated. Erger® treatments efficiently enhanced budburst, with a result equivalent to HC + MO treatment. The budburst rate increased as the Erger® dose increased, also causing the increment of the return bloom in the following year. However, doses of 4 and 5% caused the death of shoots. The activity of the peroxidases and the content of H2O2 in the buds were affected by the treatments. Yield and fruit mass were different in response to treatments, although the effect varied between years. Erger® + Ca(NO3)2 spraying increase budburst in apical and axillary buds of ‘Eva’ apple tree in low-chill conditions and doses up to 3% of the commercial product do not cause toxicity.

The objective of this work was to evaluate different pruning times, performed before or after natural leaf drop, regarding their effects on the yield of 'Royal Gala' apple (Malus domestica) trees. The experiment was carried out in Vacaria, in the state of Rio Grande do Sul, Brazil, on seven-year-old trees in four harvests from 2008/2009 to 2011/2012, using a randomized block design. The following pruning times were tested: 46 days before leaf drop (DBLD); 25 DBLD; 5 DBLD; 15 days after leaf drop (DALD); 36 DALD; 55 DALD; and 75 DALD. All pruning times before natural leaf drop reduced yield per tree and fruit set. Among the pruning times before leaf drop, 46 DBLD resulted in the lowest yield. Pruning performed after natural leaf drop, still during dormancy, resulted in a higher yield per tree, in comparison with pruning times before leaf drop. The effect of pruning times on average fruit mass, pulp firmness, content of soluble solids, titratable acidity, and soluble solids/titratable acidity ratio differed between harvest years. Pruning performed at different times, before natural leaf drop, causes yield reduction in 'Royal Gala' apple trees, and the pruning time at 46 DBLD results in the lowest yield.