EFFECTS OF NON-WOVEN FABRIC AND FERTILIZER ON AIR AND SOIL TEMPERATURE, LEAF GAS EXCHANGE, YIELD AND QUALITY OF WILD ROCKET GROWN IN ORGANIC FARMING

The wild rocket cropping is still growing and currently consumers are demand¬ing organic vegetables providing for the use of agronomic techniques that reduce chemical inputs. Therefore, the aim of this study was to investigate the influence of non-woven fabric (NWF) and the interaction with a commercial organic fertilizer on air and soil temperature, leaf gas exchange, yield and quality on wild rocket. The research was carried out in southern Italy. Two cropping techniques (crop covered with NWF and not covered control - NCC) and 3 doses of organic fertilizer (0, 1, and 2 t ha^-1 of Guanito) were compared.
NWF has influenced the microclimate near the plants. Air temperature at 0.01 m in height and soil temperature at 5 cm in depth, as average of the crop cycle, were respectively about 0.8 and 1.8°C higher than those in NCC, reducing the risk of frost damage, because of a minor thermal excursion. NWF has reduced photosynthetically active radiation of 18%. Nevertheless, NWF has caused the increase of more than 5% of the net assimilation (A), probably due to the higher temperature in the soil and near the plants. Furthermore, NWF has reduced transpiration and stomatal conductance of 25.8 and 30%, respectively, leading to an increase of 42.5% in water use efficiency (WUE). Moreover, the application of fertilizer increased A and WUE. NWF has increased the weight of the plants, the yield, the percentage of waste and has reduced the nitrate content. Increasing the organic fertilizer doses has increased weight of the plants, yield, ascorbic acid and nitrate content.