Introduction. The respiration of living plant tissues and the diffusion of gases through the packaging material modify the atmosphere composition in the fresh product package. This modified atmosphere (MA) can be beneficial to the storage of fruit tissues, but, if the permeances of the films are not properly optimized, the MA may be inefficient or even detrimental. To define the optimal permeances (or permeability) for O2, CO2 and water vapor of the packaging film, the respiration rate of plant tissue must be measured as a function of temperature and atmosphere, and the O2 and CO2 concentrations that maximize shelf life must be determined. The best combination of packaging films, type and condition of fresh produce and storage temperature may be computed and verified experimentally. Materials andmethods. The work presents methods for measurement of the respiration rate of plant tissue, then the influence of temperature and the influence of O2 and CO2 contents are studied. This makes it possible to determine the optimal O2 and CO2 concentrations and the optimal gas transmission rates of packaging material. Lastly, experiments regarding the simulation of modified atmospheres are described. Conclusion. The methodology presented in our work provides helpful information to meet the need of optimal fruit and vegetable packaging.

We tested the usefulness of mulching with polypropylene landscape fabric and compost as alternatives to bare soil for growing red cabbage and watermelon. Polypropylene landscape fabric has features similar to the polyethylene film that is popular for commercial vegetable production, but its durability permits multi-year use, which would reduce excessive waste produced from the typical single-season use of polyethylene film. On the other hand, compost used as mulch enhances soil development while providing weed suppression and water retention, among other benefits. Yields of red cabbage and watermelon were measured for 3 years in plots receiving either 10 cm compost, landscape fabric, or no mulch. Labor associated with crop production and weed suppression was measured as time spent on each task. Cabbage yields over 3 years followed the treatment order of compost > no mulch > fabric, while for melon yields it was compost > fabric > no mulch. Total labor required over 3 years for both crops, according to treatments, was fabric > compost > no mulch. However, labor for the fabric-treated plots dropped sharply after the first year, because fabric was left in place after initial placement. Labor for unmulched cabbage plots increased over time due to weeding and transplanting; labor for unmulched and compost-mulched melon plots increased for the same reasons. Compost provided the highest crop yields with a moderate labor investment. Surface-applied compost substantially increased underlying soil nutrient levels. The study indicates that polypropylene landscape fabric may be a potential alternative to the more traditional polyethylene film for permanent beds in vegetable production.