Study on the effects of polyethylene mulche in decreasing populations of sucking pests, viruses vectors and yield of outdoor cantalope.

Recently polyethylene mulches have been used in vegetables, for different reasons. To evaluate the effects of colored mulches on the deterring sucking pests(aphids),decreasing viral diseases and qualitative and quantitative characters of cantaloupe fruit, the experiment was conducted in Kaboutar-abad Agricultural research station, during 2005-2007. A randomized complete block design containing 4 replications, and 6 treatments(black with aluminum strip (B+A), aluminum (A), transparent (T), red (R) , black (B) and control or without mulch) during the study. Seeds were planted after spreading the mulches and cultural practices were done. Vegetative growth, decrease of aphids population and percentage of infection to viruses, early maturity, total yield and qualitative characters were measured. Variation in the population density of sucking pests such as aphids, thrips and hoppers were estimated by yellow water trap by weeckly intervals. Viral infections in different treatments were estimated until flowering and fruting stage. Fruit quality was determined through test panel, using characters of fruit appearance, odor, flavor, tendency and total acceptability and total solid solution of fruits was also determined. Results showed that A and B+A mulches were very effective to reple aphids significantly compared to other mulches. Maximum trapped aphid number belonged to control (492, 112 and 961) and minimum number belonged to B+A mulch (171, 41 and 213). There was a significant difference among treatments for total mosaic viruses and treatments were placed in 3 groups. First group had the lowest infection including mulches of A and B+A, second group included mulches of T,R and B and third group had highest infection included control. In addition to deterring effect of mulches, growth rate of plants in mulched teatments were higher than control and they reached to flowering stage 10 days earlier. Mulches had significant effect on yield. Means of total yield (3-year average) was 48.6, 47.8, 46.7, 45.6, 44.8 and 37.6 t/ha for mulches B+A, B, R, T and C, respectively. The highest amount of early fruiting belonged to mulched treatments. Vegetative growth was higher in mulched treatments, and this was obvious at early growth period. There was no significant effect on fruit quality. There was no significant differences among mulches for fruit quality,however in 2006 quality (flover and acceptability) was higher in control treatment.