Use of Plastic Mulches for Reducing Salinity and Increasing Yield of Cantaloupe

In central region of Iran, increasing soil and water salinity and declining ground and surface water resources have increased the necessity of reducing the effect of salinity on crop yield. Utilization of plastic mulches is an effective method for reducing the salinity hazard on plant growth. In this respect, an experiment was conducted on cantaloupe using factorial combination of four irrigation water salinities of 2, 4, 6 and 8 dS m^-1 and three mulch treatments including bare soil (control), transparent (TPM), and black plastic mulch (BPM). The experimental design was randomized complete block design in three replicate. The analysis of variance showed that the effects of saline irrigation water on yield, mean weight of fruit, yield of plant, yield of marketable and non-marketable fruit were highly significant (P < 0.01), and on number of harvested fruit were significant (P< 0.05).The effect of mulch treatments on fruit yield and mean weight of fruit was highly significant (P < 0.01) and on number of fruit per m^-2 and number of fruit per plant were significant (P < 0.05). The interaction effects of saline irrigation water and mulch were not significant on any of the aforementioned parameters. The cantaloupe yield in 2, 4, 6 and 8 dS m^-1 irrigation water treatments across all mulch treatments were 5.12, 4.01, 4.03 and 2.94 kg m^-2, respectively, and were significantly different (P<0.01). The plot yield for the control, BPM, and TPM were, respectively, 2.18, 4.47, and 4.69 kg m^-2, and there was significant differences (P<0.05) between plastic mulch with the control. With increasing irrigation water salinity from 2 to 8 dS m^-1,the average soil salinity in 0 to 60 cm soil layer increased from 4.5 dS m^-1 to 11 dS m^-1. Increasing salinity of irrigation water enhanced the effect of mulch treatment on decreasing the soil salinity. The relationship between cantaloupe yield and soil salinity was Yr=100- 7.1X(ECe-2.48), where Yr, and ECe (dS m^-1) are the relative yield (yield of non-saline to saline treatment yield) and soil electrical conductivity in 0-60 cm soil layer. Therefore, cantaloupe is moderately sensitive to salinity and utilization of plastic mulches to increase earliness and decrease the effect of irrigation water salinity is recommended.