Technological watch

An experiment was conducted in China to develop guidelines for the mulching drip irrigation of commercial muskmelon crops. Three sets of factors were laid out in rows to give a three × three factorial design. First, plastic covers were placed over the entire growing area (rows and inter-rows, or full), over the rows (half), or no plastic applied (none). Second, there was one irrigation pipe per row (T1), three pipes for four rows (T3/4), or one pipe for two rows (T1/2). Finally, the plants were irrigated when the soil water content fell to 60%, 70%, or 80% of field water capacity (FC). Information was collected on net CO2 assimilation (Pn), plant growth, and yield. Overall, maximum Pn occurred with half plastic covering, one irrigation pipe for two rows, and irrigation at 80% FC. Plant fresh weight was higher with half plastic covering, one irrigation pipe per row, and irrigation at 70% or 80% FC. Yield was higher with half plastic covering, and irrigation at 70% or 80% FC. There were only small differences in the yield across numbers of irrigation pipes. These results suggest that overall productivity was better with plastic covers over the rows and irrigation at 70% or 80% FC. Differences in productivity with different numbers of irrigation lines per row were small.