Double lateral designed for operating under single line conditions in irrigated citrus plantation in brazil

Abstract

The world largest citrus plantations are located in Sao Paulo State, Brazil. Some of them are irrigated by drip systems, especially when it is expected a rising in prices from orange market or, for the local reality of production, when the plants are in the initial stages of development. By projecting the irrigation for the later stages, the systems are generally designed to support two laterals per row of trees, aiming to greaten the wet bulb diameter and hence the water necessity of these trees. However, it has been checked in the practice of the farms that, from the same doubled line design, there is an implementation of one single line in the initial stages, given that the water requirements are smaller and it is possible to reduce costs. This work reveals that, before adopting this idea, it is essential to simulate the possible occurrences, especially under situations of laterals lying on some degrees of declivity. Simulations were done for conventional and compensating emitters. The pressure variation is affected in both of cases under accentuated declivities (i.e., 5% or 7,5%) and there are possibilities of ruptures for laterals with compensating emitters under these conditions.