Does furrow irrigation system improve yield and water use efficiency of Kinnow mandarin (citrus reticulate blanco)?

Abstract

In Pakistan, orchards are irrigated using flood irrigation system that is considered sub-economical regarding water use efficiency. Considering the importance of natural water resources, there was a need to devise the method of applying irrigation water that would save water consumption, environmentally friendly and easily adopted by the growers. Thus, a research trial was conducted at Citrus Research Institute, Sargodha, Pakistan on 0.41 ha area of Kinnow mandarin. The total area was divided into two parts, half of the area was used for furrow irrigation system and the remaining half was used for flood irrigation system. Tensiometers were installed in the soil in furrow and flood irrigation system to assess the moisture condition in the soil. Irrigations were applied when tensiometer readings reached 40 centibars. The quantity of water used for irrigation was measured with a flume meter and then percentage of water saving was calculated. The study revealed that furrow irrigation system significantly improved the number of fruits per tree (1153), fruit yield (179.89 kg per plant) and juice percentage (48.38%) compared with flood irrigation system where the number of fruits per tree were711, fruit yield was 110.61 kg per plant and juice percentage was 46.31%. However, TSS/acidity ratio, and peel and rag percentage were not affected by the different irrigation systems. In furrow irrigation system 24 irrigations were applied per year with average water saving of 46.14% and water use efficiency (WUE) was 4.58 kg m-3 whereas in flood irrigation system average numbers of irrigations were 15 per year and WUE was 2.34 kg m-3only. Therefore, furrow irrigation system is recommended for the citrus growers to improve the water use efficiency, yield and fruit quality of Kinnow mandarin.