ISHS Acta Horticulturae 646: International Symposium on Irrigation and Water Relations in Grapevine and Fruit Trees
EFFECTS OF DRIP IRRIGATION ON THE AMOUNT OF WATER AND WETTED SOIL VOLUME ON "WASHINTON NAVEL" ORANGE YIELD |
| Authors: | M. García Petillo, L. Puppo, A. Chamorro, R. Hayashi |
| Keywords: | citrus, irrigation, soil wetted volume, microirrigation, irrigation management, orangeCitrus sinensis |
| Abstract:
A properly designed and operated drip irrigation system has to supply the water amount required by the crop and should also wet enough soil volume. During a five year period, the effect of both variables on "Washington Navel" orange yields were researched, under the edaphic and climatic conditions of Uruguay. Five treatments were applied; four of them (T1, T2, T3 and T4) were increasing irrigation amounts (0, 50%, 100% and 150% of the estimated ET). To apply these treatments, one irrigation drip line per tree row, with drippers, of 2, 4 and 6 l h-1 capacity, separated 1 m apart were used for treatments 2, 3 and 4, respectively. The remaining treatment (T5) received the same amount of water as T3, but with two drip lines spaced 1 m apart per tree row, and with 2 l h-1 drippers. Soil volume wetted by T3 was about 20% of the soil volume below the rows (4 m width). In T5, the wetted below row soil volume was 35%. Taking an average over the studied period, with two rather dry, one "normal", and two very rainy years, there was a highly statistically significant effect of irrigation amount, with yields of 100, 117, 127 and 128 kg tree-1 for treatments 1 to 4, respectively. The treatment with greater soil wet volume (T5) yielded 134 kg tree-1. Despite the fact that T5 didn't differ significantly from T3, each year it showed a clear trend to higher yields. Fruit size showed the same trend as total yield. | |
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