Effects of irrigation at critical stages of ontogeny of the banana cv. ‘Robusta’ on growth and yield
Keywords:Banana, Yield, Irrigation
AbstractIrrigation of banana stands during the first and second 60-day periods after planting had no significant effects on final pseudostem height, girth and final yield in comparison with the non-irrigated control. Irrigation during the 180 days after planting significantly (each at P = 0.01 level) increased pseudostem height and girth over the nonirrigated control. Bunches from the former treatment took significantly less time (P = 0.01) to emerge and had significantly more hands (P = 0.01) and fingers (P = 0.01) than the non-irrigated plants. Irrigation during the third 60-day period significantly increased pseudostem height and girth, (each at P = 0.01 level) reduced the time interval from planting to bunch emergence (P = 0.01) and produced signicantly more hands (P = 0.01) and fingers (P = 0.01) per bunch than the non-irrigated plants. Moreover, measurements for these parameters were larger than for the treatment irrigated during 180 days, although only significantly larger (P = 0.05) for the number of fingers per bunch. The strong negative correlation (r = -0.80) for average soil water potential over 10-day intervals demonstrated the strong influence of soil moisture stress on pseudostem elongation. Irrigation always increased the uptake of nitrogen but this was quickly offset by the apparently high leaching losses under continuous irrigation. The significantly high level of leaf nitrogen content during floral initiation and early bunch differentiation strongly suggests that a non-limiting supply of water and nitrogen at this time would give the best cost/benefit result.