Horticulture and Crop Science Department, Cal Poly State University, San Luis Obispo, CA 93407, USA.
J Econ Entomol. 2012 Aug;105(4):1293-301. doi: 10.1603/ec11321.
We conducted studies in a Paso Robles, CA, grape (Vitis vinifera L.) vineyard in 2002 and 2003 to estimate the impact of regulated deficit irrigation (RDI) intensity and duration on western grape leafhopper, Erythroneura elegantula Osborn. Treatments were based on deficit intensity, 50 and 25% of standard irrigation (moderate and severe deficits, respectively), and deficit duration, 3 or 6 wk time, initiated at the grape phenological stage of berry set. The standard irrigation served as the control, and was intended to be as close to 100% of evapotranspiration (1.0 ETc) for grape in this area. Each week we took counts ofleafhopper nymphs and estimated stomatal conductance, and at the end of each leafhopper generation we counted live, hatched and parasitized leafhopper eggs. Second generation leafhopper nymphal density was lowered by about 38 and 70% in 2002 and 2003, respectively, but in 2003 only the severe deficit had a negative effect on the third generation. This same pattern was seen in oviposition: second generation egg density was reduced by about 44% in the deficit treatments, but in the third generation only the severe deficit was lower than the control. There was little difference between the 3 vs. 6 wk duration in nymphal or egg density. The differences among treatments in second generation peak nymphal density were greater than the differences in second generation hatched eggs, suggesting that in addition to egg mortality, the deficits also affected nymphal mortality. Management strategies for maintaining leafhopper density low in the second generation and third generations include maintaining a sub-1.0 ETc irrigation strategy after the main RDI period, or reinstating the RDI to correspond to the third generation.
我们于 2002 年和 2003 年在加利福尼亚州帕索罗布尔斯的一个葡萄（Vitis vinifera L.）葡萄园进行了研究，以估计有规律的亏缺灌溉（RDI）强度和持续时间对西部葡萄叶蝉（Erythroneura elegantula Osborn）的影响。处理方法基于亏缺强度，50%和 25%的标准灌溉（分别为中度和重度亏缺）以及亏缺持续时间，即从葡萄物候期浆果设定开始的 3 或 6 周时间。标准灌溉作为对照，旨在接近该地区葡萄的 100%蒸散量（1.0 ETc）。每周我们对叶蝉若虫进行计数，并估计气孔导度，在每一代叶蝉结束时，我们对活的、孵化的和寄生的叶蝉卵进行计数。在 2002 年和 2003 年，第二代叶蝉若虫密度分别降低了约 38%和 70%，但在 2003 年，只有重度亏缺对第三代叶蝉有负面影响。在产卵方面也出现了同样的模式：在亏缺处理中，第二代卵密度降低了约 44%，但在第三代中，只有重度亏缺低于对照。在若虫或卵密度方面，3 周与 6 周持续时间之间几乎没有差异。第二代若虫高峰期密度方面，处理之间的差异大于第二代孵化卵的差异，这表明除了卵死亡率外，亏缺还影响若虫死亡率。在第二代和第三代保持低叶蝉密度的管理策略包括在主要 RDI 期后保持低于 1.0 ETc 的灌溉策略，或恢复 RDI 以对应第三代。
