文献类型： 外文期刊

作者： Chu, Qingquan ¹ ; Liu, Jiangang ¹ ; Bali, Khaled ² ; Thorp, Kelly R. ³ ; Smith, Richard ⁴ ; Wang, Guangyao (Sam) ⁵ ;

作者机构： 1.China Agr Univ, Coll Agron & Biotechnol, 2 West Yuanmingyuan Rd, Beijing 100193, Peoples R China

2.Univ Calif Cooperat Extens, 1050 East Holton Rd, Holtville, CA 92250 USA

3.USDA ARS, US Arid Land Agr Res Ctr, 21881 North Cardon Lane, Maricopa, AZ 85138 USA

4.Univ Calif Cooperat Extens, 1432 Abbott St, Salinas, CA 93901 USA

5.Shanxi Acad Agr Sci, Inst Cotton Res, 118 Huanghe Rd, Yuncheng 044000, Shanxi, Peoples R China

6.Bridgestone Amer, Agr Operat, 4140 West Harmon Rd, Eloy, AZ 85131 USA

关键词： Lactuca sativa;automated thinner;hand thinning;plant uniformity;lettuce yield

期刊名称：HORTTECHNOLOGY （ 影响因子：1.087； 五年影响因子：1.059 ）

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收录情况： SCI

摘要： The low availability and high cost of farm hand labor make automated thinners a faster and cheaper alternative to hand thinning in lettuce (Lactuca-sativa). However, the effects of this new technology on the uniformity of plant spacing and size as well as crop yield are not proven. Three experiments were conducted in commercial romaine heart lettuce fields in 2013 and 2014 in Imperial Valley, CA, to compare the effects of automated thinning and hand thinning on uniformity of in row spacing, plant size, and crop yield. Overhead images taken at 1 week after hand thinning indicate that thinning 8 to 11 days earlier by automated thinners did not affect plant size compared with the hand thinning treatment. However, lettuce plants in the automated thinning treatment were larger than plants in the hand thinning treatment 2 to 3 weeks after hand thinning. Automated thinners increased the uniformity of in-row spacing, increased the percentage of plants with the desired in-row spacing of 24 to 32 cm, and almost completely removed plants with an undesirable in-row spacing of 4 to 20 cm. As a result, individual lettuce plant weight and heart weight from the automated thinning plots was significantly greater and plants were more uniform compared with the hand thinned plants. Despite increases in lettuce plant size and uniformity in all three experiments, yield benefits of automated thinning were only significant in one of the three experiments due to larger plant populations resulting from hand thinning. This study suggests that automated thinning increases lettuce plant size and uniformity and makes it possible for growers to increase plant population and crop yield by optimizing in-row spacing.