Abstract
Despite the tremendous advances made in agricultural mechanization, the precise task of thinning lettuce seedlings is still performed by crews of workers using hand hoes in commercial field production. Finding laborers to perform this physically demanding work is becoming increasingly difficult. The objectives of this project were to 1) develop an automated machine for thinning lettuce to improve labor resource use efficiency and 2) evaluate the performance of the machine as compared to conventional methods. The prototype machine was developed to thin lettuce seedlings nominally planted 2 inches apart to the desired final plant spacing of 10-11 inches. The device is principally comprised of a machine vision system for detecting lettuce seedlings and their location and a system for intermittently delivering an herbicidal spray to kill plants. When tested at a travel speed of 1.5 mph, automated machine thinning performance in terms of plant spacing, plant spacing uniformity, number of live plants per acre and time required for a hand laborer to remove plants missed during thinning was not significantly different from hand thinning when plants were thinned using sulfuric acid (10% v/v), paraquat (1.3 pt a.i./acre) or vinegar (20% v/v) (P = 0.05). Automated machine thinning performance after hand weeding was also not significantly from hand thinning in terms of plant spacing, COV in plant spacing and plant stand when plants were sprayed with any of the five chemicals tested. Based on these results, it was concluded that the automated machine was able to reliably control spray delivery such that plants were selectively thinned to the desired final plant spacing. Yields were not significantly affected when plants were thinned using the automated machine with any of the herbicidal spray solutions tested indicating that the machine was able to deliver herbicidal spray with sufficient accuracy that seedlings are not injured. Further machine development is needed so that a unit more suitable for commercial production can be tested on a large scale to confirm these results and to determine whether such a system is viable for use in commercial production.
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Claims 7
Claim · model-written summary
Automated thinning with sulfuric acid had thinning performance statistically comparable to hand thinning.
- Taxon
- Lettuce
Lactuca sativat0 - Treatment
- sulfuric acid (10% v/v)e0
- Outcome
- plant spacing, plant spacing uniformity, number of live plants per acre and time required for a hand laborer to remove plants missed during thinninge0
- Direction
- not significantly differente0
- Comparator
- hand thinninge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“automated machine thinning performance in terms of plant spacing, plant spacing uniformity, number of live plants per acre and time required for a hand laborer to remove plants missed during thinning was not significantly different from hand thinning when plants were thinned using sulfuric acid (10% v/v)”
t0“Lettuce”
Claim · model-written summary
Automated thinning with paraquat had thinning performance statistically comparable to hand thinning.
- Taxon
- LettuceLactuca sativat0
- Treatment
- paraquat (1.3 pt a.i./acre)e0
- Outcome
- plant spacing, plant spacing uniformity, number of live plants per acre and time required for a hand laborer to remove plants missed during thinninge0
- Direction
- not significantly differente0
- Comparator
- hand thinninge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“automated machine thinning performance in terms of plant spacing, plant spacing uniformity, number of live plants per acre and time required for a hand laborer to remove plants missed during thinning was not significantly different from hand thinning when plants were thinned using sulfuric acid (10% v/v), paraquat (1.3 pt a.i./acre)”
t0“Lettuce”
Claim · model-written summary
Automated thinning with vinegar had thinning performance statistically comparable to hand thinning.
- Taxon
- LettuceLactuca sativat0
- Treatment
- vinegar (20% v/v)e0
- Outcome
- plant spacing, plant spacing uniformity, number of live plants per acre and time required for a hand laborer to remove plants missed during thinninge0
- Direction
- not significantly differente0
- Comparator
- hand thinninge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“automated machine thinning performance in terms of plant spacing, plant spacing uniformity, number of live plants per acre and time required for a hand laborer to remove plants missed during thinning was not significantly different from hand thinning when plants were thinned using sulfuric acid (10% v/v), paraquat (1.3 pt a.i./acre) or vinegar (20% v/v)”
t0“Lettuce”
Claim · model-written summary
Following hand weeding, automated thinning showed no significant difference from hand thinning in spacing or stand for any of five sprays.
- Taxon
- LettuceLactuca sativat0
- Outcome
- plant spacing, COV in plant spacing and plant stande0
- Direction
- not significantlye0
- Qualifier
- after hand weedinge0
- Comparator
- hand thinninge0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Automated machine thinning performance after hand weeding was also not significantly from hand thinning in terms of plant spacing, COV in plant spacing and plant stand when plants were sprayed with any of the five chemicals tested”
t0“Lettuce”
Claim · model-written summary
The machine reliably delivered selective sprays to achieve the desired final plant spacing.
- Taxon
- LettuceLactuca sativat0
- Outcome
- selectively thinned to the desired final plant spacinge0
- Value
- 10-11 inchese1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“the automated machine was able to reliably control spray delivery such that plants were selectively thinned to the desired final plant spacing”
e1“desired final plant spacing of 10-11 inches”
t0“Lettuce”
Claim · model-written summary
Automated thinning with the tested spray solutions did not significantly affect lettuce yield.
- Taxon
- LettuceLactuca sativat0
- Treatment
- automated machine with any of the herbicidal spray solutions testede0
- Outcome
- Yieldse0
- Direction
- not significantly affectede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Yields were not significantly affected when plants were thinned using the automated machine with any of the herbicidal spray solutions tested”
t0“Lettuce”
Claim · model-written summary
Further machine development and large-scale commercial testing are recommended.
- Taxon
- LettuceLactuca sativat0
- Outcome
- Further machine development is needede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Further machine development is needed so that a unit more suitable for commercial production can be tested on a large scale to confirm these results and to determine whether such a system is viable for use in commercial production”
t0“Lettuce”
The same questions in other papers
herbicide · yield · Lactuca sativa (garden lettuce)Positive and negative results
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- positive
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See all 38 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.