Automated solutions for fresh market fruit and vegetable harvesting have been studied by numerous researchers around the world during the past several decades. However, very few developments have been adopted and put into practice. The reasons for this lack of success are due to technical, economic, horticultural, and producer acceptance issues. The solutions to agricultural robotic mechanization problems are multidisciplinary in nature. Although there have been significant technology advances during the past decade, many scientific challenges remain. Viable solutions will require engineers and horticultural scientists who understand crop-specific biological systems and production practices, as well as the machinery, robotics, and controls issues associated with the automated production systems. Focused multidisciplinary teams are needed to address the full range of commodity-specific technical issues involved. Although there will be common technology components, such as machine vision, robotic manipula-tion, vehicle guidance, and so on, each application will be specialized, due to the unique nature of the biological system. Collaboration and technology sharing between commodity groups offers the benefit of leveraged research and development dollars and reduced overall development time for multiple commodities. This paper presents an overview of the major horticultural and engineering aspects of robotic mechanization for horticultural crop harvesting systems.
T. Burks, F. Villegas, M. Hannan, S. Flood, B. Sivaraman, V. Subramanian, and J. Sikes
David E. Yarborouph
Hand raking was compared to a non-mechanized machine and to two self propelled harvesters for yield and harvest time. Experimental design was split-plot replicated six times with four harvesters/plot with each raker using each machine in each plot. The machines were operated adjacent to one another. Hand raking resulted in the highest yield recovery of all harvesters. Average yield varied by raker from a high of 4831 kg/ha to a low of 3884 kg/ha. The Bluevester harvester recovered 91% of hand harvest and was 1.6 times faster than hand raking while the Darlington machine harvested one half of hand harvest in one quarter of the time. The Easy Pick recovered 81% of hand harvest but was twice as fast. Mechanical harvesters took less time but recovered fewer berries. A economic analysis is needed to fully evaluate these machines.
Lawrance N. Shaw
The use of containerized transplants will increase in the future because of greater survival rates and improved yields. Many transplant operations are already mechanized. Fully automatic field transplanting is highly feasible in the future for several vegetable crops and may become a common practice with most commercial crops. Technology is developing that uses the greenhouse growing trays as magazines to be loaded into the transplanting machines. Automatic field transplanters will then set plants into the soil at rates of 3 to 4 per second. To accomplish this, the following are required: highest quality uniform seedlings; greater seedling tolerance to handling stresses; no dead or missing plants in transplant trays; standardized cell containers; and precise cell arrangement to allow whole rows of plants to be mass removed simultaneously to reach the highest transplanter machine capacity. Plant production and greenhouse growing systems need to be modified to facilitate automatic field transplanting.
Steven C. Adams
Seed vigor has a very subtle effect on the productivity of greenhouses producing vegetable transplants, celery, cauliflower, lettuce, etc. and on todays highly mechanized automatic or semi-automatic transplanting operations. As greenhouse production technology moves from traditional bare root to plug/tray growing systems and as automatic and semi-automatic transplanting operations increase in number, the impact of poor seed vigor is realized.
Measures to mitigate the impact of poor seed vigor in the nursery are: Seed density grading; increased growing cycle in the nursery, hand culling or replanting. Measures to mitigate the impact of poor seed vigor in automatic transplanting operations: increase the number of people following the planter to replace poor vigor plants; use hand fed transplanters.
The wild lowbush blueberry (Vaccinium angustifolium) in Maine and the Maritime Provinces of Canada has been managed for hundreds of years, first by native Americans and more recently by European settlers. Early production practices consisted of periodic free burns over large tracts of land for pruning and weed control. New practices have centered on intensifying production and include flail mow pruning, mechanical harvesting, herbicides for weed control, and monitoring pest populations. Most recently, land smoothing for improved mechanization and leaf sampling for nutrient analysis have been adopted. Land smoothing allows producers with rough land to use labor-saving equipment and apply pesticides more precisely. Leaf analysis predicts nutrient availability much more accurately than soil testing.
Stephen M. Southwick and Kitren G. Weis
Selection and propagation of rootstocks for apricot (Prunus armeniaca L.) varies worldwide in response to local climate, soils, and cultivars. In this paper we review published research focused on these local selective practices. Additionally, we review the current development of apricot rootstocks and suggest new research avenues to satisfy the needs of commercial apricot growers. Rootstocks are identified by their responses to biotic and environmental stresses, with specific adaptive characteristics that enable establishment and production under unique zonal ecologies. Desirable characteristics include scion compatibility, adaptation for heavy or wet soils, pest and disease resistance, ease of propagation, control of vegetative vigor, effects on dormant season physiology of the scion, precocity, fruit quality, and productivity. Interstocks that can overcome incompatible rootstock-scion combinations are covered. As worldwide consumer demand for apricots increases with improved apricot cultivars, rootstock selections and propagation must be developed for niche fruit with specific characteristics, intensive production systems, mechanized harvest, and marginal site selection.
Bruce W. Wood and Deane Stahmann
An ever increasing cost:price squeeze on the profitability of pecan (Carya illinoinensis) farming is driving a search for alternate husbandry approaches. `Wichita' and `Western' trees maintained at relatively high tree population density, by mechanized hedge pruning and topping, produced greater nut yield than an orchard treatment in which tree population density was reduced by tree thinning (144% for `Wichita' and 113% for `Western Schley'). Evaluation of three different hedge pruning strategies, over a 20-year period, identified a discrete canopy hedge pruning and topping strategy using a 2-year cycle, as being superior to that of a discrete canopy hedge pruning and topping strategy using an 8-year cycle, but not as good as a continuous canopy hedge pruning and topping strategy using a 1-year cycle. An evaluation of 21 commercial cultivars indicated that nut yields of essentially all cultivars can be relatively high if properly hedge pruned [annual in-shell nut yields of 2200 to 3626 lb/acre (2465.8 to 4064.1 kg·ha-1), depending on cultivar]. Comparative alternate bearing intensity and nut quality characteristics are reported for 21 cultivars. These evaluations indicate that pecan orchards can be highly productive, with substantially reduced alternate bearing, when managed via a hedge-row-like pruning strategy giving narrow canopies [3403 lb/acre (3814.2 kg·ha-1) for `Wichita' and 3472 lb/acre (3891.5 kg·ha-1) for `Western Schley']. North-south-oriented (N-S) hedgerows produced higher yields that did east-west (E-W) hedgerows (yield for N-S `Wichita' was 158% that of E-W trees and N-S `Western Schley' was 174% that of E-W trees).
These data indicate that mechanized hedge pruning and topping offers an attractive alternative to the conventional husbandry paradigm.
J.O. Payero, M.S. Bhangoo, and J.J. Steiner
1 Forrner Graduate Research Assistant. 2 Professor. Dept. of Plant Science and Mechanized Agriculture, California State Univ., Fresno, CA 93740. 3 Research Agronomist. Contribution of California Agricultural Technology Institute, California State
James W. Shrefler, Charles L. Webber III, and Otis L. Faulkenberry III
Producers of organic vegetables often report that weeds are a troublesome production problem. It has been documented that corn gluten meal (CGM), a by-product of the wet-milling process of corn, is phytotoxic. As a preemergence or preplant-incorporated herbicide, CGM inhibits root development, decreases shoot length, and reduces plant survival of weed or crop seedlings. The development of a mechanized application method for CGM and the ability to apply the material in a banded pattern would increase its potential use in organic vegetable production, especially in direct-seeded vegetables. Therefore, the objective of this research was to develop a mechanized method to uniformly apply CGM to the soil surface in either a broadcast or banded pattern. An applicator was assembled using various machinery components (fertilizer box, rotating agitator blades, 12-volt motor, and fan shaped gravity-fed row banding applicators). The equipment was evaluated for the application of two CGM formulations (powdered and granulated), three application rates (250, 500, and 750 g·m–2), and two application configurations (solid and banded). Field evaluations were conducted during Summer 2004 on 81-cm-wide raised beds at Lane, Okla. Differences between CGM formulations affected the flow rate within and between application configurations. The granulated formulation flowed at a faster rate, without clumping, compared to the powdered formulation. While the CGM in the banded configuration flowed faster than the solid application. It was determined that the CGM powder used with the solid application configuration was inconsistent, unreliable, and thus not feasible for use with this equipment without further modifications. These evaluations demonstrated the feasibility of using equipment, rather than manual applications, to apply CGM to raised beds for organic weed control purposes. Several design alterations may increase the efficiency and potential usefulness of this equipment. If research determines equivalent weed control efficacy between the two CGM formulations, the granulated formulation would be the preferred formulation for use in this equipment. This equipment would be useful for evaluating the benefits of banded applications of CGM for weed control efficacy and crop safety for direct seeded vegetables.
M. ODA, K. Tsuji, K. Ichimura, and H. Sasaki
Horizontal grafting, in which scion and rootstock are cut and grafted horizontally at the hypocotyls, is essential for mechanization of grafting. The present studies have been conducted to improve the survival ratio and the growth of cucumbers grafted on Cucurblta spp. through horizontal grafting at the hypocotyls. The survival ratio of `Nankyoku 2' (Cucumis sativus) which had six vascular bundles at the hypocotyl was different when it was grafted on `Unryuh' or 'Kongoh' (C. moschata), six vascular bundles. The survival ratio of the scion grafted on `Dairoku' (C. maxima) which had twelve vascular bundles was the lowest. It was found that the survival ratio inversely correlated with the difference in the diameters of the hypocotyls of the scion and the rootstock. Fresh and dry weights of survival scions on `Unryuh' and `Kongoh' were almost same and heavier than that on `Dairoku'. It is suggested that minimizing the differences in the diameters and the numbers of the vascular bundles of the hypocotyls between the scion and the rootstock promotes the survival ratio and the growth of cucumbers which are horizontally grafted on Cucurbita spp..