Cayenne pepper fruit adhere tightly to the calyx/receptacle, increasing the cost of hand harvest and restricting mechanical harvest. Eight (8) cayenne pepper genotypes were selected from field observations to characterize fruit detachment forces(FDFs) and examine potential relationships between FDF and other fruit parameters. A preliminary greenhouse experiment revealed two genotypes with consistently lower FDFs and two with consistently higher FDFs over several progressive harvest. A field experiment confirmed these characteristics. No correlation between any fruit parameter and FDF was found to be consistent over the genotypes studied.
Kay P. Gersch, Carl E. Motsenbocker, and Gregory A. Lang
Justin R. Morris
Interest in grape juice has risen as the public becomes more aware of natural foods and the specific evidence of healthful benefits of grapes. Among major preharvest conditions that influence quality of grape juice are climate, soil, cultivar, vineyard management, and maturity. Each of these factors exerts its own influence, but complex interactions among these factors must be recognized. For mechanically harvested juice grapes, cultivar takes on special importance to quality and yield as do the production system, harvest machines, postharvest handling systems, and processing method. Grape juice composition has been extensively studied, and production and processing methods have improved over the years. The following discussion deals with developments in grape juice production.
Reuben B. Beverly, Allen W. Byous, and Tommy Nakayama
Vegetable soybean (Glycine max L.) represents a potential high-value specialty crop for small farmers in the southern Piedmont region of the United States; practical and affordable mechanical harvest technology will facilitate production. A trial planting of vegetable soybean was used to test the ability of a commercial one-row harvester used currently for snap bean and lima bean production systems to harvest soybean. The upright growth habit and excessive herbage of vegetable soybean necessitated harvest in two passes over the row, which produced in-pod yield of 7050 lb/acre (7900 kg ha-1). Adaptation of this technology has the potential to facilitate development of a vegetable soybean production industry.
Blair Buckley and Katharine Pee
Ease of pod detachment is an important consideration when selecting cultivars for mechanical harvest at the mature-green stage. Sixteen southernpea cultivars and breeding lines were evaluated for pod detachment force. The cultivars varied in pod detachment force. MN-13 had the largest detachment force with a measurement of 2.18 kg. Royal Cream had the smallest detachment force with a measurement of 1.2 kg. Pod length, pod diameter, pod weight, basal pod fill, and length of peduncle synapse was recorded for each pod sampled for detachment force. There was no clear association between pod detachment force and the five traits.
Our efforts are concentrated on quantifying spatial variability for tree vigor, yield, fruit quality, and profit. We use aerial photography to quantify tree vigor. For mechanically harvested hazelnuts, a prototype weight based yield monitor has been evaluated. This approach may also work for quantifying yield in mechanically harvested sweet cherries. For perishable hand-harvested crops, the GPS locations for individual bar-coded bins can be used to calculate bin density and estimate yield. Bar codes can also be used to track quality in the packing-house. Since profit depends on yield, size, and packout, it is not always intuitively obvious which areas of an orchard are most profitable. Defining which areas are most profitable, and identifying the problems associated with low-profit areas (poor yield, small size, storage loss, bruising, culls, etc) is an important step. Identifying areas producing fruit that stores poorly is a high priority. An evaluation of low- and high-profit areas may lead to alternate management plans. Anything from investing in more supervision of harvest labor and initiating different pruning regimes to attempts to obtain more uniform tree vigor can be evaluated. By delineating test areas with GPS boundaries, profit data in future years can quantify the success of different management approaches. For example, concentrating expensive inputs on the portion of trees (30% of total) that may produce the majority of gross returns, while not even harvesting fruit from regions (1% to 5% of total) that consistently produce poor quality fruit may be a sound strategy.
Gregory E. Welbaum
Seed production in the family Cucurbitaceae is more complicated than in dry-seeded grain crops because seeds mature within a moist fruit and are often held at high moisture content for several weeks before seed harvest. Muskmelon (Cucumis melo L.), a member of this family, was used as a model system to contrast seed development with crops that are dry at maturity. A detailed time course for `Top Mark' fruit and seed development is presented based on previous studies. In muskmelon fruit, precocious germination is inhibited osmotically by the low water potential of the surrounding fruit tissue. Muskmelon seeds exhibit primary dormancy that affects viability very early in development but has a greater effect on seed vigor and is removed by afterripening during dry storage. Osmotically distended or fish-mouth seeds are dead seeds that occur in cucurbit seed lots after aging kills the embryo without disrupting the semipermeable endosperm that completely surrounds and protects the embryo. Cucurbit seed crops should be harvested before the onset of fruit senescence to prevent aging of the seeds inside. Open-pollinated cucurbit seed crops are frequently once-over mechanically harvested. Mechanical harvesting combines seeds from many stages of development into a single seed lot, which may adversely affect quality and increase seed to seed variability. Hand harvesting cucurbit fruit at the optimal stage of development could improve seed quality in some instances but is more costly and time consuming and would increase production costs.
Troy A. Larsen* and Christopher S. Cramer
Current onion varieties that are grown in New Mexico were developed for hand harvesting and not for mechanical harvesting. In order for onion production in New Mexico to remain a viable commodity, firmer onion varieties need to be developed for mechanical harvesting. In this study, bulb firmness of onions was examined in short and intermediate-day onion entries comparing a qualitative `finger pressure' method with a digital FFF-series durometer. After harvesting and curing of the onion bulbs, dry outer scales were removed before durometer measurements were taken at two perpendicular points on the vertical center axis of the bulb. Following the durometer measurements, bulb firmness was rated by `finger pressure' applied to multiple points on the vertical center axis. For intermediate and late-maturing entries, durometer measurements and firmness rating were positively correlated in a strong fashion (r = 0.77 to 0.87). Early maturing entries, NMSU 02-25 and NMSU 02-03 both had high durometer averages and firmness ratings. `NuMex Crimson' and `NuMex Crispy' had the highest durometer averages and firmness ratings among intermediate maturing entries while `NuMex Solano' and NMSU 01-06 had the highest among late maturing entries. From our results, the durometer can be useful in providing a quantifiable measure of bulb firmness.
Ursula K. Schuch, Leslie H. Fuchigami, and Mike A. Nagao
Unsynchronized flowering and fruit ripening of coffee prohibits mechanical harvesting and results in high labor costs. Coffee (C.arabica c. Guatemalan) trees were sprayed at the beginning of the 1988 and 1989 flowering season with solutions of benzyladenine (BA), gibberellic acid GA3 (GA), and Promalin (PR) or were pruned in 1988 to determine effects on synchronizing flowering and ripening. Growth regulators affected the time to flowering and harvesting compared to the control, however, treatment effects were dependent on the time of growth regulator application. Application of PR and GA at 100 mg/l in Jan 1988 shortened the average days to flowering by 16 and 13 days, and the average days to harvest by 15 days compared to the control. Pruning of three apical nodes of primary lateral branches in Feb 1988 caused delays in flowering, reduced flower and fruit number per tree, and caused branch dieback.
Three different types of pickling cucumber (Cucumis sativus) were planted in the field with 4 replications in a randomized complete block design. The cultivars selected were standard leaf, “little leaf”, and standard X “little leaf” crosses. The growth of populations of cucumber fruit from each of the three types was measured over a 14 day period which included the optimum harvest date for mechanically harvesting the fruit. A plant sample one m2was randomly selected, the population of fruit diameter and length in each sample was measured daily. The standard leaf types were the first to reach a harvest date. The standard X “little leaf” crosses were next, followed by the “little leaf” cultivar. The differences in days to harvest could be 14 days or more between the standard and “little leaf types. The distribution of fruit by number and volume will be presented. Using this information a harvest date for maximum economic return can be predicted for each of the cultivars.
JALORO is a multiple virus resistant (MVR) open pollinated pepper cultivar developed by Texas Agricultural Experiment Station at Weslaco. This pungent, cylindrical (fruit with blunt end) yellow jalapeño cultivar possesses high levels of resistance to several isolates of Texas tobacco etch virus, potato virus Y, pepper mottle virus, tobacco ringspot virus, cucumber mosaic virus and tobacco mosaic virus. The genotype combines desirable characteristics of commercial hot yellow wax `Caloro'(TMR), the jalapeño genome from `Jalapeño-L' and Jalapeño 1158, and MVR genes from AC2207 (hot serrano) and PI 264280. `Jaloro' has the ability to set fruit at temperatures above 35C. It has a concentrated flower setting habit, sets fruits earlier and matures more uniformly than `Caloro'. The singlestem plant will support a heavy set of large thick yellow jalapeño fruit which can be mechanically harvested. It is suited for fresh market in salads or as a processed product, pickled whole, sliced as `nacho' rings or diced in picante sauces.