A completely mechanized system for production, harvesting and handling strawberries (Fragaria × anassa Duch.) for processing is described. Pre-harvest cultural factors, including bed preparation, plant population, harvest date and clonal evaluation and adaptability to mechanical harvesting, were studied for 4 years. ‘Cardinal’, ‘Earlibelle’, and Arkansas breeding line A-5344 were well suited for once-over mechanical harvesting under Arkansas conditions considering yield, quality, and organoleptic evaluation. Plant population densities in the matted row system used in this study generally had little effect on yield or quality, unless a clone was of low vigor and poor runner plant producer. As harvest date was delayed, quality and useable yield often decreased. However, a minimum of a 6 day harvest period for mechanical harvesting existed for the cultivars tested. The results of this study indicate that once-over mechanical harvesting of strawberries is feasible when the proper cultivar is grown on properly shaped beds with good cultural practices and adequate postharvest handling procedures.

The interactive effects of aeration rate, storage temperature, harvest maturity, and storage duration on respiration and ripening of tomato fruits (Lycopersicum esculentum var. Roma) were studied. Slow aeration rate strongly reduced the climacteric but did not affect ripening. Low Two replications were conducted. Each sample (15 fruits, about 1 kg) was enclosed in a 3.78-liter jar with gas flow connections. Rates of CO2 evolution were determined daily for 16 consecutive days. In preliminary experiments we observed that both 02 uptake and CO2 evolution were suppressed by slow air flow rates. The suppressed respiration due to slow air flow rate was not accompanied by a shift in the respiratory quotient. Therefore, only CO2 evolution was measured as an index of respiration in the present study.On the 4th, 8th, 12th, and 16th days of storage one sample was removed from each experimental condition for determination of firmness, color, and the concentration of CO2 in the internal atmosphere of the fruits.Respiration. CO, was determined by gas chromatography. A rubber septum was present in the effluent line, and samples were withdrawn into a gas-tight syringe. The 1-ml samples were chromatographed on a column of 60 to 80 mesh silica gel, 24 inches long and one-fourth inch in diameter. Helium was used as the carrier gas at 13 psi, and the column and thermal conductivity detector were maintained at 130 C. CO, production rates were calculated by the formula of Biale (1).Analysis of Internal Gas Atmosphere. Five fruits from each treatment were removed from the respiratory chamber and immediately submerged under water. A hypodermic needle was inserted approximately 1 cm into the core tissue of the stem scar, and a 0.65 ml sample was withdrawn. Samples of 0.5 ml were analyzed under the same chromatographic conditions previously described.Other Analyses. Firmness of five fruits was determined with an Asco firmness meter. A 1 kg prestress load was applied for 10 sec, and a stress load of 1.5 kg was applied for 30 sec (6). All 15 fruits of each sample were frozen intact and later thawed and pulped through a 0.028 mesh screen in a laboratory pulper. Color of the deaerated samples was determined with a Gardner color difference meter standardized with a standard having the values: L, 24.1; a, 24.2; b, 11.6. The data were analyzed by statistical methods of Snedecor (13). RESULTS AND DISCUSSIONTemperature and air flow rate were the strongest variables affecting respiration. Analysis of variance revealed their effects to be independent. All experimental effects were described by two second order interactions: air flow rate X maturity X days of storage and temperature X maturity X days of storage. Certain regression analyses were also conducted.Effect of Air Flow Rate on Respiration and Ripening. The air flow rates which were used in this study were intentionally quite slow. Especially at the slower air flow rate, the system is never in complete equilibrium. We believe that this does not introduce error of sufficient magnitu...

The response of an Arkansas breeding-line 5344 of strawberry (Fragaria X ananassa Duch.) to 0, 1 or 2 hand pickings prior to once-over machine harvest and to the timing of the machine harvest was examined for 3 years on the same planting. Increased yields from 1 or 2 hand pickings prior to machine harvest were lost by delaying machine harvest past the estimated optimum time (80 to 85% ripe fruit). Machine-harvested yield was reduced by hand picking and/or by delaying the time of machine harvest past the optimum period. Machine- harvested fruit quality was reduced in % soluble solids, acidity and color compared to the quality of hand-picked fruit but tended to improve as the number of hand pickings prior to machine harvest increased. Organoleptic evaluations of fruit puree from all harvesting treatments were rated acceptable.

The development of a mechanical harvester for erect blackberries is traced from its inception to commercialization. The harvesting and production system tested in this study required productive, erect cultivars that are mechanically pruned to form continuous hedgerows. An acceptable processed product is obtained from the system.

Ethylenethiourea (ETU) residue originating from ethylenebisdithiocarbamate (EBDC) fungicides sprayed in the jield was evaluated in canned spinach. The effect of leaf type, mechanical injury, holding temperature and washing solution on levels of ETU were studied. A smooth leaf cultivar had lower ETU residues than savoy and semisavoy. Leaf-injured spinach had higher ETU residues than the intact control. Spinach washed in water reduced the ETU level to less than 5 ppm, while addition of sodium hypochlorite (300 ppm) and a basic detergent (0.1%) further reduced ETU levels to less than 1 ppm. Increasing the washing time from 1 to 3 min did not significantly reduce the residual ETU levels. High holding temperatures (21°C) resulted in canned spinach with low but not significantly direrent levels of ETU as compared to low temperatures (2°C).