Sodium dehydroacetate solutions in concentrations up to 0.8% were found to be effective in reducing discoloration of cut and bruised surfaces of mechanically harvested snapbeans and in reducing some mold and bacterial damage. Techniques for objectively measuring color differences using the Hunterlab Meter D 25 are described.
Danish cabbage was stored for several years from late November until April at 0°C and in various combinations CO2, O2 and N2. The best combinations of gas mixtures ranged between 21/2 to 5% of O2 and CO2 with N2 making up the remainder. These combinations reduced weight loss due to respiration and also trimming loss. In atmospheres of low O2 and CO2 tension, heads retained their green color, were succulent and firm, and remained dormant longer. Very low O2 and CO2 treatments had a sweeter taste than normal cabbage, while treatments with slightly higher CO2 had more pungent tastes characteristic of fresh cabbage. Treatments with 71/2% O2 and air checks were bland in taste. Color data were recorded by Hunterlab Color Difference Meter.
A neo-decanoic mixture including xylene and surfactants (NDA) used at rates of 33.6 to 44.9 kg/ha (3040 lb./acre) destroyed onion foliage in 2 weeks, and reduced foliage moisture content to 50% of control.
Stored samples of onions from commercially grown fields sprayed with maleic hydrazide both by ground spray apparatus and by helicopter showed that acceptable sprout control could be attained with either application method. Comparison of samples within fields, however, indicated that helicopter spray may not always be uniformly effective.
Cabbage (Brassica oleracea var. capitata L.) was stored for 6 months at 1°C in 100, 85 and 75% relative humidities under 2 atmospheric regimes: normal air and 5% CO2 –2.5% O2 with the balance N2 (controlled atmosphere, CA). Disease, direct weight and color losses were less at 100% relative humidity than at either 85% or 75% relative humidity. CA treatments showed less disease and had better green color than corresponding air treatments for all humidities. Based on high humidity air storage as the control treatment, the ‘Harris Resistant Danish #277 (HRD) showed a greater response to high humidity CA storage in terms of color retention than ‘Green Winter’ (GW). However, GW was the better adapted of the 2 cultivars to all storage treatments tested in that it deteriorated less rapidly.
Onion foliage sprayed before harvest with a neo-decanoic acid mixture (Wiltz-65) became bleached and limp. The rate of water loss from bulb necks was accelerated. Residue analysis shows that at concentrations sufficient to wilt tops, about 1 ppm is recoverable from bulbs before storage, none after 4 months’ storage. Neck rot was increased in 2 cultivars which form double bulbs but not in one where bulbs grow singly.
Four cultivars and several breeding lines of storage cabbage were grown by direct seeding and by transplanting over 2 seasons. Weights and densities of heads harvested at successive intervals in conjunction with heat units and available solar radiation yielded estimates of the time to maturity and the mature time interval in the field before splitting is likely to occur. Most cultivars of storage cabbage are ready for harvest when they have attained a density of 0.72–0.80 and a weight of 2.2–3.0 kg which corresponds to accumulation of 1000 to 1050 C heat units (10°C base) and 50,000 to 5000 gm/cal/cm2 solar radiation units. The interval between maturity and splitting varied from less than 1 week to more than 6 weeks depending upon cultivar and weather conditions.