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- Author or Editor: C.W. Coggins Jr. x
Abstract
A mutant of tomato obtained by treatment of seeds of the Canary Export variety with p32 produces only an occasional flower at a considerably longer time after seeding than the original variety. The mutant requires a longer time for fruit development, expresses less apical dominance, and also differs from Canary Export in flesh color of the fruit, leaf shape and internode length (2).
Abstract
Starch in the roots of mandarin trees (Citrus reticulata Blanco cv. Kinnow) was drastically reduced by an “on” crop. This was related to prolonged bud dormancy, delayed spring growth and an “off’ crop the following year.
Abstract
In a 5-year factorial fertilizer experiment, an increase in leaf N from 2.54 to 2.71% by soil applications of urea, reduced creasing and fruit size and increased green color on the fruit at harvest. Leaf K was increased from 0.47 to 0.67% by soil application of K2SO4 and to 0.65% by foliar application of KNO3; except for degree of fruit color and leaf N content, effects of soil- and foliar-applied K differed little and both increased yield, fruit size, and green color on the fruit and reduced creasing. Increasing leaf P from 0.132 to 0.139% had little influence on factors influencing the value of the fresh-fruit crop. Gibberellic acid (GA) sprays increased green color on the fruit and reduced creasing. The effects of N, K, and GA on reducing creasing and increasing green color on the fruit were strongly additive. There was an inverse relation between creasing and green color of fruit. Each problem can be reduced but at the expense of the other, and both problems cannot be reduced simultaneously. Packinghouse statements showed that monetary returns/tree were increased about 75% by K treatments without GA; 17% with GA alone; 61% with GA + soil-applied K; and 42% with GA + foliar-applied K.
Abstract
Degreening occurred when 1000 ppm 2′,4′-dichloro-1-cyanoethanesulphonanilide (R33417) was applied preharvest or postharvest to regreened ‘Valencia’ oranges [Citrus sinensis (L.) Osbeck] when light was present. Part of the light effect may have been due to increased rind temperatures because some degreening occurred when treated fruit were held in darkness at 40°C. Little or no degreening, however, occurred in darkness at 25 or 4°C. Some postharvest degreening occurred in the absence of R33417 in darkness at 40°C and considerable degreening occurred on fruit which were exposed to light but not treated with R33417 even when rind temperatures were considerably lower than 40°C. Results obtained with untreated fruit agree with the currently accepted view that intense light can cause chlorophyll destruction, however, excised orange fruit were much more susceptible to degreening by intense light than attached citrus leaves. Based on the combined effects of light, temperature, and R33417 on degreening we speculate that the chemical potentiates the destructive effects of intense light and high temperatures on chlorophyll. Evidence that light does not convert R33417 into a biologically active compound, and preliminary evidence that R33417 reduces the extent of ethylene degreening are presented.
Abstract
Gibberellic acid (GA3) applied to navel orange [Citrus sinensis (L.) Osbeck] trees in the whitewash spray mixture [15 lb. Ca(OH)2 + 2 lb. CUSO4 · 5H2O + 3 lb. ZnSO4 · H2O/100 gal - pH 12.6], commonly used in the San Joaquin Valley of California, had no effect on rind resistance to puncture or on rind color. Whitewash applied as a separate spray 6 hours prior to, or 1 day after, GA3 yielded full effect of GA3. The full GA3 effect was obtained also when it was applied as a constituent of a neutralized Cu, Mn, Zn mixture. Effectiveness of GA3 was reduced in the laboratory when it was applied in suspensions containing as little as 0.15 g/l (0.125 lb./100 gal) of Ca(OH)2 and no reduction occurred when smaller amounts of Ca(OH)2 were used to produce alkaline water with pH values of 8.0 through 11.0. We propose that the compatibility of GA3 with dry deposits of whitewash was due to conversion of Ca(OH)2 to CaCO3 and that the lack of compatibility with more highly alkaline suspensions of Ca(OH)2 was due to the conversion of GA3 to the 1 → 3-lactone.
Abstract
Avocado (Persea americana Mill.) fruit from various locations in California were analyzed for oil and subjected to taste tests every 2 weeks throughout the fruiting season over a period of 5 years. Oil content at acceptable taste differed among cultivars, and the 8% requirement was too low to serve as a good maturity standard for many cultivars. While the date of acceptable taste of fruit grown at the same location was not significantly different from year to year, it varied significantly among and within the widespread avocado production areas. Dry weight, which was highly correlated with increasing oil content, was evaluated as a maturity index. The dry-weight analysis with a microwave oven was much easier than determining oil content. The average dry weight at 8% oil (the existing legal standard in California) was 19.4% for ‘Bacon’, 19.1% for ‘Fuerte’, 19.8% for ‘Hass’, 18.9% for ‘Pinkerton’, and 18.4% for ‘Zutano’ fruit. Dry weight at acceptable taste was 20.0% for ‘Bacon’, 21.0% for ‘Fuerte’, 22.8% for ‘Hass’, 20.0% for ‘Pinkerton’, and 20.2% for ‘Zutano’.