Carol J. Adams

Paternal and maternal effects on fruit and seed characteristics in cherimoya (Annona cherimola Mill.)

Abstract Studies were conducted to determine the effect of maternal and paternal parents on fruit and seed characteristics in cherimoya. Using two commercially important cultivars in California as maternal parents (‘White’ and ‘Booth’) and three cultivars as paternal parents (‘White’, ‘Booth’ and ‘Chaffey’), we found that both maternal and paternal parent cultivars had significant effects on quantitative and qualitative fruit and seed characteristics. Maternal cultivar had a significant effect on mean seed weight, fruit set, surface morphology of carpels, and the percentage of carpels with protuberances. Pollen parent cultivar also produced significant differential effects on fruit and seed characteristics or xenia. Pollen parent cultivar had significant effects on fruit characters such as fruit length, fruit weight and percentage fruit set. Seed characters significantly affected by pollen parent included seed weight per fruit, seed number and mean seed weight. Other fruit characters such as fruit diameter, length diameter ratio, grams of fruit flesh per seed, and days to maturity, although not significant at the P

Effects of clonal rootstocks on 'Hass' avocado yield components, alternate bearing, and nutrition

Summary Growth, yield, and leaf nutrient concentrations were measured in ‘Hass’ avocado (Persea americana Mill.) trees grown on one of ten clonally-propagated rootstocks (‘Borchard’, ‘D9’, ‘Duke 7’, G1033, G755A, G755B, G755C, ‘Thomas’, ‘Topa Topa’, or ‘Toro Canyon’) over a 10-year period in southern California. After 10 years, trees on ‘Borchard’ were larger than trees on all other rootstocks. Trees on all rootstocks displayed an alternate-bearing pattern, typical of avocado. Alternate-bearing was most pronounced in trees grafted onto ‘Topa Topa’ and ‘Toro Canyon’. Rootstocks in the G755 series had the lowest alternate-bearing index, but also had the lowest yields.Trees on ‘Duke 7’ and ‘Borchard’ had the highest cumulative yields, and trees on G755A, G755B, and G755C had the lowest yields. Differences in yield were due to differences in the number of fruit per tree, not individual fruit weight. When yield was evaluated in terms of canopy efficiency (kg fruit m–3), no rootstock outperformed ‘Duke 7’, the industry standard rootstock. Leaf concentrations of all nutrients examined (N, P, K, Ca, Mg, S, Zn, Cl, Mn, B, Fe, and Cu) were within, or close to the recommended ranges. P, Ca, and S were higher, and Fe was lower in high-yielding years in all rootstocks.

Effect of oleocellosis, desiccation, and fungal infection upon the terpenes of individual oil glands in Citrus latipes

Abstract Mono- and sesqui-terpenes of individual oil glands of Citrus latipes fruits were analyzed for their homogeneity. The effect of oleocellosis, desiccation, Penicillium and Phytophthora infection upon the individual terpene components was investigated and expressed in a discriminant analysis and in canonical variables. Each oil gland contained the entire spectrum of terpenes specific for each species, and the biggest difference in affected glands was due to Penicillium infection.

Humidity as a Modifier of Vegetation Responses to Ozone: Design and Testing of a Humidification System for Open-Top Field Chambers

A system was designed, constructed, and tested for increasing the relative humidity in open-top field chambers used for air pollution studies. The system consisted of a propane-fired steam boiler capable of generating 454 kg hr−1 of dry steam at 0.1055 g cm−2 (15 PSI), ducting to supply humidified air to open-top chambers, and humidistats to control the humidity level In each chamber. Performance tests showed that under warm, dry conditions (air temperatures of 30°C and ambient relative humidity of 10 percent) the humidity level could be increased by 43 percent in each of two chambers or 25 percent in each of six chambers. At higher ambient humidities or cooler ambient temperatures, greater increases in relative humidity could be achieved. Temperature rise in the humidified chambers was 2.0-4.5°C vs. nonhumidified chambers on warm days due to the injected steam and solar heating of the galvanized steel ducting. Insulating the ducting reduced this difference to 1.6- 2.3°C. Bean plants (Phaseolus vulgaris) ...