Search Results
Abstract
Laboratory and field application methods of (methyl 1-(butylcarbamoyl)-2 benzimidazolecarbamate) (benomyl) and oil were evaluated for their influence on net photosynthesis of leaves of potted apple trees. Superior 70-second viscosity oil applied as a dip caused a significant reduction in net photosynthesis of young leaves at both the 1.26 ml and 2.52 ml/liter levels, with the greater reduction at the higher level. Benomyl alone or in combination with oil had no influence on net photosynthesis. Spray application in the laboratory or by commercial field sprayers had no effect on net photosynthesis of fully expanded leaves.
Abstract
Succinic acid-2,2-dimethylhydrazide (daminozide) and (2-chloroethyl)phosphonic acid (ethephon) and multiple applications of selected pesticides were tested for their influence on net photosynthesis (Pn) and transpiration (Tr) of leaves of apple (Malus domestica Borkh.). Application by aerosol, spray, soil surface incorporation, and fumigation using commercially available pesticide materials adaptable to each had no influence on Pn. Rates of aldicarb in excess of 5 g/20 cm diameter pot (2.9 liter) caused a reduction in Pn. Rates above 14 g/20 cm pot reduced Tr and induced leaf chlorosis and defoliation. One to 3 applications of diazinon, methomyl, and oxamyl had no affect on Pn or Tr but 5 applications reduced Pn and had no effect on Tr. Plictran decreased Pn of both ‘Delicious’ and ‘Golden Delicious’ leaves after 5 applications. A single application of daminozide or ethephon had no measurable influence on Pn or Tr. The growth regulators did not alter the influence of pesticides on Pn. Plictran and oxamyl increased the severity of leaf spotting on ‘Golden Delicious’.
Abstract
Various treatments resulting in physical stress to leaves of apple (Malus domestica Borkh.) were tested for their influence on net photosynthesis (Pn) and transpiration (Tr). Brushing to simulate handling or wind rubbing reduced both Pn and Tr in one study and had little effect in another. Shaking 1 min/day had no influence on Pn or Tr. Six or more 1-cm cuts/leaf reduced Pn and had no effect on Tr. Removal of 20% of the leaf area and twenty-four 1-cm cuts/leaf reduced Pn in young expanding leaves; the amount of cut surface exposed by injury was more important than the amount of leaf area removed. Scoring and feeding of two-spotted spider mites [Tetranychus urticae (Koch)] reduced Pn.
Abstract
Spray adjuvants alone and combined with benomyl in single and multiple applications were tested for their influence on net photosynthesis (Pn) and development of apple scab caused by Venturia inaequalis (Cke.) Wint. on trees of apple (Malus domestica Borkh.) grown in the greenhouse. Triton CS-7 increased and ×-100 and 70 second oil deceeased Pn. Nu Film 17, Triton B-1956, Regulaid and ×-77 when combined with benomyl had no influence on Pn. Addition of Biofilm, Nu Film 17 or 70 second oil to benomyl did not improve apple scab control. Three sprays of benomyl plus oil decreased Pn of fully expanded leaves, and 5 sprays decreased Pn of both expanded and newly expanding leaves with the latter showing the greatest reduction.
Abstract
Lowbush blueberry plants had greater flower bud formation with more primordial meristems and more advanced floret primordia and lower concentration of anthocyanins in leaves at warmer temperatures than at cooler temperatures.
Abstract
Outward diffusion of CO2 from ‘Stevens’ and from native seedling cranberries (Vaccinium macrocarpon Ait.) collected in 1971 and held 6 months at 3°C proceeded at the rate of 4.55 and 2.56 μl/cm2-hr, respectively. The rate of movement of O2 into ‘Stevens’ was 2.64 and for a native seedling was 3.28 μl/cm2-hr. For cranberries collected in 1972 and held 1 month at 3°C the respective values for CO2 were 1.48 and 1.53 and for O2 they were 3.09 and 3.65 μl/cm2-hr.
Abstract
Nectar from flowers of the lowbush blueberry, Vaccinium angustifolium Ait was found to evolve acetaldehyde at a rate of approx 0.047 μg/g nectar/hr and ethyl alcohol, the only other volatile detected, in smaller amounts.
Abstract
Ethrel at 30 and 50, GA 50, and Alar 2000 ppm were applied as whole tree sprays to ‘Early Amber’ and ‘Flordasun’ peach trees in a commercial orchard in Central Florida. Ethrel (applied at a seed length of 12 mm) and GA at 50 ppm (2 weeks following petal fall) consistently prevented browning of puree and sliced peaches for 24 hours. The results with Alar were inconsistent.
Abstract
Chemicals deposited on foliage varied by a factor of three to five times when sprays were applied with an airblast sprayer to apple (Malus domestica Borkh.) trees in various training systems. Deposits were higher with vertical than horizontal training systems, smaller tree sizes, and less-dense tree canopies of spur-type trees. The Lincoln canopy tree training system prevented good spray penetration because the airblast spray pattern was split by the horizontal nature of the canopy.