Off-target loss in ornamental nurseries with different spray techniques.

Information is lacking on spray techniques to reduce off-target loss on the ground and via spray drift from the treated area in nursery applications. Airborne deposits at three elevations on sampling towers and on the ground at several distances from the sprayer were investigated with the three spray treatments in an open field without crops. Tests were conducted with an air blast sprayer equipped with conventional hollow cone nozzles (HC), low drift nozzles (AI), and conventional hollow cone nozzles with a drift retardant (HCDR) in an open field without crops. To compare field test results, wind tunnel experiments were conducted to assess spray deposits on the floor beyond 0.4 m downwind distance from the nozzles and airborne deposits at 2.1 m downwind from the spray discharge point with the three spray techniques. Droplet size distributions across spray patterns were measured with a laser particle/droplet image analysis system. There was no significant difference in airborne deposits for the three elevations at both 15 and 30 m downwind from the sprayer between AI and HC methods except for 3.05 m elevation at the 15 m distance although the average airborne deposits with AI were lower than that with HC. The downwind spray deposits on the ground at 15 and 30 m from the sprayer with AI were higher than that with HC and HCDR. Compared with conventional hollow cone nozzles, drift reduction from air induction nozzles or the spray mixture with drift retardant was significant in wind tunnel tests but was not significant in field tests.

Evaporation and wetted area of single droplets on waxy and hairy leaf surfaces.

Understanding the evaporation of pesticide droplets and wetting of Leaf surfaces can increase foliar application efficiency and reduce pesticide use. Evaporation time and wetted area of single pesticide droplets on hairy and waxy geranium leaf surfaces were measured under the controlled conditions for five droplet sizes and three relative humidities. The sprays used to form droplets included water, a nonionic colloidal polymer drift retardant, an alkyl polyoxyethylene surfactant, and an insecticide. Adding the surfactant into spray mixtures greatly increased droplet wetted area on the surfaces while droplet evaporation time was greatly reduced. Adding the drift retardant into spray mixture slightly increased the droplet evaporation time and the wetted area. Also, droplets had Longer evaporation times on waxy leaves than on hairy leaves for all droplet diameters and all relative humidity conditions. Increasing relative humidity could increase the droplet evaporation time greatly but did not change the the wetted area. The droplet evaporation time and wetted area increased exponentially as the droplet size increased. Therefore, droplet size, surface characteristics of the target, relative humidity, and chemical composition of the spray mixtures (water alone, pesticide, additives) should be included as important factors that affect the efficacy and efficiency of pesticide applications.

Suppression of Botrytis Blight of Begonia by Trichoderma hamatum 382 in Peat and Compost-Amended Potting Mixes.

Inoculation of an industry standard light sphagnum peat potting mix with Trichoderma hamatum 382 (T382) significantly (P = 0.05) reduced the severity of Botrytis blight, caused by Botrytis cinerea, on begonia plants grown in a greenhouse. In data combined from three experiments, the degree of control provided by T382 did not differ significantly (P = 0.05) from that provided by weekly topical sprays with chlorothalonil. In addition, T382 significantly (P = 0.05) increased shoot dry weight and salability of flowering plants. Incorporation of composted cow manure (5%, vol/vol) into the light peat mix also significantly (P = 0.05) decreased blight severity while shoot dry weight and salability were increased. Blight severity on plants in this compost mix did not differ significantly (P = 0.05) from that on those in the light peat mix inoculated with T382. Finally, T382 and chlorothalonil did not significantly (P = 0.05) affect blight severity, shoot dry weight, or salability of plants grown in the compost mix. Spatial separation was maintained in begonias between the biocontrol agent T382 and the pathogen. It was concluded, therefore, that the decrease in disease severity provided by inoculation of the peat mix with T382 most likely was due to systemic resistance induced in begonia against Botrytis blight. The suppressive effect of the compost mix against Botrytis blight was unusual because composts typically do not provide such effects unless inoculated with a biocontrol agent capable of inducing systemic resistance in plants to disease.

Evaluation of fan-pattern spray nozzle wear using scanning electron microscopy.

Worn nozzles on spray equipment severely affect the efficiency of crop management systems while causing unnecessary pesticide contamination of non target areas. Scanning electron microscopy (SEM) that has been applied for direct measurement of pesticide deposition, was used to observe worn and unused brass and stainless steel fan-pattern spray nozzles. Wear and other changes were observed in both nozzle materials. Scanning electron microscopy can provide nozzle manufacturers with greater insight and needed information on nozzle mechanics to improve performance. More reliable delivery of pesticide spray should enhance integrated pest and disease management and crop protection for growers.

Forming an integrated documentation system.

A new documentation system changed not only the pieces of paper people write on, but also the way they deliver patient care. The patient record integrated all disciplines' care plans, assessments, flow sheets and Kardex into one document.

Ovipositional behavior of lesser peachtree borer in presence of host-plant volatiles.

Reactions of lesser peachtree borer [Synanthedon pictipes (G&R)] to volatiles of peach wood, either natural or chemically fractionated, were observed. Mated females were stimulated by and responsive to such materials and deposited significantly more eggs on substrates, including unnatural hosts, that had been treated with aqueous mixtures of bark-canker materials. Stimulation to oviposit occurred even when the female was blinded, indicating the presence of chemical cues. Natural canker-bark extracts immediately stimulated ovipostion and for a few hours significantly increased the number of eggs laid. However, average fecundity was not increased. Antennectomy did not significantly decrease response to volatiles by gravid females, and alternate sites of such chemoreception were not located. Complex mixtures derived by solvent extraction, steam distillation, and volatiles trapping from bark, canker, and gum all had activity. Observations of insect behavior in outdoor cages and also in the laboratory indicated that visual, chemosensory, and mechanosensory receptors are involved in host finding and oviposition.