The use of beneficial nematodes as part of integrated pest management strategies is increasing especially for the control of soil inhabiting arthropods, however few studies have been published evaluating the efficacy of foliar applications for control of leafminer (Liriomyza trifolii). The objective of this study was to determine the more effective species of commonly used Steinernema (S. carpocapsae, S. feltiae) in the control of leafminer (Liriomyza trifolii). Greenhouse cut flower stocks of Dendranthema grandiflora grown in raised beds were infected with a well-established population of L. trifolii. Plants were treated with a coarse aqueous spray containing commercial preparations of each of the two nematode species at a rate of 1 million nematodes/5 square meters and a water control. Treatments were replicated three times in a randomized block design. Two days after treatment, larvae of L. trifolii were removed from the leaves and examined for parasitism.
Z.-H. Shu, E.E. Cary, M. Rutzke, and G.H. Oberly
Natural and 10B-enriched boric acid solutions were sprayed on whole trees or certain parts of `Reliance' peach trees (Prunus persica L. Batsch) to estimate the uptake and translocation of B. The tissues were analyzed for total B and 10B: 11B ratio. The single or multiple spray treatments of 233 mg B/liter applied at full bloom (FB), FB + 2 weeks, and FB = 4 weeks did not increase B concentrations in leaves or stems collected 45,75, and 105 days following FB. Individual limbs sprayed with 0,200,400,600, or 1200 mg B/liter did not affect B concentrations in six aerial plant parts harvested 3 days following treatment. Boron uptake and translocation were also studied by applying 30 μl of 600 mg B/liter from 10B-enriched boric acid as spot treatments to various peach plant parts. Leaves, stems, and fruit absorbed 10B and translocated it to nontreated tissues. However, only a small amount of 10B was absorbed by 3 days after treatment.
Benjamin D. Taylor and Benjamin K. Hoover
talcum powder are legally required to wear personal protective equipment including a respirator, gloves, protective eyewear, long sleeves, and long pants ( Brooker Chemical Corp., n.d. ; OHP, Inc., 2010 ). The efficacy of foliar spray application of IBA
Frank J. Peryea
Postbloom zinc (Zn) sprays are replacing dormant and postharvest sprays as the primary means for applying Zn in commercial apple (Malus ×domestica) orchards. We conducted a multiyear field study comparing the phytoavailability of Zn in 11 commercially available Zn spray products, plus reagent-grade Zn nitrate and a water-sprayed control, applied postbloom at identical Zn concentrations to `Golden Delicious' apple trees. Two sprays were applied per season (mid-May and mid-June), at per-spray rates of either 0.5 lb/acre in 2000 or 1.0 lb/acre in 2001 and 2002. No sprays were applied in 2003 in order to evaluate carry-over effects. The Zn sprays had no effect on fruit number, bitter pit or russeting, or on leaf green color. Zinc concentrations of detergent plus acid-washed leaves (a procedure used to remove surface residues of the Zn sprays) sampled in August and of unwashed winter buds sampled the following January were used as indices of tree Zn status. Leaf Zn concentration generally increased in the order: Zn phosphate < Zn oxide = Zn oxysulfate < chelated/organically complexed Zn ≤ Zn nitrate. There was little consistent difference among chelated and organically complexed Zn products. Leaf Zn concentration varied considerably between seasons, and was not related to Zn application rate. All of the Zn sprays increased leaf Zn concentrations to desirable levels. Because the inorganic Zn-based products typically are substantially less expensive per unit of Zn, it may be less costly and just as effective to use a higher rate of an inorganic Zn product as to use a lower rate of a more expensive chelated or organically complexed Zn product. On the other hand, use of low rates of highly phytoavailable Zn products minimizes release of the nutritionally essential but potentially ecohazardous metal into the environment. There was no detectable lasting effect of the three previous seasons of Zn sprays on leaf Zn in 2003. Similarly, there was no detectable effect in any year of the Zn spray treatments on bud Zn concentration the following winter. These results suggest that the amount of Zn supplied by the sprays at the tested rates was insufficient to promote substantial Zn accumulation within the trees, thereby validating the recommendation for annual application of Zn nutritional maintenance sprays.
Frank J. Peryea
Two multiyear field studies were conducted to compare the phytoavailability and effectiveness of a variety of commercial foliar B fertilizer sprays applied at the pink flowering stage to 'Fuji'/EMLA.26 apple trees grown under irrigated semi-arid conditions. Treatments included products that differed by initial chemical form of B, physical state, and presence of additives of varying composition. Additional treatments were polymeric urea added to one B product and soil application of one B product. Boron application rates varied from 0.56 to 1.68 kg·ha–1·yr–1. All of the B sprays increased flower cluster B concentration in all years. The B sprays at the lower rate sometimes but not always increased leaf B concentration. Increasing the B rate substantially increased plant tissue B concentrations. In general, there was little substantive difference between the tested products/product mixtures on plant tissue B concentrations. Flower cluster B in the ground-applied B treatment was similar to the water control; however, leaf B concentration corresponded to the B spray treatments, indicating effective uptake of B from the soil during the early summer. Sodium polyborate-based products increased flower cluster Na concentration but not leaf Na concentration. The amount of Na contributed by Na polyborate-based products applied at commercial rates apparently was too small to be of horticultural concern. Fruit quality was excellent and was not affected by the experimental treatments in any year. Flower cluster and leaf B concentrations returned to near or at control levels in the season following the last spray application, validating the recommendation for annual B fertilizer applications to maintain adequate tree B status.
T. Casey Barickman, Dean A. Kopsell, and Carl E. Sams
plants positively increases Ca partitioning between ‘Micro’ tomato leaf and fruit tissue. Therefore, this study examined how root and foliar spray ABA applications, individually and in combination, affect the partitioning of Ca between the leaves and
Amir Rezazadeh, Richard L. Harkess, and Guihong Bi
Harkess, 2015 ). Flurprimidol is effective as a foliar spray or substrate drench for height control ( Currey and Lopez, 2011 ; Krug et al., 2005 ). Daminozide is not a triazole but rather suppresses plant height by reducing the conversion of GA to active
Frank J. Peryea, Denise Neilsen, and Gerry Neilsen
The recommendations for boron (B) sprays in deciduous tree fruit orchards have changed little over the past 50 years. We conducted two 3-year field studies evaluating the effect of two modifications to the existing recommendation for B maintenance sprays on apple (Malus ×domestica) tree nutritional status. A widely recommended Na polyborate-based commercial B spray product was used as the B source. Postbloom sprays of B applied at the recommended annual B maintenance rate of 0.56 kg·ha-1 to `Scarlet Gala' apple trees consistently increased fruit B concentration but had a weaker effect on leaf B concentration in early August, the recommended timing for sampling leaves for mineral element analysis. Applying half or all of the annual B maintenance rate in a spray at the pink flowering stage increased flower cluster and early-season leaf B concentrations as well as having positive effects on fruit and leaf B concentrations. The pink sprays increased flower cluster Na concentration but had no effect on leaf and fruit Na concentrations. In the second study, one-quarter of the annual B fertilizer requirement was tank-mixed with each of four biweekly CaCl2 sprays applied starting in early June for bitter pit control. This treatment consistently increased `Scarlet Gala' fruit B concentration but had a lesser effect on August leaf B concentration. It did not interfere with fruit Ca status, and increased both fruit and leaf Na concentrations. Leaf Na concentration in all treatments was substantially lower than levels associated with specific Na toxicity of deciduous fruit trees. The results of these experiments indicate that applying B sprays at the pink flowering stage timing and tank-mixing B with CaCl2 sprays applied for bitter pit control are useful practices to enhance B spray efficacy and convenience of application.
Jing Tian, Li-Ping Wang, Yan-Juan Yang, Jin Sun, and Shi-Rong Guo
/night). T1+ = plants under 28/18 °C with Spd foliar spraying; T2 = plants under 42/32 °C; and T2+ = plants under 42/32 °C with Spd foliar spraying. Each histogram represents a mean value of three independent experiments and the vertical bars indicate se (n
Danise Coon, Derek W. Barchenger, and Paul W. Bosland
ornamental pepper cultivars that do not require pinching or a uniconazole foliar spray to develop a dwarf or semidwarf plant habit. The 12 currently available ornamental pepper cultivars were chosen based on their popularity as nursery-potted plants, whereas