Non Technical Summary
The production of specialty crops is important to the Great Lakes states, which hold a combined 100,000 acres of bearing apples (NASS 2007), the state of Michigan being a national production leader behind Washington and New York. Profitability in domestic and global fruit markets requires meeting high food quality standards, often through the judicious use of crop protection materials, including pesticides. Studies show that airblast sprayers are a relatively inefficient means of delivering pesticides to their target, with only 29 to 56% of the applied spray solution being deposited on the tree canopy, and the remaining product drifting to ground or other off-target end points. Trunk injection represents an alternative delivery system for crop protection materials to specialty crops like apples. Preliminary research on trunk injection in apples shows encouraging "proof of concept" results for controlling disease and insect pests of apples. Preliminary research on apples indicates that applying insecticides by trunk injection results in a discriminatory distribution in the tree that is favorable in terms of dietary tolerances, with the vast majority of residues ending up in foliage versus fruit. Determining the physiological response of apple trees to various micro-injection systems is critical to knowing which delivery techniques will be sustainable for commercial apple production, where the long term health of the trees will directly impact long term yield. We believe that trunk injection technology brings significant potential benefits for fruit crop and ecosystem health and will improve the ability of fruit growers to transition to environmentally-friendly production systems, improve plant protection under in- climate conditions, while becoming more energy efficient, and ecologically and economically sustainable.
Animal Health Component
Research Effort Categories
Goals / Objectives
The goal of this project is to development trunk injection as an alternative delivery system for crop protection materials in apples, so as to optimize pest management, while reducing the negative effects of pesticides associated with drift, worker exposure and impact on beneficial organisms. We believe that trunk injection technology will bring benefits for fruit crop and ecosystem health and will improve the ability of fruit growers to transition to environmentally-friendly production systems, improve plant protection under in- climate conditions, while becoming more energy efficient, and ecologically and economically sustainable. We propose to investigate the use trunk injection technology under two objectives; 1) Optimize application timings and rates of trunk injection materials to address issues of plant protection, resistance management, pollinator safety and pesticide load, and 2) Compare compound delivery efficiency and wounding associated with various trunk injection techniques. We expect from objective 1 to identify a suite of pesticide active ingredients, with optimized formulations, rates and application timings, which will be effective for trunk injection to control primary disease and insect pests of apple. We expect from objective 2 to identify the optimal trunk injection tools/techniques that minimize injury to apples trees.
Field studies will be initiated at the Michigan State University Trevor Nichols Research Center in Fennville, MI, to optimize the effectiveness of trunk injection technology in semi-dwarf apples, Malus domestica, for the control of key apple insect pests. Previously untested active ingredients, such as spinosad, chlorantraniliprole, thiamethoxam, azadirachtin, or pyrethrum will be tested against a "current winner" from our preliminary studies, imidacloprid or emamectin benzoate, by injecting rates (1 g AI per tree) of formulated product mixes. These compounds will be tested in semi-dwarf apples, Malus domestica Borkhausen 'Empire' for control of obliquebanded leafroller, spotted tentiform leafminer, potato leafhopper, rosy apple aphid, green apple aphid, Oriental fruit moth, codling moth, apple maggot, and plum curculio in apples. Trunk injections will be made at the petal fall stage and season-long plant protection will be measured by conducting a series of field evaluations for the incidence of these pests and levels of injury to the fruit and foliage. Field-based bioassays will be conducted at approximately 7 and 45 days after treatment on a key direct pest to attain a more controlled measure of compound effectiveness and persistence. Field residue samples will be taken from treated trees for each compound and test regime. Leaf and fruit samples will be collected prior to treatment application and then 1, 7, 14, 30, 45, 60 and 90 DAT. Plant tissue samples for each treatment will be collected and held in dichloromethane for GC or HPLC analysis as described by Wise et al (2007). Disease control studies will be initiated at the MSU TNRC in Fennville, MI, to optimize the effectiveness of trunk injection technology for the control of key apple diseases. Apple scab severity will be evaluated on leaves and fruit, 5 times, in 2-3 days manner after sampling, and fruit will be evaluated at harvest. Spur scab and terminal scab evaluations will be performed by methods described by Sundin et al. (2010). Residue samples will be collected from fruit and foliage as described above, then stored, processed, and analyzed in Pesticide Analytical Laboratory at MSU, using HPLC, by methods described by Wise et al. (2007). Tissue damage and wound closure on trunk injection ports studies will be initiated at the TNRC, and injection treatments will be compared to untreated control. Trunk injections of will be performed approx. 1 foot above ground, in 4 injection ports equally spaced and oriented towards world sides and separated longitudinally approx. 2". We will determine the tissue damage and wound healing rate (closure) by measuring inner wound diameter multiple times with a digital caliper. The depth of the injection port will be measured with thin metal ruler.