Site-specific management of meloidogyne chitwoodi in Idaho potatoes using 1,3-dichloropropene; approach, experiences, and economics

Fumigation for nematode management in irrigated potato production systems of Idaho is widely practiced. Spatially uniform fumigation with large scale soil injection equipment is the only labeled application method for 1,3-dichloropropene. Plant-parasitic nematode species exhibit spatially variable population densities that provide an opportunity to practice site-specific fumigation to reduce chemical usage and production costs. During 2002-2008, 62 fields intended for commercial potato production in eastern Idaho were sampled using a geo-referenced grid sampling system for plant-parasitic nematode population densities. In total, 4,030 grid samples were collected representing nearly 3200 ha of commercial potato production. Collectively, 73% of the grid samples had no Columbia Root Knot (CRN) (Meloidogyne chitwoodi) or CRN densities below the detectable limit. Site-specific fumigation is the practice of varying application rate of fumigant based on nematode population density. In 2007, 640 ha of potato production were site-specific fumigated for CRN nematode control in eastern Idaho. On average, this practice resulted in a 30% reduction in chemical usage and production cost savings of $209 ha-1 when 1,3-dichloropropene is used as the sole-source of nematode suppression. Further reductions in usage of 1,3-dichloropropene can exceed 50$200 ha-1. Based on farm-gate receipts and USDA inspections provided by potato producers from 2001-2011, potato tuber yield and quality have not been adversely affected using site-specific fumigation

Spatially distributed control netowork for flow proportional chemical injection with center pivot irrigation

The agricultural production practice of injecting a chemical into an operating irrigation system and applying it to the field area with the water is known as chemigation. Chemigation is a widely adopted practice with center pivot sprinkler irrigation. However, the practice of chemical injection at a constant rate with center pivot sprinkler irrigation systems equipped with an end gun and/or swing?arm corner watering system results in systematic chemical application errors ranging from 7% to 21% due to systematic changes in system flow rate. Chemical injection proportional to center pivot sprinkler system flow rate is one approach to reduce systematic chemical application errors. The objective of this project was to test the feasibility of using real?time monitoring of center pivot sprinkler irrigation system operating status to control chemical injection rate proportional to calculated system flow rate, thus minimizing systematic chemical application errors. A spatially distributed control network was developed to facilitate real?time monitoring of end gun and swing?arm corner watering system operating status and pressure. The spatially distributed control network consisted of three network nodes at specific locations along a center pivot sprinkler irrigation lateral that used the 480 VAC 3?phase power cable on the center pivot sprinkler irrigation system as the communication medium. The spatially distributed control network was installed on a commercial 460?m (1510?ft) long center pivot sprinkler system equipped with an end gun and swing?arm corner watering system. Performance of chemical injection proportional to calculated flow rate based on real?time center pivot sprinkler irrigation system operating status was evaluated by injecting Rhodamine WT dye into the center pivot sprinkler irrigation system water supply and measuring its concentration in the applied water. Mean dye concentration varied by 26% under constant rate chemical injection and 2% under flow proportional chemical injection due to systematic changes in center pivot sprinkler irrigation system flow rate. Use of the flow proportional chemical injection system reduced the coefficient of variability in measured dye concentration of applied water by 54% from 0.100 to 0.046. Use of the spatially distributed control network for calculating center pivot sprinkler system flow rate eliminates the need for straight sections of unobstructed piping at the chemical injection site. Display and/or data logging of real?time center pivot sprinkler operating status is an added benefit of using the spatially distributed control network. This information provides the ability to monitor, diagnose, and troubleshoot center pivot sprinkler system operation. Commercialization and adoption of the technology could reduce systematic chemical application errors and facilitate maintenance and operation of center pivot sprinkler irrigation systems equipped with an end gun and/or swing?arm corner watering system

Planting System Effect on Yield Response of Russet Norkotah to Irrigation and Nitrogen under High Intensity Sprinkler Irrigation

Conversion of potato ridged-row planting systems to wide bed planting systems may increase water and nitrogen use efficiency in commercial irrigated potato production systems by reducing the amount of irrigation water and water applied nitrogen fertilizer bypassing the potato root zone. Wide bed planting systems consist of planting multiple rows on a wide bed with 20 to 35% higher plant population than found in conventional ridgedrow planting systems. The objective of this study was to evaluate the effect planting system has on yield response of ‘Russet Norkotah’ potato to irrigation and nitrogen. Planting systems evaluated were (1) conventional ridgedrow with dammer-diking; (2) 3.7 m wide bed with five potato rows spaced 66 cm between adjacent rows centered on the bed and; (3) 3.7 m wide bed with seven potato rows spaced 46 cm between adjacent rows. Six irrigation amounts, 50, 70, 85, 100, 115, and 130%, of estimated evapotranspiration after tuber initiation and four nitrogen rates, <20, 50, 100, and 150%, of conventional recommendations were applied to the three planting systems. Interactions between irrigation amounts and nitrogen rate were significant for total and U.S. No. 1 yield, irrigation water use efficiency, and gross return in one or both study years. Interactions between nitrogen rate and planting system were significant for total and U.S. No. 1 yield, irrigation water use efficiency and gross return in the first year of the study. Interactions between irrigation amount and planting system were not significant. In the first study year, total and U.S. No. 1 yields were significantly increased 12 and 19 percent, respectively, under the 7-row bed planting system compared to ridged-row planting system. Comparison of ridged-row planting system and 5-row bed planting system on 31 commercial potato fields in eastern Idaho representing a combined area of 2,800 ha over 5 years resulted in significantly higher total yield and irrigation water use efficiency with the bed planting system. The 5-row bed planting system averaged 6% higher total yield, 5% less water application and an 11% increase in irrigation water use efficiency. The results of this study demonstrate that under high intensity rate sprinkler irrigation in the soil and climatic conditions prevalent in eastern Idaho, bed planting systems provide viable production alternatives for irrigated potato production that may increase total yield, gross return, and irrigation water use efficiency

Effects of Planting Configuration and In-Row Plant Spacing on Photosynthetic Active Radiation Interception for Three Irrigated Potato Cultivars

Research studies have evaluated the production of potatoes (Solanum tuberosum L.) grown in conventional and bed planting configurations. However, intercepted photosynthetically active radiation (PAR) from these planting configurations has not been quantified. A study conducted in 2008 and 2009 quantified and compared the intercepted PAR from three planting configurations (four row conventional ridged-row [4RC], five row bed [5RB], and seven row bed [7RB]), and from different plant spacings of cvs Russet Burbank, Russet Norkotah, and Ranger Russet potatoes under sprinkler irrigation. A second study was conducted in 2007 to evaluate the relationship between PAR and leaf area of Russet Norkotah and Russet Burbank for the three planting configurations. These studies were conducted at the USDAARS Northwest Irrigation & Soils Research Lab in Kimberly, ID, on a Portneuf silt loam (coarse–silty mixed mesic Durixerollic Calciorthid). The canopy of Russet Norkotah and Ranger Russet potatoes grown in 5RB and 7RB planting configurations intercepted more PAR during the early vegetative and tuber initiation growth stages compared to the 4RC planting configuration at equal populations in 2008 and 2009 at all measurement dates. The canopy of Russet Burbank intercepted more PAR during the early growth stage in 2008 when planted in the bed planting configurations compared to the 4RC planting configuration, but not on the July 17, 2008 and July 9, 2009 dates. The canopy cover of Russet Burbank potatoes planted in the 4RC planting configuration tended to catch up with the bed planting configurations quicker than the other two cultivars. In general, the quantity of PAR intercepted as affected by planting configuration did not influence total tuber yield and other measured production variables. Cumulative PAR interception 0–72 days after planting (DAP) was increased 35%, 38%, and 32% for the 5RB and 65%, 69%, 23% for the 7RB relative to the 4RC planting configuration for Ranger Russet, Ranger Norkotah, and Russet Burbank, respectively. Cumulative PAR interception for the season was increased 15%, 16%, and 4% for the 5RB and 23%, 23%, 5% for the 7RB relative to the 4RC planting configuration for Ranger Russet, Ranger Norkotah, and Russet Burbank, respectively. The relationship between intercepted PAR and leaf area for Russet Norkotah during the early vegetative and tuber initiation growth stages was significantly different between the three planting configurations, with intercepted PAR at a given leaf area in the order of 7RB>5RB>4RC. For Russet Burbank, the relationship was significantly different for the 5RB and 7RB compared to 4RC planting configuration only, with intercepted PAR at a given leaf area in the order of 7RB05RB>4RC

Site-specific management of meloidogyne chitwoodi in Idaho potatoes using 1,3-dichloropropene; approach, experiences, and economics

Fumigation for nematode management in irrigated potato production systems of Idaho is widely practiced. Spatially uniform fumigation with large scale soil injection equipment is the only labeled application method for 1,3-dichloropropene. Plant-parasitic nematode species exhibit spatially variable population densities that provide an opportunity to practice site-specific fumigation to reduce chemical usage and production costs. During 2002-2008, 62 fields intended for commercial potato production in eastern Idaho were sampled using a geo-referenced grid sampling system for plant-parasitic nematode population densities. In total, 4,030 grid samples were collected representing nearly 3200 ha of commercial potato production. Collectively, 73% of the grid samples had no Columbia Root Knot (CRN) (Meloidogyne chitwoodi) or CRN densities below the detectable limit. Site-specific fumigation is the practice of varying application rate of fumigant based on nematode population density. In 2007, 640 ha of potato production were site-specific fumigated for CRN nematode control in eastern Idaho. On average, this practice resulted in a 30% reduction in chemical usage and production cost savings of $209 ha-1 when 1,3-dichloropropene is used as the sole-source of nematode suppression. Further reductions in usage of 1,3-dichloropropene can exceed 50$200 ha-1. Based on farm-gate receipts and USDA inspections provided by potato producers from 2001-2011, potato tuber yield and quality have not been adversely affected using site-specific fumigation

Spatially distributed control netowork for flow proportional chemical injection with center pivot irrigation

The agricultural production practice of injecting a chemical into an operating irrigation system and applying it to the field area with the water is known as chemigation. Chemigation is a widely adopted practice with center pivot sprinkler irrigation. However, the practice of chemical injection at a constant rate with center pivot sprinkler irrigation systems equipped with an end gun and/or swing?arm corner watering system results in systematic chemical application errors ranging from 7% to 21% due to systematic changes in system flow rate. Chemical injection proportional to center pivot sprinkler system flow rate is one approach to reduce systematic chemical application errors. The objective of this project was to test the feasibility of using real?time monitoring of center pivot sprinkler irrigation system operating status to control chemical injection rate proportional to calculated system flow rate, thus minimizing systematic chemical application errors. A spatially distributed control network was developed to facilitate real?time monitoring of end gun and swing?arm corner watering system operating status and pressure. The spatially distributed control network consisted of three network nodes at specific locations along a center pivot sprinkler irrigation lateral that used the 480 VAC 3?phase power cable on the center pivot sprinkler irrigation system as the communication medium. The spatially distributed control network was installed on a commercial 460?m (1510?ft) long center pivot sprinkler system equipped with an end gun and swing?arm corner watering system. Performance of chemical injection proportional to calculated flow rate based on real?time center pivot sprinkler irrigation system operating status was evaluated by injecting Rhodamine WT dye into the center pivot sprinkler irrigation system water supply and measuring its concentration in the applied water. Mean dye concentration varied by 26% under constant rate chemical injection and 2% under flow proportional chemical injection due to systematic changes in center pivot sprinkler irrigation system flow rate. Use of the flow proportional chemical injection system reduced the coefficient of variability in measured dye concentration of applied water by 54% from 0.100 to 0.046. Use of the spatially distributed control network for calculating center pivot sprinkler system flow rate eliminates the need for straight sections of unobstructed piping at the chemical injection site. Display and/or data logging of real?time center pivot sprinkler operating status is an added benefit of using the spatially distributed control network. This information provides the ability to monitor, diagnose, and troubleshoot center pivot sprinkler system operation. Commercialization and adoption of the technology could reduce systematic chemical application errors and facilitate maintenance and operation of center pivot sprinkler irrigation systems equipped with an end gun and/or swing?arm corner watering system