Insects.
If using Nexter or Nexter SC to control mites, please note that rate is different for chemigation than for other application methods! The rate listed in the Chart Book is for broadcast application and NOT for chemigation. The rate for chemigation is lower for both formulations of Nexter.
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Nexter pyridaben |
* 3.5 -7.0 oz/A by chemigation (4.4 – 10.67 oz/A by ground rig) |
2 apps/season. Ground and chemigation only – no aerial application. Hold water for 3 days after application. No flow-through bogs. 5 hours of drying time required. |
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Nexter SC pyridaben |
*5.6 – 11.2 oz/A by chemigation (7.5-17.0 oz/A by ground rig) |
Also note that the PPE is different for the two formulations. A respirator is required for Nexter (has “Warning” on label), while Nexter SC does not.
Recent fruitworm and Sparganothis damage is visible in some spots, but applying insecticides now will not help much!
Cranberry Plant Tissue and Soil Testing.
Soil and tissue tests can be used to diagnose deficiencies of mineral elements, monitor soil pH, and aid in the making decisions for fertilizer. These tests are also required for Nutrient Management record keeping. A soil test alone is virtually useless in determining a fertilizer recommendation for cranberry. We recommend testing soil every 3-5 years to monitor any change in soil pH. We recommend tissue sampling every 2 ‑ 4 years. Regular tissue testing meets the mandate for testing in the Massachusetts Nutrient Management Regulations since this is the UMass recommended testing for cranberry.
Because soil test results for phosphorus are difficult to interpret for cranberry soils, tissue tests are more useful for setting target fertilizer ranges than soil tests. Because levels within the cranberry plant can fluctuate throughout the growing season, research has identified the time between Aug 15 and Sept 15 as the period when nutrient levels are most stable - and therefore the best time to collect tissue samples.
Collect one composite sample for each management. A management unit may vary in size but will generally be a single variety that is treated uniformly. For routine analysis, usually one sample per bog is adequate. If your acreage is more than 10 acres or is of varied productivity or differing varieties, taking more than one sample may provide more specific information.
The best time to sample cranberry bogs is when the soil is not waterlogged. Wet soils give falsely high P values. Soil samples may be collected with tissue samples in the late summer if no sanding is planned. Otherwise, sample soil in the spring.
Tissue samples: Samples for cranberry tissue analysis should include upright tips only (do not strip off the leaves) and should NEVER contain roots, soil, runners, fruit, or trailing woody stems. Do not collect samples when plants are wet. Collect no more than the top 2 inches of new growth (mix flowering and vegetative uprights). As you walk a transect across the bog, collect enough material to make about 1 – 1.5 cups (at least 50 upright tips). Always request nitrogen determination. This increases the test cost, but nitrogen levels in the tissue test are an important indicator of plant status and the success of fertilizer programs.
Soil samples: Samples for analysis of soil nutrients should NOT contain stems, leaves, or the surface duff layer (trash). These are all organic contaminants and will bias the organic matter (OM) determination for the sample. The inclusion of some roots is generally unavoidable. Use a soil probe with a 1-2 inch diameter to collect cores of 4-6 inch depth. Minimum requirements: 4 cores for up to 1 acre; and 1 core for each additional 2 acres up to a total of 10 cores/management unit. After the trash layer on the surface of each is discarded, these cores are combined to make a sample. Collect enough soil to fill a 1 qt plastic bag about ¾ full. At home, open the bags and dry the soil at room temperature for a day or two. Clearly mark each sample bag. OM determination (usually an additional charge) is often useful.
Methods of analysis vary by lab – so it is best to pick a lab and stick with it over the years. For phosphorous, the UMass Soils Lab uses the Morgan test. However, the Bray test for soil P is the most commonly used in other labs for samples from the eastern United States. Standard P ranges for both methods are provided in the Chart Book.
