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United States Department of Agriculture

Agricultural Research Service

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Research Project: Determining Optimum Nutritional, PGR, and Handling Regimes to Manage Plant Growth and Maximize Post-harvest Life

Location: Application Technology Research

Project Number: 5082-21000-017-07-S
Project Type: Non-Assistance Cooperative Agreement

Start Date: Aug 1, 2013
End Date: Jul 31, 2018

Determine optimum N:P:K ratios for managing plant growth on bedding and potted flowering plants and determine postharvest effects of such fertilizer regimes.

These studies are part of a long term project to determine optimum nutritional and plant growth management regimes for production of floriculture crops and to determine the postharvest effects of the production regimes and handling procedures. Nitrogen, phosphorus and potassium are the primary nutrients that have the greatest impact on plant growth. Plugs of two bedding and potted flowering plant species will be grown using a complete fertilizer until transplanting and for two weeks after transplanting in the final container. After transplanting, plants will be fertigated using various ratios of N:P:K (1:0.2:1, 1:0.2:0.75; 1:0.2:0.5; 1:0.2:0.25, 1:0.2:0; 1:0.4:1; 1:0.1:1; 1:0:1) until plants reach marketable stage. Nitrogen will be set at 150 mg L-1 N. Micronutrient levels will be similar among the treatments. Data collected at termination of the production phase will include date of anthesis, plant height and diameter, overall quality, tissue nutrient values, substrate nutrient values, and foliar SPAD readings. After the production phase is completed plants will be stored in boxes for two days at 15°C. Data collected after unboxing will include number of yellow/abscised leaves and number of abscised flowers. Bedding plants will be placed under 70% shade in a polyethylene covered greenhouse simulating a commercial garden center. To simulate a home environment potted flowering plants will be placed in a postharvest evaluation room maintained at 21 ±2°C and 60±10% relative humidity under a PAR flux of approximately 20 mol•m-2•s-1 light from white fluorescent tubes at bench level on a daily 12 h•d-1. Data will be collected after 7 days will include number of yellow/abscised leaves, number of abscised flowers, and SPAD readings.

Last Modified: 05/28/2017
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