Organic Fertility Tomato Study

New Orleans site prior to tilling in February, 2014. This is located adjacent to the Morial Convention Center.

First tilling with a moldboard plow by Adley Peltier from the Botanic Gardens at Burden.

Site after first tilling in February, well drained area with full sun.

Based on a need to develop more data regarding organic fertility in vegetable crops, the LSU AgCenter has designed a two year study to determine the value of an organic fertilizer as a substitute for conventional fertilizer for the urban agriculture community.


1. Evaluate the efficacy of a local source organic fertilizer (composted chicken manure) on yield and quality of standard tomato cultivar.

2. Compare the economics of production of organic fertilizer source to conventional fertilizer sources at recommended amounts of nutrients on yield and quality of a stand tomato cultivar.

3. Monitor diseases and disease incidence and severity within a standard Integrated Disease Management (IDM) program.

4. Evaluate the microbial (generic E. coli and total coliforms) and physical (pH, ORP, temperature) qualities of irrigation water over the growing season.

Rationale: Recent trends in gardening indicate an interest in vegetable production using environmentally friendly practices. Many of the urban agriculturalists engaged in vegetable growing are well educated but lack basic knowledge of plant science and horticultural practices. Organic products are often advertised as environmentally friendly, safe, and economical, but lack any comparative, unbiased data to substantiate this claim. Several organic fertilizers are advertised and marketed as comparable to conventional recommended fertilizers in yield and cost. Many questions regarding the use and value of organic fertilizers and cultural practices are presented to parish agents and specialists. We have very little comparative data of organic compared to conventional fertilizers. Demonstration plots placed in strategic locations have proven to be an effective way of dissemination of knowledge. Information can be effectively disseminated through field days and /or personal visits to plots.


Locations: This study will be replicated at Burden Museum and Gardens, Red River Station and the New Orleans Convention Center.

Seeds of  the ‘Bella Rosa’ tomato will be hot water treated prior to seeding. Transplants will be produced in LSU Hill Farm greenhouses beginning the last week of January (2014) using sustainable practices. All transplants will be planted into the field between March 15 and April 1, 2014, depending on the production site location.

Field plots at all locations will be on raised rows at least 48” apart. Pre-plant fertilizer treatments will be applied in February and a t-tape type irrigation line will be laid on the flat top row before black plastic mulch is applied. A 12-16” flat surface is desired.

Ten plants will be placed into each plot. Each fertilizer treatment will be replicated three times, totaling 30 plants per fertilizer treatment and 90 plants per location. See plot map.

Plot Map (0.2 acres)


Skip Row

Skip Row















Each color represents a fertilizer treatment.

Fertilizer treatments will be as follows:

1. 600 lbs of 8-24-24 per acre rate (48-144-144). Recommended rate (RED) side-dress with CaNO3

2. 600 lbs of 3-2-3 organic fertilizer (18-12-18). Recommended rate (BLUE) side-dress with Nitrate of Soda

3. 1600 lbs of 3-2-3 organic fertilizer (48 -32-48) plus 600 lbs 0-16-0 Bone meal (0-96-0), plus 430 lbs of 0-0-22 sul-po-mag (0-0-95). Total nutrients applied will be 48-144 -144) (GREEN) side-dress with Nitrate of Soda.

IDM Program:

Diseases will be monitored and managed using a standard IDM program.

1. Seed will be hot water treated prior to seeding to eliminate bacterial pathogens that are on or within the seed coat. A preventative fungicide (Captan or Thiram) will be re-applied to the seed to prevent damping-off.

2. Transplants will be treated with Agri-Mycin 17 2-3 days prior to transplanting. If bacterial disease symptoms are observed prior to transplanting Agri-Mycin 17 or Champ WG will be applied on a 7-10 day schedule. Seedlings (3-4 week-old) should be monitored daily for disease symptoms.

3. At planting transplants will be drenched with Fontelis to protect against Southern blight.

4. A preventative spray program of Quadris Top alternated with Bravo Weather Stik will be initiated 3-4 weeks following transplanting.

5. Sustainable pesticides will be selected and applied as needed.

Water Quality:

1. Water (120 ml, 5 replications) will be collected and evaluated for coliforms and generic E. coli throughout the production period (beginning, early, late and end of season).

2. The following parameters will be measured at each sampling:

a. pH

b. oxidation reduction potential (ORP)

c. temperature

Data Collection:

1. Water quality (see above).

2. Disease presence, incidence and severity will be measured from seeding through to the last harvest date. The total number of plants per plot with disease symptoms will be counted. Foliar disease symptoms will be rated on a scale of 0-100%. Fruit will be evaluated for diseases, sorted, counted and weighed at each harvest.

3. Plant vigor and size will be noted at first harvest. Average plant height will be recorded and plant foliage will be given a visual rating of 0-5 (0 being dead and 5 full and dark green foliage).

4. Yield will be measured by harvesting at breaker stage on a weekly basis for 5 weeks. The total number and weight of fruit per plot will be recorded.

5. The marketable yield (based on USDA standards) will be determined by separating the marketable fruit from total harvest.

6. Earliness will be determined by weights of marketable fruit from the first three harvests.

7. Yield evaluation will be made on early and total marketable yield per plant.

Dissemination of results: Data will be analyzed and presented in charts, tables or other appropriate forms for presentation at field days. The data will be presented at the annual Louisiana Fruit and Vegetable Field Days at the Burden Museum and Gardens. Out-field tests will be used at field days arranged by the local county agents and LCES personnel involved. This entire trial will be replicated in the spring 2014 and spring 2015 seasons. Final results will be prepared in such a way to be published in Hort Technology or comparable refereed journal.

3/11/2014 6:23:31 PM
Rate This Article:

Have a question or comment about the information on this page?

Innovate . Educate . Improve Lives

The LSU AgCenter and the LSU College of Agriculture