Updated: Apr 26
We are working on registering a bacterial based product (Chitatrol) as a bio pesticide to replace fungicide applications for large scale applications. The product has been registered in many other countries and will be available in Canada soon.
Efficacy Study for Chitatrol
Conducted for Biopesticide Registration in
“PROVINCIA VALVERDE MAO” DOMINICAN REPUBLIC.
Black Sigatoka is a fungal disease that causes up to 50% banana yield loss, and is caused by the fungus Mycosphaerella figiensis.
During the period from January 23 to April 30, 2017, Phase 1 efficacy test was carried out in the banana region of Santiago Province, Dominican Republic, evaluating the application Chitatrol Powder and Chitatrol aqueous blend (Simple Hydration of Powder in Water) formats for the control of Black Sigatoka.
The local “Best Practice” application of fungicide is based applying a fungicide immediately when the index “Evolutionary Development of the Disease” reaches the 200 level. This means that a ready-to-use liquid or powder that does not require significant preparation time would be preferable to a curative solution that may take 2 to 4 days to prepare prior to application. Therefore, Phase I did not include the “brewing” procedure, which is preferred for greater cost efficiency and efficacy.
Phase 2 was conducted from July 22 to August 19, 2017, in the Coral Castle Project, which consists of 85 hectares of organic banana crops. Coral Castle Project is in the province of Valverde Mao, in the northeast of the Dominican Republic. The Chitatrol and “local best practice fungicide” dosing commenced 90 days after planting.
At this stage of the crop cycle, and due to high rainfall and high temperatures during that period, the bananas were experiencing a high Evolutionary Development of the Disease (the major forecasting parameter used for timing the fungicide treatments to the banana crop). In the Dominican Republic, an Evolutionary Development of the Disease value greater than 200 indicates that fungicide application is immediately required.
II. CHARACTERISTICS OF THE CULTIVAR
III. CHITATROL CHARACTERISTICS
The standard Chitatrol Powder was used in Phase 2, and standard brewing procedures were used as well.
IV. Difference between Phase 1 and Phase 2
During Phase 1, ready-to-use Chitatrol powder was applied at dose rates of 226 grams, 454 grams, and 904 grams per hectare.
During Phase 2, the intention was to demonstrate the difference in efficacy between ready-to-use powdered Chitatrol, and “brewed, brewed” Chitatrol.
Whether for ready-to-use powder, or brewed versions of Chitatrol, 1500 grams per Ha was the chosen dose rate in Phase 2 procedures. Note: the dose in Phase 2 for both ready-to-use Chitatrol and “Brewed” Chitatrol was higher than the strongest Phase 1 dose (908 grams per hectare), as the banana crop was already at a high value for Evolutionary Development of the Disease when dosing began (90 days after planting, with the index well in excess of 200).
Chitatrol was brewed as follows for each dose during Phase 2:
· 200 litres of water were added to an open top, 55 gallon drum
· The drum was equipped with 25 litres per minute of diffused air, and a small heater to maintain temperature at 27 C
· The 200 litres of water were chlorinated to sterilize, then dechlorinated, and brought to 27 C
· 908 grams (2 lbs) of Chitatrol were added to the aerating drum
· Aeration was maintained for 72 hours, at which time the batch was considered complete
Upon completion of the batch, liquid from the bioreactor was used within 24 hours of batch completion to treat the banana plants for control of Black Sigatoka.
V. PROCEDURES for FUNGICIDE PREPARATION AND APPLICATION
During Phase 2, the banana farm used Phyton-27 (Phyton Corporation, Bloomington, MN), as the “control / best practice” fungicide. Phyton 27 information as follows:
· Phyton 27 is a broad-spectrum, systemic bactericide + fungicide. Phyton 27 contains copper sulphate pentahydrate (21.4 %), equivalent to 5.43% copper metal.
· Label Dosage: 1 L / ha. 1 litre Phyton-27 is diluted into 100 gallons of water then applied. According to product label and SDS, Phyton-27 can be used in 20 or more successive weekly applications.
VI. GEOGRAPHICAL AND AGRO ECOLOGICAL LOCATION
Phase 2 was conducted at the Coral Castle Farm in the province of Valverde Mao, in the northeast of the Dominican Republic. Coral Castle Farm grows 85 hectares of organic banana.
VII. TRIAL DESIGN PROTOCOL
Block Design was used to define the trial areas at random. For this, each Block was then then divided into three distinct treatment cells T1, T2, and T3 (see example Chart 2 below). The designated area of each cell (10 m x 10 m) conformed to the recommendations for Black Sigatoka research.
Chart 2: (Note that NemaFix = Chitatrol)
During Phase 2, each cell received three product applications, specifically at 90, 104 and 118 days after planting. Actual dates of dosing were July 22, August 5, and August 19, of the year 2017.
A. Phyton-27 Dose (T1)
As per the label dose of 1 litre per hectare, each 10 x 10 cell received a dose of 10 ml Phyton-27. A single 20-litre backpack sprayer was loaded with 54.6 ml Phyton-27 and filled with water.
This backpack sprayer was used to dose Phyton-27 in each 10 x 10 m cell. Each T1 / 10 x 10 m cell was dosed with 3.67 litres of backpack solution. At this aqueous application rate, each cell received 10 ml Phyton-27 per dose (1 litre per Hectare equivalent)
B. Ready To Use Chitatrol (T2)
To achieve the intended dose of 1500 grams powdered ready-to-use Chitatrol per hectare, 81.7 grams of powdered Chitatrol were added to 20 litres of water in the backpack sprayer.
Using this backpack sprayer, Each T2 / 10 x 10 m cell was dosed with 3.67 litres of backpack solution. At this aqueous application rate, each T2 cell received 15 grams ready-to-use Chitatrol per dose (1500 grams per Hectare equivalent)
C. Brewed Chitatrol (T3)
Brewed Chitatrol was taken from the finished “activation batch” as described in Section IV. A total of 18 litres of well mixed liquid from the finished batch was added to the 20 litres backpack sprayer, and another 2 liters of water was added to fill the backpack sprayer to the 20 litres level. Once diluted this way, the backpack sprayer contained the equivalent of 81.7 grams of Chitatrol (before activation) in 20 total liters.
Using this backpack sprayer, Each T3 / 10 x 10 m cell was dosed with 3.67 litres of backpack solution. At this aqueous application rate, each T3 cell received the equivalent of 15 grams ready-to-use Chitatrol per dose (1500 grams per Hectare equivalent). As noted, in T3 treatments, the Chitatrol was subjected to the “brewing” procedure.
Table 3 is a summary of the dose applied to each treatment cell:
D. T1 / T2 / T3 Application Dates
Applications of Phyton-27, powdered / ready-to-use Chitatrol, and brewed Chitatrol were made on the following dates (summer of 2017).
VIII. Evaluation of the Data
The parameters that make up the Evolutionary Development of the Disease are as follows:
· Youngest Infected Leaf
· Foliar Emission Rate
· Evolutionary Development of the Disease
The values of each parameter were obtained or calculated weekly, taking the average of:
· All T1 areas in each of three test blocks
· All T2 areas in each of three test blocks
· All T3 area in each of three test blocks.
Results were as follows:
A. Youngest Infected Leaf
As shown in Table 5, in T1 treatment cells (Phyton-27), infected leafs appeared at around 7 days, while the infection was delayed until 7.55 days in T2, and 7.65 days in T3.
B. Foliar Emmission Rate
The average foliar emission rate for T1 was 1.2, while that for T2 and T3 was 1.3 for each. These data are similar to those of Phase 1, where there was little difference in the foliar emission rate.
C. Evolutionary Development of the Disease
Table 6 below shows the values for Evolutionary Development of the Disease throughout the duration of Phase 2:
Table 6: Evolutionary Development of the Disease (>200 indicates significant fungal infection)
Data from Table 6 are graphed vs time in Chart 3:
During Phase 2, brewed (activation of Chitatrol) was evaluated relative to an equivalent dose of powdered Chitatrol (without activation) as well as to the local “best practice” application of Phyton-27.
The Chitatrol dose (both for brewed and ready to use variants) was 1,500 grams per ha, as the Evolutionary Development of the Disease was well above the upper threshold value of 200 at the time of the first dose.
As shown by the chart of Evolutionary Development of the Disease, the “best practice” use of Phyton-27 appeared to at least marginally slow the progression of Black Sigatoka, but the average Evolutionary Development of the Disease was 206 in the five evaluations after the first dose of Phyton-27. Limited control was attained, and the disease remained at or above the danger level.
After the initial dose, the average Evolutionary Development of the Disease was 152 for the powdered Chitatrol (ready to use), while the average value for brewed, brewed Chitatrol was 63.
The data show that doses of powdered Chitatrol (without activation) resulted in increased suppression of Black Sigatoka relative to the Best Local Practive (Phyton-27). However, activation (brewing) of Chitatrol resulted in superior suppression of Black Sigatoka, outperforming both ready to use, non-brewed Chitatrol, and the local “best practice” Phyton-27.
One consideration is that fungal diseases may appear suddenly, or become significant before the farmers notice a problem. When this is the situation, the following strategy is therefore recommended.
As noted in Section IV, standard brewing of Chitatrol (2 lbs in 50 gallons of water at 27 C, aerated vigorously with diffused air for 72 hours), the 3-day preparation time may be problematic when a fungal infection is already significant. Waiting three days might before dosing brewed Chitatrol could result in worsening infection.
Of course, planning ahead and dosing with brewed Chitatrol when fungal infections are expected makes sense, as this will prevent the infections, plus, Chitatrol has significant plant growth promoting function as well. But when this is impossible, hydrating powdered Chitatrol, without brewing, is still more effective than Phyton-27 and will provide some immediate relief of fungal infections.
When using non-brewed Chitatrol, when you cannot wait the 3 days for proper brewing, we recommend:
Applying as soon as any fungal infection is noticed
Use a dose rate of 100 to 600 grams per acre (depending on the severity of the fungal infection)
Mix with water at a sufficient ratio to obtain good coverage
Target the infected areas. If this means backpack spraying or other means to closely target the infected area, results will be optimal. Otherwise broadcast onto the crop as best as possible
While the above procedure is recommended to mitigate fungal infections that appear unexpectedly, better results will be obtained with brewed Chitatrol for best results with brewed Chitatrol, apply at the rate of 5 to 20 gallons of brewed Chitatrol per acre, targeting the infected areas as best as possible.
For more science on how Chitatrol works, check out our head scientist's presentation, where he talks about Chitatrol at about 25:45 in the video below: