SFF Project Summary
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Updated: 12 March 2008
Final reportFact sheets
Nine fact sheets have also been produced for organic kiwifruit growers on
the following topics: soil systems, basic facts of plant physiology, monitoring
soil health, compost and compost tea, chilling and flowering, pollination and
organic kiwifruit, site selection, organic pest and disease management, and
economics of organic production.
Copies of these fact sheets are available to all registered kiwifruit growers on the Zespri Canopy webiste www.zespricanopy.com. Prospective growers or other parties can request copies from contactcanopy@zespri.com.
The problem/opportunity this project will address:
The economic viability of this important fruit export sector is threatened at a time of increased demand for organic produce. Organic kiwifruit often fulfils the role of "test bed" for new, more sustainable management techniques that are later adopted by conventional growers. Organic kiwifruit orchards are 25 30% less productive than conventional kiwifruit orchards. Poor productivity is the major factor deterring growers from converting to organic production. Low productivity is primarily due to poor bud break and small fruit.
The aims of this project: To address the problems of poor bud break and fruit size in experimental work and to produce a manual for the production of organic kiwifruit.
The work proposed:
- A manual of organic kiwifruit production practice.
- Increasing bud break on Hayward kiwifruit by trials of mineral, vegetable and fish oils.
- Increasing fruit size of Hayward kiwifruit by trials of three seaweed products.
- Monitoring effects of use of Compost tea in kiwifruit orchards by analysis of soil. leaves and fruit as well as yield and fruit quality.
March 2007
Increasing bud break on Hayward kiwifruit
Aims and method
This trial is intended to identify an organic method to enhance the bud break of kiwifruit vines. The project has already had some success with oils that influence bud break. This year we applied 3 different oils (mineral, vegetable and fish) to dormant canes during August and September. Oils were applied by hand with paint brushes to both vigorous and low-vigour canes. Budburst records were taken and the amount of flowering was recorded.
In trials run by our industry partners (Satara, Seeka, Trevelyan’s and Apata post harvest entities) mineral oil, pine and fish oils were sprayed on whole vines.
Progress
The results for the spring 2006 oil applications to single canes were consistent with previous results. On vigorous canes both Excel mineral oil and the fish oil increased bud burst and the number of flowers per winter bud. However on low vigour wood neither oil significantly increased bud burst. Addition of a spreader to the Excel oil did not increase bud burst. The pine oil did not significantly increase bud burst.
The field trials on whole vines are continuing through to harvest. So far the Excel oil sprayed on whole vines did not increase bud burst as we expected. We need to improve the application technique to ensure adequate coverage of oil on the upper side of canes. This may require addition of an adjuvant. While not all results are in yet, the BioSea Bud Break oil that was applied to whole vines in field trials on one organic orchard gave a small increase in bud burst, but this was not statistically significant. We are waiting on data from the other packhouses.
Can compost tea increase productivity of kiwifruit?
Aims and method
This trial aims to measure the effect of applications of compost tea on kiwifruit vines and the soil in which they grow. Compost tea is used by some organic growers to improve the microbial conditions in the root zone and hence improve root health, nutrient uptake, and hopefully fruit size. This trial is a long term one which started in spring 2004 and will record the gradual changes which may occur over three growing seasons.
Different compost teas were applied to the soil in selected sites at seven organic kiwifruit orchards in 2004/05, 2005/06 and again in 2006/07.
The trial is currently in the third and final year.
Progress
Harvest yield data was collected at harvest in May/June, and fruit was analysed for chemical composition. The results of the 2006 harvest data did not reveal any difference in fruit weight, yield, brix or dry matter which could be attributed to the application of compost tea.
Soil samples taken over the 2006/07 summer were analysed for chemical properties at Hill Laboratories and for biological activity at the Soil Food Web laboratory. The results for soil pH, P, K, Ca, Mg, Organic Matter, CEC, Total N, Available N, showed no effect of compost tea application. There was no difference in the soil penetrometer readings or the soil moisture retention. The results for the November biological activity tests showed no difference between the control and treatment, but all measures of biological activity were very low. It was thought that this may have been due to the dry conditions at the time, so the sites were resampled in February this year. The second sample confirmed the results of the November samples, again showing lower activity. The active bacterial biomass of the compost tea soils is higher than the control in most of the samples, but the significance of this has not yet been tested. The other soil biology tests show no clear effect which could be due to the compost tea applications.
Fruit counts and samples will be taken at harvest to measure yield and harvest attributes.
Development and production of fact sheets and manual for organic kiwifruit growers
Aims
To gather current knowledge on organic kiwifruit production into one accessible resource that will be available to all growers.
Progress
Zespri and HortResearch are jointly developing a set of fact sheets which will sum up the collective current knowledge that relates to organic kiwifruit production. This will include a survey of growers, a literature review and the various fact sheets.
The fact sheets are mostly complete and have been circulated for review.
Quarterly Update: October 2006
1) Increasing bud break on Hayward kiwifruit In this third and final year we are:
a) Screening and testing some more oil (plus adjuvants) on single canes
b) Conducting trials, using whole vines, of BioSea fish oil, Excel mineral oil plus a spreader and a pine oil (Enhancer).
c) Doing some extra microscopal work to try to identify the mechanism that makes the oils more active when used with adjuvants. The oils have been applied and the bud break is being measured during the spring, as the buds develop.
2) Can compost tea increase productivity of kiwifruit?
This is the final year for this section of our project. As in the first two years, compost tea from several manufacturers is being applied to the soil of organic orchards while leaving control plots which have no compost tea. Soil, leaf and compost tea samples are collected during the growing season and fruit will be collected at harvest. We hope to detect measurable changes in soil biology and chemistry which might lead to better yields of kiwifruit.
3) Development and production of fact sheets and manual for organic kiwifruit growers
This part of the project aims to gather current knowledge on organic kiwifruit production into one accessible resource that will be available to all growers. Zespri and HortResearch are jointly developing a set of fact sheets which will sum up the collective current knowledge that relates to organic kiwifruit production. This will include a survey of growers, a literature review and the various fact sheets. The fact sheets are mostly complete and will be progressively circulated for review over the next four months.
March 2006
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Increasing bud break on Hayward kiwifruit
Aims
This trial seeks to identify some organic alternatives to enhance bud break in kiwifruit. We applied 3 different oils (mineral, vegetable and fish), in a range of concentrations and on two different dates, to dormant canes during August and September on 2004. Budburst records were taken and flowering dates recorded. More oils and combinations of oils and nitrogenous additives and adjuvants were applied in the spring of 2005. In addition to this, the best fish oil from last year was tested on whole vines in commercial orchards.
Results
The results for the 2005 oil applications have not been as consistent as in 2004. The warm winter and spring conditions produced poor natural bud burst and it seems that it is more difficult to influence budburst in such seasons. While one of the oils (Excel) had a positive effect on Hayward bud burst, the rest were not as effective as in 2004. The addition of a spreader to the oil improved the effect.
While not all results are in yet, the BioSea Bud Break oil that was applied to whole vines in field trials on four organic orchards does not seem to have had a big effect on budburst.
We need to further investigate the reasons for the inconsistent results.
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Increasing fruit size on Hayward kiwifruit
Aims
This trial aimed to screen some commercial seaweed extracts for their effectiveness in stimulating fruit size in Hayward and Gold kiwifruit. No differences were detected in the limited trials carried out in 2004. Resources for this project have been redirected to the bud burst investigation.
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Can compost tea increase productivity of kiwifruit?
Aims
This trial aims to measure some of the effects of applications of compost tea on kiwifruit vines and the soil in which they grow. This trial is a long term one and will record gradual changes over three growing seasons.
Different compost teas were applied to the soil of plots marked out in seven organic kiwifruit orchards over the 2004/05 and 2005/06 growing seasons. A variety of soil, leaf and fruit tests were made.
Results
The data from the first year (of what will be a three year trial) establish a base line from which we hope to be able to observe changes in the biological composition of the soil and vines over the next two years.
We measured soil fertility with standard soil tests, soil biological activity using the Soil Food Web laboratory, leaf and fruit composition and crop yield.
The results from the first growing season showed no significant differences between the various compost tea treatments and the control plots. There was considerably more variation in the results between the different participating orchards than between the treatments within the same orchard.
So far there is no clear pattern emerging yet in the data from the current season. However any changes are likely to be slow to emerge and we have one more season to run on this project. Work is continuing.
September 2005
1) Increasing bud break on Hayward kiwifruit Aims
This trial seeks to identify some organic alternatives to enhance bud break in kiwifruit. We applied 3 different oils (mineral, vegetable and fish), in a range of concentrations and on two different dates, to dormant canes during August and September on 2004. Budburst records were taken and flowering dates recorded. More oils and combinations of oils and adjuvants have been applied to whole canes to repeat the process this growing season. Results There are some encouraging initial results that have come out of the project so far. All oils used had a positive effect on Hayward bud break, with a 10% increase in the number of winter buds bursting being achieved. The higher percentage bud burst resulted in a corresponding increase in flowers numbers. The date of bud burst was delayed by some oils and some high rates damaged buds. We have applied the best performing oil (BioSea Bud Break) to whole vines in field trials on four organic orchards to observe the effects on bud burst and fruit numbers in the 2005/06 growing season.
2) Increasing fruit size on Hayward kiwifruit
Aims
This trial aimed to screen some commercial seaweed extracts for their effectiveness in stimulating fruit size in Hayward and Gold kiwifruit. Three seaweed extracts, Seamac, Agrisea and Kingkelp, were applied at different times and rates to kiwifruit after fruit set. Different application methods were evaluated using Seamac as the common agent. Fruit was dipped, fruiting shoots were sprayed and whole vines were sprayed. Fruit size on the treated canes and vines was recorded throughout the growing season.
Results
1. Effect of seaweed extracts on green - there was no increase in fruit size recorded from any of the products.
2. Effect of seaweed extracts on gold - there was no increase in fruit size recorded from any of the products.
3. Effect of application method, timing and rate - none of the products had any effect on fruit size.
We had planned to use the first year results of this trial to screen products for more detailed field trials in the coming growing season. The lack of response in the first stage has caused us to re-evaluate this part of the project. There seems little point in further testing products when we have not identified any that were better than our control.
This is a valuable finding. Organic (and conventional) growers have been using these products for many years, based on the manufacturers’ recommendations. Growers have had only anecdotal reports to support their use of such products. The results for this trial mean that now we have evidence that they may not work as well as we hoped. It is important to note that the results we have are for the work carried out in one season, on one property. It is possible that the products work better in other seasons or at other locations.
3) Can compost tea increase productivity of kiwifruit?
Aims
This trial aims to measure some of the effects of applications of compost tea on kiwifruit vines and the soil in which they grow. This trial is a long term one and will record gradual changes over more than one season. Different compost teas were applied to the soil in selected sites at seven organic kiwifruit orchards over the 2004/05 growing season. Six of these orchards are continuing with the trial and will be applying more compost tea over the 2005/06 growing season.
Results
The data from the first year (of what will be a three year trial) establish a base line from which we hope to be able to observe changes in the biological composition of the soil and vines over the next two years. We measured soil fertility with standard soil tests, soil biological activity using the Soil Food Web laboratory, leaf and fruit composition and crop yield. The results to date show no significant differences between the various compost tea treatments and the control plots. There was considerably more variation in the results between the different participating orchards than between the treatments within the same orchard.
to June 2005
1) Increasing bud break on Hayward kiwifruit
Aims
This trial seeks to identify some organic alternatives to enhance bud break in kiwifruit. We applied 3 different oils (mineral, vegetable and fish), in a range of concentrations and on two different dates, to dormant canes during August and September on 2004. Budburst records were taken and flowering dates recorded. More oils and combinations of oils and adjuvants will be screened this season.
Results
There are some encouraging initial results that have come out of the project so far. All oils used had a positive effect on Hayward bud break, with a 10% increase in the number of winter buds bursting being achieved. The higher percentage bud burst resulted in a corresponding increase in flowers numbers. The date of bud burst was delayed by some oils and some high rates damaged buds. We will be applying the best performing oils to whole vines in field trials this growing season.
2) Increasing fruit size on Hayward kiwifruit
Aims
This trial aimed to screen some commercial seaweed extracts for their effectiveness in stimulating fruit size in Hayward and Gold kiwifruit. Three seaweed extracts, Seamac, Agrisea and Kingkelp, were applied at different times and rates to kiwifruit after fruit set. Different application methods were evaluated using Seamac as the common agent. Fruit was dipped, fruiting shoots were sprayed and whole vines were sprayed. Fruit size on the treated canes and vines was recorded throughout the growing season.
Results
1. Effect of seaweed extracts on green - there was no increase in fruit size
recorded from any of the products.
2. Effect of seaweed extracts on gold - there was no increase in fruit size
recorded from any of the products.
3. Effect of application method, timing and rate - none of the products had any
effect on fruit size.
We had planned to use the first year results of this trial to screen products for more detailed field trials in the coming growing season. The lack of response in the first stage has caused us to re-evaluate this part of the project. There seems little point in further testing products when we have not identified any that were better than our control.
This is a valuable finding. Organic (and conventional) growers have been using these products for many years, based on the manufacturers’ recommendations. Growers have had only anecdotal reports to support their use of such products. The results for this trial mean that now we have evidence that they may not work as well as we hoped. It is important to note that the results we have are for the work carried out in one season, on one property. It is possible that the products work better in other seasons or at other locations.
3) Can compost tea increase productivity of kiwifruit?
Aims
This trial aims to measure some of the effects of applications of compost tea on kiwifruit vines and the soil in which they grow. This trial is a long term one and will record gradual changes over more than one season.
Different compost teas have been applied to the soil in selected sites at seven organic kiwifruit orchards
Results
This is the first year in what will be a three year trial. Any effect from compost tea is unlikely to be observed in the first year. The leaf and soil test results and harvest data are used to establish the baseline, from which any changes in the following seasons can be compared. Data from the 2004/05 season will be available in the next quarterly update.
