A Question ofInvasiveness

By Ken Love

Feb. 11,2004


There is a question of invasiveness regarding some of thechoices for fruit in the 12 trees project. In a poll of Big Island chefs fourfruit types they choose are on various invasive lists, including their numberone choice of Mysore raspberry. This can be addressed in a number of ways. Witha balance of proper horticulture, effective marketing and protective fruitwraps, invasiveness should not be an issue. A brief outline of the fruit andhorticultural procedures for its production follows.


The species in question are:


Botanic name               CommonName           HawaiianName


1.         Psidiumcattleianum   Strawberry guava         waiawi

2.         Physalisperuviana       Capegooseberry         poha

3.         Rubisnieveus              Mysoreraspberry        --

4.         Eriobotryajaponica     Loquat                         --



Strawberry guava


Native to Brazil, strawberry guavais thought to have been introduced to Hawaii in 1825 by the British voyagingship Blonde. Invasive references mention the fruit as problematic in moist andwet rainforest areas. In Kona, especially the lower elevations, there are veryfew trees. Those that exist are cultivated in home gardens. In some cases theyseldom fruit for lack of rainfall or immature fruit will abort.  In South Kona starting at the 1200-footelevation the trees will fruit in years where there is a significant amount ofrainfall. There has been no significant amount fruit on wild or cultivatedtrees (without irrigation) in the past 16 months. Previously these trees haveproduced a fair amount of fruit, larger when the trees are shaded or when thefruit is thinned. These are what chefs have expressed an interest in. In orderto provide culinary quality, the fruit must be grown in protective bags

(http://www.hawaiifruit.net/bags.htm)  to prevent birds, fruit flies and otherpests from attacking it. Trees are kept at a height, which is conducive tobagging and harvesting without the use of ladders or picking devices.


In a marketing test a few yearsago, approximately 60 pounds a week here harvested and sold at a local store inCaptain Cook. Other samples were sent to chefs where the fruit was used on thebuffet line and with in-room amenity baskets at hotels. With a current workingprice of $2.00 per pound, we are unable to purchase enough fruit for furthermarketing tests with hotels or groceries. As the trees in South Kona did notflower last year, further tests will have to wait. 


The fruit is spread by seeds thatare prolific but not viable for long periods of time.

As all fruit for culinary purposesis grown in protective bags, fruit from trees planted as part of the 12 treesproject would be contained. A growing guide for strawberry guava would warn ofthe potential for invasiveness in moist areas and encourage the use ofprotective wraps. It would also encourage fruit thinning and potentially theharvest of fruit from wild but public areas thus decreasing possible futureinvasiveness.



There are 2910 references to “Strawberry guava inHawaii” on Google.








Weeds of Hawaii’s Pastures and Natural Areas by PhilipMotooka et al.



Cape gooseberry or Poha


Native to Peru, Chiles and Brazil, the poha is generallythought to be naturalized in Hawaii from 1000 to 6000 foot elevations in mesicto wet forest areas. Thought to have arrived in Hawaii prior to 1825, it hasbeen cultivated with some success. The fruit is popular to the point whereCTAHR has published a Horticultural fact sheet and propagation guide. In 1966the university worked to develop equipment for husking poha. A quick poll of 20restaurants, both free standing and in hotels, revealed that all but 2 use pohain some of their dishes. Many of the Internet searches feature Hawaiianproducts with poha.


Poha has been included in the “other” categoryin the Hawaii Agriculture Statistics Service fruit survey signifying that thereis a marketed production. In the newly issued survey, poha has earned its owncategory.


In January and February of 2004 both state and USDAinspectors checked shipments of poha coming into Hawaii from outside the stateshowing that the demand for the fruit is growing. The working retail price is$7. Per pound. Yield per plant is 300 berries or just over 2 pounds per bush.With recommended spacing, an acre of poha can yield 3000 pounds of fruit in thecourse of a season.


In order to achieve a maximum yield, poha is generallychecked daily during harvest season in order to prevent insect damage once thehusk has fallen. As the bush is seldom over four feet in height, it is easilytrellised and can be netted to prevent bird damage.



There are 470 references to “Poha in Hawaii” onGoogle.







Weeds of Hawaii’s Pastures and Natural Areas by PhilipMotooka et al.



Mysore raspberry


Native to India andBurma, the berry was said to be introduced to Hawaii in the 1880s.

It is listed as noxious for a number of areas that the stateidentifies. “Risk areas are moist and wet forests from almost sea levelto 7000 foot elevation” Areas identified in much of the referencematerial below, refer to elevations above the 2000 foot level where there issignificant rainfall. The 12 trees project site is at about 300 foot elevationin a dry area. Irrigation would be required for the plants.


In the newly issued Hawaii Agriculture Statistics Servicesurvey, Mysore berry has earned its own category.


The fruit was the number one choice of Big Island chefspolled as part of the 12 trees project. http://www.hawaiifruit.net/12trees.html  .The working price is $7.00 per poundwith 3000 fruit or about 13 pounds per cane grouping. Over the past 8 yearswe’ve worked extensively with 2 cane groups that have not spread at allin a 10 acre area.

Cultivated in many countries and parts of the US, includingKona, the berry can be controlled with proper horticulture, pruning andharvesting. Weekly pruning prevents the thorny cane shoots from becoming out ofcontrol. Harvesting every few days prevents animal destruction of ripe fruit.At one Kona site, the plant is trellised and cut back twice yearly. Withpruning, plants can be shaped and kept at a three to four foot height making itpossible to net or place a screened box around the canes.  For the purpose of yield, trellisingseems to be more effective.  Thiscombined with aggressive pruning of shoots can prevent invasiveness.



There are 1280 references to “Mysore berry inHawaii” on Google.










Weeds of Hawaii’s Pastures and Natural Areas by PhilipMotooka et al.



Indigenous to Southern China, the loquat was first thoughtto have entered Hawaii with early Chinese immigrants in the 1870s.

The state has identified risk areas as moist and wet areasup to 5000 foot elevation.  Said tobe spread by birds and animals, the loquat can easily be contained with properhorticulture by using examples set in Spain, China and Japan. They are thelargest commercial producers of the fruit. In China and Japan the fruit is thinnedin the green stage then wrapped in protective bag until harvest.  This insures the fruit is pest free andhas no bird damage. Trees are kept at a two to three meter height to facilitatewrapping and harvesting of fruit.


Loquat has been included in the “other” categoryin the Hawaii Agriculture Statistics Service fruit survey signifying that thereis a marketed production. In the newly issued survey, loquat has earned its owncategory.


Arguably one of the most popular fruits in the world, theloquat is virtually unknown in the U.S. It represents a considerable marketpotential for Hawaii as our harvest time is months ahead of other locationswhere the fruit is very popular. The potential for marketing in Japan is beinginvestigated although no request for a pest risk assessment has been submitted.At present, there is not enough commercial production to warrant the request.Japan’s production begins in late March and peaks in May while in Hawaiiharvest begins in late November with peaks in January. Multiple flowering andfruiting is fairly common although not regular without irrigation. Hawaii couldprovide the fruit for the New Year gift giving season in Japan once productionand quality standards are established. The market potential in Japan would be assessedat a multi-million dollar level.


With current production estimated at 2000 pounds and pricedat $2.50 to $3.50 a pound,

The extent of distribution has been limited to hotels, a fewlocal groceries in Kona and farm stands. Demand by hotels alone far exceeds production with additional requestsfor quantity of fruit from other islands and wholesalers.


The Big Island chefs choose loquat as the third mostrequested fruit they would like to work with, following the Mysore berry andfigs. It is one of he world’s oldest cultivated fruits with an estimated900 named varieties. Most parts of the plant have some use. The leaves havebeen used in tea for thousands of years in China where loquat herbal coughmedicine is also common. New varieties that have passed the USDA quarantineperiod are expected to help create new opportunities for Big Island farmers.



There are 17 references to “Loquat invasiveness inHawaii” on Google.

There are 9360 references to “Loquat in Hawaii”on Google.















Weeds of Hawaii’s Pastures and Natural Areas by PhilipMotooka et al.





Although there is always a chance that fruit from cultivatedfruit trees can “escape” into the wild, the issue can be addressedwith proper horticulture. Following the examples set in Asia, protective fruit wrapping isessential for fruit quality and consistency regardless of theinvasiveness.  Frequent harvestingfor freshness is another key to the success of building markets for unusualfruit.


The goals of the 12 Trees Project are to promote sustainableagriculture while providing positive economic alternatives for farmers. This,combined with the simultaneously building of production and markets for 12types of fruit chosen by chefs, will help to enhance rural economic developmentfor farmers and fruit growers.