In temperate climates, fall is usually harvest season. In the tropics, crops ripen year-round. For those who want to harvest their fruit at its peak and have it last on the shelf or in transit, specific advice can be helpful.
The University of Hawaii recently released a publication that gives advice on harvesting and handling many types of fruit. “Quick Harvest and Postharvest Tips for Better Quality and Longer Postharvest Life” covers lots of exotics as well as more common fruit that many of us grow in our backyards.
You’ll find information on fruit maturity, harvesting, storage and packing for 31 fruits in this publication. A chart with additional information on storage temperatures and humidity as well as postharvest life and ethylene sensitivity is included.
The publication notes that “no single criterion to judge harvest stage is available” for avocados. We knew that. They do however cite several helpful tips. Sharwil and some other varieties, show skin dulling at harvest time, while Kahaluu lightens and dulls at maturity. Though skin color is not always a clue, a full black color on the Malama indicates ripeness. Another way to test is to pick a few full-grown fruit with stems attached. If they take longer than a week to ripen and soften, they are not ready for harvest.
With bananas, the publication advises harvesting when the fruit is fully filled out. Bananas will suffer less damage in transport if you cut the fruit into hands and pack it carefully. Even when green the fruit is easily bruised and requires care in handling.
The best time to harvest breadfruit is dependent on your taste. If you want a starchy vegetable it should be harvested earlier than if you want to eat it soft and sweet. Latex drips on the outside of the fruit as well as color changes from green to yellowish are good indicators of maturity. Breadfruit is one of the tropical fruits that will last longer if kept cool.
Starfruit or carambola should be harvested when yellow. Though they are best when the midrib sections of the fruit are orange, the fruit can ripen off the tree. If starfruit are being transported, they will likely suffer less damage when they are not fully ripe. They can last up to 21 days with refrigeration.
The publication notes that jaboticaba also will last longer with refrigeration but shelf life for this fruit once harvested is usually less than a week. Washing the fruit immediately in cold water can help extend the postharvest shelf life.
Jackfruit is best when fully ripe and sweet. The fruit usually gets softer as it approaches ripeness. Tapping the fruit to listen for a hollow sound is another way to test for ripeness. Experienced growers will often make three diagonal cuts in the stem above the fruit to drain the latex and speed up ripening. Cool temperatures and good ventilation can help jackfruit last for several weeks postharvest.
Papayas that are at least one-quarter yellow are ready to harvest and will ripen fully off the tree. The more yellow on the fruit, the sweeter and softer it will be. Though fruit harvested at one-quarter ripe may last up to three weeks on the shelf, tree-ripened fruit will be sweeter and more flavorful.
Knowing when to harvest lilikoi is easy as the fruit usually falls from the vine once it is ripe. Because the skin is thick, the fallen fruit is usually not damaged and will ripen further once it falls. Lilikoi is another fruit that benefits from cold storage postharvest.
Poha is a wonderful fruit to have as a gardener’s snack. It is popular with kids and chickens love them. It has also become popular in Hawaiian regional cuisine. Though chefs and market buyers prefer to buy them without the paper lantern husks, the extra labor required seriously diminishes any profit possibilities and shortens their shelf life.
Check out the full publication at ctahr.hawaii.edu/oc/freepubs/pdf/F_N-36.pdf.
Tropical gardening helpline
Patricia asks: This year my passion fruit has some green spots and brown patches which I haven’t seen before. The fruit seems the same on the inside but tastes a bit more sour than last year. We have had more rain than usual this summer. Any ideas what this could be?
Answer: On checking with Scott Nelson — snelson@hawaii.edu or The Plant Doctor phone app — it seems likely that you have anthracnose, Glomerella cingulate, on your passion fruit. Though this disease can be serious, it may only affect the outside of the fruit this season if you pick and use them soon after they drop. Though it can eventually affect the leaves, stems and flowers, if you have a good supply of fruit this year, it has probably not progressed to the latter stages. Most anthracnose spores are host specific so they will not likely spread from lilikoi to other plants.
The disease may have gotten started if or when you did not pick up rotting fruit from the ground in the past. It is hard to get rid of anthracnose in our warm, wet climate where passion fruit grows best. Once it gets started, however, you can do several things to control it. Collect the fallen fruit as soon as you can. Anthracnose is usually spread by water or wind but can sometimes be vectored by fruit flies. The flies will come once the fruit starts to rot on the ground. Fruit fly control can be helpful.
Several options for fruit fly control are available. Contact Mike Klungness at mklungness@pbarc.ars.usda.gov or Steven.Souder@ars.usda.gov if you want to do large-scale control. Andrea Kawabata at UH CTAHR cooperative extension in Kainaliu may also have information as well as lures for traps for smaller farms or gardens. Several homemade trap designs are available online as well.
Once the season is over, you should prune your vines. Get rid of any infected flowers, fruit or leaves. Healthy new growth may be somewhat resistant to the disease. To be absolutely sure you don’t continue the cycle, you can remove your current plant and plant another in a different location.
You can apply a fungicide after you prune and again before fruit forms to kill spores that spread the disease. Be sure to use a fungicide that the label specifies is safe to use on passion vine.
Meanwhile, enjoy collecting and consuming this year’s harvest and plan to take action at the end of lilikoi season.
Email plant questions to konamg@ctahr.hawaii.edu for answers by Certified Master Gardeners. Some questions will be chosen for inclusion in this column.
Diana Duff is a plant adviser, educator and consultant living on an organic farm in Captain Cook.