Jump Starting New Pawpaw Variety Production for the Industry: Developing Grafting and Top Working Approaches for Growers

View the project final report

• 2016 annual report
• 2017 annual report

Commodities

• Fruits: general tree fruits

Practices

• Crop Production: agroforestry
• Production Systems: permaculture

Pawpaw, a tree fruit native to the Eastern U.S., is in small-scale commercial production with its popularity on the rise. Pawpaw fruit have fresh market appeal for farmers markets and Community Supported Agriculture (CSAs), and processing appeal for frozen pulp production for sale to gourmet restaurants. Many small farmers have seedling pawpaw trees or wild trees that produce small yields and low quality fruit. New commercially available pawpaw varieties are now available and new cultivars are being developed that will increase yield, fruit quality, and consumer demand.

There are over 100 limited resource farmers in Kentucky alone who have small plantings of seedling pawpaw trees or wild trees that with grafting and top working could serve as rootstock and enable rapid production from grafts of high quality and high demand pawpaw fruit. Bark inlay is a grafting technique which allows the union of a rootstock limb or trunk (at least 1 to 2 inches in diameter) that is much larger in size than the scion piece. This technique has been used by apple producers to change the variety of an existing orchard (top working), adding a branch of an untested scion cultivar to an existing tree for observation, or repairing a tree that may have had a branch broken off by storm damage or fruit overloading. This technique has not been well developed for pawpaw and represents a method for growers to change over to higher yielding and high quality fruit cultivars.

Experiments will be conducted using established seedling trees with methods to reduce negative effects of spring heating of grafts, as well as improve timing for successful spring grafting and cultivar selection to optimize this technique for farmers. The objectives of this proposal are to: 1) develop methods to optimize bark inlay grafting success by cultivar, grafting time, and heat reduction on grafts on large pawpaw seedling rootstock trees in the field at KSU and grower locations, 2) examine scion take, flowering, and fruiting response time of varieties propagated by inlay grafting, and 3) create extension bulletins and YouTube videos concerning how to successfully graft and top work pawpaws and offer to growers; hands on grafting workshops will also be offered. Grower trials will serve as demonstrations and workshop sites in coordination with the Kentucky Nut Growers Association and the Ohio Pawpaw Growers Association. This proposal will not only increase yields but will enhance high quality marketable fruit; thereby promoting a sustainable fruit production system with low inputs for limited resource farmers.

1) Develop methods to optimize bark inlay grafting success by cultivar, grafting time, and heat reduction on grafts on large pawpaw seedling rootstock trees in the field at KSU and grower locations,

2) Examine scion take, flowering, and fruiting response time of varieties propagated by inlay grafting to select for easy to propagate varieties,

3) Create extension bulletins and YouTube videos concerning how to successfully graft and top work pawpaws and offer to growers; hands on grafting workshops and “Third Thursday” workshops.