State Chapter: Ohio Pawpaw Growers Association Contact the pawpaw discussion group: http://groups.yahoo.com/group/Ohiopawpaw Fall 2017 NAPGA Facebook page: http://www.facebook.com/NorthAmericanPawpawGrowers Volume 17, Issue 2 October. While “when they ripen” is subject to a large host of factors, it is the clear starting place President’s Patch by to begin. Typically pawpaws ripen in southern Ohio from late August to early October, but by As winter creeps along and I scramble to selecting early ripening cultivars, you can extend catch up on the newsletters, new handouts, the harvest season on both ends of the “normal” correspondence, old promises of handouts, season, early and late. This provides the grower etc., I thought that I would again express with a longer harvest season and thus, a longer some thoughts on one aspect of pawpaw culti- time to market your fruit. vation. As a starting point, I have collected a Another important consideration is selecting large majority of the existing varied genetic pawpaws for different uses. We have very little, material that is or has been commercially avail- if anything, to select cultivars for specific uses able, over 120+ cultivars. but just lump them together we they are sold. Speaking with new members about the We all know or should know that pawpaws do pawpaw cultivars that they are interested in, have different taste, texture, size, number of the conversation usually boils down to the larg- seeds, thickness of peel, etc. If this was not true est fruit and sometimes taste. However, there then why are we selling so many different culti- may be other factors to be considered when vars? Pawpaws can be eaten fresh, bread, pies, selecting pawpaw cultivars to plant. cakes, smoothies, salad dressing, sauces, pud- I am going to suggest a couple of addition- dings, wine, craft beer, drinking vinegars, etc. al characteristics that we should consider in se- Continued page 5 lecting pawpaw cultivars to plant. The first characteristic that we should consider is when Inside this issue the fruit ripens, i.e., early or late. I need to go through my notes and publish the data that I Mission Statement President’s Patch 1 NAPGA/OPGA Ambrosia Beetle & have documented on when pawpaws ripen. In Fusarium 2 some years, I have fruit that will ripen the last is an organization of pawpaw enthusiasts, backyard and Ambrosia Beetle. cont 3 week of July and some that ripens well into late commercial pawpaw growers, small and large, dedicated to Ambrosia Beetle, cont 4 promoting the superior traits of the pawpaw plant and fruit, NAPGA & OPGA past newsletters are archived at Nyomi’s Delicious 5 Ohio State University, Piketon, Ohio developing a pawpaw industry and marketing plan, http://southcenters.osu.edu/horticulture/publications/ preserving and studying the Asimina Webworm 6 newsletters/Ohio-pawpaw-growers-association-newsletters wild pawpaw genetics. Misc. Pictures 7 Recipe 8 Please check with Ron ([email protected]) regarding your membership status. NAPGA / OPGA Info 8 Ambrosia Beetle and Fusarium Wilt, Part II This is the third article on Ambrosia beetle, There are about 36 genera of ambrosia bee- one written by Jerry Lehman (“Pawpaw Pickin's,” tles, some of which include up to 200 species, Vol 17, Issue 1, Spring 2017) and one by Ron have been recorded throughout the world. A Powell (“Pawpaw Pickin's,” Vol 15, Issue 2, Fall number of species breed in living trees, but de- 2015). There is more to this complex than just teriorating, dying, or recently cut trees, logs, injury and death caused by the feeding of Am- pulpwood or stumps are usually preferred. All brosia beetles. species require a considerable amount of mois- There is no explicit definition of “ambrosia” ture for development. Seasoned timber is never beetles; however, the following criteria are often infested. used: There are three types of ambrosia beetle 1. Fungi represent the main source of food tunnels: consumed by both the adult beetles and 1. Simple larvae. 2. Branches 2. Fungi are transmitted by the beetles from one host to another and between genera- 3. Compound tions. Simple tunnels 3. Beetles are not able to survive and devel- are un- op on a fungus-free diet composed only branched, often of plant tissue. penetrating deeply into the Since no research on ambrosia beetles at- wood. tacking the North American pawpaw has been Branched tun- done, only non-specific comments can be made. nels penetrate Numerous species of beetles are known as am- deeply into the brosia beetles or pin-hole borers, because in all wood and then cases, both the adults and larvae feed on a mold break up into type of fungus, known as “ambrosia”. The bee- several branch- tles introduce this fungus into tunnels bored into es, which ex- the sapwood and sometimes heartwood of trees. tend in various The female ambrosia beetles possess specialized directions in the same plane. Compound tunnels pockets called mycangia. These structures are also branch off from a single entrance gallery variously located in and on the body of the in- but have egg niches extending from the sides of sect. In a few species, these organs are found in the tunnel. As these tunnels are excavated by the male. the female beetles, the beetles push the excre- ment (frass) and sawdust backwards, or to the Contact NAPGA or OPGA: http://www.NAPGA.com or http://www.Ohiopawpaw.com Contact the pawpaw discussion group: http://groups.yahoo.com/group/Ohiopawpaw NAPGA Facebook page: http://www.facebook.com/NorthAmericanPawpawGrowers 2 Ambrosia Beetle and Fusarium Wilt, Part II, cont. outside. The sticky mix- presence of a tiny (1/8”) entry hole (shot-hole) ture clings together as it on the underside of the affect branch. is extruded from the en- All stages of the beetle may be found in in- trance holes and has fested branches. Small infestations of the am- been commonly de- brosia beetle can be controlled by pruning out scribed as “frass tooth the infested twigs and branches. Spraying is of picks”. There are a num- limited value due to the overlapping genera- ber of ambrosia beetles tions. that produce the tooth pick-like” symptoms. Am- Maintaining healthy trees and shrubs is the brosia beetle galleries first line of defense against the ambrosia bee- differ from those of other tles attacking weak hosts. Maintenance in- wood boring insects in cludes: that they are: 1. Proper fertility 1. Uniform diameter, 2. Proper soil pH throughout 3. Adequate soil moisture 2. Free of borings or other refuse Long-residual sprays, if used, must be made to trunks and branches at short intervals through- 3. Their walls stained black or brown. out the growing season to provide complete Ambrosia beetles differ from the bark beetles protection of trees. Jerry Lehman in his article in several ways. While bark beetles burrow in on ambrosia beetles mentions that there is a the phloem spray that can be applied to control ambrosia or at the beetles when they are active. juncture of Just like the term ambrosia beetles, the term the bark and ambrosia fungi don’t refer to a specific group of sapwood, fungi. There are a number of fungi that were ambrosia adopted by the beetles during their evolution. beetles bore Fusarium sp. is one such fungus. There are through the three basic features that define ambrosia fungi: bark and in- 1. There are mechanisms assuring that the to the sap- fungi remain predominant associates of a wood. given ambrosia beetle, transmitted hori- The first signs of injury by the ambrosia bee- zontally between generations in my- tle are the drooping, wilting, yellowing of the cangia. foliage on the terminals of infected twigs and branches. Upon close inspection will reveal the Contact NAPGA or OPGA: http://www.NAPGA.com or http://www.Ohiopawpaw.com Contact the pawpaw discussion group: http://groups.yahoo.com/group/Ohiopawpaw NAPGA Facebook page: http://www.facebook.com/NorthAmericanPawpawGrowers 3 Ambrosia Beetle and Fusarium Wilt, Part II, cont. 2. The fungi are polymorphic producing fila- ments in the wood and a yeast-like mor- phology in mycangia. 3. The fungi provide nutrition to the beetles. The fusarium wilt fungi are difficult to con- trol. Schemes to eradicate the fungus are limited by the ability of the fungi to survive in soil for long periods, with or without a host plant, and the colonization of the vascular tissues within the plant. Once the fusarium fungus is intro- duced into a garden, nursery or field, it can live indefinitely in a variety of soil types, independ- ent of any host plant. This ability to survive eliminates, as an effective control measure, any normal rotation program or general sanitation. often starting on one side, and stunting of the plant. The disease symptoms often begin at the base of the tree and progress upwards, causing the leaves to wilt, wither, and die. References: Symptoms of fusarium wilt are easily con- 1). University of Illinois Extension. RPD No. 650. fused with root or crown rots, stem cankers, “Fusarium wilt diseases of herbaceous ornamentals.” borer injury, drought, compacted or poor soil 2). Wikipedia. :Fusarium wilt.” and two other widespread wilt diseases: Verticil- lium and bacterial wilt. Overall symptoms are 3). Lehman, Jerry. “Ambrosia Beetle.” Pawpaw Pickin's, Vol 17, Issue 1, Spring 2017. the same, a wilting, withering, and dying of the foliage. Only by close observation and experi- 4). Powell, Ron. “Fusarium, Part I”. Pawpaw Pickin's, Vol 15, Issue 2, Fall 2015. ence can you determine the true cause. The typical symptoms of fusarium wilt in- clude a drooping and yellowing of the leaves, Contact NAPGA or OPGA: http://www.NAPGA.com or hyyp://www.Ohiopawpaw.com Contact the pawpaw discussion group: http://groups.yahoo.com/group/Ohiopawpaw NAPGA Facebook page: http://www.facebook.com/NorthAmericanPawpawGrowers 4 attention.