Garden Talk: July 15, 2010
From NGA Editors
Nutrient Value of Organic Eggplant
Many proponents of organic gardening have long maintained that not only are organic methods better for the soil, the environment and the safety of gardeners, but they produce nutritionally superior crops as well. But there hasn't been a lot of hard evidence to back up their claims.
Now research done in Spain suggests that, at least in the case of eggplants, organic methods may result in a crop with higher nutritional value. In a study published in the Journal of Agricultural and Food Chemistry (58(11), June 9, 2010, 6833-6840), there were significant differences in the concentrations of certain nutrients in eggplants that were grown using organic methods as opposed to conventional ones. For example, levels of potassium, calcium and magnesium were higher in the organically produced eggplants. According to the researchers, there was an increased benefit when plants were grown in soil that had been managed organically long term and that simply adding more fertilizer to conventionally grown eggplants did not increase their nutrient value relative to organic produce.
While this is only one trial with one crop, it reinforces the importance to all gardeners of building up the soil to produce healthy and nutritious crops.
For an abstract of this research, go to: Effects of Organic and Conventional Cultivation Methods on Composition of Eggplant Fruits .
Fresh Plants for Southern Gardeners
Gardeners in northern parts of the country may be harvesting tomatoes and peppers, but if they are thinking about planting, they are considering quick growing, cool season crops like spinach, lettuce and cole crops. Not so southern gardeners. Folks in these warm areas of the Gulf Coast and Southwest have a different planting schedule than the rest of the nation, with a lot of good growing weather still ahead of them. But they often have a hard time finding transplants available for sale for their late season gardens.
To accommodate these gardeners in the southernmost areas of the country, the Natural Gardening Company, a mail-order source for organic seeds and transplants, is expanding its offerings for the 2010 summer planting season. In addition to a complete range of tomato seedlings, including main crop, cherry, plum and specialty varieties, they offer transplants for basil, peppers, eggplants, cucumbers and zucchini. The varieties include Genovese basil, Ace pepper, Fairytale eggplant, Diva cucumber and Cocozelle zucchini, some of the company's best known and most well-liked vegetable varieties.
The plants will be available from July through September. Plants in 3-inch pots are available in groups of six, twelve, eighteen or additional multiples of six. Gardeners may order the vegetable seedlings through the company's website or by calling 707-766-9303. All Natural Gardening Company seedlings are certified organic by CCOF.
For more information on Natural Gardening Company's offerings, go to: Natural Gardening Company.
Pest Resistance in Elms
Just about everyone is familiar with the devastating effect Dutch elm disease (DED) has had on populations of American elm. Much research has gone into developing trees resistant to this disease. A number of resistant elms have been identified, some of them natives, more from East Asia. Unfortunately, Dutch elm disease isn't the only problem to afflict elms. A number of other pests can cause problems on these trees, including Japanese beetles, gall aphids and leafminers. One of the latter, the European elm flea weevil, is a leaf miner that was first found in this country in 2003 and is expected to spread across the US.
The National Elm Trial (NET) is a program in which elms are being evaluated in 15 states for resistance to DED as well as other pests. As reported in the July-August 2010 issue of Hortideas, evaluations at the NET site in Lexington, Kentucky by researchers at the University of Kentucky Department of Entomology have shown that all of the DED-resistant elms in the trial were susceptible to at least some of these other pests. American elm cultivars such as 'Valley Forge', 'Princeton' and 'New Harmony' were more susceptible to the leafminer Agromyza aristata than hybrid elms. But some of the hybrids, such as 'New Horizon' were more susceptible to sawfly and gall aphid damage. Most of the hybrid elms were susceptible to European flea weevil infestation; 'Morton Accolade' was the least susceptible hybrid tested. 'Jefferson' American elm was quite resistant to this flea weevil; it was, however, a favorite of Japanese beetles.
Research continues under the NET program, its goal being to find elms that not only resist DED, but that resist other troublesome pests as well, in the hopes that one day these stately trees can again grace our landscapes.
For more information on the National Elm Trial, go to: National Elm Trial.
Ask the Expert at the USDA
The US Department of Agriculture (USDA) has launched a new, on-line, on-demand knowledge database, called 'Ask the Expert'. This new service connects with existing UDSA knowledge systems, so consumers can visit one site and get access to expanded information and resources on subjects such as food, nutrition, food safety, energy, the environment and conservation. Frequently asked questions are stored in an on-line database that pulls data and information from all the USDA's agency resources.
Over the next six months, the system will expand, with additional questions and answers added based on public inquiries, new information and search patterns.
To visit the 'Ask the Expert' database, go to: Ask the Expert.