Gordon Johnson, Extension Vegetable & Fruit Specialist; gcjohn@udel.edu
Each year, the ASHS has an annual meeting bringing together scientists working with specialty crops (vegetables, fruits, ornamentals). This year the meeting is in Washington DC. The following are some notes from sessions I have attended over the last 2 days that have relevance to our Delmarva growers.
- Sweet corn planted into selected biodegradable black plastic mulches were shown to provide equal weed control, production, and earliness to standard black polyethylene mulch and eliminate mulch disposal costs.
- Pepper production under biodegradable plastic mulch was equivalent to standard black plastic mulch again eliminating the need for mulch disposal.
- Low rate compost application in potato (1 ton/a) reduced nitrogen needs and improved quality and yield in potato production.
- Reduced curing temperatures and time of curing as well as delayed vine termination (mowing just before digging) reduced internal defects in ‘Covington’ sweet potato
- Using white or reflective mulch did not improve broccoli production compared to black plastic mulch (we have a similar study currently in Delaware)
- Progress is being made in breeding beets for lower levels of geosmin, the compound that gives beets the earthy taste.
- Grafting tomatoes onto certain vigorous rootstocks can improve yield in high tunnel production, even in the absence of soil-borne disease.
- From Matt Kleinhenz at Ohio State University “Commercial microbe-containing crop biostimulants are advertised to maintain or enhance crop growth. More than two-hundred such products ranging in composition (e.g., bacterial, fungal, both; cfu/ml) are currently available. To date, outcomes from standard statistical approaches common in product evaluations, variety trials, and cultural management comparisons show that significant increases in yield or quality have been rare, regardless of inoculation parameters or experimental conditions.”
- A multistate project is underway to see if there are long term benefits to the “soil balancing” philosophy of soil management — specifically, balancing percentages and ratios of calcium, magnesium, and potassium through applications of lime, gypsum, and other materials to improve soil physics (tilth) and biology and, thereby, crop yield and quality and weed control. Past, shorter-term studies have shown no benefits to soil balancing but some growers and crop advisors disagree. This multi-state research aims at answering claims that University research on soil balancing has not been long term and thus is biased.
- Recently, a finely ground (<0.5 micron) liquid limestone-based product (Top Flow 130; Omya, Oftringen, Switzerland) was developed for agriculture use to be injected through drip irrigation tubing. Research by Tim Coolong in Georgia showed that Top Flow 130 could be used to adjust pH in a plasticulture system, but that the effects would occur within a zone of 4 inches on each side of the drip irrigation tubing. This may be useful for situations where pH has dropped below 5.2 in plasticulture beds.
- UV blocking plastic in high tunnel covers were shown to reduce Japanese beetle activity greatly in high tunnel raspberry production.