Search Results
You are looking at 1 - 7 of 7 items for :
- Author or Editor: Joseph R. Heckman x
- HortTechnology x
Yield responses of `Blue Vantage' cabbage (Brassica oleracea L.) to P fertilizer and two commercially available biostimulants—ROOTS and ESSENTIAL-were evaluated on soils very high in P fertility. Head yield was not increased with P fertilizer when cabbage was transplanted into soil with Mehlich-3 soil test P indexes ≥ 112 ppm (112 mg·kg-1). Neither of the biostimlants applied as a root drench at transplanting influenced head yield or plant tissue nutrient analysis.
Scientists have sought to stimulate plant growth using carbonated irrigation water for more than 100 years. The mechanisms by which carbonated water may increase plant productivity and the influence of environmental and cultural growing conditions on those mechanisms are not completely understood. Several greenhouse and field studies have demonstrated that carbonated irrigation water can increase crop yield significantly while others have shown that carbonated irrigation water does not influence plant productivity. It is unlikely that carbonated irrigation water will be recommended commercially until the conditions are delineated under which a positive and economically advantageous growth response is ensured.
A key to profitability in many “u-pick” pumpkin (Cucurbita pepo) farm operations is producing attractive, marketable fruit while maintaining suitable field conditions for consumer entry during periods of inclement autumn weather. The use of municipal leaves collected from urban areas may help improve fruit quality and field conditions in u-pick pumpkin operations. In 2005 and 2006, an experiment (randomized complete block design) was conducted to compare four different production systems on pumpkin yield and fruit quality. Treatments consisted of no leaf mulch (bare soil) plus herbicide with 25 lb/acre nitrogen (N) sidedressed (treatment 1), leaf mulch without herbicide with 25 lb/acre N sidedressed (treatment 2), no leaf mulch (bare soil) with herbicide with 75 lb/acre N sidedressed (treatment 3), and leaf mulch without herbicide with 75 lb/acre N sidedressed (treatment 4) during the production season. In 2005, there were no differences in the total number and weight of harvested fruit and weight of orange fruit between production systems. Although the presence of leaf mulch reduced the total number and percentage of orange fruit harvested, there were no significant differences in average weight of orange fruit between production systems. Average weight of orange fruit was significantly higher and similar at both sidedress N rates in both leaf mulch production systems compared with bare soil. In 2006, there were no differences in total number of fruit, number of orange fruit, and percentage of orange fruit at harvest between production systems. Total weight, weight of orange fruit, and average fruit weight of pumpkin fruit was significantly higher and similar at both sidedress N rates in both leaf mulch production systems compared with bare soil. Sidedress N should be applied in accordance to plant growth and environmental factors to overcome any expected N deficiency from N immobilization because of the presence of the leaf mulch and other environmental factors. Applying municipal leaves to the soil surface exhibited a marked advantage over bare soil in producing clean fruit. In both years, the percentage of clean fruit at harvest was higher in both leaf mulch production systems compared with bare soil.
Every autumn an abundance of leaves from various species of shade trees [e.g., oak (Quercus sp.), maple (Acer sp.)] are collected from urban landscapes. In 1988, shade tree leaves were banned from landfills and combustion facilities in New Jersey because it was an unsustainable practice. Composting and mulching leaves and using them as a resource was proposed. The purpose of this review is to summarize studies of mulching and amending soils with shade tree leaves and their potential to benefit agricultural production. Research sponsored by New Jersey Agricultural Experiment Station on soils and crops found that land application of shade tree leaves was beneficial for building soil organic matter content, protecting against erosion, and controlling weeds when used as a mulch. In general, crop yields and quality were improved with leaf mulch. Collected shade tree leaves on average have a relatively high carbon-to-nitrogen (N) ratio and the potential to cause a temporary deficiency of soil N availability. However, with good agronomic practices and well-timed N fertilization, crops perform well after shade tree leaves have been applied without increasing the recommended N fertilizer application rate.
Cover crops included in a crop rotation can help increase nitrogen (N) availability to subsequent crops, raise soil organic matter, and suppress emergence and growth of various weed species. However, weed suppression by cover crops has mostly been investigated shortly after cover crop termination and not over a longer period spanning into the next cropping season. The effects of sunn hemp (Crotalaria juncea) and sorghum-sudangrass (Sorghum Ă—drummondi) planted the previous year on N availability before transplanting of late summer cabbage (Brassica oleracea), weed germination and growth, and cabbage yield was examined in field studies conducted in 2018 and 2019 at Pittstown, NJ. Results established that there was little evidence for a functional difference in soil N availability for fall cabbage production because of previous cover crop type. Heavy rainfall events both years may have caused major losses of available N that might otherwise be expected to come from N mineralization of residues of legume cover crop like sunn hemp. During the cover crop season, smooth pigweed (Amaranthus hybridus) and common lambsquarters (Chenopodium album) dry biomass was 77% and 82% lower, respectively, in sorghum-sudangrass compared with sunn hemp plots. The subsequent season following sorghum-sudangrass cover crop, dry biomass of broadleaf weeds was lower by 74% and 56% in June and July, respectively, compared with preceding sunn hemp. Smooth pigweed, common lambsquarters, and hairy galinsoga (Galinsoga quadriradiata) were the weed species most consistently affected by preceding sorghum-sudangrass cover crop with biomass decreased by up to 80%, 78%, and 64%, respectively. Thus, it appears that sorghum-sudangrass can provide suppression of some broadleaf species over a relatively long period and is indicative of sorghum-sudangrass allelopathic activity. On the contrary, density and biomass of grassy weeds as well as commercial yield of transplanted cabbage were unaffected by the preceding cover crop. These results suggest that sorghum-sudangrass cover crop could be integrated to transplanted cole crop rotation for providing weed suppression benefits without altering crop yield in New Jersey organic vegetable cropping systems.
Vegetable growers have expressed concerns regarding the accumulation of copper in soil where copper-based fungicides are used and have requested guidance for copper pesticide applications. Elevated soil copper levels have the potential to become toxic to sensitive crops and impact soil health. In response, total and available soil copper levels were surveyed using soil analysis of samples from 15 New Jersey farms representing organic and conventional production methods. Lettuce (Lactuca sativa) was grown in the sampled soil in a greenhouse trial and evaluated for signs of copper toxicity. We found that all 15 farms were using copper fungicide preventative sprays during the previous 2 years. The soil copper levels of these farms were higher in copper-applied soils than the corresponding noncopper-applied soil. Soil copper levels were not near or in excess of established clean-up limits at any of the locations. Greenhouse-grown lettuce in the sampled soils was not negatively impacted by the copper levels. Due to the increase in the total and soluble soil copper levels, growers should use best management practices to prevent the accumulation of excessive amounts of copper in the soil over time.
Although not considered an essential nutrient, silicon (Si) can be beneficial to plants. Si accumulator species such as pumpkin (Cucurbita pepo var. pepo) can absorb Si from soil. Si uptake may reduce plant susceptibility to fungal diseases such as cucurbit powdery mildew (Podosphaera xanthii and Erysiphe cichoracearum). We previously reported that wollastonite, an Organic Materials Reviews Institute–approved natural mineral, can increase soil Si level, increase soil pH, provide pumpkin plants with Si, and increase their resistance to powdery mildew. In this study, we examined the optimum application rate of wollastonite for pumpkins grown in pots and exposed to cucurbit powdery mildew. We confirmed that wollastonite has liming capabilities similar to regular limestone. Regardless of the application rates, wollastonite and limestone showed similar effects on soil chemistry and plant mineral composition. Pumpkin plants grown with the lower doses of wollastonite amendments (3.13 and 6.25 tons/acre) had the greatest tissue Si concentrations and demonstrated the greatest disease resistance. We conclude that wollastonite is a useful material for organic cucurbit (Cucurbitaceae) growers who want to increase soil pH and improve plant resistance to powdery mildew at the same time. Applying wollastonite at rates beyond the amount required to achieve a desirable soil pH for pumpkin production did not further increase Si uptake, nor did it further suppress powdery mildew development.