Progress report for LNE22-449R
Foliar nickel (Ni) application as nickel sulfate (NiSO4•6H2O) solution is a micronutrient treatment with supplementary fungal control. Nickel nutrient is an established method to improve urea nitrogen intake, increase crop yield, reduce abiotic heat stress, and supplement fungal leaf and fruit rot control.
This research hypothesizes that applying Ni for cranberry improves yield and abates fungal control resistivity.
Therefore, the objective of Ni treatment for cranberry production are:
- Evaluate foliar nickel application for cranberry, including:
- assessment of nickel phytotoxicity, and practices for minimizing environmental impact
- foliar nickel contribution to leaf blight and fruit rot suppression as part of fungal control
- crop nutrition: improved urea nitrogen conversion by plants, yield, and abiotic stress tolerance
- Develop best practice recommendations for cranberry Ni application
Ni application trials will take place in greenhouse potted plants and field plot trials to evaluate these objectives. Experimental work will:
- Test the effect of nickel intake on cranberry growth and yield first in potted plants and then in the field, using standard ‘berryland’ soil, plant tissue analysis method, and nickel analysis protocol developed by the research group.
- Cultivate leaf blight fungal species, run inoculation trials in potted cranberry plants, and evaluate fruit rot development in field trials.
The northeast Atlantic region accounts for 40% (15,700 acres, $91million-year) of all cranberries grown in the US, where most (+95%) cranberry farms are in Massachusetts (MA) and New Jersey (NJ). As a result of climate change, cranberry producers are experiencing production losses from heat stress, and an increase in fungal control requirements. A conservative cost analysis model, using results from other nickel trials, predicts 0-5% increase in yield with 10% reduction of post harvest fruit rot and <10% reduction in fungicides application.
Preliminary results of nickel availability in two cranberry trial soils (Chatsworth, NJ) found it has limited availability in the root zone (22±13 mg/kg), with plant tissue nickel intake of 2.1±1.2 mg/kg. Preliminary phytotoxicity trials of both direct soil introduction and foliar spraying Ni application revealed that lower nickel doses improved apparent plant growth morphology with increased plants size and leaf color vibrance (n=12). This preliminary finding indicates a potential benefit for Ni application for cranberry growers and that additional research is likely to benefit these producers. Engagement with cranberry producers is used to adopt Ni treatment to growers needs, including:
- teaming with the Marucci Cranberry and Blueberry Research Center (Chatsworth, NJ)
- collected grower feedback during field days
- advisory panel input.
Outcome goals for this research are the development of best management recommendation for Ni application for cranberry growers, resulting in 0-10% improvement of crop yield, <10% reduction in fungicide applications and a significant decrease of fruit rot.
1. Conducted research will evaluate foliar nickel application for cranberry, including:
a. assessment of nickel phytotoxicity, and practices for minimizing environmental impact.
b. foliar nickel contribution to leaf and fruit pathogen suppression for supplementary fungal.
c. crop nutrition: improved urea nitrogen conversion by plants, increased yield, and abiotic stress tolerance.
2. Best practice to apply nickel for increased crop yield and reducing fungicide applications.
3. Novel approach: adopting foliar nickel as part of a nutrition management plan. Incorporating foliar nickel application
by cranberry growers using best management plan recommendations from this research and be supported by outreach
Scope: Cranberry plants from two varieties: Mullica Queen, and Crimson Queen, are evaluated for nickel (Ni) response to determining the Ni phytotoxicity threshold, the effect of competing cations transport on Ni intake, and nutrient application effect on leaf rot and fruit rot development.
Plants: Cranberries were grown from transplant in 2x2 inch pots under a controlled environment (greenhouse) over the 2022 growing season (May-October) and then transferred to outdoor placement to allow dormancy. Field trials were carried out at Rutgers cranberry research bogs, where 5x5 feet plots with a 1-feet hems were marked with flags over established 2-3 years old bogs.
Nickel delivery: Nickel is applied either as the commercially available nickel plus (5-0-0; 5.7 Ni) or nickel sulfate (NiSO4·6H2O), with application ranges of 0-100 mg/plant. The delivery of Ni is either as soil or foliar spray. To evaluate the synergic relation between Ni uptake and competing cations, Ni is applied in 1:0, 1:1, and 1:3 mg plant-1 ratios with zinc and iron.
Plant response: Response to nickel is evaluated qualitatively by visual indexing of each potted plant for color (1-10), dead leaf (% 0-100), and overall growth (1-10). Quantitative evaluation is done by leaf chlorophyll (SPAD 502, spectrum technologies) and a canopy normalized difference vegetation index (NDVI) reading (CM1000, spectrum technologies).
Nickel accumulation: Cranberry leaf and fruit samples are analyzed for major and microelement content. The dried sample is acid-digested (HNO3, HCl) and analyzed using Inductively Coupled Plasma (ICP-OES/MS)
Leaf and fruit rot: The effect of leaf and fruit rot is evaluated by comparing the extent of infection between Ni-free and applied Ni treatments. While leaf rot can be evaluated in controlled greenhouse experiments, the complexity of fruit rot can only be evaluated in field plots. Plants in greenhouse pots are inoculated with local rot strains with a known taxonomy identified using RNA PCR for the leaf rot trial. Following inoculation, the extent of leaf rot is monitored and recorded. To evaluate Ni effect on fruit rot, a representative 1x1 feet sub-plot is marked in each of the cranberry bog field plots near harvest time (September-October), and the rate of fruit rot infection is counted by harvesting and sorting the fruit. Additional analyses with multi-spectrum imaging is used to quantify the fruit cover in sampled fruit.
Ongoing research work throughout the first year of nickel trials evaluated the delivery of nickel (foliar/soil application), the effect of competing cations, and toxicity response in preliminary greenhouse and field cranberry bog trials. The cranberry varieties selected for trial were crimson queen (CQ) and mullica queen (MQ), which were transplanted into 2x2 pots for greenhouse trials and grown in experimental research bogs for field trials at The Philip E. Marucci Center for Blueberry and Cranberry Research and Extension (Chatsworth, NJ).
a. cranberry model plant trials in a controlled environment greenhouse:
Results from the mixed urea-Ni application (Nickel plus, NIPAN) to potted cranberry plants in the greenhouse are outlined in Figure 1. Cranberry plants from both varieties (CQ, MQ) showed high sensitivity to soil urea application resulting in burnout of all plants. In contrast, foliar urea application resulted in more vegetative growth than plants that did not receive foliar urea, with multiple new shoots observed for each growth stem. While results for urea application did not show a significant difference between Ni-urea and urea treatment, the finding regarding the foliar urea response and the sensitivity to soil urea application is of interest for further study in the following season. Comparison of chlorophyll content (SPAD) and growth index values (growth, color, dead leaf) showed no significant difference between varieties (MQ, CQ) and nickel application rate (0-20 mg). This is in contrast to the expected results since 20 mg nickel plant-1 is the suggested application rate for small vegetable and fruit plants. one possible reason for the lack of nickel response is the nickel loss through leaching in the model plants. A revised model plant setting will address this issue by modifying the growth system setting to limit wash-off with drip irrigation and collect leachate from selected pots for mass balance of nutrient.
Experiments on the role of competing cations in nickel intake were evaluated using chlorophyll content (SPAD) and growth evaluation (growth, color, dead leaf), as shown in Figure 2. The result showed limited growth response to treatments, with similar color, size, and chlorophyll content between varieties and competing cations application rates. A repeat application to plants will apply higher nutrient rates and re-evaluate the growth response.
An additional study looks into Ni toxicity response applied 0-100 mg Ni plant-1 as NiSO4 (aq) (Figure 3). Results show that higher Ni application rates (40, 100 g) for both cranberry varieties (CQ, MQ) had the least successful growth average, but results were not significantly different between 5-100 mg Ni. Additional studies will evaluate Ni toxicity under an improved model plant irrigation system, as mentioned above. The average MQ variety growth was slightly improved compared to CQ when Ni was applied to the soil. A reverse trend was observed for the foliar application Ni where the CQ variety grew better. However, the results were fairly similar, with most growth parameters not significantly different. A follow-up study will re-apply Ni at 0-1000 mg plant-1 under an improved model plant setting with drip irrigation to prevent leaching off Ni.
b. Feild trials at cranberry bogs.
The preliminary Ni trial occurred in two cranberry bogs growing CQ and MQ, located at the Rutgers Cranberry research farm, both bogs were established with 2-3 years-old plants. Within each bog, five 5x5 feet sub-plots with 1 feet hems were marked with corner flags for experimental units. Foliar Ni was applied with an air sprayer at 0, 0.02, 0.06, 0.12, and 0.6 lbs Ni acre-1. Due to several problems with the research bogs growth during the 2022 season, no valuable data was collected, and field application will resume in different bogs through the 2023/24 seasons
Based on research experience with Nickel nutrition of cranberry, Rutgers Cooperative Extension is examining the need for this micronutrient in a wide range of horticultural crops grown across New Jersey. Thus, although this SARE project focuses on cranberry, we expect the findings to have broader implications for many horticultural and agronomic crops.