Improving Production Practices for Three Niche Crops in Response to Shifting Climatic Opportunities

Progress report for ONE22-409

Project Type: Partnership
Funds awarded in 2022: $21,470.00
Projected End Date: 04/30/2024
Grant Recipient: Cornell Cooperative Extension
Region: Northeast
State: New York
Project Leader:
Elizabeth Buck
Cornell Cooperative Extension
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Project Information

Project Objectives:

This project seeks to improve the horticultural potential for three niche crops that are experiencing changing production feasibility in the Northeast as the climate warms. One trial will be conducted in each crop; treatment economic comparisons will be made for okra and sweet potato trials.

1) Sweet Potato
Compare the early season growth and yield of new regionally adapted varieties to standard, southern-bred varieties that grow too slowly in our climate to realize a full harvest. We will also investigate the effect of row cover on early crop vigor.

2) Okra
The okra trial aims to meaningfully hasten flowering and lengthen harvesting season over bareground production using low-cost season extension tools: black plastic mulch, row cover, and both.

3) Asparagus
The asparagus trial will observationally compare the phenologic development and summer stress tolerance of standard varieties against new northern-adapted and popular southern varieties. Future varietal choices must show resilience to spring temperature swings to avoid frost damage and must tolerate hot summers. The best choice will have delayed spring emergence and heat tolerance.

For each trial, we will produce clear-cut, immediately applicable variety and cultural recommendations so growers can make production decisions to improve crop performance and profitability by an anticipated 10%.


The climate in the Northeast is rapidly changing. That presents production opportunities and challenges for specialty crop growers. Sweet potatoes and okra are crops for which the warming climate present opportunity – production is no longer considered too marginal in much of the Northeast. Growers can now enjoy the high-value income from these in-demand crops. While the plants do well in our hotter summers, production remains challenged by the short growing season. Finding ways to speed crop establishment and reduce the days to maturity would directly translate into improved yield and profitability for these two crops.

Unlike okra and sweet potato, asparagus is a traditional, high-value Northeast crop that is experiencing climate-change driven threats. Asparagus emergence is driven by spring air and soil temperatures. Increasingly we are experiencing wild swings in spring weather, with days above 60 in March and April followed by freezes. This primes asparagus to emerge from the ground only to get frosted and become unmarketable. Abnormal May temperatures in the 70s increase the rate of asparagus growth and can dramatically condense harvest. The increased crop load means that farmers often do not have enough labor to pick all of the asparagus in time and must suffer economic loss. Since plantings live 12-15 years, we should be screening for cultivars that have good tolerance to the stressful future summer conditions. Those stress-adapted varieties also must fern out soon enough and senesce late enough to accumulate carbohydrates and sustain themselves over the long-term.

These 3 crops are popular with strong demand in direct-to-consumer markets. The 2017 ag census has 838 acres of asparagus and 709 growers in the 7 Northeast states; 31A of okra and 176 farmers; 167A of sweet potato and 320 farmers. The okra and sweet potato numbers are likely large undercounts. Many marginalized growers who prize okra and sweet potato are poorly represented in the ag census. Local data suggests there are 67 sweet potato growers in western NY alone and over 200 acres now raised in the state, a 55% increase over the 2017 census. Interest in both crops is increasing, especially in urban areas. 

Local sweet potato prices are $2-3/lb for roots and $3/lb wholesale for leaves. Okra fetches $4/lb. Improving early season growth or gaining more growing season could increase productivity and crop profitability by 10%. This is a large and meaningful economic improvement, especially for low-income growers who tend to be from historically marginalized communities. The low-cost and durability of the season extension techniques makes these proposed horticultural solutions financially accessible.

Asparagus sells for $5/lb retail or $3/lb wholesale. Identifying varieties that have innate resilience to excessive spring temperature swings will directly translate into less loss of marketable crop due to increased frost avoidance. Varieties with more favorable phenologic developmental responses to our changing temperature regimes will help prevent economic loss due to crop maturing too quickly or becoming too stressed.  

Proposed Solutions:
Regionally adapted sweet potato varieties bred in Canada are now being released. These varieties are of high interest to our local growers and appear to be a drastic improvement over currently available options. A variety trial would test these new offerings against current standards, quantify their performance in our fresh market production systems, provide growers a chance to see regionally-adapted varieties, and allow for economic comparisons.  

Row cover is widely used as a warming tool in early spring conditions. Warming-grade row cover does not get used in June and July because it is believed to be too hot for most crops. However, this presents a prime opportunity for promoting strong early growth of sweet potato and okra transplants that crave more heat than we typically experience in late May and early June, and particularly for improving overnight temperatures.  Row cover may also provide a more favorable environment for sweet potato slips by reducing desiccation from windy conditions while they grow roots, thereby shortening the time of establishment. We will trial row cover in both crops to see if it provides an advantage to early crop vigor and maturity.

Okra tends to be grown open field from transplants on the urban, suburban, and handful of rural farms currently raising the crop in WNY.  Using black plastic to warm the soil is likely to benefit okra by allowing for earlier transplanting, but alone may not be sufficient to spur aboveground growth in the cooler air. It will be trialed alone and in combination with row cover.

There is a unique opportunity to observe and characterize the phenological development and heat stress tolerance of ten asparagus varieties. Use plants established for an existing yield and market acceptability variety trial that offers regional standard, improved northern, and southern adapted varieties. We propose tracking the timing and rate of each variety’s development across one growing season and relating phenology to growing degree days. Tying development to growing degree days instead of the calendar will allow us to examine varieties for suitability in different projected future climate conditions.

This project supports NESARE’s outcome statement by enhancing the feasibility and profitability of 3 high-value niche crops as the climate changes using environmentally responsible, low-cost production techniques. This work is expected to benefit growers from Black, immigrant, and urban farmer communities. Sweet potato is used in Black and some immigrant communities for both the root and the greens. Many refugee growers from Buffalo have an interest in increasing the productivity of their sweet potato plantings. Okra is a culturally important ethnic crop among Black farmers that is also of high interest to members of the Congolese and Somali Bantu communities farming in suburban Buffalo, urban Syracuse, and Utica. Project staff will work with existing community partners to conduct outreach with these grower groups. Overall, grower investment in the project is high. In addition to general interest and need, three farms asked to host the sweet potato trials, two asked to host the okra, and I get calls about a dozen inquiries annually about asparagus varieties. 


Click linked name(s) to expand/collapse or show everyone's info
  • Matt Agle - Producer
  • Paul Fenton - Producer
  • Wil Moss - Producer


Materials and methods:

Work on this project is scheduled to begin in February 2023.


Sweet Potato Trial
We will establish a split-plot randomized complete block design trial with four replications to compare the growth and yield potential of four varieties of sweet potatoes under two cultural management practices.  The four varieties will be two regionally adapted Canadian-bred introductions (‘Radiance’ and ‘Luminance’) and two domestic choices popular with Northeast growers (‘Covington’ and the partner grower’s standard choice). Each plot will be 25 feet long with double staggered rows spaced 14” on a black plastic and trickle tape bed with a 12” in-row spacing. The raised beds will be approximately 64” on center. Purchased sweet potato slips will be transplanted using a waterwheel transplanter. 

After transplanting, each plot will be split in half.  Each half of a plot will randomly be assigned to either the “row cover” or “no cover” cultural management practice.  Plots in the “row cover” splits will be covered with floating row cover supported on small metal hoops spaced 5-6 feet. Row cover will be weighed down by soil. The plants under the row cover split will be checked every 2-3 days during the first 10 days to ensure that they are not dying due to unanticipated effects. Row cover will remain in place for 3 weeks except for temporary removal to perform crop maintenance tasks or unless severely adverse crop effects are observed.

The percent of plants surviving in each split plot will be recorded 3 weeks after planting. Vine size of ten plants per split plot (n=160 plants per cultural practice, 320 plants total) will be measured 3 weeks after planting.  Vine size will be recorded as length of the dominant branch. Samples plants will be randomly selected from the center 10 feet of each split plot. The vigor assessment will be repeated at 6 weeks after planting.  Number of shoots per plant may be included at the 6 week after planting vigor assessment if plants are well-branched.

Pest and disease pressure will be assessed in August.  Anticipated pressure includes feeding damage from flea beetles and the presence of virus.  Both of these will be recorded on a % severity and % incidence scales.  It is necessary to quantify any pest or disease damage prior to harvest because failure to do so when they are present means that the yield results interpretation would be both statistically noisy and logically incomplete, potentially leading to faulty conclusions. By quantifying any pest/disease pressure, the effect of the damage can be statistically separated from the yield effects caused by differences in variety or early cultural management practices and ensure the logical integrity of the project results.

Harvest will occur at the first sign of cool nights and before any frosts. We anticipate using custom tractor work or renting a potato digger to facilitate harvest. Plots boundaries will be marked in the aisles with spray paint, and the varieties will be visually distinct enough to avoid confusion. Ten plants from the center of each split plot will be used to collect harvest data.  All tubers will be carefully collected from these plants and gently placed in plot-marked bins for curing. Curing will occur in a greenhouse for at least 1 week. After curing, roots from each split plot will be graded into USDA grades and weighed by grade, including culls. We will track the input costs associated with each treatment split plot and use price information from the grower’s farmstand to determine the economic value of each grade to determine the sale value of each treatment.  

Statistics will be a simple ANOVA structured for a split-plot trial design since all data is continuous in nature. Tukey's HSD test will be used to separate means. Data taken on a % scale is unlikely to be normally distributed and may need to be transformed or run on its natural beta distribution.  The approach will depend on the nature of the data and the capabilities of the statistical analysis software used. 


Okra Trial

This trial will be a simple randomized complete block design with four reps of four treatments: bareground, black plastic, row cover, or black plastic plus row cover.  Each 3’ wide plot will be 30’ long and house a single row of okra spaced 18” in row. The field will be prepared in the middle of May.  Crop transplanting will occur once the soil in the black plastic treatment consistently reaches 80 degrees and the forecast air temperature will stay over 60 degrees, hopefully around May 25. Soil temperature will be monitored with a soil thermometer and will provide a more biologically accurate target planting date than a calendar. Row cover supported by metal hoops will be applied immediately after transplanting.  It will remain on the crop for 2 weeks, aside from when it is temporarily removed to provide water and other crop maintenance.

Crop vigor measured as height will be recorded for 10 plants from the center of each plot 2, 4, and 6 weeks after transplanting. Yield data will be recorded as number and total weight of marketable fruit per plot per harvest date.  The first and last date of harvest per plot will also be recorded. Economic potential will follow the above methodology. A disease/pest/weed assessment will be taken in mid to late August as described above. Anticipated problems include excessive weeds in the bareground and row cover plots, bacterial infections, and aphids.   

Statistical analysis will be very similar to the sweet potato trial except that okra analytical tests will reflect the simplified plot design structure.


Asparagus Trial

The observational aspargus trial will be overlaid on an existing young variety trial that was established to investigate consumer acceptability, yield, and specialty production attributes. Please see trial map for field layout details.

We will track growing degree days throughout the season using the Climate Smart Farming GDD tool, which incorporates weather observations at a 2-kilometer resolution scale. We will record the date that each of the 10 varieties emerges. We will flag 10 spears per plot on one day each week and record their height when we harvest all tagged spears on the same day later that week. We will repeat this for 4 weeks. This will allow us to track relative growth rate by variety, and we will compare this information to GDDs accumulated in the inter-harvest timeframe. We will record the date when harvesting ends and begin to observationally track phenological development into the full fern stage. During summer we will observe plants for signs of heat stress, which primarily presents as stunting and slow growth without other obvious causes. We will record dates of the phenological senescence process in the fall. Statistical analysis will attempt to regressing crop development and compare the fit to the growing degree day progression as well as other relevant weather factors.

Participation Summary

Education & Outreach Activities and Participation Summary

Participation Summary:

Education/outreach description:

Grower outreach and knowledge transfer is at the core of the CCE Cornell Vegetable Program’s mission. Our staff are experienced teachers who can teach in a wide variety of formal and informal settings. CVP staff on this project have developed teaching skill sets in active learning teaching techniques and are incorporating more facilitated discussion and peer-led educational elements into outreach approaches. Project staff have also received training on writing for various audience groups and how to effectively communicate scientific results to non-technical audiences. We are well-versed in meeting planning and educational material prep and have educational aids and tools available on-hand.

Outreach efforts will use our large network of grower, industry, and professional colleague contacts to recruit growers to attend meetings and broadly distribute written trial summaries. We will directly contact growers with interest in these crops via postcard, email, and newsletter announcements.

Project staff have authentic existing programming partnerships with the Greater Buffalo Urban Growers, the CCE Urban Ag Program Work Team, Providence Farm Collective (an incubator & training farm for Asian & African refugee growers), the Intertribal Agriculture Council, and key Black farmers in western NY.  We will seek input from these groups on how best to create welcoming meeting spaces and co-advertise planned events.  

Event & where

Outreach style

Expected stakeholder audience

Audience recruitment

Number reached

Summer field meeting - host farm TBD.

Trial tour, grower storytelling, group discussion

Vegetable growers, including urban and New American farmers

Postcards to area growers;

Work with a local refugee grower incubator farm (Providence Farm Collective) & the Greater Buffalo Urban Growers to promote event to their farmers


Local Winter Meeting - Batavia or Newark, NY.

Co-presentation with grower and project staff, group discussion about how to apply info on  attendees’ farms

Vegetable growers, ag service providers

Newsletter event announcements, postcards to local growers, direct emailing to growers interested in these crops


Statewide Winter Veg Expo 2024

Presentation with an interactive grower interview/panel

Vegetable growers including BIPOC farmers, ag service providers

Statewide event promotion. Leverage Expo’s outreach efforts and financial scholarship for historically marginalized growers to co-promote Expo attendance with the Black Farmers United and the Intertribal Agriculture Council.


3 newsletter articles, 1 for each trial

Newsletter article

Vegetable growers & ag service providers throughout the Northeast

All three articles will run in the Cornell Vegetable Program’s VegEdge newsletter (circ. 750).

One article will be reprinted in the ENY Commercial Horticulture Program’s Produce Notes (circ. 300) and another will be reprinted in UMass Amherst’s VegNotes (circ.   2850)


Additionally, I plan to present the results of this project at the Great Lakes Vegetable Working Group annual meeting in late February of 2024.  This is after the project will have termed and is therefore not included in the budget or timeline. This extra event will reach another 30 vegetable Extension & university research personnel from 9 states and 3 provinces, all of whom could act as impact multipliers and extend project findings to their local growers.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.