World Crops Research Update - Okra The 2017 Growing Season

Transcription

1 World Crops Research Update - Okra The 2017 Growing Season Vineland is publishing this Research Update which summarizes Vineland s findings on okra production during the 2017 growing season. Temperatures and precipitation The summer in Vineland, ON was cool and wet compared to Cumulative Growing Degree Days (GDD, base 10ºC) from the time of planting until final harvest for 2017 and 2016 were 1,236 and 1,560 GDD, respectively (see Graph 1). Total precipitation for the 2017 and 2016 growing seasons were mm and mm, respectively. Picture 1: Okra transplants in black plastic beds (June 8, 2017). A large hail storm hit the Niagara, ON region June 26 and led to widespread flooding and crop damage (see Picture 2). These conditions delayed harvest by one full month compared to Four cultivars in testing since 2015 were selected to assess spacing for optimal production on black plastic row covers. Clemson, Elisa, Jambalaya and Lucky Green were planted in Graph 1: Cumulative Growing Degree Days (GDD) comparing 2016 and 2017 growing seasons. Production trials in 2017 Vineland s okra trials were planted on raised black plastic beds June 8 (see Picture 1) and in production until October 12. The cool and wet weather conditions delayed planting by one week compared to Picture 2: Hail damage to okra transplants (June 27, 2017). 01

2 double rows, 30 cm apart with in-row spacing of 25, 30, 38, 46 and 56 cm. Four cultivars from Thailand-based East-West Seeds were tested alongside the spacing trials. Beendiya, Dorotha, Maha, and Olathe (see Picture 3) were planted in double rows at 46 cm in-row spacing. The pods of these varieties are dark green with five ridges. Graph 2: Total marketable yields on different in-row spacings. Elisa was the first hybrid to reach harvest at the end of July followed by Beendiya, Clemson, Jambalaya, Dorotha, Maha and Lucky Green. Olathe was the last variety to reach full production. Results Okra planted on in-row spacing of 25 to 30 cm produced the highest yield of marketable pods (see Graph 2). Picture 3: Varietal differences between okra pods. Jambalaya yielded the highest marketable yield per hectare at all in-row spacings while Elisa yielded the lowest (see Table 1). Table 1: Okra spacing per variety. 02

3 New Asian varieties Dorotha, Beendiya, Maha and Olathe were tested on 38 cm in-row spacing only. At such spacing, Dorotha showed the highest marketable yield per hectare and Olathe the lowest one (see Graph 3). It should be noted only one Dorotha plot survived the full growing season (more information under the Pest management section), and therefore the data relies on only one replicate. Dupont TM Exirel TM was applied for their control. The wet and cool soil created ideal conditions for Fusarium and Verticillium wilt to proliferate in plants. By the end of the growing season it was apparent that Dorotha, Maha and Elisa were amongst the most susceptible cultivars (see Picture 4). The Bhindi-type okra Dorotha and Beendiya produced a marketable yield of 11.4 t/ha and 9.7 t/ha, respectively at 38 cm in-row spacing, which was the highest yielding of the Bhindistyle okra. Elisa produced 7.5 t/ha for the same spacing. Picture 4: Okra plant showing an advanced stage of Fusarium wilt infection (September 11, 2017). Graph 3: Total yield comparisons of varieties tested at 38 cm spacing. Jambalaya consistently produced the highest yield and number of marketable pods for all replicates throughout the growing season. Pest management As 2017 was a cool and wet season, pest pressure was lower than in Aphids and Japanese beetles were observed on crops and A regular scouting program should be used throughout the summer months to detect and identify pests quickly to avoid economic loss. It is important to examine both the upper and under sides of leaves when looking for common pests such as aphids, thrips, leafhoppers and spider mites. For additional information on pest management, please consult the Ontario Ministry of Agriculture, Food and Rural Affairs Publication 838, Vegetable Crop Protection Guide

4 Harvest Plots at Vineland were harvested three times weekly. It is essential to harvest okra regularly as pods quickly become overgrown and unmarketable. To meet retailers specifications, okra must be harvested when it is 6.3 cm to 11.5 cm in length and 12.7 mm to 25.5 mm in diameter. The average weight of okra pods is dependent on variety (see Table 2). For the 2017 growing season, Clemson produced the heaviest pods with an average weight of 14.9 g and Elisa produced the lightest ones at an average of 9.8 g. Elisa, Beendiya, Dorotha and Olathe cultivars produce pods which are typically long and slender and are more popular in Asian markets. On the other hand, Clemson, Jambalaya, Lucky Green and Maha cultivars produce pods which are short and thicker and are more popular with American and Caribbean markets. As Elisa consistently produced (relatively) low weight pods, some growers experienced challenges trying to pack 13 pounds of Elisa okra into a 13-pound wholesale box. Table 2: Average pod weight of okra cultivars in Okra production peaked during the week of August 21, yielding 671 kg/ha in a single harvest compared to early July when 20 to 82 kg/ha were harvested. The yield curve resembles a sharp bell curve and must be taken into consideration when forecasting supply volumes over the entire growing season. Picture 5: Okra research plots at Vineland s Research Farm (August 18, 2017). 04

5 Vineland Research and Innovation Centre 4890 Victoria Avenue North, Box 4000 Vineland Station, ON L0R 2E0 tel: VinelandResearch vinelandresearch.com About Vineland s Feeding Diversity: Bringing World Crops to Market As part of a collaborative group of partners determined to build a local ethno-cultural vegetable marketplace, Vineland is leading research on new crop varieties (okra, Asian and Indian eggplant), production technologies, postharvest innovations, consumer insights and market development. Vineland s production team is trialing new varieties to assess agronomic performance and disease resistance, while postharvest scientists are working to optimize storage conditions to preserve the quality of ethno-cultural vegetables through the distribution chain and at retail. Picture 6: Harvested okra (September 17, 2017). Takeaway messages Vineland s Research Farm received 23 per cent less GDD in 2017 compared to 2016 Cooler spring temperatures can delay crop development, while a wet summer can increase pathogen pressure resulting in economic loss Despite cool and wet weather, Jambalaya grown on 25 cm spacing still yielded 14.1 t/ha, making it economically viable, but this was 39 per cent lower than in 2016 Under adverse growing conditions, higher density plantings provide the highest yield. In-row spacing of 25 to 30 cm is recommended for most okra varieties. Jambalaya and Lucky Green gave the highest marketable yields, while Olathe and Elisa have the lowest. To review other research updates, visit vinelandresearch.com and click on research programs/feeding diversity. If the information contained in these research updates is of interest to you or if you have any questions, please contact Viliam Zvalo, PhD, Research Scientist, Vegetable Production at: x808 or viliam.zvalo@vinelandresearch.com 05