Organic vegetable production requires careful management
CRYSTAL SPRINGS, Miss. (PRESS RELEASE) – According to an MSU press release, organic produce sells for a premium because of the promise made to consumers about the way it was grown and because making good on that promise is challenging.
Crops marketed as organic in the U.S. promote ecological balance and conserve biodiversity in all cultural, biological, mechanical, and even approved chemical practices. Synthetic fertilizers, sewage sludge, irradiation and genetic engineering are not allowed, and products must be grown without prohibited substances and methods from the field to the final point of sale.
Successfully producing crops under these conditions can be difficult, especially in a climate such as Mississippi’s where ideal growing conditions for vegetables are also ideal for insect pests and disease.
Mississippi State University research has long supported the safe and efficient production of produce crops and in recent years has included organic production in the practices it supports. Jermaine Perier, Extension entomologist, brought these efforts into the spotlight this summer with a conference focused entirely on growing organic crops successfully in the state.
“Pest management, including weeds, diseases and insects, can be challenging for organic farmers, not only because of the National Organic Program protocols, but because of the limited amount of Organic Materials Review Institute products available,” Perier said.
“This makes it even harder to manage pest outbreaks like insects when preventative steps are overlooked,” he said. “To make matters worse, issues with insecticide resistance require a wide range of products to facilitate rotations. Limited options mean limited rotations.”
Perier said advance planning for organic production is equally important as running the operation.
“For insect management in any system, prevention is the best course of action,” Perier said. “Keys to lowering seasonal pest pressures include choosing sturdy varieties, planting at the right time and in the right locations, scouting and monitoring for insects, and sanitation.
In a garden, good sanitation refers to the state of the garden and the tools used in it.
“Garden tools should be well-kept and free of residues and pest-harboring materials, unwanted plant material and other objects,” Perier said. “That means cleaning and disinfecting garden tools between uses, and removing diseased fruits and plant tissue from gardens and properly disposing of these tissues.”
Other sanitation practices include getting rid of infested plants and removing fallen fruit and dead or decaying plants. Remove materials that harbor insects, such as fallen limbs, rocks and leaf litter, and weeds and volunteer crops from plantings.
Over the years, researchers have developed and tested methods that integrate different approaches for managing insect populations. These strategies are a part of a broader approach referred to as integrated pest management, or IPM, and Perier said taking an IPM approach is the bare minimum for any organic grower hoping to successfully produce a crop.
“Management needs to be multilayered and incorporate as many compatible IPM strategies as possible,” Perier said.
“Preventative management is better than curative management,” he said. “Prevention includes those horticultural practices needed to make the plant grow. IPM makes you understand that these practices are not separate from your pest management.
“Manage the plant system and know that a healthy plant fights back against pests. It is impossible to manage what you are unaware of, so scouting and monitoring for pests with or without traps is the second line of defense, one that affects the success of all other management,” he said.
Timothy Ayankojo, an Extension vegetable specialist working from the North Mississippi Research and Extension Center in Verona, said organic growers should establish and follow a good strategy for their crops.
“Soil health is the foundation of good organic production,” Ayankojo said. “You should feed the soil, not just the plant.”
Improve soil health by building organic matter, which builds structure and water holding capacity. Healthy soil has enhanced microbial activity and is not compacted.
Plant nutrient needs are met with fertilizer, and in organic production, these include materials like compost, poultry litter and feather meal, which are repurposed animal production byproducts. Timing of fertilizer application is key.
Disease management can be difficult because the climate in Mississippi is also ideal for plant disease.
Rebecca Melanson, Extension plant pathologist working from the Central Mississippi Research and Extension Center in Raymond, said disease development requires a virulent pathogen, a susceptible host and a favorable environment.
“If any one of these conditions is absent, disease will not develop,” Melanson said. “Disease management aims to modify one of these conditions so that disease development does not occur.”
Several management practices can help reduce disease overall, but every practice is not effective against every disease. The first step in disease management is correct diagnosis of the disease present. Once you know which disease is present, use disease management practices known to be effective for that disease.
“Always begin with healthy, disease-free plants and select appropriate varieties that perform well and have resistance to diseases that commonly occur in your area,” Melanson said. “Choose a proper planting site, follow recommended cultural practices, such as plant spacing, pruning, and fertilization, and practice good sanitation in the garden.”
Pawel Orlinski, Extension vegetable specialist, said weed management is one of the biggest challenges in organic systems.
“Most herbicides that are commonly used in vegetable production can’t be used in organic production, but there are many other strategies that can be utilized,” Orlinski said. “Covering the soil will prevent most weed seeds from germinating, and either plastic or organic mulch can be used for that.
“Other strategies, such as mechanical cultivation, hand weeding or flame weeding, can complement mulching. Weeds are easier to control when they are young, so preventing them from becoming a major problem is key,” he said.
Learn more about organic vegetable production at https://extension.msstate.edu/agriculture/crops/commercial-horticulture/organic-fruit-and-vegetables.
