potato 5-9-12 CLEAN - Vegetableipmasia.org

ORGANIC POTATO PRODUCTION 14. NONPATHOGENIC DISORDERSEnvironmental factors can cause symptoms that appear to be diseases but are actually not caused by a pathogen or insect.Table 14.1.1 provides a list of disorders that may be confused with diseases.Table 14.1.1 Nonpathogenic disorders. Disorder Management Option Recommendation Air pollution Variety selection. Andover and Norland are particularly sensitive varieties. Hollow heart Internal necrosis Blackspot Variety selection. Maintain uniform growing conditions. Variety selection. Minimize heat stress. Avoid bruising tubers. Maintain tuber turgor. Varieties differ in severity. Avoid growing oversized tubers. Utilize appropriate plant spacing. Irrigate and fertilize for specific variety requirements. Varieties differ in susceptibility. Irrigation reduces soil temperatures and increases calcium uptake. Minimize impact events during harvesting, transporting, grading, and handling. Store in high humidity and warm before handling operations. Secondary tubers Avoid old seed. Purchase good quality seed and keep in cold storage. Greening Growth cracks Knobs Weed damage to tubers (Quack grass and Canada thistle grow through tubers) Avoid tuber exposure to light. Maintain even soil moisture. Maintain even soil moisture and fertility. Weed management. Keep tubers well covered with soil in the field and store them in the dark after harvest. Maintain even soil moisture, especially during rapid tuber growth stage. See Section 9: Moisture Management See Section 9: Moisture Management. Maintain uniform soil fertility conditions. Have a program to reduce perennial weeds in fields. Secondary tubers Avoid old seed. Purchase good quality seed and keep in cold storage. 15. INSECT MANAGEMENTEffective insect management relies on accurate identificationof pests and beneficial insects, an understanding of theirbiology and life cycle, knowledge of economically importantlevels of pest damage, a familiarity with allowable controlpractices, and their effectiveness, in other words, IntegratedPest Management (IPM).Regular scouting and accurate pest identification areessential for effective insect management. Thresholds usedfor conventional production may not be useful for organicsystems because of the typically lower percent mortality andshorter residual of control products allowed for organicproduction. The use of pheromone traps or othermonitoring or prediction techniques can provide an earlywarning for pest problems, and help effectively focusscouting efforts.The contribution of crop rotation as an insect managementstrategy is highly dependent on the mobility of the pest.Crop rotation tends to make a greater impact on reducingpest populations if the pest has limited mobility. In caseswhere insects are highly mobile, leaving a greater distancebetween past and present plantings is better.Natural Enemies Learn to identify naturally occurring beneficial insects, andattract and conserve them in your fields by providing a widevariety of flowering plants in or near the field and avoidingbroad-spectrum insecticides. In most cases, a variety ofnatural enemies are present in the field, each reducing pestpopulations. The additive effects of multiple species ofnatural enemies, attacking different host stages, is morelikely to make an important contribution to reducing pestpopulations than an individual natural enemy speciesoperating alone. Natural enemies need a reason to bepresent in the field, either a substantial pest population,alternative hosts, or a source of pollen or nectar, and maynot respond to pest buildup quickly enough to keep572012