A-Acetyl Thiaxolidin-4 Carboxylic Acid (AATC) 5.0 %
Inert Ingredients: Adjuvants, surfactants, in buffered solution 95.0 %
Total 100.0%

YIELD PLUS is a plant nutrient solution based on a derivative of L-cysteine. The product enables most plants to tolerate certain types of stress for longer periods of time than they could do otherwise. The product is particularly helpful to plants suffering from osmotic stress situations, caused by heat and/or lack of moisture, in which the plant undergoes maximum stress for a few hours during, and following, the period of maximum transpiration, usually associated with mid-day high temperatures. With YIELD PLUS helping the plant tolerate stress for a few hours, the plant does not immediately invoke its primitive defence mechanisms, such as shedding flowers, shedding fruit, slowing or stopping metabolic processes, etc., which could retard growth or reduce fruit load, and subsequent yield. The product can also help plants tolerate stress due to cool temperatures early in the season, up to the point which the plant variety is genetically and physiologically capable of coping.

The following results have been observed when YIELD PLUS treated plants have been compared with untreated plants, both having been subjected to the same stress conditions. The product works at its optimum when weather conditions are adverse, ie. Cold, frost (early), heat, wind, drought etc.

  • enhanced root structure
  • enhanced vegetative growth
  • better flowering set and retention
  • better seed germination and early seedling vigour when used as a seed treatment
  • better crop establishment
  • reduced transplant shock when plants are treated before transplant, in transplant water and/or after transplant, or root dipped
  • faster vegetative growth of perennial and annual plants.
  • reduced time to fruit bearing size
  • in green houses and nurseries, plants better tolerate stress caused by too much water, alternated with dry periods.
  • helps plant tolerate stress resulting when heat, low humidity and wind cause plants to transpire more moisture than their root uptake system can provide
  • helps plants take better advantage of available nutrients, including micro-nutrients, particularly when under stress
  • prevent shedding of leaves, flowers and fruit due to stress.
  • increased vigour helps plants natural disease resistance

YIELD PLUS is not a substitute for good agronomic practices including fertility, proper selection of varieties, disease control, etc. YIELD PLUS will not enable the plant to do anything it is not genetically capable of doing but it can help the plant realize more of its genetic potential, when certain limiting factors occur, due to stress, and the stress occurs for a normal period of time. Faster growth, will require more nutrients and other growth factors, so they must be provided. Optimum performance can be obtained from the plant by using YIELD PLUS along with an adequate balanced program of macro and micro nutrients, and other good agronomic practices. YIELD PLUS can be a valuable cultural management tool, under most growing conditions. For each crop, it is important to understand the probability of stress occurring, the symptoms and consequences of the kinds of stress to which the plant would likely be subjected under the conditions in which it will be grown.

A good preventive program gives better results than waiting until the plant has suffered stress loss, before using YIELD PLUS. Apply YIELD PLUS a few days before the plant is likely to encounter stress conditions. If stress symptoms are present before the first application has been made, the plant will have already suffered some consequences from that stress. YIELD PLUS can still be used, to help plants better tolerate the stress which they are already suffering. It will minimize the consequences of future stress, and give positive economic results, but not as great as when the product is used in a preventive program.

YIELD PLUS is not a "cure-all". It is a plant stress management tool which sophisticated growers can use to economic advantage as part of a good cultural program.


The active ingredients of YIELD PLUS enter the plant system at very low concentrations, and enable the plant to accumulate higher levels of proline, when under stress, than the plant could do normally, when under stress. When the stress period is ended, the excess proline reverts to glutamine. Published research studies show that plants tend to accumulate proline, when subjected to certain forms of stress, and that stress tolerant varieties accumulate more proline than do susceptible varieties.


YIELD PLUS can help plants during all phases of growth, from time of planting until harvest, if they are subjected to stress. Treat seed before planting to improve germination and enhance early seedling growth and root formation. Sustain plant vegetative growth, at optimum rate, even during periods of stress, with applications each 2 to 4 weeks, beginning when the plant has two or more true leaves. Apply YIELD PLUS to nursery plants one week before transplanting to reduce the effect of transplant shock. For transplanted plants, apply YIELD PLUS immediately after transplanting, and each 2 to 4 weeks thereafter. Bare root plantings should be dipped in a solution containing 1 to 2% YIELD PLUS prior to transplant. Plants are particularly susceptible to stress at time of flowering and fruit set. The objective is to introduce sufficient active ingredients into the plant to bring the concentration to an effective level. The amount of product needed to do this will depend on the mass of the plant being treated. For this reason, the most economic application method for many crops would be to prepare a spray solution of known concentration of YIELD PLUS, and spray the plants until the leaves have been covered, and spray solution starts to run off the leaves. A spray solution containing 100 ml of YIELD PLUS in each 100 litres of water is recommended. An agricultural grade non-ionic wetting agent should be used to aid penetration, particularly in plants having waxy or hairy leaves. If the water is alkaline, it should be buffered to pH 5.5 or lower. A pH of 5.0 is optimum for uptake by most plants.

In hot climates, apply YIELD PLUS in the cool of the morning while plant metabolism is highest. Under cool conditions, apply at warmest period of the day. Do not apply immediately before rain, or sprinkler irrigation, as plants need 4 to 6 hours to absorb most of the active ingredient through the leaves. YIELD PLUS can be mixed with most plant protection products, and fertilizers, except in alkaline mixtures.

Copyright 2000 Yield-Plus Agricultural Products CC

This page last updated July 2000