Ask a producer how his crop was in 1998 and he or she will probably begin by describing their canola crop. Canola has and will continue to be the crop which contributes the most to overall profitability. The severity of frost damage that occurred with zero-till canola in 1998 cannot be simply overlooked as an anomaly that we hope will not occur again. In today’s competitive market place no producer whether zero-till or conventional can sustain such losses.

As an agriculture representative and farmer the two weeks after the frost of May 28^th and the subsequent frosts of May 30^th and 31^st were probably the busiest that I have experienced. Recommendations were literally involving tens to hundreds of thousands of dollars as producers had to decide whether or not to reseed since reseeding deadlines for Crop Insurance were close at hand. Historical data and recommendations from Manitoba Agriculture and the Canola Council were decidedly against reseeding promoting canola’s ability to regrow and compensate for plant thinning. It soon, however, became readily apparent to me that not all frost damage was the same. The hardest hit fields were without question the zero-till canola fields. This was primarily a result of the additional moisture found in zero-till fields. Moist undisturbed soils quite simply stay cooler longer. This is a side affect that we should not overlook and should acknowledge. The better job you did at conserving moisture the cooler your soil was and the harder you were most likely hit by frost.

Early seeded canola which had progressed to the 3-4 leaf stage prior to the frost was less affected than the more typical mid-May seeded fields which were in the much more vulnerable cotyledon 2 leaf stage. The advanced stage of growth was more tolerant not only because of the ability of these plants to regrow but also because the early seeded fields had more time to retain heat once the seedbed was disturbed. An undisturbed seedbed retains moisture longer and consequently will also stay cooler long. Most zero-tillers would admit that in most years their canola stand is never as aggressive as neighboring conventional fields early in the growing season. Once the zero-till fields canopy and the landscape of the field changes color from a reflective white to a dark green the crop and soil absorbs and retains more heat. It is at this point that our zero-till fields take off utilizing the now valuable moisture to grow aggressively, making up for and surpassing any early season delays. As a result in order to maximize heat retention in our zero-till soils seeding early, may very well be a good strategy. Seeding early of course has always been a good idea however I think it is even more beneficial to zero-till producers since a warm soil is probably the most limiting factor to crop production especially early in the spring.

Zero till fields were not only the hardest hit but also had the greatest variability in damage. Low lying areas where generally the greatest yield potential is found were the hardest hit and were virtually wiped out. In many fields these areas might only represent 10-25% of the acres but might contribute as much as 30-40% towards total yield. This of course further complicated the decision on whether or not to reseed. Reseeding is never a popular and most often not a profitable option. As a result the decision to reseed was a difficult one but inevitable for many zero till producers.

The results from reseeding were certainly mixed. On our farm our only regret was that we did not reseed an additional 200 acres. Fields that were left became a haven for weeds such as wild oats, cleavers, and buckwheat. Much of this weed problem was a result of an uncompetitive crop and second flushes. These fields had reduced yields, high dockage and will now have weed problems for years to come.

Our reseeded fields were not sprayed out with Roundup prior to reseeding. The rationale here was that surviving plants from our first seeding could help reduce the green count in our sample in the event of any early fall frost. Swathing would be done at night to minimize shelling as a result of the two maturities in the field. This worked out remarkably well with only minimal shelling occurring. Reseeding was done in the same direction as the first seeding operation to minimize disturbance. Phosphate at 20 lbs active was seed placed. The addition of phosphate seemed to give our reseeded crop some added vigor that was noticeably absent in other reseeded canola fields. Our reseeded canola was up in 5 days and was approximately 10 days behind surviving plants.

Fortunately we experienced an open fall in regards to frost allowing our reseeded crop to yield between 20 to as high as 35 bushels per acre. Our average reseeded yield will likely be approximately 28 bushels per acre.

Certainly no zero till producer wants to experience another canola growing season like 1997 again. We are constantly on a leaning curve and must adapt our zero till system accordingly. The major change that I see us implementing is seeding our canola earlier in the growing season. Early seeding has always been a good idea however it is even more critical for zero till producers since the soil only really begins to warm up once we seed through it. Our most limiting factor early in the growing season is not moisture but heat. In order to take full advantage of our growing season we must seed early. Plants which germinate and grow under cooler air temperatures tend to tolerate frost better than plants that germinate and grow under warm temperatures. Early seeding also allows for better timed corrective measures if disaster does strike.

This last year has seen a major correction in what I call the zero tillage adoption chart. In 1997 we received only 4 inches of moisture for the entire growing season and grew a 35 bushel/acre canola crop. Conventional canola fields were yielding in the 20-22 bushel/acre range. The interest in zero tillage gapped higher as many zero till producers collected what I called their zero tillage dividend cheque. This year on 22 inches of moisture and the spring frost zero till canola saw yields reduced when compared to conventional fields. The interest in zero tillage declined filling the gap left previously. Now support is holding with those who realize and are committed to the long term benefits of zero tillage. Over the last two years our zero till canola still has us money ahead and is why we are still bullish zero till. As with any bull market a correction is a good thing since it points out that no system is perfect and that we should not take anything for granted. The wet fall and the recent memory of last summers abundant rainfall has many producers becoming somewhat complacent in regards to moisture once again. The zero tillage chart may be poised to turn higher since trends generally change when least expected.