Principles of Crop Establishment Gary Martens, Department of Plant Science, University of Manitoba Winnipeg MB R3T 2N2

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1 136 Principles of Crop Establishment Gary Martens, Department of Plant Science, University of Manitoba Winnipeg MB R3T 2N2 Proper crop establishment may be challenging in the spring of 2005 because of the difficult harvest conditions experienced in the fall of Good crop establishment is crucial for obtaining excellent yields and high profits. Modern seeding equipment allows many producers to be direct seeders with very little soil disturbance at seeding time. For the spring of 2005 some fields may have tire track ruts, unharvested crop or unevenly spread crop residue resulting in the necessity of some land preparation before seeding. Spring soil disturbance with wide sweeps have been shown to encourage weed growth in a number of studies (Anderson et.al. 1998)(Blackshaw et.al. 1994) but the relationship of weed density to tillage is not always consistent (Swanton et.al. 1999) (Derksen et.al. 1993). It will be prudent to watch weed density in the spring of 2005 due to unusual land preparation practices. There are a number of factors that affect good crop establishment. One of the most important, in light of last year s wet conditions is seed quality. Poor quality seed can lead to lower than optimum plant populations which leads to lower yields and less profitability. Seed quality is measured by freedom from foreign material, freedom from disease and by germination. The Seeds Act, the regulations governing pedigree seed does not now take weathering including frost into account as a separate factor; it is built into germination. Dormancy can be a factor in some varieties. If germination is low in the first test immediately after harvest, a germination test after a chilling period may be done to determine level of dormancy. The seed labs that I spoke to indicated a higher level of seed borne diseases in the 2004 seed crop. Seed treatments may be useful in allowing good plant populations to establish from marginal seed. Inoculant where required should be well maintained in storage in the package and on the seed. Inoculant on seed is extremely vulnerable to decline in viability if stored for longer than one day especially in hot conditions. (Roughley et.al. 1995). This is one of those years where 2003 seed, inspite of its age will probably be of higher quality than fresh seed. The pedigree seed tag identifies the year as the first two digits. The seed tag means this seed was grown in The digit after the first dash indicates where the seed was grown. A 6 means Manitoba, 7 = Saskatchewan and 8 = Alberta. The next six digits identify the grower and the last two digits identify the class of seed (4 = certified) and the seed lot. Even with good germination, a good plant population is not guaranteed. The condition of the seed bed can have a large impact on the actual emergence of the seed. In a study published by Sylvia Borstlap and Martin Entz (Borstlap et.al. 1994) emergence using a Noble hoe drill ranged from 29% to 100%. Percent crop emergence at two locations and two years Canola Field Peas Wheat Location Year ZT CT ZT CT ZT CT Carman % 32% 40% 40% 42% 44% Carman % 100% 87% 81% 100% 90% Portage % 67% 87% 89% 89% 83% Portage % 67% 65% 68% 87% 98% Calculated from Borstlap, S and M. H. Entz Zero-tillage influence on canola, field peas and wheat in a dry subhumid region: Agronomic and physiological responses. Can. J. Plant Sci. 74: In Marnie L. Hamill s Masters Thesis: The Effect of Cultivar, Seeding Date, Seeding Rate and Nitrogen Fertility on Oat Yield and Milling Quality (Hamill, M.L. 2002) she reported oat emergence in 1999 at 55% for both Morden and Winnipeg and 65% for Carman using a double disk press drill.

2 137 Seed quality and percent emergence and of course seeding rate will determine the plant population. Most crops can adjust to a wide variation in seeding rates, however Manitoba Crop Insurance Corporation uses some minimum plant populations to establish potential yield. Minimum Plant Populations required for Full Yield Crop Minimum Plant Population Canola 40 plants per square metre Flax 400 Field Peas 50 Fababeans 25 Buckwheat 50 Lentils 70 Field beans 63,000 per acre Grain corn 18,000 Silage corn 22,000 Data from Manitoba Crop Insurance Corporation Cereals and Sunflowers are listed as plant population required to reach a certain yield Plants/metre Wheat Barley Oats Plants/acre Sunflower bu/ac 18 bu/ac 21 bu/ac lb/ac Data from Manitoba Crop Insurance Corporation Improper plant populations can also be a result of seeder settings and operation. Seeding too shallow into dry ground, too deep in cold wet soils, or improperly calibrating (especially due to unique seed weight and size) can account for unexpected plant populations. Too much fertilizer with the seed can affect plant population, but is less of an issue in wet soils such as we may have in the spring of Safe levels of seed placed nitrogen placed vary with crop kind, soil texture, moisture level and seed bed utilization (SBU) percent. (Soil Fertility Guide, MAFRI page 6) Seed placed phosphorous can also have an impact, especially on some colored beans and on flax. An increase in seeder speed generally increases plant populations, increases variability of the plant population and decreases yield. In crops that depend on precision planting like grain corn and confectionary sunflowers for example a small change in plant population can have a significant effect on yield and quality. A study from Purdue University in Indiana showed a decrease in yield of corn of approximately 2 bu/ac for every 1 mph increase in planter speed from 4 mph up to 7 mph.(nielsen et.al. 1995) Beck, a corn seed company in the United States showed that planter speed affected gaps and doubles which led to a decrease in yield (

3 138 Gaps and Doubles per 1/1000 acre mph from Five to six and one half miles per hour was found to be an optimum planter speed for the planters tested. Ron Lyseng in The Western Producer newspaper reports that Eugene Breker formerly of Concord has built a new double disk air drill called the Fargo Aire Drill which claims high seed placement accuracy up to 9 mph. (Ron Lyseng 2004). Land preparation may need to be carried out in the spring of 2005 to establish a proper seed bed. In some cases this may result in delayed seeding. For most areas of Manitoba and for most crops the principles to follow is plant as early as possible. Delayed planting typically results in reduced yield and in some cases reduced quality. % Yield Seeding Date vs. Yield Risk Area Date (MW) Wheat Canola Flax From Manitoba Crop Insurance Corporation. The warm season (C4) plants typically perform better if not seeded too early.

4 139 from Manitoba Crop Insurance Corporation. Good crop establishment is crucial to obtaining excellent yields and high profits. If the crop does not get a good start, the potential of the crop to perform well is reduced. The spring of 2005 will likely produce challenges for good crop establishment. Attention to detail, taking all the above mentioned factors into account should allow for a great start for most crops in most situations. Planting a crop in a suitable field (no adverse herbicide residues, proper crop rotations), as early as recommended, as shallow as possible (keeping moisture in mind), with a well calibrated and adjusted seeder pulled at a reasonable speed using known quality seed at the appropriate seeding rate (taking potential emergence into account) should lead to a well established crop. References Anderson,R.L.; Tanaka,D.L.; Black,A.L.; Schweizer,E.E Weed community and species response to crop rotation, tillage, and nitrogen fertility. Weed Technology v. 12 (3) p Blackshaw,R.E.; Larney,F.O.; Lindwall,C.W.; Kozub,G.C Crop rotation and tillage effects on weed populations on the semi-arid Canadian prairies. Weed Technology. v. 8 (2) p Swanton, C.J., Shrestha, A., Roy, C.R., Ball-Coelho, B.R., Knezevic. S.Z Effect of tillage system, N, and cover crop on the composition of weed flora. Weed Science. 47: Derksen,-D.A.; Lafond,-G.P.; Thomas,-A.G.; Loeppky,-H.A.; Swanton,-C.J Impact of agronomic practices on weed communities: tillage systems. Weed Science. v. 41 (3) p Borstlap, S and Entz, M.H Zero-tillage influence on canola, field pea and wheat in a dry subhumid region: Agronomic and physiological responses. Canadian Journal of Plant Science. 74: Marnie L. Hamill, Masters Thesis: The Effect of Cultivar, Seeding Date, Seeding Rate and Nitrogen Fertility on Oat Yield and Milling Quality

5 140 Soil Fertility Guide. Manitoba Agriculture, Food and Rural Initiatives. mg-5662 Nielsen, R.L Planting speed effects on stand establishment and grain yield of corn. Journal of Production Agriculture. 8: accessed December 8, 2004 Ron Lyseng. The Western Producer. November 18, vol. 82. no. 46. page 29. Manitoba Crop Insurance Corporation. Accessed December 8, R. J. Roughley, R. D. M. Simanungkalit, L. G. Gemell, E. J. Hartley and P. Cain Soil biology & biochemistry vol: 27 iss: 4 pg: 707. Growth and survival of root-nodule bacteria in legume inoculants stored at high temperatures K.Vessey, University of Manitoba. Oral Communication December 16, 2004.