{"id":1029,"date":"2017-04-03T13:02:06","date_gmt":"2017-04-03T13:02:06","guid":{"rendered":"http:\/\/agrilife.org\/texasrowcrops\/?p=1029"},"modified":"2017-04-29T13:33:29","modified_gmt":"2017-04-29T13:33:29","slug":"within-row-plant-spacing-ensuring-planter-accuracy-of-seed-drop","status":"publish","type":"post","link":"https:\/\/agrilife.org\/texasrowcrops\/2017\/04\/03\/within-row-plant-spacing-ensuring-planter-accuracy-of-seed-drop\/","title":{"rendered":"Within-Row Plant Spacing\u2014Ensuring Planter Accuracy of Seed Drop"},"content":{"rendered":"

by\u00a0Calvin Trostle, Extension Agronomy, Lubbock, (806) 723-8432, ctrostle@ag.tamu.edu<\/a><\/p>\n

In recent newsletters for Texas Grain Sorghum Association I first discussed row spacing for grain sorghum then especially in-row spacing<\/u> of seed drop and the accuracy (or lack thereof) of uniform seed spacing within the row (see http:\/\/texassorghum.org\/sorghum-tips<\/a>).\u00a0 Here, I expand the with-in row discussion to all Texas row crops.<\/p>\n

On a smaller scale of about two to six inches within any row spacing, it may seem the uniformity of seed spacing is not that important for row crops.\u00a0 Yes, it is true that the root system, for example, will basically still explore the same area and leaf area will be about the same.\u00a0 But varieties (or hybrids) of corn, grain sorghum, cotton, soybean, guar, or cowpeas do respond differently to spacing around the individual plant with more tillering or branching than others.\u00a0 This can be a positive effect (a plant accounts for extra space and yield potential by tillering or additional branching to compensate for a gap in the row) or negative effect (excess tillering is not desirable in moisture-limited production).<\/p>\n

Having uniform plant spacing within the row is a plus\u2014as is your planter actually placing the correct number of seed that you desire.\u00a0 <\/em>We are most immediately concerned about larger gaps of 12\u201d or more\u2014they are obvious, especially if you are planting 3 to 6 seeds per foot of row.\u00a0 Sometimes trash or other factors in the field (as well as worn out equipment like a trash whipper or disc opener) may interfere with seed placement and emergence (Fig. 1), but the same principle applies like I discussed in sorghum row spacing, uniformly distributed plants is favorable.<\/p>\n

The faster you plant on rough ground you will also lose incrementally some of your uniform spacing in the seed drop.\u00a0 I am not the first one to advise producers to \u201cslow down\u201d when you are planting.<\/p>\n

Confirming the Desired Seed Drop of Individual Planter Units<\/strong><\/p>\n

In recent testing on a late model John Deere 8-row air-vacuum planter at one of our AgriLife Research facilities, I found two rows dropped 17% or more seed than they should have, and one row was 20% less than what was targeted.\u00a0 Pending the production conditions this creates a potentially non-agronomic plant population within the row.<\/p>\n

I recommend a two-fold approach:<\/p>\n