Article taken from The Press and Journal
Oilseed rape has been put through its paces at Agrovista’s Grow Crop Gold trials site at Southesk Farms, Brechin.
The farm site, which is managed by Neil Macleod, has seen some very good yields, according to Agrovista’s local agronomist, Grant Reid.
The investigations at Southesk have been into variable seed and fertiliser rates, cultivation practices and companion planting.
“We’ve had 12 trial plots of the variety Harper which was sown straight into stubble on August 22 last year and cultivated using either the Great Plains Simba STX or the Vaderstad Spirit Strip Tiller,” said Mr Reid.
“The plots were harvested on August 5 this year and yields ranged from an equivalent of 5.17t/ha up to 6 t/ha and were probably so high because oilseed rape crops did not stop growing over the autumn and winter months.”
He added that: “Fewer plants per row – determined by row widths and seed rate – resulted in higher yields because plants were allowed to develop more branching, more pods and more seeds per pod.”
The plots were sown at row widths – 550mm and 334mm. Seed rates went as low as 7.5 seeds per metre row length. The highest yielding plot was sown at 15 seeds per m row length (45 seeds/m2) and at a row spacing of 334mm.
“This is consistent with other Agrovista Grow Crop Gold trials, our result have shown that even rates of 45 seeds/m2 are too high and that growers could reduce rates to as low as 25-30 seeds to achieve this all-important branching.
“Low plant numbers at Southesk created what we would expect – visibly very different, open crop canopies with many more side branches,” he said. “The plants had larger stem circumstances, were slightly taller and retained far more green leaf area.”
He suggested that plants also took advantage of getting the extra fertiliser available to them due to the lower population and that wider, more open canopies allowed light still to penetrate through to the leaves for photosynthesis. “In denser canopies plants don’t branch so well which results in less photosynthesising leaves, great inter-plant competition, reduced number of seed pods and – in some situations – increased disease risks.”
One other point he noted from the trials is that where nitrogen was placed in the seedbed at sowing, the plants treated was slightly further ahead of other plots throughout the growing season. “This is worth growers doing if a crop is being sown later than ideal.”
At Southesk and Agrovista’s other Grow Crop Gold sites, companion crops have been studied to determine yield and soil structure improvements.
Companion plant mixes of berseem clover, purple vetch and common vetch were sown in some of the Southesk oilseed rape plots at rates of 10kg/ha and 20kg/ha. Mr Reid said that “while in the autumn there was visual differences to the crop, overall there was no yield advantage for the crop at the site; however, the trend at our other trial sites this year has been a crop yield benefit.”
He said that there was a marked improvement in the soil structure as a result of the berseem clover acting as a “pan buster” to break up any compacted areas in the soil profile. “Where companion plants were grown, there was a friable well structured soil left behind.”
Noted in the companion plant plots was also an improved crop green area index. “There is also perceived benefits of companion plants helping to reduce flea beetle damage to OSR plants and now that the neonic restrictions are in place we will monitor the effect with great interest this coming season,” which Mr Reid said was an important point for growers to remember this autumn.
Oilseed rape has been put through its paces at Agrovista’s Grow Crop Gold trials site at Southesk Farms, Brechin.
The farm site, which is managed by Neil Macleod, has seen some very good yields, according to Agrovista’s local agronomist, Grant Reid.
The investigations at Southesk have been into variable seed and fertiliser rates, cultivation practices and companion planting.
“We’ve had 12 trial plots of the variety Harper which was sown straight into stubble on August 22 last year and cultivated using either the Great Plains Simba STX or the Vaderstad Spirit Strip Tiller,” said Mr Reid.
“The plots were harvested on August 5 this year and yields ranged from an equivalent of 5.17t/ha up to 6 t/ha and were probably so high because oilseed rape crops did not stop growing over the autumn and winter months.”
He added that: “Fewer plants per row – determined by row widths and seed rate – resulted in higher yields because plants were allowed to develop more branching, more pods and more seeds per pod.”
The plots were sown at row widths – 550mm and 334mm. Seed rates went as low as 7.5 seeds per metre row length. The highest yielding plot was sown at 15 seeds per m row length (45 seeds/m2) and at a row spacing of 334mm.
“This is consistent with other Agrovista Grow Crop Gold trials, our result have shown that even rates of 45 seeds/m2 are too high and that growers could reduce rates to as low as 25-30 seeds to achieve this all-important branching.
“Low plant numbers at Southesk created what we would expect – visibly very different, open crop canopies with many more side branches,” he said. “The plants had larger stem circumstances, were slightly taller and retained far more green leaf area.”
He suggested that plants also took advantage of getting the extra fertiliser available to them due to the lower population and that wider, more open canopies allowed light still to penetrate through to the leaves for photosynthesis. “In denser canopies plants don’t branch so well which results in less photosynthesising leaves, great inter-plant competition, reduced number of seed pods and – in some situations – increased disease risks.”
One other point he noted from the trials is that where nitrogen was placed in the seedbed at sowing, the plants treated was slightly further ahead of other plots throughout the growing season. “This is worth growers doing if a crop is being sown later than ideal.”
At Southesk and Agrovista’s other Grow Crop Gold sites, companion crops have been studied to determine yield and soil structure improvements.
Companion plant mixes of berseem clover, purple vetch and common vetch were sown in some of the Southesk oilseed rape plots at rates of 10kg/ha and 20kg/ha. Mr Reid said that “while in the autumn there was visual differences to the crop, overall there was no yield advantage for the crop at the site; however, the trend at our other trial sites this year has been a crop yield benefit.”
He said that there was a marked improvement in the soil structure as a result of the berseem clover acting as a “pan buster” to break up any compacted areas in the soil profile. “Where companion plants were grown, there was a friable well structured soil left behind.”
Noted in the companion plant plots was also an improved crop green area index. “There is also perceived benefits of companion plants helping to reduce flea beetle damage to OSR plants and now that the neonic restrictions are in place we will monitor the effect with great interest this coming season,” which Mr Reid said was an important point for growers to remember this autumn.