‘Attention to detail’ brings top wheat yields

Press, 9 December 1983, Page 22

‘Attention to detail’ brings top wheat yields

Ample evidence was presented at the field days of the Tasman 1.C.1. Wheat 83 competition to show that growing a winning crop of wheat involved more than mixing and applying chemicals correctly — although that had to be done as well.

Two of the nine competitors have already (perhaps two months from harvest) opened a significant gap on the rest.

If they had any secrets they were not about to give them away to growers who attended the field days. Their success probably stems from that oft-quoted adage (attributed to M.A.F. agronomy adviser Mr Bede Cloy) “attention to detail.”

But that cannot be the whole story. As field day commentator, competition organiser and Lincoln College lecturer, Dr Warwick Scott said: “You can get out into the field and peer knowledgeably at an ear of wheat,” and thereby presumably attending very diligently to detail.

But if such undivided attention actually tells you anything, like the fact that there are too many “greebies, nasties and lurgies” lunching on your wheat crop, it is probably going to cost you something. You are going to have to spray again and add to your input costs for the competition, thereby lessening your chances of winning a competition based on net financial return per hectare and not just yield.

To complicate matters further, a competitor cannot afford to kill everything that moves or grows on his wheat plot. For instance, there are harmful bugs and not-so-harmful bugs. The rosegrain aphid need not be sprayed until 60 to 70 aphids per leaf are observed, according to the collective entomological wisdom. But stripe rust, a sort of inanimate predator, must be (Shot on sight. Even the application methods and the chemical weapons used vary considerably and every method and chemical has its proponents, as even a layman visitor to the field days could not fail to observe. Attention to detail could obviously lead to headaches, myopia and a list of costs as long as your arm. At present around $lOO per hectare separates the competitors with the highest and lowest cost inputs. Relativities are unlikely to change, with standard harvesting costs only remaining to be added.

Another thing that the experts were agreed upon was that further spraying from now on was unlikely to be of any benefit.

But on Dr Scott’s “guesstimates,” about 0.6 of a tonne per hectare of yield separates first and second and second and third.

On present prices 0.6 of a tonne is over $lOO of gross return — more than enough to confirm the lead (in the over-all net return competition) of the current yield leader, even if he had the highest costs and the competitor coming second had the lowest.

At present Mr Ray Maginness, of Leeston, the leader with a guesstimated yield of 6.7 tonnes, has spent $343 per ha, including $l4l for three applications of spray for stripe rust, weeds and aphids. The last two sprays were with 500 ml of Tilt per ha. In comparison the secondplaced Geraldine-Temuka group, including M.A.F. Timaru adviser, Mr David Montgomery, has spent $335, including $137 per ha on spraying. Dr Scott commented that both these competitors had spent about the same for spraying in total but had spent it quite differently. The Geraldine-Temuka group has opted for four separate sprayings for stripe rust, using 200 gm or 200 ml per ha each time. Mr Montgomery commented to the field days crowd that it was cheaper to spray five times at a low rate than three times at a higher rate and he believed that it gave better control. The representatives of the chemical companies did not give advice at this point, although they were not backward in coming forward later in the tour when some controlled droplet applications (C.D.A.) advocates had their say.

Mr Maginness’ plot was the earliest sown, on May 6, which earned him the approval of commentator Dr Scott. The crop was several days ahead of others, had a high dry matter available for the grain to use in setting, had a large number of spikelets per ear and a high number of grains per spikelet. Dr Scott urged caution on the determination of grains per spikelet, however, saying that because many grains had not yet set this figure was imprecise. The lower rate of nitrogen application by Mr Maginness compared with the Geraldine-Temuka group also favoured a larger grain size, said Dr Scott. He stressed that nitrogen applications did have an adverse effect on grain size though, of course, over-all dry matter production was increased.

Following soil testing on the Lincoln competition site which showed that enough nitrogen was available for about 4.5 tonnes of yield most competitors applied nitrogenous fertilisers and on the cost structure of the competition 50kg of N per ha cost about $5O plus $7 application, charge. Mr Maginness applied 58kg and Geraldine-Temuka 81kg. The group of three competitors who had estimated

yields around 5 to 5.5 tonnes per ha emphasised the variety of approach which has been one of the features of this year’s competition compared with the last. Third-placed Mr John Tait, of Ashburton, sowed Kopara (when most other competitors this year and last stayed with Rongotea) and after an exceptional plant count at the two leaf stage of 300 per square metre, decided to direct drill nitrogen at 54kg per ha in mid-September across the rows.

“The crop was too thick so I drilled across the rows to break down some of the tillers,” he said. Later in mid-October he repeated the nitrogen application in what he admits was an attempt to get total yield up. This raised his total costs to $364 per ha, the highest in the competition so far and without a significant lead on yield he seems to have no chance of heading off the leaders.

It is perhaps disappointing to see the Kopara entry thus placed, because the only other competitor to sow other than Rongotea, the Gifford brothers from Blenheim with Oroua, were never in the hunt after a spring sowing and an unhealthy dose of rust. They have the lowest cost input so far but it has been predicted that they will make only 4.5 tonnes per ha, although they maintain 5 tonnes is still likely.

Another of the “fivetonners," Mr Ivan Maw, of Methven, is well-known as a ploughing match competitor and administrator. He and Mr Gordon Carter, of Greenpark, the current Mobil Silver Plough champion, have continued their be-tween-the-furrows rivalry into the growing and harvesting of the crop. Mr Maw is estimated to have about 0.8 tonnes per ha lead on Mr Carter at present (5.4 tonnes versus 4.6 tonnes) but these two and a third competitor, Mr K. Gallagher, of Loburn (4.2 tonnes) reportedly drew the least fertile side of the competition paddock. The third “five-tonner,” who was actually estimated to be coming fifth in terms of yield, Mr Don Wright, of Sheffield (5.2 tonnes) set the cat among the chemical company pigeons by giving an endorsement of C.D.A. spraying at 200 ml a.i. per ha concentrations rather than the recommended dosing of twice that. He invited his friend and C.D.A. adviser, Mr lan McCormick, of Oxford, to speak. Mr McCormick said that he had been copping flak from chemical companies who had said that the half dosages would not do the jobs required but that he would stick by his C.D.A. guns and even halve the rates a further time on his own crops. He promptly copped some more flak. A representative from Ciba-Geigy N.Z., Ltd,

Mr Gary McDrury, said that reducing rates in such a way could lead to build up of resistance through incomplete kills. This response was not popular with the head of the Plant Health Diagnostic Centre of the M.A.F. at Lincoln, Dr lan Harvey, who said there was little evidence to show that rust could build up resistance to Tilt (or Bayleton) in the manner described. Anyway new rust-con-trolled chemicals were on the way which could be alternated with the present chemicals in the future. A representative from Bayer then explained that local climatic conditions around Lincoln had appeared to favour the early build up of rust on crops established with Bay-tan-treated seed. The company had no indication from elsewhere that the efficacy of Baytan was declining. Despite these uncertainties, the competition has been a hit with farmers and already eight have put forward their names for next year. A further four have offered their properties as a site.

As Dr Scott pointed out, the competition was limited in its value as a direct comparison of cultivars, methods and chemicals.

“Tremendous promotional or commercial hay can be made out of a competition like this but scientifically it is hogwash,” he said. Conditions were not

nearly precisely enough controlled to make scientifi-cally-valid comparison possible, he said, but there was no denying the interest generated by the competition.

I.C.I. Tasman Wheat 83 Yield Component “Guestimates” compiled by Dr Warwick Scott Competitor Ears/ Spikelet/ Grains/ Grains/ Grain Yield sq m ear spikelet sq m wt (mg) t/ha R. Maguinness 520 18.9 1.58 15,528 43 6.7 Cliffords 550 15.5 1.46 12,447 36 4.5 Geraldine/Temuka 580 18.9 1.36 14.908 41 6.1 J. Tait 390 19.8 1.77 13,668 40 5.5 Robinsons 480 17.2 ... 1.37 11,311 41 4.6 D. Wright 460 19.1 1.38 12,125 43 5.2 K. Gallagher 410 18.7 1.24 9,507 44 4.2 G. Carter 450 19.4 1.21 10,563 44 4.6 I. Maw (Methven Ploughing) 490 19.9 1.26 12,286 44 5.4