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Healthy Fruit 1998 Vol. 6:3

April 15

Quietly Advancing

On the surface, it was a quiet week in Massachusetts. Yet with temperatures ranging from 60 to 70 on many days, growth kept moving right along.

McIntosh growth stages for various locations:

  • Ashfield 1/2" green
  • Belchertown 4 or 5 leaves back; early tight cluster
  • Northboro tight cluster
  • Sterling very early tight cluster
  • Wilbraham early tight cluster

Time Critical!

  • Notching
  • Be ready for scab sprays.
  • TPB and LM getting active.
  • Plant!
  • Plan for Nova Scotia.
  • High density group meeting at Broderick's.

The Time for Notching is Nearing Its End

tree

Notching is one of the few reliable means of enhancing branch development in apples. Young trees particularly can benefit from notching as a way to encourage new branches in specific parts of the tree. The process is simply to make a cut through the bark into the wood, perpendicular to the stem, and just above a bud that you wish to produce a shoot. The cut can be made with a hacksaw blade and should be about _" long. The best timing is between 4 and 2 weeks before bloom, but is still somewhat effective at bloom. Two-year-old wood is ideal for notching, but it can work on older wood as well. Results are nearly as good on one-year-old wood, but chances of breakage in the notching process increase dramatically. Choose the largest buds, since they will result in the longest shoots. Overall, you should expect in excess of 70% of these notch buds to produce useable shoots.

Planting Trees

With the season as progressed as it is, it seems like its too late to be discussing planting, but I am sure that many of you have the same problems that I do: The trees aren't here yet! For those of you who haven't planted yet, consider the points below that were derived from a research project that we conducted a few years ago.

  • Use of tree planter, in general, results in similar tree performance to the use of an auger. Be aware that planting is much much faster with a tree planter. Sometimes it can be too easy to plant trees with a tree planter! Also, soil amendments must be applied over a wider area if a tree planter is used, i.e. you can't concentrate on the hole itself.
  • Amend the soil to improve growth of the newly planted trees. If you are using an auger, mix the soil to be returned to the hole 50-50 with peat moss or compost. Our research showed a 15 to 25% increase in tree growth during the first three years resulting from organic matter additions.
  • Fertilizers can harm newly planted trees very easily. Apply less than 0.1 lb of nitrogen per tree, preferably with a soil drench after the soil has settled. We found that increasing nitrogen resulted in reduced growth in the early years.
  • Mulch can improve early growth and flower bud formation, particularly where soil moisture is limited. Consider using wood chips, since they don't encourage vole activity as much as hay or straw mulch does.
  • Do not wait on establishing irrigation. The payback for irrigating young trees can be greater than that for mature trees.

Tarnished Plant Bug Few But Active

Captures of tarnished plant bugs on white sticky rectangle traps remain low throughout the state, with no monitored blocks exceeding an average of 3 TPB/trap. Although most orchards appear to have few TPB present, activity of those that are present has increased, triggered by the warm daytime weather of this week (4/8-4/14). Signs of TPB activity, such as oozing punctures on buds, have become apparent in those areas that have reached early cluster, but injury levels appear light thus far.

If insecticidal control is necessary, Guthion, Imidan, and Lorsban remain the materials of choice. Remember, pyrethroids (Asana, Ambush, or Pounce) can lead to mite problems.

Leafminers Lift-off

Last season produced the highest trap captures of first-generation leafminers that we have recorded, with some blocks exceeding 1000/trap. Given this, along with the likelihood of a high rate of overwintering survival, there is again the potential for heavy LM activity early in the season.

Emergence of LM adults has begun in earnest in some of the earlier-developing areas of the state. In two orchards nearing tight cluster, captures have reached 30/trap, signifying high populations which warrant treatment shortly after petal fall. Materials labeled for use against LM include Vydate (no later than early pink) and synthetic pyrethroids (Asana, Ambush, Pounce) from early to late pink. We do not recommend use of either of these materials due to their well-documented negative effect on predatory mites.

Alternative chemicals which fit within an IPM approach to orchard management include Provado and Agrimek, with either applied at petal fall. Recent studies in Massachusetts and Pennsylvania indicate that petal fall applications are by far the best timing for control of LM, and that Agrimek (applied with oil) offers better control than Provado, with control lasting at

Pear Psylla

Sites prone to infestation of pear psylla that received an application of either Agrimek or Pyramite last season were relatively clear at harvest, thus carry-over of last year's population is likely very low. Adults have been present and active for several weeks with light egglaying, and we do not expect heavy early-season activity.

Apple Tour to Nova Scotia

The High Density Study Group is planning a tour in the Kentville area of Nova Scotia, including Agriculture Canada's research station and surrounding orchards. We will be hosted by Charlie Embree of Agriculture Canada and Bill Craig of the Province of Nova Scotia.

At this point we are uncertain of our means of transportation. Our choices are:

Option 1: Charter a bus and drive all the way (~700 miles). This option would entail leaving early on Tuesday (July 7), arriving in Kentville late in the evening. We would tour on Wednesday (July 8), stay overnight, and depart via bus early Thursday (July 9), arriving home late in the evening. The cost would be approximately $300 per person (assuming double occupancy in the hotel) and three full days.

Option 2: Charter a bus and take it on the Scotia Prince (ferry out of Portland, ME). We would leave at about 5:00 PM Tuesday (July 7) and travel to Portland for a 9:00 PM departure on the ferry. The ferry would arrive in Yarmouth, NS at about 9:00 AM on Wednesday (July 8). We would drive to Kentville (about 2.5 hours from Yarmouth), lunch, and begin our tour in the afternoon. We would tour until dark and return to Yarmouth to stay in a hotel overnight. The ferry would depart at 10:00 AM on Thursday (July 9) and arrive in Portland at 8:00 PM. We would arrive home before midnight. The cost would be approximately $300 per person (assuming double occupancy in the ferry cabins and the hotel) and two and a half days.

Option 3: Charter a plane from Boston to Halifax and a bus to Kentville. We would leave Boston mid morning on Tuesday (July 7) and fly to Halifax, where we would rent a bus and travel to Kentville (about an hour drive). We would stay overnight in a hotel and tour on Wednesday (July 8). Our tour would end at about 3:00 PM, and we would travel back to Halifax to return via plane to Boston. The cost would be approximately $350 per person (assuming double occupancy in the hotel) and two full days.

Each of these options will require some kind of commitment soon. There will be a High Density Study Group meeting at 1:00 PM on Thursday, April 23, at Bill Broderick's orchard. If you cannot make that meeting and you are interested in going, please call me (413-545-2963) and tell me what option you prefer. If I am not in, please leave a message. We need to decide

Scab Update

There really isn't much new, except that we are that much closer to the first significant infection period. The pieces are in place: with growth, we have a lot of new, susceptible tissue; there's plenty of inoculum now, running anywhere from 10% in the hills, to 25 or 30% in most areas. If we have some significant wetting, watch out.