Fruition Hor­ti­cul­ture

The Orchardist - - Contents - By Toni String­field, Fruition Hor­ti­cul­ture

Why be or­ganic?

Fall­ing re­turns, de­clin­ing ma­ture mar­kets where the or­ganic cat­e­gory is well es­tab­lished and sought af­ter, and a lack of un­der­stand­ing of the dif­fer­ence be­tween or­ganic and nonor­ganic in emerg­ing Asian mar­kets all mean tough times for or­ganic ki­wifruit grow­ers. Or do they?

In a re­cent pre­sen­ta­tion to or­ganic grow­ers, Ze­spri rep­re­sen­ta­tives demon­strated that de­clin­ing or­chard gate re­turns per hectare (OGR/ha) for or­ganic Hay­ward grow­ers were not due to mar­ket­ing is­sues but rather lay in de­clin­ing yields. The tray price over the pe­riod 2005 to 2013 had varied from $5.34 to $6.38 with an av­er­age of $5.85, but yields had de­clined from a high of 6,947 trays per hectare (tr/ha) in the 2008/09 pro­duc­tion year to 5,634 tr/ha in the 2011/12 year. In­deed in the high pro­duc­tion year of 2008/09 the tray price was a low $5.67 but grow­ers re­ceived an av­er­age OGR/ha of $39,403. In the 2011/12 year with yields at 5,634 tr/ha and a tray price of $6.18 grow­ers con­se­quently made only an av­er­age OGR/ha of $34,846. See ta­ble be­low.

whaT has led To The de­clin­ing Yields foR oR­ganic ki­wifRuiT gRow­eRs?

Cer­tainly the high pro­duc­tion year of 2008/09 lead­ing up to the pay­ment year of 2009/10 had good win­ter chill­ing in the Bay of Plenty. But so did the fol­low­ing year, when pro­duc­tion fell to 6,180 tr/ha. The early high chill in 2009 should have favoured high yield. The two pro­duc­tion sea­sons 2010 to 2012 did fol­low on from lower win­ter chill years and pos­si­bly this con­trib­uted much to the lower pro­duc­tion fig­ures for th­ese two sea­sons. See Chart 1. Early win­ter chill in 2012 was more ex­treme than in ei­ther of the pre­vi­ous two win­ters and may have as­sisted grow­ers in lift­ing yield to 5,799 tr/ha; but in 2013 chill was on a par with 2010, which could in­di­cate that or­ganic grow­ers will strug­gle to get a good crop over the com­ing sea­son. See Tau­ranga Win­ter Chill Chart. Does a lack of rain­fall ac­count for the low pro­duc­tion in the 2009/10 year? There was rain up un­til the end of Jan­uary, though much of that fell as dribs and drabs with the big­gest fall be­ing 21mm on Jan­uary 31. From Fe­bru­ary to the end of April there was lit­tle rain, and some ear­lier har­vest­ing grow­ers may

have got caught out with light fruit that had ap­peared to size show­ing up at the pack­house. Over­all though, the fruit size in­creased from the pre­vi­ous year. In­deed over the pe­riod of our data, or­ganic fruit set a record for its large size in the 2009/10 grow­ing sea­son. The very dry sea­son to the mid­dle of April 2013 did not al­ter the size pro­file from pre­vi­ous years, com­ing in at a 35.4 count av­er­age. See Tau­ranga Rain­fall chart.

There was a sub­stan­tial in­crease in or­ganic hectares in the 2008/09 and 2009/10 sea­sons. If some of th­ese new or­chard hectares were new plant­ings of or­ganic ki­wifruit that may ex­plain some of the loss of pro­duc­tion, but usu­ally or­chards reg­is­ter as or­ganic af­ter a 3-year con­ver­sion pe­riod dur­ing which grow­ers also get to grips with the chal­lenges of the new grow­ing regime. This seems less likely to be part of the cause of re­duced yield af­fect­ing or­ganic grow­ers.

The de­cline in yield has also co­in­cided with the dis­cov­ery of Pseu­domonas sy­ringae pv. ac­tini­diae (Psa). There were at least ten or­ganic or­chards (or or­chards in tran­si­tion to be­ing or­ganic) in the im­me­di­ate vicin­ity of the first quar­an­tined or­chards when Psa was an­nounced as be­ing present in New Zealand.

Or­ganic grow­ers may have dis­con­tin­ued prac­tises such as trunk girdling with the dis­cov­ery of Psa to re­duce the risk of in­fec­tion. Know­ing that they have a re­duced tool­box to pro­tect their vines chem­i­cally, risk re­duc­tion through me­chan­i­cal means will have been high in the minds of or­ganic grow­ers. Or­ganic Hay­ward grow­ers how­ever were not just us­ing trunk girdling to raise dry mat­ter and fruit weight but to in­crease re­turn bloom to set a larger crop the fol­low­ing year. With the loss of this tech­nique yields are likely to have re­duced for those grow­ers who used trunk gir­dle prior to the dis­cov­ery of Psa. Con­ven­tional Hay­ward grow­ers were also us­ing trunk girdling and some have dis­con­tin­ued this tech­nique in the face of the Psa risk, but ap­pli­ca­tion of bud break en­hancers such as HiCane means that they place less re­liance on girdling as a yield lifter.

Or­ganic grow­ers also used spring cane tip­ping to in­crease early bud­burst and con­se­quently yield. The sap flow that re­sults from spring tip­ping, in a pe­riod of the year with fre­quent spring show­ers, in­creases Psa risk and so makes this prac­tice much less likely to be used by or­ganic grow­ers in Psa pos­i­tive ar­eas.

There are sev­eral fac­tors that may have im­pacted in­di­vid­ual or­ganic grow­ers’ yields in re­cent years. With­out know­ing why or­ganic grow­ers have suf­fered such de­clines in yield it is hard to ad­vise what they should do. The cli­mate fac­tors are be­yond grow­ers’ con­trol, and cau­tion around the use of tools such as trunk girdling and tip­ping at bud burst since the ar­rival of Psa has made it harder for or­ganic grow­ers to lift yields back to pre-Psa lev­els.

So to re­turn to the orig­i­nal ques­tion of why would you be an or­ganic ki­wifruit grower? Are green or­ganic ki­wifruit grow­ers

a) a bunch of gree­nie hip­pies with no con­cern for the bot­tom

line; or b) a bunch of over-achiev­ers who think con­ven­tional grow­ing

is for pussies?

The green or­ganic ki­wifruit grow­ers I know are nei­ther, but do of­ten have a strong com­mit­ment to en­vi­ron­men­tal val­ues and are very high achiev­ing peo­ple who cer­tainly want to make a buck. De­spite the chal­lenges, the change­able cli­mate and Psa, there is still a buck to be made grow­ing or­ganic ki­wifruit.

Source: Fruition Hor­ti­cul­ture

Source: Na­tional In­sti­tute of Weather and At­mo­spheric Re­search

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