Man­ag­ing the sea­son you’re in

The Orchardist - - Orchard Management - By Ruth Un­der­wood

Ev­ery ki­wifruit grow­ing sea­son is dif­fer­ent.

What hap­pened last sea­son is of­ten top of mind and we set out ready to solve or pre­vent the prob­lems of last sea­son. The real suc­cess comes when we are able to solve or pre­vent the prob­lems of this sea­son.

Many of you will have come off one of your best ki­wifruit yields in re­cent years at the 2018 har­vest. How do you avoid a dip in yield for 2019? I’ll de­scribe some strate­gies through the rest of the sea­son to in­crease the chance of the next har­vest be­ing as good as the last one, by fo­cussing on the sea­son we’re in.

PUT ON FER­TILISER TO SUP­PORT SPRING GROWTH

Sup­port canopy growth in spring as it’s when most of the nu­tri­ents re­quired for the sea­son are taken up by ki­wifruit vines. Sup­ply from cy­cling of nu­tri­ents in the soil may be lim­ited by cool soil tem­per­a­tures, so the fer­tiliser com­po­nent of nu­tri­ent sup­ply is es­pe­cially im­por­tant in this spring pe­riod. We have to be ju­di­cious with fer­tiliser quan­ti­ties, to con­serve lim­ited world­wide re­sources, so part of us­ing them ef­fi­ciently is ap­ply­ing them in good time for peak vine up­take.

MIN­IMISE CANOPY IN­TER­FER­ENCE IN SPRING

Ki­wifruit has a rel­a­tively long pe­riod be­tween bud­break and flow­er­ing com­pared with other de­cid­u­ous fruit. This pe­riod is a great op­por­tu­nity for the vine to build re­sources in the canopy be­fore the de­mands of flow­er­ing and fruit growth start. Canopy work in this pe­riod should be min­i­mal and aim­ing to di­rect where growth oc­curs, but only re­mov­ing a small por­tion of the de­vel­op­ing leaf area. Crush­ing tips or tip­ping are good strate­gies. Leaves take over a month of de­vel­op­ment be­fore they are con­tribut­ing to vine re­sources, so we need to get this leaf-area work­force up and run­ning as quickly as pos­si­ble. Rapid canopy de­vel­op­ment in this pre-flow­er­ing pe­riod is par­tic­u­larly help­ful if a high crop the past sea­son or other stresses like a dry au­tumn have de­pleted vine re­sources.

MIN­IMISE SOIL COM­PACTION

It’s been pretty wet re­cently and run­ning heavy equip­ment across soggy soils cre­ates com­paction dam­age that im­pairs soil stor­age and sup­ply of wa­ter and nu­tri­ents, and doesn’t fix it­self quickly. Com­paction can make the soil too dense, poorly aer­ated and slower to warm up. Avoid ex­cess traf­fick­ing of heavy equip­ment on wet soils and con­sider re­duc­ing weights such as by work­ing on the bet­ter ar­eas when the sprayer tank is full or us­ing partly-filled sprayer tanks (although check the mea­sure­ments are ac­cu­rate for part-filled tanks), or even ac­cess­ing tracked equip­ment if that can be used for the ac­tiv­ity needed. Also iden­tify ar­eas that may ben­e­fit from adding lo­calised drainage or di­ver­sion of run-off next year af­ter har­vest. If there are ar­eas where the ground has dried into ruts, spread­ing some soil or me­tal on the area will make it safer work­ing in that area too.

BE READY FOR FROSTS

If you have frost pro­tec­tion equip­ment make sure it is ready to op­er­ate and the alerts are in place. The lat­est dam­ag­ing frost I can re­call was in mid-Novem­ber, so you wouldn’t want to bring down over-un­der sprin­klers un­til late Novem­ber. All spring growth stages are vul­ner­a­ble to ef­fects from frosts and low tem­per­a­tures. Be­cause these of­ten oc­cur over sev­eral con­sec­u­tive days, check the sys­tem is ready to go again for the next night af­ter each use.

Re­mem­ber the pas­sive frost mea­sures like keep­ing the sward short, shel­ter trimmed or bases cleared. These ac­tiv­i­ties help air move­ment which re­duces the chance of cold air col­lect­ing and caus­ing frost dam­age. Hav­ing rel­a­tively bare soil helps too, such as af­ter mulching and weed con­trol, as the dark soil ab­sorbs heat dur­ing the day which pro­vides a bit of warm­ing overnight.

If it does get dry it’s the ar­eas with more chal­leng­ing soil con­di­tions that are likely to be af­fected first. They tend to have a nar­rower band be­tween be­ing too wet and be­ing too dry. If you have over-un­der sprin­klers that are still in their ‘up’ po­si­tion but it’s get­ting dry, ap­ply any ir­ri­ga­tion at a time of day when the canopy won’t stay wet for too long, as a pro­longed wet canopy can pro­mote dis­ease in­clud­ing bu­drot. Even be­ing next to a dense shel­ter­belt can keep the canopy wet for longer, so watch for this and note to trim or thin such shel­ters if it is a prob­lem.

HOW DO WE RECOG­NISE WHAT THIS SEA­SON IS PRO­VID­ING?

Count­ing flower buds and fruit is al­most no-one’s favourite job but it is one of the most im­por­tant jobs in man­ag­ing the or­chard. These counts en­able you to know how num­bers are track­ing com­pared to tar­gets as well as to pre­vi­ous sea­sons. If num­bers are down, try to fig­ure where the drop has oc­curred. Is it lower win­ter buds to start with or fewer flow­ers be­ing pro­duced on a sim­i­lar quan­tity of wood? Some­times you can see if there are flower­buds that have stopped grow­ing or

aborted – it’s use­ful if they were dou­bles and triples but a prob­lem if you have too few flow­ers left on each fruit shoot or too many blind shoots.

Spring can be a volatile time on the or­chard – things can look grim but only a few warmer weeks later it can be hard to find the prob­lem ar­eas that were so con­cern­ing ear­lier. Our eye is drawn to im­per­fec­tions, which can seem neg­a­tive, but these ob­ser­va­tions can be use­ful. For ex­am­ple, late bud­break on in­di­vid­ual vines can be an early sign of a dis­ease prob­lem – watch for this in ar­eas where you have had Ar­mil­laria root rot pre­vi­ously.

DO FRUIT THIN­NING EARLY – AT FLOWER­BUD STAGE WHERE POS­SI­BLE

It’s great we can see fruit shape fea­tures at the flower bud stage. Thin­ning them off be­fore flow­er­ing saves vine re­sources that are then avail­able to fuel the fruit you will carry through to har­vest. Flats and fans missed for re­moval be­fore flow­er­ing are some­times not as clearly seen again un­til well into Jan­uary.

If your counts show high flower­bud num­bers, work through what po­ten­tial crop that is and de­cide if that is fea­si­ble to carry through or whether some should be re­moved to a more fea­si­ble crop­ping level. Com­par­i­son to counts at the same time in pre­vi­ous sea­sons can be very use­ful here. For ex­am­ple, on some or­chards last year we found there were about 30 per­cent more flow­ers than car­ried the bestever crop on a high-yield­ing or­chard. It made com­plete sense to re­move enough to bring cropload back sim­i­lar to pre­vi­ous, good sea­sons rather than carry so much and risk prob­lems. It’s still im­por­tant to leave a mar­gin of well- shaped flow­ers to al­low room to re­move de­fects that show up later in the sea­son, but not too great a mar­gin.

Thin­ning is costly but worth­while if your num­bers are high. It al­lows you to space the fruit you keep across the canopy – re­mov­ing more in ar­eas where leaf-cover is sparse and match­ing fruit num­bers to the strength of shoots – in­di­cated by their leaf num­ber. Where num­bers are re­ally high, rip­ping off weak shoots car­ry­ing many flow­ers will im­prove vine leaf to fruit ra­tios and may be quicker to do.

Sim­i­larly, if the high flower den­sity is mostly in the mid­dle of the bay, just work­ing in the cen­tre few wires of each bay may work well and is faster. Keep­ing thin­ning in­struc­tions sim­ple also helps to get a good job done. I’ve found a tech­nique like only thin­ning shoots shorter than a handspan, and re­duc­ing them to a spec­i­fied num­ber of flow­ers (usu­ally be­tween two and four) works well. We’ve all got dif­fer­ent sized hands but most handspans are 15-25cm so you will be di­rect­ing peo­ple to thin from the weak shoots.

If your counts show flower num­bers are down, still thin off flats and fans un­less there are so few of them it’s not worth putting a team through the block. When num­bers are down, each fruit is pre­cious. A gain in fruit size can help to off­set lower num­bers and spac­ing out the fruit you have may help re­duce losses to pests and dis­eases. If num­bers are down, also pay spe­cial at­ten­tion to ac­tiv­i­ties that re­duce re­jects like ty­ing up the ends of shoots that will hang be­low the canopy and get bat­tered by ma­chin­ery driv­ing through the block.

For young vines that won’t pro­duce a com­mer­cial crop, re­move flow­ers to di­rect the vines re­sources into grow­ing the vines per­ma­nent frame­work. The pur­pose of leav­ing any flow­ers on these vines is to check the vine lay­out is as in­tended, such as place­ment of male and fe­male vines. The other in­for­ma­tion they pro­vide, such as tim­ing of flower open­ing, is prob­a­bly dif­fer­ent to tim­ing on ma­ture vines, so is only use­ful for a new and dis­tinctly dif­fer­ent site or va­ri­ety where all new in­for­ma­tion is valu­able. Oth­er­wise, these fruit are tak­ing away vine re­sources that you want put into grow­ing the per­ma­nent parts of the vine for com­mer­cial-scale crop­ping in fu­ture sea­sons.

If you’re spend­ing lots on thin­ning, don’t nec­es­sar­ily plan to prune harder next win­ter. Thin­ning is ex­pen­sive, but worth­while in the crop qual­ity as you have the abil­ity to se­lec­tively re­move the dud or ex­cess fruit. When you prune harder in win­ter in­stead, you lose some of those op­tions. If you’ve pruned too hard and re­duce your crop, that af­fects your in­come for much more than a year.

POL­LI­NA­TION

Good pol­li­na­tion is a func­tion of weather, pollen avail­abil­ity from male vines or pur­chased pollen, pollen ploidy and bee prepa­ra­tion. Keep in touch with your bee­keeper about hive num­bers, sugar feed­ing and likely dates. Don’t skimp on hive num­bers if flower num­bers are down. It’s still a rel­a­tively mod­est cost in the scheme of things and you want enough well-pre­pared bee­hives that the bees will pol­li­nate the crop even if there are only short bursts of good for­ag­ing weather.

Pollen avail­abil­ity is likely a con­straint. Har­vest­ing the early male flow­ers for pollen won’t im­pair your pol­li­na­tion and pro­vides a re­source for bad weather or next sea­son if stored cor­rectly.

Al­ways keep bee-safety top of mind, and ac­cess for trucks ar­riv­ing with hives in the night. Pro­vid­ing wa­ter bees won’t drown col­lect­ing can help if con­di­tions are dry, as the bees won’t have to travel too far to get the wa­ter they need.

FOL­LOW-UP RE­SULTS OF WIN­TER AC­TIV­I­TIES

Fol­low up re­sults from bud­break ap­pli­ca­tions to add to your knowl­edge. Was the most suc­cess­ful tim­ing best be­cause of weather con­di­tions at ap­pli­ca­tion time, stage of vine dor­mancy or amount and tim­ing of chill­ing dur­ing the win­ter? Was it mostly to do with the con­di­tions around bud­break time aris­ing from those ap­pli­ca­tions? It is worth think­ing these things through to fig­ure how strongly this year’s re­sults are in­di­cat­ing the best tim­ing for fu­ture sea­sons.

When we’ve had a good last sea­son, we can be less than alert to the po­ten­tial prob­lems or per­ils ahead. What makes each sea­son dif­fer­ent is the com­bi­na­tion of sea­sonal con­di­tions, the grow­ing tech­nolo­gies we use and the con­di­tion of the vines we are work­ing with.

Man­ag­ing an or­chard is com­plex – con­di­tions can dif­fer markedly from sea­son to sea­son, but you can use your tools to coun­ter­act the un­help­ful ones and keep track of the fea­tures and im­pact of the sea­son as it de­vel­ops. You won’t be able to elim­i­nate dif­fer­ences be­tween sea­sonal re­sults, but should aim to min­imise drops in pro­duc­tion af­ter high yield­ing years.

From top: Good canopy de­vel­op­ment be­fore flow­er­ing pro­vides fuel for fruit growth.

Newspapers in English

Newspapers from New Zealand

© PressReader. All rights reserved.