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本科畢業(yè)設計外文翻譯
板栗切口機的設計
院(系、部)名 稱 : 歐美學院機電科學與工程系
專 業(yè) 名 稱:機械設計制造及其自動化
學 生 姓 名:
學 生 學 號:
指 導 教 師:
年12月10日
學院教務處制
畢業(yè)論文(外文翻譯)
美國板栗產(chǎn)業(yè)
羅伯特·C.霍赫穆特、羅伯特·華萊士、彼得 J.van Blokland 和 Jeffrey G.威廉姆森
這是原始文件的修訂副本,介紹了生產(chǎn),銷售,和栗子生長在東南亞美國的情況,通過RD華萊士和PJ VanBlockland。佛羅里達大學的1989年,食品資源經(jīng)濟系。工作人員報告。
1序言
美國是少數(shù)幾個國家在世界上能生長栗子和不具有顯著的商業(yè)板栗產(chǎn)業(yè)之一。因為美國有板栗產(chǎn)業(yè)這樣一個小的(世界產(chǎn)量的不到1%)產(chǎn)業(yè),進口到美國的栗子的數(shù)量與每年的總價值超逾2千萬元。新的栗子品種開發(fā),先進的傳播,文化的技術現(xiàn)在允許美國擴大在商業(yè)板栗產(chǎn)業(yè)。栗子可就在佛羅里達州小農(nóng)誰正在尋找他們的業(yè)務多元化,一個可行的替代作物。
2歷史
農(nóng)作物有很多的歷史重要性,因為世界各地的食物來源如栗子。栗子是最早木本作物被馴化了,甚至在中國詩歌中提到5000余年前的一個。北美的歐洲殖民者發(fā)現(xiàn)的新大陸幾乎是一個堅實的板栗林。美國栗樹曾經(jīng)在東部森林中最常見的樹木中,從緬因州到喬治亞州,西至密西西比河。
這個令人驚訝的有用的樹提供防腐性木材,這是用于幾個項目,從柵欄柱到家具。板栗樹也是單一的來源,除了其美麗的堅果作物。但是從東方在1904年意外引入的栗疫病(栗疫病菌),在不到40年殺害了幾乎所有的美國栗樹在美國。在美國板栗的損失被認為是西方歷史上最偉大的植物災害之一。
板栗產(chǎn)業(yè)高度發(fā)達的歐洲,在世界的東方。韓國和中國是板栗產(chǎn)業(yè)發(fā)達的兩個國家;同時這些國家產(chǎn)生超過40%的世界栗子。其他主要的板栗生產(chǎn)國包括意大利,土耳其,玻利維亞,日本,西班牙和葡萄牙。栗子對美國的主要出口國是意大利,中國和韓國。
板栗進口到美國的4,500噸增加到2003年的5,400萬噸,2004年同比增長,表明栗子在美國的消費者的需求在不斷增長。進口到美國的栗子每年的價值超過2000萬美元。
這是抗栗疫病和生產(chǎn)大,甜堅果 - - 新美國x中國雜交板栗品種的發(fā)展有助于使國內(nèi)板栗產(chǎn)業(yè)在美國可能的擴展,包括在佛羅里達州。新板栗品種具有毫不遜色與進口堅果競爭的高品質(zhì)特性。然而,美國商業(yè)板栗產(chǎn)業(yè)是相對較新;大多數(shù)種植者有不到10年的經(jīng)驗。為板栗生產(chǎn)大國,包括加利福尼亞州,俄勒岡州,華盛頓州,密歇根州,佛羅里達州,俄亥俄州和弗吉尼亞州。
3 板栗經(jīng)濟學
栗子可以是生產(chǎn)力和盈利果園作物。樹木開始后三到五年來承擔,而改良品種可以在到期日,從1000 - 1,500斤以上的產(chǎn)量每畝每年。螺母從$0.75-2.50元一斤批發(fā),(根據(jù)螺母的大?。┖?2-5.00元一斤零售,供給取決于市場。
國產(chǎn)栗子的市場一直主要通過本地或直接的市場銷售方式。一些美國種植者通過互聯(lián)網(wǎng)在超過10美元每磅小批量的價格做廣告的新鮮栗子,但這個價格包括聯(lián)邦快遞或UPS運費和手續(xù)費。本地的,直接面向消費者的銷售可能高達$4.00或5.00元一斤,但這樣的價格在銷售大幅下降到經(jīng)紀人,批發(fā)商,連鎖超市等大型市場。
美國種植栗子數(shù)量大,價格必須要與進口堅果競爭力,和美國生產(chǎn)的質(zhì)量必須優(yōu)于質(zhì)素的外國買家,他們的美國客戶都習慣。
在美國種植栗子作物有達到美國市場早于進口的栗子,用更好的質(zhì)量控制,并沒有國際航運的成本優(yōu)勢。然而,在移動大量栗子的成功的關鍵是通過市場營銷,消費者和經(jīng)銷商的教育,并與有識之士在食品配送服務關系的發(fā)展。營銷是沒有過去存在的小種植者很多機會,現(xiàn)在可以通過互聯(lián)網(wǎng),但有針對性的市場推廣力度,食品行業(yè)也可以是非常有價值的。
生長在美國的四種栗子和他們幾個雜交種品種
?美國栗子(板栗齒。)有小的,甜的堅果,直立生長形式,極易受到栗疫病。
?歐洲栗(Catanea)也枯萎病易感,且只能在疫病非疫區(qū)生長。歐洲板栗樹有一個直立的樹的形式,并從歐洲栗子的堅果可以是相當不錯的一些品種。然而,許多品種及種苗生產(chǎn)堅果的味道平淡,或苦,難以剝離。
?中國板栗(板栗)是高度抗枯萎病,有些品種產(chǎn)生良好的規(guī)模和甜蜜味道也很容易剝離的堅果。中國板栗樹,有時在生長形態(tài)挺拔,但很多是低,傳播和多支在地上。
?日本栗子(板栗籽)粒小,傳播,產(chǎn)生較大的,可憐的品嘗堅果抗枯萎病樹。日本栗子大多用于雜交。
?Chinkapins(數(shù)種)生產(chǎn)小型,甜堅果(每毛刺之一),通常是灌木狀的形式,不用于商業(yè)螺母生產(chǎn)。
在栗屬的成員的關系非常密切和雜交的容易。雜交提供了一些有前途的商業(yè)品種中最有潛力的。在歐洲,大部分板栗育種已經(jīng)完成,日本x歐洲的雜交品種。在日本和韓國,多數(shù)商業(yè)化生產(chǎn)的今天與中國x日本雜交品種。
在美國,一些最近開發(fā)的美國x中國混合動力車提供的特點,優(yōu)秀的商業(yè)品種為佛羅里達的組合。
圖1。
美國x中國雜交板栗樹。
5螺母的質(zhì)量和檔次
大?。?
在任何品種的一個主要關注的是生產(chǎn)螺母的大小。對于營銷到一個新的或預先包裝市場中,大尺寸是必需的(圖2)。雖然美國農(nóng)業(yè)部門(USDA)沒有采用任何標準的栗子大小,在2001年提出由美國農(nóng)業(yè)部以下尺寸的標準(表1)。
圖2。
客戶喜歡較大的個體堅果。
進口商有時用于基于每磅堅果的數(shù)目(表2)大小的標準。堅果超過每磅40支小的都很難通過大規(guī)模的營銷系統(tǒng)(經(jīng)紀和食品雜貨連鎖店)來分發(fā),因為美國的渴望更大的板栗大?。▓D3)中。小栗子一般都是在美國市場不太理想的,并帶來了更低的價格。然而,如果該栗子用于烘干,面粉或糖果,大小并不重要。
圖3。
各種螺母尺寸板栗品種之一。
味道:
味道也很重要。有些品種具有較高的含糖量,甚至生吃。栗子中的碳水化合物轉(zhuǎn)成糖的堅果成熟和干燥。栗子烹調(diào)前固化是很重要的,襯托出堅果的味道。美國栗樹是相當甜美的。一些中國的栗子和美國雜交種有非常甜美的堅果。一些歐洲和中國的品種,通過比較,而不是甜的。
易于剝離:
重要性的第三螺母的特點是容易剝離的螺母。該薄膜或“皮膚” ,圍繞內(nèi)核是苦,吃之前必須拆除。在某些類型的栗子,膠片被嵌到內(nèi)核中,這使得螺母難以剝離,因此,不良的飲食質(zhì)量的粗糙表面。許多歐洲栗子有這樣的不良特性。
在法國區(qū)分栗子的基礎上,容易剝離的類型之間。栗子,栗子原產(chǎn)于地中海,有表面光滑的內(nèi)核,很容易剝離,并具有向內(nèi)生長的薄膜。該種栗子以更高的價格在法國和美國的商店出售,但是這兩種類型的板栗運到美國,他們是美國消費者的青睞。
美國和中國的栗子,其雜交種往往有流暢的內(nèi)核和更容易剝離。
容易剝離是重要的商業(yè)處理,以及用于接受消費者;內(nèi)核一點點消失在剝離過程中,那很容易去皮栗子需要少得多的時間和費用,除去藥膜。
6繁殖
主要類型在今天的美國銷售的板栗樹是中國板栗苗。中國苗栗子一般都是可變的螺母尺寸,口味,樹形態(tài)和生產(chǎn)力。該樹結的3-8年,遠遠晚于嫁接樹種。在某些情況下,比嫁接樹更耐寒更加旺盛。栗子在美國的大多數(shù)現(xiàn)有的種植面積是苗。在作物的質(zhì)量很大的可變性降低板栗的銷路。
嫁接和芽接繁殖是對栗子的克隆最常見的方式。
栗子有時會受到砧木/接穗不親。造成這種不兼容的因素是生態(tài)和遺傳。接穗嫁接到砧木具有不同的同工酶可能會顯示活力差,不一致的農(nóng)作物,甚至死亡的移植物上面的接穗。移植物在非常寒冷的氣候或嚴重發(fā)熱或干旱后失敗了。
生長環(huán)境:
栗子可以生長在各種氣候條件和環(huán)境中,但適合種植桃子的范圍通常被認為是適于生長的許多板栗的栽培品種。栗子也遍及用于山核桃生產(chǎn)領域在佛羅里達州生長良好。
生產(chǎn)堅果的最佳條件包括溫暖和相對較長的生長季節(jié)和溫和的冬天。灌溉是建議最大的螺母生產(chǎn)尤其重要的果園初步建立。雖然栗子花下旬,春季霜凍可能會損壞新的成長新芽,并應避免低洼霜口袋。
栗子喜歡pH值5.0-6.5,排水良好的高地沙壤土。土壤不應該受到積水和/或定期泛濫。如果機械收割機的使用,在野外太多斜坡在使用機器造成困難,而且潮濕的土壤條件,秋雨可以通過果園抑制方便移動。北佛羅里達特別適合于不斷增長的栗子。從奧蘭多向北穿過佛羅里達狹長地帶的領域包括板栗種植已成長為超過40年。
果園種植和生產(chǎn):
樹苗間距差異很大取決于品種。然而, 20*20 ( 108株/畝)是常見的。這個間距產(chǎn)生了樹木的緊密堆積之間的最佳平衡,以提高早期生產(chǎn)的果園和需要薄樹的作為冠開始觸摸。
栗子需要水分和肥料的管理良好的供應。滴灌建議節(jié)約用水,有效地提供水源的樹木而已,而不是雜草在非作物區(qū)行之間。施肥方案應根據(jù)土壤測試。然而,一個常見的應用栗樹是1磅10-10-10或每樹齡高達15磅每棵樹在春天應用年類似的分析。灌溉施肥,或頻繁通過滴灌系統(tǒng)飼養(yǎng),是有效的,與營養(yǎng)物質(zhì)的浸出損失較少促進增長。栗子是沉重的饋線和氮是正確的快速增長尤其重要。像許多檳榔樹,栗子啟動緩慢,需要2-3年才能完全建立。毛刺應在第一個三年中刪除,以更好地促進樹木生長。
大多數(shù)板栗果園類似山核桃的方式管理,用干凈的栽培下兩行之間的行和草皮覆蓋作物。年輕的板栗果園可間作一行作物,如花生常年,三葉草,草或小水果作物,直到板栗收獲開始在5年后種植。
7 修剪
栗子承擔對兩性的柳絮(纖細,圓柱形的花簇) ,這是位于目前的年新梢生長的基地附近。增長的新丫發(fā)生在太陽光的地方,在樹枝的頂端。修剪應盡量陽光提供給樹的數(shù)量。開放式中心樹(如桃樹),讓陽光照進花瓶形的中間,以及頂部和兩側(cè)。歐洲的果園和日本和韓國的果園修剪以這種方式。 蘋果,山核桃,胡桃常用修剪系統(tǒng)產(chǎn)生 - 創(chuàng)建一個錐形樹已經(jīng)支承表面都繞錐的外側(cè)。這種方法也可以接受的栗子使用。
直立的樹木更好地應對機械震動以去除堅果。非常分散的樹木可能會更加難以擺脫的堅果,因為樹枝傾向于下垂,增加了振動篩的振動。證據(jù)也表明,較小的樹可能比那些太高,易于收獲更可取和修剪,隨著遺傳特征,將是重要的在確定最終的樹的形狀和大小。許多小的樹板栗品種產(chǎn)生了良好的佛羅里達很少修剪。
8果園害蟲管理
栗子有幾個嚴重的害蟲。板栗疫?。ɡ跻卟【┲饕煽莘N植抗性品種淘汰。只有抗枯萎病樹應考慮種植在佛羅里達州。墨疾病,疫霉根腐病菌,已在美國東南部的一個問題,但可以通過果園地面管理控制,保持土壤排水良好,不受潮濕的環(huán)境,這對促進感染。墨一直是一個問題在歐洲和美國的太平洋海岸,在那有長,潮濕的冬天領域。
鹿和松鼠可以在栗子常見的野生動物害蟲。鹿圍欄可以是必要的,如果鹿是本地的害蟲,以及可能需要的螺母的收獲如果松鼠或鹿是問題。
板栗象鼻蟲(象鼻蟲),奠定了在發(fā)展中的堅果卵,和成熟的堅果有蟲在里面收獲成長,導致堅果變成滯銷。象鼻蟲花,冬天地上樹下的蛹。很少有農(nóng)藥被標記為板栗象鼻蟲的控制權,所以衛(wèi)生習慣是關鍵。
收獲完成后,收集所有多余的毛刺,堅果和樹葉雜物和可能的話燒滅。
東方栗癭蜂(栗癭蜂)是一種嚴重的害蟲,形成蟲癭在不斷發(fā)展板栗芽,從而停止螺母生產(chǎn)。生物和化學控制是尚未無效的這個黃蜂,但是一些韓國品種展示抵抗黃蜂。強烈建議不要從那里癭蜂蟲害發(fā)生地區(qū)的移動板栗樹或材料。
授粉和螺母形成:
栗子是雌雄同株;男性和女性的花著生在同一棵樹上(圖4)目前的季節(jié)芽。鮮花出現(xiàn)在當前季節(jié)增長的秘訣,后葉子已經(jīng)完全展開,和足夠的后期,以避免(5月上旬至中旬在美國佛羅里達州)任何晚春霜凍。栗子是自育(不會自花授粉),因此,需要授粉。不完全授粉,將導致僅在一個或兩個螺母形成的毛刺的內(nèi)部;剩下的堅果也不會填寫。栗子主要是風授粉的昆蟲,雖然也可能有助于授粉。樹應以至少8:1品種種植。嫁接樹開始承擔在兩到四年,種苗將承擔五至七年。延遲生產(chǎn)的嫁接樹很可能會發(fā)生,因為授粉樹不開花充分早年(種植后第三年至第五年)。
圖4。
雄花和雌花在同一棵樹上。
螺母的發(fā)展,并填寫主要發(fā)生在過去兩到三個星期后熟(圖5)之前。螺母在這段時間獲得其大部分重量,而且由于堅果是40%的水和40%的碳水化合物,一個良好的水供應,無論是從季節(jié)性降雨或灌溉,是最大限度地提高螺母的生產(chǎn)至關重要。從開花到采收時間從110-150天不等,視品種。作為堅果成熟,毛刺開始裂開,并且螺母被釋放的毛刺或飛邊落在從樹的堅果還在里面(圖6)。
圖5。
苞(中心),成熟的栗子(左)和未成熟的栗子(右)。
圖6。
板栗毛刺裂接近收獲的季節(jié)。
9采收和儲藏
栗子的收獲是傳統(tǒng)上用手工勞動完成的,其中,在小果園,可以比機械收獲更有效。因為栗子是高碳水化合物,它們衰變迅速,必有收獲每隔兩到三天消除的時間花在堅果在地面上的金額。
栗子的機械收割是大致相同的山核桃,杏仁,核桃或行業(yè)。振動器是成功的,因為從樹上將毛刺去除的手段。螺母和毛刺可以被收集,無論是在catch框架或在樹下地面網(wǎng)狀網(wǎng),或是堅果可以拿起各種機械山核桃收割機或設計用于其他堅果作物收割機。
一旦從果園收集,螺母和毛刺是分開的,并且將螺母直接進入冷卻器。該毛刺是通過去毛刺裝置,諸如那些用于除去胡桃的殼,或山核桃吸塵器運行。綠色毛刺與不發(fā)達堅果(尚白)可以單獨舉行,直到成熟的堅果在數(shù)天。
螺母洗滌,然后按大小分級,并存儲在緊密編織的,但透氣網(wǎng)袋在32華氏度和85%的濕度。栗子將持續(xù)長達半年,當這些條件下儲存。在較高溫度下,將螺母將衰減比,因為在較低溫度下更高的生物活性的更快。高濕度是必需的,因為堅果會脫水,失去其質(zhì)量在大多數(shù)冷卻器??焖俳?45-60分鐘),熱水( 125O F)可以殺死許多腐爛的有機物和板栗象鼻蟲幼蟲。熱水浸漬后,將螺母在冷水中冷卻,然后存儲在32O F。
處理
整個栗子,可去皮罐裝或冷凍。這種處理通常增加了產(chǎn)品的貨架壽命比新鮮堅果和,更重要的是,降低了消費者的勞力和時間的制劑的量。添加到去皮和包裝產(chǎn)品的價值是巨大的,可能是重要的在增加栗子的市場規(guī)模,尤其是增加使用的螺母超越傳統(tǒng)栗子的季節(jié),感恩節(jié)和圣誕節(jié)。預打包為適應栗子美國市場的一個非常重要的考慮因素。
機械可用于機械剝離和包栗子。去皮,冷凍栗子將保留他們的口味長達兩年。栗子也可以曬干后磨成面粉。在歐洲和東方,栗子粉早已高度在做面包,面食和糕點珍貴的甜味。特產(chǎn)板栗產(chǎn)品正變得越來越普遍可在美國市場,并通過網(wǎng)絡銷售。
市場營銷
用于在美國長大許多堅果發(fā)達的配送系統(tǒng)也可用于在這個國家種植栗子。種植者與大型,高品質(zhì)的栗子可與進口的栗子作物有利競爭,因為國內(nèi)的種植者可以達到美國市場的時間較早,并提供一個新鮮的產(chǎn)品,因此,賣出高價。
有在美國種植優(yōu)質(zhì)板栗許多有潛力的市場。美味和健康食品市場和餐館提供的網(wǎng)點,消費者通常在嘗試和學習新的食品產(chǎn)品的興趣。民族法語,意大利語和東方市場已經(jīng)攜帶板栗產(chǎn)品,有興趣找本地的,高品質(zhì)的栗子來源。幾乎所有的連鎖超市進行進口栗子在感恩節(jié)和圣誕節(jié)。當?shù)厣鐓^(qū)農(nóng)貿(mào)市場正變得越來越受歡迎,在佛羅里達州,并作為出口市場的堅果。網(wǎng)絡銷售也可以是一個成功的方法賣栗子和栗子的產(chǎn)品。
9營養(yǎng)
栗子是一種高營養(yǎng)的食物。與大多數(shù)堅果,這是高脂肪(山核桃和核桃) ,栗子只有一絲贅肉,三分之一其他堅果,如花生或腰果的熱量。栗子也有顯著量的維生素C的唯一螺母和無膽固醇。栗子的蛋白質(zhì)品質(zhì)優(yōu)異和可比較的氨基酸含量是雞蛋的。栗子被認為是“一個糧食,生長在樹上, ”是類似的營養(yǎng)糙米。
栗子好吃,并且可以在各種不同的方式,包括在火上烤或清蒸在湯,燉菜,蛋奶酥,開胃餡料和甜點的使用做好準備。栗子可干燥后制成的面食或甜面粉糕點和面包。菜泥或蜜餞,板栗是全歐洲最喜歡的甜點。用途和很高的營養(yǎng)品質(zhì),從多年生木本作物這種多樣性所做的栗子一種流行的食物來源,包括整個歷史以及在世界各地的許多不同的文化。
表:
表1中。
美國農(nóng)業(yè)部于2001年提出的標準,栗子成績。
大小分類
最小直徑 (英寸)
最大直徑 (英寸)
猛犸
1 3/8
不是最大
巨型
1 1/41
1/2
巨人
11/81
3/8
大
1
1 1/4
表2
基于每磅堅果的數(shù)量板栗大小標準
等級
堅果/磅級號碼
A
36-39
AA
27-30
AAA
22-24
AAAA
19-20
AAAAA
18或更小
腳注
1 :
這份文件是HS1155 ,由一系列的園藝科學系和佛羅里達州合作推廣服務,食品和農(nóng)業(yè)科學研究所,美國佛羅里達大學之一。首次由愛迪斯出版于2009年,2012年8月評論,這是原始文件的修訂副本,栗子成長在南方的介紹到生產(chǎn),市場營銷,經(jīng)濟學,由RD華萊士和PJ VanBlockland 。佛羅里達大學的1989年,食品資源經(jīng)濟系。工作人員報告。
2 :
羅伯特C. Hochmuth ,多縣擴展代理,薩旺尼谷農(nóng)業(yè)推廣中心;羅伯特·D ·華萊士,商業(yè)種苗,栗山苗圃,阿拉楚阿,佛羅里達州;彼得·范Blokland ,教授,食品和資源經(jīng)濟學,印度河流域研究和教育中心,和Jeffrey G.威廉姆森教授,園藝科學系,美國佛羅里達大學。蓋恩斯維爾,佛羅里達州32611 。
食品和農(nóng)業(yè)科學研究所(獨立財務顧問)提供平等機會的機構授權只對與相對于種族,信仰,膚色,宗教,年齡,殘疾非歧視性功能的個人和機構提供研究,教育信息等服務,性別,性取向,婚姻狀況,國籍,政治觀點或隸屬關系。有關獲取其他UF / IFAS延長出版物的更多信息,請聯(lián)系您所在縣的UF / IFAS擴展辦公室。
農(nóng)業(yè), UF / IFAS推廣服務,佛羅里達大學IFAS ,佛羅里達州A&M大學合作推廣計劃,以及縣委員的合作委員會的美國能源部。尼克T.廣場,院長UF / IFAS擴展。
本文來自
http://www.renrendoc.com/p-316064.html
Production and Marketing of Chestnuts in the Southeastern United States1
Robert C. Hochmuth, Robert D. Wallace, Peter J. Van Blokland, and Jeffrey G. Williamson2
This is a revised copy of the original document, An Introduction to Production, Marketing, and Economics of Growing Chestnuts in the South East United Sates, by R.D. Wallace and P.J. VanBlockland. 1989. University of Florida, Dept of Food Resource Economics. Staff report. #354
Introduction
Chestnuts (Castanea sp.) are represented by several species of trees in the beech family (Fagaceae). The chestnut is native to warm, temperate areas the Northern Hemisphere.
The United States is one of the few nations in the world that can grow chestnuts and does not have a significant commercial chestnut industry. Because the United States has such a small (less than 1 percent of world production) chestnut industry, chestnuts are imported to the United States in quantities with total annual value exceeding $20 million.
Development of new chestnuts cultivars, advances in propagation, and cultural techniques now allow for expansion of the commercial chestnut industry in the United States. Chestnuts may make a viable alternative crop for small farmers in Florida who are looking to diversify their operations.
History
Few tree crops have as much historical importance as a food source throughout the world as do chestnuts. Chestnuts were one of the earliest tree crops to be domesticated and were even mentioned in Chinese poetry more than 5000 years ago. The European settlers of North America found the New World was virtually one solid chestnut forest. The American chestnut was once among the most common trees in the eastern forest, from Maine to Georgia and west to the Mississippi.
This amazingly useful tree offers rot-resistant lumber, which was used for several items, from fence posts to furniture. The chestnut tree was also a source of tannin, in addition to its beautiful crop of nuts. But the accidental introduction of the chestnut blight (Cryphonectria parasitica) from the Orient in 1904 killed almost every American chestnut in the United States in less than 40 years. The loss of the chestnut in the United States is considered one of the greatest botanical disasters in Western history.
The chestnut industry is highly developed in Europe and in the Orient. The Republic of Korea and China are the top two countries for chestnut production; together these countries produce more than 40 percent of the world's chestnuts. Other major chestnut-producing countries include Italy, Turkey, Bolivia, Japan, Spain, and Portugal. The primary exporters of chestnuts to the United States are Italy, China, and The Republic of Korea.
Chestnut imports to the United States increased from 4,500 metric tons in 2003 to 5,400 metric tons in 2004, an increase that indicates the growing demand for chestnuts among U.S. consumers. The annual value of chestnuts imported to the United States is more than $20 million.
The development of new American x Chinese hybrid chestnut cultivars -- which are resistant to chestnut blight and produce large, sweet nuts -- have helped to make possible expansion of the domestic chestnut industry in the United States, including in Florida. The new chestnut cultivars have high-quality characteristics that compete favorably with the imported nuts. However, the commercial U.S. chestnut industry is relatively new; most growers have less than 10 years of experience. Major states for chestnut production include California, Oregon, Washington, Michigan, Florida, Ohio, and Virginia.
Chestnut Economics
Chestnuts can be a productive and profitable orchard crop. Trees begin to bear after three to five years, and improved cultivars can, at maturity, produce from 1,000 - 1,500 pounds or more per acre every year. The nuts bring from $0.75-2.50 per pound wholesale, (depending on nut size) and $2-5.00 per pound retail, depending on the market.
Marketing of domestic chestnuts has been primarily through local or direct market sales methods. Some American growers advertise fresh chestnuts via the Internet at prices of more than $10 per pound in small quantities, but this price includes FedEx or UPS shipping and handling. Local, direct-to-consumer sales may be up to $4.00 or 5.00 per pound, but such prices decrease considerably in sales to brokers, wholesalers, grocery chains, and other large markets.
To move American-grown chestnuts in large quantities, prices must to be competitive with imported nuts, and quality of American production must be superior to the quality to which foreign wholesale buyers and their American customers are accustomed.
Chestnuts crops grown in the United States have the advantage of reaching American markets earlier than imported chestnuts, with better quality control, and without the costs of international shipping. However, the key to success in moving large quantities of chestnuts is through marketing, education of the consumer and distributors, and the development of relationships with knowledgeable persons in food-distribution services. Many opportunities for marketing that did not exist in the past for small growers are now available through the Internet, but targeted marketing efforts to the food industry can also be very valuable.
Chestnut Species and Hybrids
Four species of chestnuts and several of their hybrids are grown in the United States today.
· American chestnuts (Castanea dentata) have small, sweet nuts, upright growth form, and are highly susceptible to chestnut blight.
· The European chestnut (Catanea sativa) is also blight susceptible and can only be grown in blight-free areas. European chestnuts trees have an upright tree form, and the nuts from European chestnuts can be quite good from some cultivars. However, many of the cultivars and seedlings produce nuts that are bland or bitter in taste and difficult to peel.
· Chinese chestnuts (Castanea mollissima) are highly blight resistant, and some cultivars produce nuts of good size and sweet taste that are also easy to peel. Chinese chestnut trees are sometimes upright in growth form, but many are low, spreading and multiple branched at the ground.
· Japanese chestnuts (Castanea crenata) are small, spreading, blight-resistant trees that produce large, poor tasting nuts. Japanese chestnuts are mostly used for hybridization.
· Chinkapins (several species) produce small, sweet nuts (one per burr), are often of shrubby form and are not used for commercial nut production.
The members of the genus Castanea are very closely related and interhybridize readily. Hybrids offer some of the best potential for promising commercial cultivars. In Europe, most chestnut breeding has been done with Japanese x European crosses. In Japan and Korea, the majority of the commercial production today is with Chinese x Japanese hybrid cultivars.
In the United States, some of the recently developed American x Chinese hybrids offer the combination of characteristics that make for excellent commercial cultivars for Florida (Fig 1).
Figure 1.?
American x Chinese hybrid chestnut tree.
[Click thumbnail to enlarge.]
Nut Quality and Grades
Size
A primary concern in any cultivar is the size of the nuts produced. For marketing to a fresh or pre-packaged market, large size is required (Fig 2). While the U.S. Department of Agriculture (USDA) has not adopted any standards for grades of chestnuts, the following size standards were proposed by the USDA in 2001 (Table 1).
Figure 2.?
Customers prefer larger individual nuts.
[Click thumbnail to enlarge.]
Importers have sometimes used size standards based on the number of nuts per pound (Table 2). Nuts smaller than 40 count per pound are difficult to distribute through mass marketing systems (brokers and grocery chains) because of the American desire for larger chestnut sizes (Fig 3). Smaller chestnuts are generally less desirable in the American market and bring a lower price. If, however, the chestnuts are used for drying, pureeing, flour or candies, size is not as important.
Figure 3.?
Various nut sizes among chestnut cultivars.
[Click thumbnail to enlarge.]
Taste
Taste is also very important. Some cultivars have a higher sugar content, even raw. The carbohydrates in chestnuts turn to sugar as the nuts mature and dry. Curing is important before cooking chestnuts, to bring out the flavor of the nuts. The American chestnut is quite sweet, as are chinkapins. Some of the Chinese chestnuts and the American hybrids have very sweet nuts. Some of the European and Chinese varieties are, by comparison, not as sweet.
Ease of Peeling
The third nut characteristic of importance is ease of peeling the nut. The pellicle or “skin” that surrounds the kernel is bitter and must be removed before eating. In some types of chestnuts, the pellicle is ingrown into the rough surface of the kernel, which makes the nuts difficult to peel and, therefore, poor eating quality. Many European chestnuts have this undesirable characteristic.
The French distinguish between types of chestnuts based on the ease of peeling. Marrons, a chestnut native to the Mediterranean, have smooth-surfaced kernels that are easy to peel, and the chataignes having an ingrown pellicle. The marrons command a much higher price in the stores in France and in the United States than do the chataignes, but both types of chestnut are shipped to the United States where they are popular among American consumers.
The American and Chinese chestnuts and their hybrids more frequently have smooth kernels and are easier to peel.
Ease of peeling is important in commercial processing, as well as for acceptance by the consumer; a little bit of the kernel is lost in the peeling process, and chestnuts that are easily peeled require much less time and expense to remove the pellicles.
Propagation
The predominant type of chestnut trees sold in the United States today is Chinese chestnut seedlings. Seedling Chinese chestnuts are generally variable in nut size, taste, tree form and productivity. The trees bear in 3-8 years, much later than grafted stock. The trees are, in some cases, more vigorous than grafted trees and more cold hardy. Most existing plantings of chestnuts in the United States are seedlings. Wide variability in the quality of the crop reduces the marketability of chestnuts.
Grafting and budding are the most common ways of propagation for clones of chestnuts.
Chestnuts can sometimes be affected by root stock/scion incompatibility. Factors causing this incompatibility are both ecological and genetic. Scions grafted onto rootstock with differing isoenzymes may show poor vigor, inconsistent crops, and sometimes death of the scion above the graft. Grafts fail more in very cold climates or after severe heat or drought stress.
Location and Site
Chestnuts can be grown in a wide variety of climates and environments, but the range that is suitable for growing peaches is often considered to be suitable for growing many of the chestnut cultivars. Chestnuts also grow well throughout the areas in Florida used for pecan production.
The best conditions for the production of nuts include a warm and relatively long growing season and a mild winter. Irrigation is recommended for maximum nut production and is especially important in initial orchard establishment. Though chestnuts flower late, spring frosts can damage new growing shoots, and low-lying frost pockets should be avoided.
Chestnuts prefer a well drained, upland sandy loam of pH 5.0-6.5. The soil should not be subject to standing water and/or periodic flooding. If mechanical harvesters are to be used, too much slope in the field can create difficulties in using the machinery, and wet soil conditions with autumn rains can inhibit easy movement through the orchard. North Florida is especially suited to growing chestnuts. Areas from Orlando north through the Florida Panhandle include chestnut plantings that have been growing for more than 40 years.
Orchard Planting and Production
Orchard spacing varies greatly depending upon the cultivar. However, 20X20 (108 trees/acre) is common. This spacing creates the optimum balance between close packing of the trees to increase early production of the orchard and the need to thin trees as the crowns start to touch.
Chestnuts require a well managed supply of moisture and fertilizer. Drip irrigation is recommended to conserve water and effect