Meadow Orchard Research Articles

High Density Planting and Meadow Orcharding in Guava for Higher Return

Due to the extensive tree canopy, the traditional method of cultivation has had difficulty achieving the intended levels of productivity. As a result, it became necessary to enhance the current manufacturing system in addition to impressing with its productivity. There is a current tendency for fruit trees to be planted more densely or in meadow orchards to control tree size, keep desired architecture, and make operations like pruning, pest control, and harvesting easier. The meadow orchard system is a novel idea for guava planting, providing densities of 5000 trees per hectare at a spacing of 1 m by 2 m. In contrast to conventional well-branched trees, this system is controlled to create a simpler and smaller structured framework starting in the first year. Guava trees are topped and hedged to encourage the development of fruit buds in the first year. Regular topping and pruning helped to reduce the size of the tree canopy. In the first year after sowing, trees produced flowers and fruit.

Approach for graph-based individual branch modelling of meadow orchard trees with 3D point clouds

The cultivation of meadow orchards provides an ecological benefit for biodiversity, which is significantly higher than in intensively cultivated orchards. However, the maintenance of meadow orchards is not economically profitable. The use of automation for pruning would reduce labour costs and avoid accidents. The goal of this research was, using photogrammetric point clouds, to automatically calculate tree models, without additional human input, as basis to estimate pruning points for meadow orchard trees. Pruning estimates require a knowledge of the major tree structure, containing the branch position, the growth direction and their topological connection. Therefore, nine apple trees were captured photogrammetrically as 3D point clouds using an RGB camera. To extract the tree models, the point clouds got filtered with a random forest algorithm, the trunk was extracted and the resulting point clouds were divided into numerous K-means clusters. The cluster centres were used to create skeleton models using methods of graph theory. For evaluation, the nodes and edges of the calculated and the manually created reference tree models were compared. The calculated models achieved a producer’s accuracy of 73.67% and a user's accuracy of 74.30% of the compared edges. These models now contain the geometric and topological structure of the trees and an assignment of their point clouds, from which further information, such as branch thickness, can be derived on a branch-specific basis. This is necessary information for the calculation of pruning areas and for the actual pruning planning, needed for the automation of tree pruning.

Effect of Plant Growth Regulators on Growth, Fruit Setting and Quality of Guava (Psidium guajava L.) in Meadow Orchard

The present study, "Effect of plant growth regulators on growth, fruit setting, and quality of guava (Psidium guajava L.) in meadow orchard," was carried out in the years 2021–2022, at Central Research Farm, Department of Horticulture, Sam Higginbottom Institute of Agriculture & Sciences, Prayagraj (U.P.). Ten treatments made up the experiment with: control, three concentrations of gibberellic acid (GA3) at 75, 100, and 125 ppm, three concentrations of naphthalene acetic acid (NAA) at 200, 250, and 300 ppm, and three concentrations of chlormequat (CCC) at 400, 500, and 600 ppm. These treatments were evaluated in Randomized Blocked Design with three replications. The results showed that a combination of different plants growth regulators had a significant impact on the guava plant's growth and yield parameters, including its height (5.81 m), total number of flowers per plant (178.6), fruiting buds per plant (151.8), number of fruits per plant (127.1), fruit set (71.2%), plant spread (E-W-6.00 m & N-S- 5.89 m), fresh fruit weight (115.5g), and dry weight (78.5g), Fruit diameter (polar-8.46cm & radial-8.16cm), total soluble solids (TSS) 10.170Brix, total sugar (9.2%), and yield/plant (14.7kg) were all found to be higher under the treatment T4 Naphthalene acetic acid (NAA) @200ppm, whereas acidity (0.56%) was at its highest in T0 Control.

First Report of Colletotrichum nymphaeae Causing Anthracnose on Almond in Hungary.

Almond (Prunus dulcis [Mill.] D. A. Webb) is cultivated in commercial orchards in southwestern Hungary while numerous backyard orchards predominate in Buda Hills and central Hungary. In July 2019, anthracnose symptoms and necrotic twigs were observed across almond genotypes in a meadow orchard of Óbuda and in the genebank collection of the Hungarian University of Agriculture and Life Sciences. Fruits of some genotypes were damaged 100%, whereas others to a lesser degree or asymptomatic. Orange slightly sunken lesions on fruits produced gum. Near the diseased fruits the young shoots shriveled, the stalks became necrotized, on twigs necrosis developed. Isolates obtained from orange conidial masses from epicarp, necrotized tissues from twigs, and stalks were grown on PDA for 7 days at 25 ֯C in the dark. Upper surfaces of the colonies were white to pale gray, black solid mycelial structures were formed, the reverse side varied white to salmon. Acervuli were not formed, but conidia were produced from hyphae. Conidia were unicellular, hyaline, smooth-walled, cylindrical, predominant with both end rounded, or one end acute. Morphometric measurements of conidia showed mean length ± SD × width ± SD = 18.0 ± 2.2 × 4.7 ± 0.6 μm (n = 100). The isolates were morphologically identified as Colletotrichum acutatum sensu lato (Damm et al. 2012). Sexual morph was not observed. Three monosporic isolates were used for molecular identification. Partial nucleotide sequences were amplified from three loci, internal transcribed spacer (ITS), β-tubulin (TUB2) and calmodulin (CAL) after White et al. (1990); Glass and Donaldson (1995) and Weir et al. (2012), respectively. The ITS sequences (GenBank accessions MW425388 to MW425390) of the three isolates revealed that they belong to the C. acutatum species complex while BLAST results showed that TUB2 sequences (GenBank accessions MW428285 to MW428287) had 99.3% identity with C. nymphaeae strain CBS515.78, whereas the CAL sequences (GenBank accessions MW428288 to MW428290) had 100% with C. nymphaeae strain FREC138. The phylogenetic tree containing all the valid species of C. acutatum species complex confirmed that the isolates clustered to C. nymphaeae with high bootstrap support. The fungus was identified as Colletotrichum nymphaeae (Pass) Aa based on molecular biological evidence. In vivo pathogenicity tests were conducted on ten healthy fruits, and ten twigs by inserting mycelial agar plugs (5 mm in diameter) onto wounded pericarp and phloemissues, which were then wrapped in wet cotton and Parafilm®. The control treatments received sterile PDA discs. After 15 days, necrotic lesions 12 to 19 mm in diameter developed on fruit, 9 to 18 mm on twig. Control fruits, and twigs were asymptomatic. Koch's postulates were fulfilled with the reisolation of the pathogen from symptomatic tissues. The ITS, ACT and CAL sequences of the reisolated Colletotrichum were determined and found identical to the original isolates. Anthracnose symptoms are known on almond fruits in several almond growing regions all over the word caused by Colletotrichum acutatum, C. godetiae, C. fioriniae, C. simmondsii, and C. gloeosporioides (Adaskaveg et al. 1997; López-Moral et al. 2000; de Silva et al. 2021; Shabi et al. 1983;). To our knowledge, this is the first report of Colletotrichum nymphaeae causing anthracnose of almond globally.

Responses of half shoot pruning on growth, flowering and yield in meadow orchard of guava

Responses of half shoot pruning on growth, flowering and yield in meadow orchard of guava

English

  A study was conducted during 2009 to 2010 and 2010 to 2011 to find out the effect of irrigation and fertigation scheduling on growth and yield of guava (Psidium guajava L.). The experiments were laid out in factorial randomized block design with sixteen treatment combinations which included four irrigation levels (basin, 50, 75 and 100% irrigation of irrigation water/cumulative pan evaporation) along with four fertigation levels, including, basal dose, 50, 75 and 100% water soluble fertilizers and replicated thrice. The nitrogen, phosphorus and potassium (NPK) fertilizers were applied through fertigation as well as soil application to test various attributes of 3-years-old guava cv. Shweta under meadow (ultra high density) orcharding. The investigation indicated that 100% irrigation of irrigation water/cumulative pan evaporation (I3) through drip resulted in maximum plant height (1.97 m), canopy volume (0.98 m3), girth of primary branches (2.41 cm), leaf area (62.94 cm2) and fruit weight (163.71 g). However, I2 (75% irrigation of irrigation water/cumulative pan evaporation) resulted in maximum plant spread east west-north south (1.91 to 1.79 m), fruit yield/plant (5.87 kg) with benefit:cost ratio of 2.62. Use of 60, 30 and 30 g NPK/plant/year produced maximum leaf area (63.39 cm2), fruit weight (162.43 g) and fruit yield/plant (6.01 kg). Interaction effect of irrigation and fertigation levels showed that 100% irrigation of irrigation water/cumulative pan evaporation + 100% water soluble fertilizers gave maximum plant height (2.07 m), canopy volume (1.24 m3), girth of primary branches (2.48 cm), leaf area (66.08 cm2), fruit diameter 6.69 cm (polar) and 5.97 cm (equatorial), fruit weight (182.17 g), yield/plant (6.59 kg). However, maximum benefit:cost ratio of (2.91) was obtained as 75% irrigation of irrigation water/cumulative pan evaporation + 75% water soluble fertilizers.   Key words: Guava, irrigation, fertigation, meadow orchard, yield.

The apple meadow orchard for ciders and the agro-forests of cocoa trees – A cross-perspective on the evolution of arboriculture in Brittany and in Latin America

La réédition de l’article « L’adieu sans regret aux pommiers hautes tiges en Bretagne », publié dans les actes du séminaire de l’École nationale supérieure du paysage de Versailles (2001), est l’occasion de fournir des éléments de comparaison avec d’autres régions productrices de fruits dans lesquelles nous avons également réalisé des enquêtes auprès de plusieurs générations d’agriculteurs d’une même famille. Une culture tropicale, la cacaoculture, semble particulièrement bien illustrer l’évolution récente de l’agriculture dans le monde, et les divergences d’opinion qu’elle suscite à travers les générations. Notre analyse comparative est fondée sur la base de résultats de recherche obtenus dans les régions du Guayas (Équateur) et du Chiapas (Mexique). Les témoignages recueillis mettent en lumière des réactions différenciées dont l’origine relève moins d’un contexte géographique caractérisé que d’une inégale appropriation des innovations technico-agronomiques développées par des instituts de recherche ou des firmes multinationales. Les politiques publiques pèsent de tout leur poids sur les stratégies d’exploitation privilégiées par les agriculteurs dans le sens où elles leur offrent, à juste titre ou non, des perspectives économiques. L’industrie agroalimentaire dans son recouvrement le plus large déstabilise également le socle de l’identité paysanne en disqualifiant les savoir-faire locaux, dont les pratiques agricoles et les variétés culturales. Dans les trois régions citées, elles correspondent chacune à des terroirs fruitiers reconnus à l’échelle nationale et/ou internationale, le constat est finalement assez proche.

O pessegueiro em pomar compacto: X. Comportamento de cultivares e seleções sob poda de encurtamento dos ramos pós-colheita

Pesquisou-se o comportamento vegetativo e reprodutivo de 14 cultivares e seleções de pêssego e nectarina, cultivados no sistema de pomar compacto, em espaçamento de 4 m x 1,5 m (1.667 plantas.ha-1), sob poda de encurtamento dos ramos, em pós-colheita. Essa poda, caracterizada pelo corte dos ramos produtivos a 20-30 cm de sua inserção, foi realizada no final de novembro, logo após a colheita de frutos do ciclo anterior. A partir dos resultados obtidos no biênio 1997-98, verificou-se que os cultivares e seleções mais produtivos foram (média bienal do número e kg de frutos por planta respectivamente): Aurora-1 (161, 13,9); IAC 680-13 (142, 12,4); Régis (156, 12,2); Talismã (128, 11,9) e IAC 680-178 (130, 10,1). Os cultivares Delicioso Precoce, Jóia-1, Tropical, Flordaprince e IAC 2380-55, com produção intermediária, obtiveram índices entre 6,0 e 8,8 kg de frutos por planta. Durante os dois anos do experimento, as váriáveis fisiológicas analisadas - área de secção transversal do tronco, volume da copa, número e massa dos frutos por cm² de tronco - apresentaram diferenciação estatística entre cultivares e seleções. A poda de encurtamento dos ramos, em pós-colheita, evitou a alternância de produção dos cultivares e seleções pesquisados.

O pessegueiro em pomar compacto. IX. dez anos de produção de cultivares sob poda drástica bienal

O objetivo deste trabalho foi comparar o desenvolvimento vegetativo e reprodutivo de quatorze cultivares e seleções de pessegueiro (Prunus persica L. Batsch) e nectarineira cultivadas no espaçamento de 4 x 1,5 m (1.667 pl/ha), sob poda drástica bienal da copa. Pelos resultados obtidos no decênio 1986-95, verificou-se que as cultivares e seleções mais produtivas foram (número e kg de frutos/planta respectivamente): Aurora-1 (112; 9,2), IAC 680-178 (94; 8,5), IAC 680-13 (95; 8,1), Talismã (99; 8,1), Régis (98; 7,8) e Flordaprince (91; 7,7). No ano agrícola de 1995, as variáveis analisadas, área da secção transversal do tronco, área da folha, número e massa dos frutos por cm² de tronco, apresentaram diferenciação estatística entre cultivares e seleções. A poda drástica bienal da copa ocasionou, tanto em material precoce quanto mediano, diminuição de produção a cada duas safras, não chegando, porém, a prejudicar a produtividade média do pomar.

O PESSEGUEIRO NO SISTEMA DE POMAR COMPACTO: VIII. CARACTERIZAÇÃO DE CULTIVARES E SELEÇÕES PARA DIFERENTES DENSIDADES POPULACIONAIS

Caracterizou-se no período de 1991-94, na Estação Experimental de Monte Alegre do Sul (22o41'S; 46o43'W e 40 HF-7), IAC, o desenvolvimeento de treze pessegueiros e cinco nectarineiras, cultivados em três lotes contíguos, nos espaçamentos adensados de 4m x 0,5m; 4m x 1m; e 4m x 1,5m, correspondendo a 5000, 2500 e 1667 indivíduos por hectare respectivamente. As copas das plantas foram podadas drasticamente, a cada dois anos, após a colheita. Registrou-se o número de nós de gemas por metro de ramo e de gemas vegetativas e floríferas por nó e a porcentagem de pegamento, o ciclo de crescimento, a massa e a época de colheita dos frutos. Os maiores índices de desenvolvimento foram verificados em Talismã, Aurora-1, Aurora-2, Jóia-1, Tropical e Flordaprince, registrando-se acima de 40 nós de gemas por metro de ramo, 2,50 gemas vegetativas e floríferas por nó e 40% de frutificação efetiva. Os dois últimos cultivares, além de IAC 282-24, se apresentaram como os mais precoces, amadurecendo os frutos com 80 - 85 dias após a floração, com colheitas entre fins de setembro e início de outubro. Os frutos com maior massa foram encontrados em Douradão, ultrapassando a média de 120 gramas nas três densidades populacionais. O sistema de pomar compacto, com poda drástica bienal das copas, não alterou as características principais dos cultivares e seleções, notando-se, apenas, tendência de redução de alguns parâmetros fisiológicos nos espaçamentos mais adensados.

The status and potential of using controlled parentage in operational reforestation in New Brunswick

Tree improvement programs began in New Brunswick in the 1970s, and, by the early 1990s, most of the seed used in reforestation was from seed orchards. Initial research such as fertilizer trials and other flower induction methods focussed on increasing seed orchard yields. Trials have also been established to investigate parental contribution to seed orchard production. As the New Brunswick Tree Improvement Council breeding programs advance into the second generation, two new approaches have been developed to capture genetic gain more efficiently. The use of controlled breeding followed by vegetative multiplication of black spruce has been adopted operationally by J.D. Irving, Limited, and a jack pine meadow orchard has been established by the New Brunswick Department of Natural Resources and Energy. This paper presents an overview of these programs and the future challenges of using controlled parentage in operational reforestation stock production.

O pessegueiro no sistema de pomar compacto: VII. comportamento de novas seleções IAC sob poda drástica bienal

Pesquisou-se durante seis anos o comportamento reprodutivo de cinco novas seleções de pêssego e nectarina em Monte Alegre do Sul (22°41'S; 46°43'W e 40 HF-7). Os pessegueiros e nectarineiras cultivados nos espaçamentos de 4 x 0,5m e 4 x Im, equivalentes a 5000 e 2500 plantas/ha, respectivamente, foram podados drasticamente, a cada dois anos, após a colheita. Em ambos espaçamentos,'Aurora-2* e IAC 282-24 apresentaram as melhores produções acima de 19 toneladas/ha. Verificou-se nos ciclos subseqüentes a cada poda da copa, tendência de menor produção das plantas, principalmente em material de ciclo mediano. No segundo ano após a poda drástica, os pessegueiros e nectarineiras produziram normalmente. No espaçamento de 4 x 0,5m, as plantas apresentaram acréscimo médio de 12% na produção, em relação a 4 x lm, diminuindo porém, o peso do produto final. Os maiores frutos com peso médio acima de l00g foram produzidos pelas seleções IAC 6782-83 e IAC 282-24.

PERFORMANCE OF FOUR PEACH TRAINING SYSTEMS OVER EIGHT YEARS

The low density, free-standing Open Center (OC) training system for peach production is inexpensive to establish and maintain. However, a lengthy establishment period is required before profitable yields are obtained and uneven distribution of fruiting wood within and between trees reduces potential fruit production and quality. Redhaven/Lovell trees were planted in 1985 to evaluate four peach training systems: OC, Central Leader (CL), Y-Trellis (YT), & Meadow Orchard (MO) planted at 278, 1111, 2222, & 3333 trees/ha, respectively. YT trees were trained with two scaffold limbs oriented across the row, each supported at the top by one wire (8 feet above ground). MO was managed as the Intensive System described by Erez. Irrigation was not available. Crop was reduced by drought in 1988 and by frost in 1990 & 92. YT produced profitable yields in the third season, with good light distribution throughout the canopy. OC trees required seven years to reach yields of YT. Excessive shoot growth following spring frosts has been difficult to manage in CL and MO, resulting in shading out and loss of fruiting zone. Training system has affected fruit number more than fruit size or quality.

INTERACTION OF TRAINING SYSTEM, SUMMER PRUNING AND ROOT PRUNING ON YIELD AND CANOPY DENSITY OF PEACH

Factorial combinations of ± root pruning (RP) and ± summer pruning (SP) were initiated in 1991 as subplots within a Redhaven/Lovell study of orchard training systems: Open Center (OC), Y-Trellis (YT), Central Leader (CL), and Meadow Orchard (MO) established in 1985. Root pruning was imposed at bloom (March 28) at 76 cm from the trunk to a depth of 45 cm. Summer pruning consisted of preharvest removal of water sprouts (June 5). Canopy density, quantified by transmittance of PAR radiation through the canopy, was greatest in OC and MO and least in YT and CL systems. SP and RP treatments further reduced canopy density by 35 to 80%. There were no main or interactive effects of SP and RP on 1991 yields or fruit quality, and also no interactive effects of orchard systems with SP and RP. Thus, SP and RP reduced canopy density without negative effects on fruit. RP, however, advanced harvest date by ca 4 days. A parallel study was also initiated in 1991 to determine the effects of root pruning distance (30, 60, 90 cm from the trunk, or no RP) on canopy density, yield, and fruit quality of mature, OC-trained Redhaven/ and Jefferson/Lovell. Reduction in canopy density without loss of yield or fruit size was obtained at a RP distance between 60 and 90 cm.

O pessegueiro no sistema de pomar compacto: VI. Frutificação efetiva e raleio químico em seleções IAC

Verificou-se o potencial de frutificação e o efeito da pulverização de uréia a 12%, no raleio de frutos, em cinco pessegueiros e duas nectarineiras, cultivados em pomar compacto, na Estação Experimental de Monte Alegre do Sul (22°41'S. e 46°43'W.), do Instituto Agronômico de Campinas (IAC). Dos cultivares e seleções pesquisados, 'Talismã', IAC 6782-83, IAC N 2680-91, 'Aurora-2' e IAC 282-24 apresentaram as maiores taxas de frutificação natural, a saber: 60,9; 54,2; 44,6; 41,4 e 40,0% respectivamente. A uréia a 12%, pulverizada na plena floração, mostrou-se efetiva no raleio dos frutos, reduzindo as frutificações para a faixa de 12-17%, considerada adequada para pessegueiros e nectarineiras sob altas densidades de plantio. O número médio de pêssegos e nectarinas remanescentes por ramo foi, respectivamente, de 1,1; 1,6; 1,8; 1,9; 2,0; 2,6 e 3,2 para IAC 280-28; IAC 6782-83; 'Aurora-2'; IAC 282-24; IAC N 1880-76; IAC N 2680-91 e Talismã'. A produtividade não foi prejudicada pela ação raleadora da uréia a 12%. As plantas em que permaneceram até dois frutos em média, por ramo, apresentaram produtos de melhor padrão.

Influence of tree spacing on performance of ‘Garnet Beauty’ peach

A peach ( Prunus persica (L.) Batsch.) spacing trial was established using trees of cultivar ‘Garnet Beauty’ on Lovell rootstock or self-rooted ‘Garnet Beauty’. Fruit yield, fruit size, tree growth and pruning time were measured over an 8 year period. Yields for the first 3 years were greatest from trees managed as a meadow orchard; however, cumulative yields during the 8 year study were lowest from trees managed as a meadow orchard or spaced 1 m in-row. There were no significant differences in cumulative yield among trees spaced 6.1 m × 7.6 m to 3 m × 6.1 m, and over 60% of the fruit from these spacings were 64 mm in diameter or larger. Yield efficiency of trees spaced 3 m or 4.6 m × 6.1 m declined as trees matured compared to trees spaced 6.1 m or 4.6 m × 7.6 m.

O pessegueiro no sistema de pomar compacto: IV. Intensidade e época de raleio dos frutos dos cultivares Tropical e Aurora-1

A intensidade e a época do raleio dos frutos do pessegueiro podem influenciar diretamente a qualidade do produto, razão pela qual foram pesquisadas em um pomar compacto (4.167 plantas por hectare), sob poda drástica anual de renovação da copa. O experimento foi executado na Estação Experimental de Jundiaí (23°08'S e 46°55'W), do Instituto Agronômico (IAC), sob clima do tipo Cwa, mesotérmico úmido, também denominado de tropical de altitude, com cerca de 80 horas anuais de frio abaixo de 7°C. Utílizaram-se os cultivares Tropical, de maturação bem precoce (fins de setembro), e Aurora-1, de maturação precoce (meados de outubro). Efetuou-se o raleio com 30, 40 e 50 dias pós-antese (DPA), deixando-se 30, 60 e 90 frutos por planta. Os melhores resultados, reunindo fatores qualitativos e quantitativos, foram obtidos no raleio aos 30 DPA, mantendo-se 60 frutos por planta. Neste tratamento, o 'Tropical' apresentou frutos com peso médio de 60,9 gramas, o que equivale à produção de 3,654kg/planta (15,2t/ha); com o 'Aurora-1', o peso médio dos frutos foi de 72,0 gramas, correspondendo à produção de 4,320kg/planta (18,0t/ha). Aqualidade final do produto diminuiu à medida que se atrasou a época do raleio e, principalmente, quando se manteve maior quantidade de frutos por planta. O 'Tropical' adaptou-se melhor ao sistema de pomar compacto: floresceu no 9° mês e seus frutos amadureceram no 12ª mês após a poda drástica da copa.

INFLUENCE OF SPACING ON PEACH TREE PERFORMANCE

Performance of peach trees at seven spacings were evaluated over an 8-year period. Treatments were `Garnet Beauty' on Lovell spaced 3.0 or 4.6 × 6.1 m and 4.6 or 6.1 × 7.6 m, self-rooted `Garnet Beauty' spaced 1.0 × 6.1 or 7.6 m then thinned to 3.0 × 6.1 or 7.6 m 4-years after planting, and self-rooted `Garnet Beauty' spaced 1.0 × 2.0 × 5.5 m managed as a meadow orchard with alternate rows pruned to 30-cm height after harvest. Trees spaced 4.6 × 6.1 m or closer were mechanically hedged beginning 4-years after planting to 9 m tall and 6 m wide. Trees in all treatments, except 1.0 × 2.0 × 5.5 m, were trained to an open-center and hand-pruned annually. Trunk area and canopy area of trees spaced 3.0 × 4.6 m or closer were smaller than trees in other spacings by 5-years after planting. Cumulative yield per ha of trees spaced 1.0 × 2.0 × 5.5 m was greater than yield from other spacings 2- through 4-years after planting, then less 6- and 7-years after planting. There were no significant differences in yield/ha among the other spacing treatments. Fruit size was not affected by treatment. Yield efficiency of trees spaced 3.0 or 4.6 × 6.1 m decreased by 8-years after planting compared to trees spaced 4.6 or 6.1 × 7.6 m, indicating a reduction in fruit bearing growth. Hand pruning time was proportional to tree spacing.

Evaluation of pecan/peach interplanting systems

Pecan ( Carya illinoensis (Wang.) K. Koch) trees spaced 12.2 m by 12.2 m were interplanted with peach trees ( Prunus persica (L.) Batsch.). Treatments consisted of: cultivar ‘Redhaven’ on Lovell rootstock planted 1- or 2-trees between pecan trees within rows; self-rooted ‘Redhaven’ trees planted to a decreasing density system between pecan trees (spaced 0.5-m in-row, alternate trees removed when crowded); self-rooted ‘Redhaven’ trees planted to a meadow orchard between pecan trees (spaced 0.5 m by 2 m, cut to 30-cm height after harvest in alternate years); no peach trees interplanted. Cumulative yield, after 4 years production, was less from the meadow-orchard system than the other systems. Fruit size was larger from the 1- and 2-tree systems than either the decreasing density or meadow-orchard systems. Pecan tree cross-sectional trunk area was greatly reduced by any peach interplantings.

A Reliable Actinometric Method for Characterizing the Light Regime in Plant Canopies

Abstract The actinometric method, based on photolysis of uranyl oxalate, was adapted for measuring integrated light irradiance in plant canopies. The unique characteristics of the new actinometers are their small size, the avoidance of pressure build-up in the measuring cell, the good correlation with quantum sensors, and their response to the cosine law. The proposed system is inexpensive and reliable, integrates light measurement over a relatively long period, and needs little additional instrumentation. Numerous measurement points scattered in plant canopies can be determined simultaneously by this method, thus improving assessment of the light regime in fields and orchards. This paper describes such measurements in a peach meadow orchard planted at 2 densities, where 27 actinometers were dispersed in each density treatment and replicate